ELECTRO-MOTIVE DIVISION GENERAL MOTORS CORPORATION
GT46MAC INDIAN STATE RAILWAYS LOCOMOTIVE SERVICE MANUAL
EMD Part No. S00171EP Road Nos. 12001 thru 12013
Electro-Motive Division General Motors Corporation La Grange, Illinois 60525 USA Telephone: 1-800-255-5355 Fax: 708-387-6626
ELECTRO-MOTIVE DIVISION GENERAL MOTORS CORPORATION
NOVEMBER, 1999(To order this publication, please use part number S00171EP)
Document Number S00171EP @Copyright November 1999 Electro-Motive Division, General Motors Corporation. All rights reserved. Neither this document, nor any part thereof, may be reprinted without the expressed written consent of the General Motors Locomotive Group. Contact EMD Customer Publications Office.
FOREWORD The purpose of this manual is to act as a guide for servicing a GT46MAC locomotive and its equipment. Although minor variations can occur, equipment selected for coverage was chosen as representative of this model. When special or extra equipment is involved, consult specific drawings or instructions as provided by the railroad. Information contained in this manual is based on data available when released for printing. Minor equipment differences are due to changes made after the manual was published.
These instructions do not claim to cover all details or variations in equipment or to provide for every possibility in connection with installation, operation, or maintenance. Should more information be desired or particular problems arise which are not covered for the user's purposes, the matter should be referred to the Electro-Motive Division. This manual is intended for qualified service personnel. It provides an overview of EMD locomotive systems and equipment as well as specific electrical and mechanical procedures which can be performed on-board the locomotive.
WARNING The term qualified, in this context, means skilled personnel; knowledgeable in proper safety procedures and trained to perform maintenance on an EMD AC Series locomotive with a 3-phase AC drive. The information herein was compiled for EMD model GT46MAC locomotives equipped with special equipment and computer software.
Information about equipment that must be removed from the locomotive for service is available in the standard EMD Maintenance Instruction format or in vendor publications. Maintenance information involving the diesel engine and its auxiliary equipment is provided in the EMD Engine Maintenance Manual. Information about locomotive operation can be found in the GT46MAC Locomotive Systems and Operation Manuals.
Forward 1
WARNING This locomotive power system operates with a very high and potentially dangerous DC Link voltage that could be present in the electrical cabinets even after the locomotive has been shut down for an extended time period. Refer to Appendix C: SAFETY PRECAUTIONS FOR GT46MAC LOCOMOTIVES before inspecting, operating, or servicing this locomotive equipment.
2 GT46MAC Locomotive Service Manual
PREFACE The GT46MAC is equipped with a microprocessor based computer control system. The microprocessor is referred to as the EM2000 Locomotive Control Computer. This computer controlled system is equipped with a Diagnostic Display System(DDS) in the cab to provide an interface between the locomotive engineer and the computer. The computer is programmed to monitor and control locomotive traction power, record and indicate faults, and allow diagnostic testing.This manual is intended to be read in sequence - it is divided into the following sections
Section 0: GENERAL INFORMATION Section 1: ENGINE STARTING Section 2: FUEL SYSTEM Section 3: LUBRICATING OIL Section 4: COOLING SYSTEM Section 5: FORCED AIR Section 6: COMPRESSED AIR Section 7: HTSC BOGIE Section 8: ELECTRICAL EQUIPMENT Section 9: ELECTRICAL CONTROL Section 10: LOAD TEST Section 11: HIGH POTENTIAL TESTING Section 12: TROUBLESHOOTING Section 13: DOWNLOAD EVALUATION SERVICE DATA PAGES A Service Data page is included at the back of some sections of the Locomotive Service Manual. This page may provide the following: 1. 2. 3. 4. 5.
Reference to part numbers for serviceable equipment. Reference to applicable Maintenance Instructions and technical manuals. Reference to applicable tool and testing apparatus numbers. Specific system values for operation or testing. Refer to the GT46MAC Locomotive Service Parts Catalog applicable to the unit being serviced for component part numbers and ordering information.
UNITS OF MEASURE Units of measurement appearing in this manual are shown in Metric and U.S. standard units. A conversion table is provided at the back of the manual to convert U.S. standard units to metric units. Forward 3
4 GT46MAC Locomotive Service Manual
TABLE OF CONTENTS WARNING ............................................................................................................................................... 2FW PREFACE ................................................................................................................................................. 3FW SECTION 0. GENERAL INFORMATION ..................................................................................... 0-1 GENERAL CHARACTERISTICS.............................................................................................................. 0-1 EQUIPMENT LOCATION ......................................................................................................................... 0-6 LOCOMOTIVE OPERATION.................................................................................................................. 0-10 DIESEL ENGINE ...................................................................................................................................... 0-12 COMPUTER CONTROL SYSTEM LOGIC CHANNELS...................................................................... 0-14 ELECTRICAL REFERENCE DESIGNATIONS ..................................................................................... 0-15 INTRODUCTION TO KNORR AIR BRAKE SYSTEM ......................................................................... 0-19 INTRODUCTION TO EM2000 LOCOMOTIVE DISPLAY................................................................... 0-22 INTRODUCTION TO FLANGE LUBE SYSTEM .................................................................................. 0-29 ALERTER (VIGILANCE) SYSTEM ....................................................................................................... 0-30 GT46MAC SAFETY PRECAUTIONS..................................................................................................... 0-31 SECTION 1. ENGINE STARTING AND STOPPING ................................................................... 1-1 INTRODUCTION ....................................................................................................................................... 1-1 STARTING EQUIPMENT.......................................................................................................................... 1-1 STARTING PROCEDURES FOR GT46MAC DIESEL ENGINES ......................................................... 1-6 STOPPING PROCEDURES FOR GT46MAC DIESEL ENGINES ........................................................ 1-14 STARTING MOTOR MAINTENANCE .................................................................................................. 1-17 SECTION 2. FUEL SYSTEM........................................................................................................ 2-1 INTRODUCTION ....................................................................................................................................... 2-1 FUEL SUCTION STRAINER..................................................................................................................... 2-2 FUEL PUMP AND MOTOR....................................................................................................................... 2-3 FUEL PUMP CIRCUIT............................................................................................................................... 2-4 PREHEATER AND MIXING VALVE ...................................................................................................... 2-6 PRIMARY FUEL FILTER BYPASS VALVE AND GAUGE................................................................. 2-10 ENGINE MOUNTED FUEL FILTER ASSEMBLY ................................................................................ 2-10 DRAINING CONDENSATE FROM THE FUEL TANK ........................................................................ 2-12 FILLING THE FUEL TANK ................................................................................................................... 2-12 FUEL STORAGE FACILITIES ................................................................................................................ 2-13 EMERGENCY FUEL CUTOFF SWITCHES .......................................................................................... 2-13 ROUTINE MAINTENANCE PARTS AND EQUIPMENT..................................................................... 2-15 SERVICE DATA - FUEL SYSTEM......................................................................................................... 2-15
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SECTION 3. LUBRICATING OIL SYSTEM ................................................................................. 3-1 INTRODUCTION........................................................................................................................................3-1 OIL LEVEL GAUGE (DIPSTICK) .............................................................................................................3-1 FILLING OR ADDING OIL TO SYSTEM ................................................................................................3-3 OIL FILTER INSPECTION AND MAINTENANCE ................................................................................3-5 BYPASS VALVE ASSEMBLY ..................................................................................................................3-8 OIL COOLER INSPECTION AND MAINTENANCE ..............................................................................3-8 HOT OIL DETECTOR ..............................................................................................................................3-10 TURBOCHARGER ...................................................................................................................................3-12 TURBOCHARGER LUBE PUMP CIRCUIT ...........................................................................................3-12 LUBRICATING OIL SAMPLING AND ANALYSIS .............................................................................3-13 PRELUBRICATION OF ENGINE............................................................................................................3-14 SERVICE DATA - LUBRICATING OIL SYSTEM ................................................................................3-15 SECTION 4. COOLING SYSTEM ................................................................................................ 4-1 INTRODUCTION........................................................................................................................................4-1 RADIATORS AND COOLING FANS .......................................................................................................4-2 COOLING FAN TWO-SPEED AC MOTOR CONTROL .........................................................................4-3 INSPECTION AND CLEANING OF RADIATORS..................................................................................4-7 HOT ENGINE CONDITION.......................................................................................................................4-8 COOLING SYSTEM PRESSURIZATION.................................................................................................4-8 OPERATING WATER LEVEL ................................................................................................................4-11 FILLING THE COOLING SYSTEM ........................................................................................................4-12 OBTAINING AN ENGINE WATER SAMPLE .......................................................................................4-13 DRAINING THE COOLING SYSTEM....................................................................................................4-13 SERVICE DATA - COOLING SYSTEM .................................................................................................4-14 SECTION 5. FORCED AIR SYSTEMS ........................................................................................ 5-1 INTRODUCTION........................................................................................................................................5-1 INERTIAL AIR FILTERS ...........................................................................................................................5-3 MAIN GENERATOR BLOWER ................................................................................................................5-4 TRACTION MOTOR BLOWER ................................................................................................................5-4 TRACTION MOTOR BLOWER INLET VANE OPERATION ................................................................5-4 TCC BLOWER ............................................................................................................................................5-6 INSPECTION AND MAINTENANCE OF THE CENTRAL AIR SYSTEM............................................5-7 SERVICE DATA - FORCED AIR SYSTEMS .........................................................................................5-16 SECTION 6. COMPRESSED AIR SYSTEMS ............................................................................. 6-1 INTRODUCTION........................................................................................................................................6-1 WLNA9BB AIR COMPRESSOR ...............................................................................................................6-2 AIR COMPRESSOR CONTROL................................................................................................................6-3 MAIN RESERVOIRS ..................................................................................................................................6-7 COMPRESSED AIR FILTERS AND DRAINS..........................................................................................6-8 GRAHAM WHITE TWIN TOWER AIR DRYER ...................................................................................6-11 KNORR/NYAB AIR BRAKE SYSTEM (CCB 1.5).................................................................................6-17 SANDING SYSTEM .................................................................................................................................6-30 MISCELLANEOUS COMPRESSED AIR EQUIPMENT .......................................................................6-35 SERVICE DATA - COMPRESSED AIR SYSTEMS...............................................................................6-41
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0 SECTION 7. HTSC BOGIE........................................................................................................... 7-1 INTRODUCTION ....................................................................................................................................... 7-1 ROUTINE MAINTENANCE AND INSPECTION.................................................................................... 7-7 TRACTION MOTORS.............................................................................................................................. 7-22 TRUCK/BOGIE REMOVAL .................................................................................................................... 7-27 WHEEL FLANGE LUBRICATING SYSTEM ........................................................................................ 7-30 SERVICE DATA - HTSC BOGIE ............................................................................................................ 7-38 SECTION 8. ELECTRICAL EQUIPMENT.................................................................................... 8-1 INTRODUCTION ....................................................................................................................................... 8-1 MAIN GENERATOR.................................................................................................................................. 8-3 COMPANION ALTERNATOR................................................................................................................ 8-14 AC AUXILIARY GENERATOR.............................................................................................................. 8-15 C1-8: DC LINK INVERTER INPUT CAPACITORS .............................................................................. 8-17 DCL123, DCL456: DC LINK SWITCHGEAR ........................................................................................ 8-18 TRACTION MOTORS.............................................................................................................................. 8-18 RADIATOR COOLING FAN MOTORS ................................................................................................. 8-19 DYNAMIC BRAKE GRID BLOWER ASSEMBLY ............................................................................... 8-20 TURBO LUBE PUMP MOTOR ............................................................................................................... 8-20 FUEL PUMP MOTOR .............................................................................................................................. 8-20 STARTING MOTORS AND SOLENOIDS ............................................................................................. 8-21 CAB EQUIPMENT ................................................................................................................................... 8-22 ELECTRICAL CONTROL (#1) CABINET EQUIPMENT ..................................................................... 8-38 DIAGNOSTIC PANEL ............................................................................................................................. 8-66 FUSE AND SWITCH COMPARTMENT ................................................................................................ 8-77 AC (#3) CABINET .................................................................................................................................... 8-80 MISCELLANEOUS LOCOMOTIVE EQUIPMENT............................................................................... 8-82 SECTION 9A. ELECTRICAL CONTROL SYSTEM .................................................................. 9A-1 OVERVIEW ............................................................................................................................................. 9A-1 MAIN GENERATOR............................................................................................................................... 9A-2 DC LINK EQUIPMENT .......................................................................................................................... 9A-3 EM2000 LOCOMOTIVE COMPUTER .................................................................................................. 9A-6 POWER SYSTEM VARIABLES .......................................................................................................... 9A-13 SECTION 9B. EM2000 LOCOMOTIVE COMPUTER .............................................................. 9B-1 INTRODUCTION .................................................................................................................................... 9B-1 HANDLING ELECTRONIC EQUIPMENT - GENERAL ................................................................... 9B-1 EM2000 LOCOMOTIVE CONTROL COMPUTER............................................................................... 9B-5 DIO OPERATION .................................................................................................................................. 9B-11 PANEL MOUNTED MODULES .......................................................................................................... 9B-29 THE EM2000 DISPLAY ........................................................................................................................ 9B-41 MAIN MENU ITEMS ............................................................................................................................ 9B-45 SECTION 9C. AC MOTOR - THEORY OF OPERATION ......................................................... 9C-1 AC MOTOR POWER OPERATION - NO LOAD.................................................................................. 9C-1 POWER OPERATION - APPLY LOAD ................................................................................................. 9C-6 INCREASE POWER .............................................................................................................................. 9C-12 DYNAMIC BRAKE ............................................................................................................................... 9C-15 PULSE WIDTH MODULATION TECHNIQUES ................................................................................ 9C-20 LOCOMOTIVE OPERATING CHARACTERISTICS ......................................................................... 9C-22
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SECTION 9D. INVERTER OPERATIONS ................................................................................. 9D-1 GTO SWITCHING ................................................................................................................................... 9D-1 DYNAMIC BRAKE/REGENERATIVE OPERATION ........................................................................ 9D-13 TCC PROTECTION SCHEME .............................................................................................................. 9D-20 SECONDARY WHEEL SLIP PROTECTION ...................................................................................... 9D-24 SECTION 9E. TCC COMPONENTS .......................................................................................... 9E-1 SAFETY PRECAUTIONS ....................................................................................................................... 9E-1 ORIENTATION AND LAYOUT............................................................................................................. 9E-2 INVERTER COMPONENTS ................................................................................................................... 9E-5 SECTION 9F. TRACTION COMPUTER MODULES.................................................................. 9F-1 TRACTION COMPUTER MODULE QUICK REFERENCE GUIDE ....................................................9F-4 POWER SUPPLIES ...................................................................................................................................9F-6 INPUTS AND OUTPUTS .......................................................................................................................9F-10 SYSTEM CONTROLS ............................................................................................................................9F-16 SECTION 9G. OPERATIONAL CONTROL MODES ................................................................ 9G-1 OP MODE DETERMINATION ............................................................................................................... 9G-1 STANDARD OP MODES (AC Only) ...................................................................................................... 9G-2 CONTROL MODES ................................................................................................................................. 9G-5 FUNDAMENTAL SIGNAL VALUES FOR 3939 THP, GT46MAC ................................................... 9G-12 SECTION 9H. LOAD CONTROL ............................................................................................... 9H-1 TORQUE................................................................................................................................................... 9H-2 ENGINE POWER CAPABILITIES ......................................................................................................... 9H-4 TRACTION POWER REFERENCE ........................................................................................................9H-8 TCC POWER CONTROLLER...............................................................................................................9H-11 FINAL VOLTAGE REFERENCE ......................................................................................................... 9H-15 LOCOMOTIVE TORQUE LIMIT ......................................................................................................... 9H-19 TCC TORQUE REFERENCE ................................................................................................................ 9H-22 MAIN GENERATOR FIELD CURRENT REFERENCE ..................................................................... 9H-27 DEFAULT LIMITS FOR NON-ACTIVE FUNCTIONS....................................................................... 9H-28 STANDARD LOAD CONTROL VARIABLES - MONITOR SYMBOLS AND DISPLAY NAMES9H-29 SECTION 9I. ADHESION ............................................................................................................ 9I-1 CONTROLLED CREEP ............................................................................................................................ 9I-1 BACK-UP WHEEL SLIP CONTROL SYSTEM...................................................................................... 9I-1 STARTING SYSTEM - WHEEL SLIP ..................................................................................................... 9I-1 DEFINITION ............................................................................................................................................. 9I-2 WHEEL SLIP STATUS VARIABLE ....................................................................................................... 9I-2 SIGNAL AVAILABILITY ........................................................................................................................ 9I-2 CONTROLLED-CREEP SYSTEM - General........................................................................................... 9I-3 CONTROLLED CREEP & SPEED LIMIT GENERATION.................................................................... 9I-8 WHEEL SLIP LIGHT.............................................................................................................................. 9I-14 SAND CONTROL LOGIC ...................................................................................................................... 9I-15 SECTION 10. LOAD TEST AND HORSEPOWER EVALUATION ............................................ 10-1 INTRODUCTION......................................................................................................................................10-1 DESCRIPTION ..........................................................................................................................................10-1 LOAD TEST PROCEDURES ...................................................................................................................10-5 CALCULATING HORSEPOWER & EVALUATING RESULTS ........................................................10-15 AUXILIARY EQUIPMENT LOAD ON DIESEL ENGINE ..................................................................10-16
4 GT46MAC LOCOMOTIVE SERVICE MANUAL
0 SECTION 11. HIGH POTENTIAL TESTING .............................................................................. 11-1 TEST EQUIPMENT .................................................................................................................................. 11-1 SAFETY PRECAUTIONS ........................................................................................................................ 11-1 MEGGER/HI-POT/WELDING PRECAUTIONS .................................................................................... 11-2 LOCOMOTIVE WELDING PREPARATIONS FOR GT46MAC........................................................... 11-2 INSULATION RESISTANCE TEST........................................................................................................ 11-6 HIGH POTENTIAL TEST ........................................................................................................................ 11-8 SECTION 12A. TROUBLESHOOTING TIPS.......................................................................... 12A-1 GROUND RELAY PROCEDURES ...................................................................................................... 12A-1 GENERATOR FIELD OVER-EXCITATION FAULTS....................................................................... 12A-1 HOT ENGINE, THROTTLE 6 LIMIT:.................................................................................................. 12A-1 KNORR SET UP TO SUPPRESS ALERTER FUNCTIONS............................................................... 12A-2 TCC OVERVOLTAGE FAULTS .......................................................................................................... 12A-2 NO COMPANION ALTENATOR OUTPUT ........................................................................................ 12A-2 CHECK FOR SLIPPED PINION ........................................................................................................... 12A-2 DIO 300 CARDS .................................................................................................................................... 12A-3 ADA 305 MODULE ............................................................................................................................... 12A-3 SECTION 12B. EM2000 AND TRACTION COMPUTER DOWNLOADS ............................... 12B-1 INTRODUCTION .................................................................................................................................. 12B-1 DOWNLOAD PROCEDURE ................................................................................................................ 12B-1 TRACTION COMPUTER COMMUNICATIONS................................................................................ 12B-6 SECTION 13. DOWNLOAD EVALUATION ............................................................................... 13-1 DC Link Overcurrent Protection................................................................................................................ 13-1 DC Link Undervoltage Protection ............................................................................................................. 13-2 DC Link Overvoltage Protection ............................................................................................................... 13-3 OPERATIONAL MODES......................................................................................................................... 13-4 TESTING OP MODES (AC and DC) ....................................................................................................... 13-7 DOWNLOAD EVALUATION ............................................................................................................... 13-19 Appendix A . DATA PACKS ...................................................................................................... A-1 Appendix B. SIGNAL DESCRIPTIONS .................................................................................... B-1 Appendix C . SAFETY PRECAUTIONS..................................................................................... C-1 Appendix D. TROUBLESHOOTING FLOWCHARTS................................................................ D-1
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6 GT46MAC LOCOMOTIVE SERVICE MANUAL
SECTION 0. GENERAL INFORMATION GENERAL CHARACTERISTICS Locomotive Model Designation: GT46MAC Locomotive Type: (C-C) 0660 Nominal Locomotive Power: 4000 CV (3939 HP)
Diesel Engine Engine Model(s): 710G3B Number of Cylinders: 16 Engine Type: Two-Stroke, Turbocharged Cylinder Arrangement: 45° “V” Compression Ratio: 16:1 Displacement per Cylinder: 11 635 cm3 (710 Cu.In.) Cylinder Bore: 230.19 mm (9-1/16”) Cylinder Stroke: 279.4 mm (11”) Rotation (Facing Flywheel End): Counterclockwise Full Speed: 904 RPM Normal Idle Speed: 269 RPM Low Idle Speed: 200 RPM
Main Generator Assembly MODEL NUMBERS: Main Generator: TA17-CA6B Traction Alternator (Includes Rectifier): TA17 Companion Alternator: CA6B TRACTION ALTERNATOR RECTIFIED OUTPUT RATINGS: Maximum Voltage: 2600 VDC Max. Continuous Current: 1250 Amperes COMPANION ALTERNATOR OUTPUT RATING: 230 Volts AC Maximum Voltage: 230 VAC Frequency at 904 RPM: 120 HZ Maximum Power: 250 KVA (Power factor 0.8) GENERAL INFORMATION 0-1
Auxiliary Generator Model:5A-8147 RECTIFIED OUTPUT RATINGS: Nominal Voltage: 74 volts DC (Rectified) Maximum Power: 18 kW
Traction Motors Model: Siemens 1TB-2622-0TA02 Quantity: 6 (3 in parallel per bogie) Type:
3 Phase AC Induction, Axle Hung with Tapered Roller Support Bearings, Forced Air Ventilated Nominal Ratings: 500 KW, 2027 VAC, 3220 RPM
Traction Inverters (Traction Control Converters TCC1, TCC2) Model: 1GE420 050 9010.00 MB74 Rating: 1430 KW Quantity: 2 (one per bogie {truck}) Type: Voltage Source Inverter With Gate Turn-Off Thyristors
Bogies Model: HTSC Gear Ratio: 90:17 DRIVING WHEELS: Quantity: 3 Wheel Sets per bogie {truck} Diameter:1092mm (43 inches) BRAKE RIGGING: Type: Single Shoe 406.4mm (16 inches) Shoe Material: Composite Cylinders Brake: 4 per bogie {truck}
0-2 GT46MAC LOCOMOTIVE SERVICE MANUAL
Compressed Air System AIR BRAKE CONTROL SYSTEM: Knorr CCB Equipment AIR COMPRESSOR: Model: WLNA9BB Type: Two Stage, 3 Cylinder Coolant: Engine Coolant Displacement at 900 RPM:7.19 M³/Min (254 Cu.Ft./Min.) Lube Oil Capacity: 9.98 Litres (2.64 US Gallons)
Locomotive Storage Batteries Model: Surrette 16CH-25 Unitized Arrangement: 2 Series-connected 16-Cell Lead-acid Batteries Total Quantity of Cells: 32 Total Potential of 2 Series-connected Batteries: 64 Volts Specific Gravity of Electrolyte: 1.250 8 hour Capacity: 500 Amp. Hr.
Supplies/Capacities Lube Oil System Capacity: 950 Litres (251 US Gallons) Cooling System Capacity:1045 Litres (276 US Gallons) Sand Boxes (8) Capacity: 0.04M³ Box (1.5 cubic ft./box) Fuel Capacity: 6000 Litres (1585 US Gallons)
Nominal Dimensions Height, over Cooling Hood: 4.16 M (13’ 7.75”) Height over Horn: 4.22M (13’ 10” Height over Cab: 3.94 M (12’ 11”) Width over Hand Rails: 2.92 M (9’ 7.12”) Width over Underframe: 2.74 M (9’ 0”) Width over Cab: 2.74M (9’ 0”) Width over Brake Cylinders: 3.07 M (10’ 1”)
GENERAL INFORMATION 0-3
Locomotive Minimum and Maximum Speeds/Tractive Effort Min. Continuous Speed At Max - Continuous Tractive Effort: 22.5 Km/h (15Mph) Max Continuous Speed (Based on T.M. Max. Rated RPM):120 Km/h (74.6 Mph) Maximum Stall Tractive Effort: 540KN Max. Continuous Tractive Effort: 400 KN Reduced Tractive Effort Limit: 294 KN
Minimum Curve Negotiation Capability Information below based on GT46MAC locomotive(s) equipped with “F” couplers, and box car equipped with “E” couplers. Single Unit: 174 meter (570.8 Ft.) Radius - 10° Curve Two GT46MAC Units Coupled: 174 Meter (570.8 Ft) Radius -10° Curve
0-4 GT46MAC LOCOMOTIVE SERVICE MANUAL
Weights NOTE: The weights listed are approximate and presented for material handling. Total Loaded Locomotive Weight on Rails: 126010 Kg (277, 800 Lbs.) Air Compressor: 1043 Kg (2300Lbs.) Auxiliary Generator and Blower Assembly: 647 Kg (1428 Lbs.) Axle/Gear/Wheel Assembly: 2631 Kg (5800 Lbs.) Diesel Engine (16-710G3B): 1793 Kg (39 600 Lbs.) Dynamic Brake Fan and Motor Assembly: 567 Kg (1250 Lbs.) Dynamic Brake Fan Motor: 91 Kg (200 Lbs.) Dynamic Brake Hatch Assembly: 1588 Kg (3500 Lbs.) Fuel Filter Assembly, Primary (Dual): 59 Kg (129 Lbs.) Fuel Pump Motor : 34 Kg (75 Lbs.) Fuel Pump (without motor): 2.2 Kg (5 Lbs.) Fuel Tank: 5779 Kg (12, 740 Lbs.) Inertial Air Filters: 159 Kg (350 Lbs.) Lube Oil Cooler: 386 Kg (850 Lbs.) Lube Oil Filter Assembly: 345 Kg (760 Lbs.) Lube Oil Filter Element: 2.2 Kg (5 Lbs.) Main Generator and Companion Alternator Assembly: 8709 Kg (19,200 Lbs.) Radiator Assembly: 1134 Kg (2500 Lbs.) Radiator Fan Assembly: 408 Kg (900Lbs.) Starter Motor: 36 Kg (79 Lbs.) Storage Battery, 16-Cell: 703 Kg (1550 Lbs.) SCR Excitation Bridge Assembly: 19 Kg (41 Lbs.) Traction Motor: 3016 Kg (6650 Lbs.) Bogie Assembly, HTSC: 21773 Kg (48,000 Lbs.) Turbocharger: 953 Kg (2100 Lbs.) Turbocharger Lube (Soakback) Pump & Motor: 34 Kg (75 Lbs.) Water Pump: 49 Kg (109 Lbs.)
GENERAL INFORMATION 0-5
1) Head light 2) Inertial Filter Air Inlet 3) Starting Fuse and Battery Knife Switch 4) Handrails 5) Cooling System Air Inlet 6) Radiator and Fan Access 7) Coupler “E/F” Type 8) Sanding Box (8) 9) Jacking Pads (4)
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0-6 GT46MAC LOCOMOTIVE SERVICE MANUAL
10) Wheels (6) 11) Fuel Tank 12) Compressed Air System Main Reservoirs 13) Battery Box 14) Trucks (3 axle 3 motor HTSC type) Qty. 2 15) Underframe 16) Dynamic Brake Grids 17) Dynamic Brake Fans (2)
Equipment Location
Figure 0-1 GT46MAC General Arrangement L/H Side - Outside view
1) Electrical Control Cabinet 2) Fuel Pump 3) Engine Starting Motors 4) Traction Control Cabinet 5) Traction Motor Cooling Air Blower 6) Main Generator/Companion Alternator Blower 7) Engine Exhaust Stack 8) Engine Exhaust Manifold
GI41958 9) 16-710G3B Diesel Engine 10) Governor 11) Engineroom Vent 12) Engine Water Tank 13) Lube Oil Cooler 14) Primary Fuel Filter 15) Air Compressor 16) Radiators 17) AC Radiator Cooling Fans (2)
18) Draft Gear 19) Air Compressor Air Filter 20) Lube Oil Filter Tank 21) Lube Oil Strainer 22) Lube Oil Sump 23) Main Generator/ Companion Alternator 24) Electrical Control Cabinet Air Filter Box 25) Traction Motors (6)
Figure 0-2 GT46MAC General Arrangement L/H Side - Internal View
GENERAL INFORMATION 0-7
1) Air Brake Rack 2) Engineers Control Console 3) Cab Door 4) Traction Control Cabinets 5) Inertial Air Filters 6) TCC Electronics Blower 7) Engine Air Filter
Figure 0-3 GT46MAC General Arrangement - TopView
0-8 GT46MAC LOCOMOTIVE SERVICE MANUAL
8) Radiators 9) Engine 10) AC Auxiliary Generator 11) Inertial Filter Dust Bin Blower and Motor 12) Electrical Control Cabinet 13) Cab Seat
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GENERAL INFORMATION The GT46MAC locomotive, shown on the preceding illustrations, is equipped with a turbocharged 16 cylinder diesel engine to drive the main generator. The main generator converts diesel engine mechanical power into alternating current (AC) electrical power. The internal rectifier banks of the main generator convert alternating current to direct current (DC) thereby providing a DC power output. The DC output from the main generator is called the DC link voltage and is applied to the traction inverters. DC link voltage varies with the throttle position from 600 VDC at TH1 to 2600 VDC at TH8. The inverters change DC power into variable AC power. There is one traction inverter for each parallel set of three traction motors. Traction inverter TCC1 and traction inverter TCC2 invert the DC link voltage into variable voltage, variable frequency, 3 phase AC power for the induction traction motors. Each of the inverters is controlled by a separate computer. Both inverter computers are in turn controlled by a primary computer known as the EM2000 Locomotive Control Computer (LCC) that monitors and controls many locomotive functions. One EM2000 display panel, mounted in the door of the main electrical locker, is driven by the EM2000 computer and indicate operating conditions, system faults, and troubleshooting information. Electrical power produced by the main generator is distributed to the inverters through heavy duty switchgear in the #1 electrical cabinet. The switchgear directs main generator output to the traction inverters based on inputs from the primary computer. The primary computer responds to input signals from the engineer controls and feedback signals from the power equipment. Each traction motor is geared directly, with a single pinion, to a pair of driving wheels. The maximum speed of the locomotive is set by the locomotive gear ratio (wheel/motor) and wheel size. The locomotive is arranged so that the short hood or cab end is considered the front (or forward) although the unit can be operated in either direction. While each locomotive is an independent power source, several units may be combined in multiple operation to increase load capacity. The operating controls on each unit are jumpered or “trainlined” to allow all the locomotives to be simultaneously controlled from the control console in the cab of the lead unit. The cab has two driver’s consoles: One facing forward and one facing rearward.
GENERAL INFORMATION 0-9
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Figure 0-4 GTMAC Power Distribution Diagram
LOCOMOTIVE OPERATION The diesel engine must be primed with fuel prior to starting. The GT46MAC, Fuel Prime/ Engine Start (FP/ ES) switch is located on the equipment rack in the locomotive long hood. Because, the GT46MAC is equipped with a Mechanical Governor, the Starting operation is the same as on earlier model locomotives. When the engine start switch is held in PRIME, the locomotive computer starts the fuel pump which pressurizes the injection system with fuel. The fuel pump moves the fuel from the fuel tank under the locomotive to the injectors. After the entire system has been supplied with fuel, the engine can be started by holding the PRIME/START switch in START. With the engine running, the fuel pump motor is powered directly by the auxiliary generator. Storage batteries provide energy to the starting motors mounted at the lower rear right hand side of the engine. Two starting motor solenoids are part of the starting motor assembly. These electrical solenoids engage the starting motor pinions with the engine ring gear. When both pinions are engaged, full battery power is applied to the starting motors to crank the diesel engine. When the diesel engine is running, it directly drives three electrical generators, a traction motor blower, an air compressor and the water and lube oil pumps. The engine-driven components in the locomotive system must convert the engine power to other forms to perform their individual functions:
0-10 GT46MAC LOCOMOTIVE SERVICE MANUAL
0 1.
The main generator rotates at engine speed, generating alternating current (AC) power. This power is then converted to direct current (DC) power by rectifier banks within the generator assembly and applied to the DC link. A switch gear (DCL) apply the DC link voltage to traction inverter circuits. The traction inverters convert the DC link voltage to 3-phase AC power for the traction motors.
2.
The companion alternator is physically coupled to the main generator. It supplies current to excite the main generator field and to power the radiator cooling fans, the inertial filter blower motor, the TCC electronic blower motor, two traction inverter blowers, and various transductors and control devices.
3.
The auxiliary generator is driven by the engine gear train at three times the engine speed. AC power from the auxiliary generator is supplied to an external 3-phase full-wave rectifier in a battery charging assembly. It is then converted to 74 volt DC power for companion alternator excitation, control system operation, and charging locomotive batteries. The auxiliary generator also supplies 74 VDC power for the fuel and turbocharger lube oil pump motor circuits, cab fans, locomotive lighting, and other miscellaneous equipment.
4.
The air compressor, rotates at engine speed and supplies the necessary air pressure for brakes and other pneumatic devices such as sanders, windshield wipers, shutter operating cylinders, the horn and the bell.
5.
The engine gear train drives two centrifugal water pumps. One large pump is used to circulate coolant through the engine cooling system and a second smaller size pump is used to circulate coolant through the turbocharger aftercoolers.
6.
The lube oil pumps are also connected to the engine gear train. They supply lubricating oil to critical operating surfaces throughout the engine.
The main generator supplies high voltage electrical energy to the electrical cabinet. This cabinet establishes the distribution of power to the traction inverters by means of motor operated switches. Relays and control devices in the cabinet direct the flow of power as dictated by the control computer. The response of the computer is determined by locomotive operating conditions and the set up of the controls in the cab. Actual operating conditions create varying tractive load requirements. This locomotive is equipped with an Electrical Mechanical Governor (Woodward). A computer controlled load management system balances electrical load with mechanical diesel engine power. The load regulator can act to reduce generator excitation in order to balance the governor speed setting from the throttle with the engine power level determined by the the computer (EM2000). Moving the throttle to a higher position signals the computer to raise engine speed and allow more current to flow through the main generator field. The increased excitation current results in an increased DC voltage to the DC link. Increasing DC link voltage supplies more power to the traction inverters. An increase in traction inverter power causes an increase in AC power to the traction motors. In this way, engine speed and locomotive DC link power are increased progressively in throttle steps.
GENERAL INFORMATION 0-11
For dynamic brake operation, the kinetic energy of the moving train is translated into electrical energy in the traction motors, which now acts as generators. This AC motor energy must first be converted to DC power (voltage) by the traction inverters (inverter/converter) and provided to the DC link. The DC link voltage is then applied to brake grids which dissipate the electrical power in the form of heat. This loss of energy causes the train to slow down (brake). The inverter (TCC#1, TCC#2) computers monitor and control each inverter to maintain the braking effort requested by the locomotive computer (EM2000), EM2000, in turn maintains the braking effort requested by the driver. Other control and protective functions are programmed into the Display Diagnostic System which is the display for the locomotive control computer (LCC). This computer monitors critical functions in the locomotive power system and provides a display message, and in some cases an audible alarm, if a fault occurs. The computer will also change diesel engine speed in response to certain improper operating conditions such as low coolant temperature or low main reservoir pressure. There are six axle hung AC traction motors located in the bogies under the locomotive. Each traction motor is geared directly to the axle on which it is mounted. These motors are supplied AC power from the traction inverters - one traction inverter for each three motor bogie. Because actual operating conditions create varying tractive load requirements a major part of locomotive control system operation involves the interrelated functions of the throttle, the locomotive control computer, the Woodward Governor and the load regulator. The Woodward system holds the engine speed at a constant RPM as set by the EM2000. It does this by varying the fuel to the injectors which controls the amount of fuel supplied to the cylinders. The load regulator “inform” the EM2000 about the engine capability to handle the load. The computer controlled load management system balances electrical load with available mechanical diesel engine power by modifying engine speed, or generator excitation regardless of throttle position. The HTSC bogies, which house the traction wheelsets, support all of the locomotive weight, it absorbs mechanical shocks while maintaining maximum traction for the wheels. NOTE An important advantage of AC traction motors is that they are much more resistant to mechanical shock or other commutator related damage associated with DC traction motors. This will be seen throughout this manual in such areas as eliminating the precaution of reducing throttle over rail crossings and eliminating the 10 second delay when changing between power and dynamic brake operation. These considerations are only necessary for when an AC unit is operating in a multiple unit consist with other DC units.
DIESEL ENGINE The diesel engine operates on a two-stroke cycle, with power applied on each downward stroke. At the bottom of each downward stroke, cylinders are aspirated through cylinder wall ports opening to a chamber (air box) that is supplied with pressurized air from the turbocharger impeller. The pressurized air scavenges spent gases from a cylinder through multiple exhaust valves in its cylinder head. As the piston moves upward, the ports are closed off and the exhaust valves close. Air is compressed in the cylinder.
0-12 GT46MAC LOCOMOTIVE SERVICE MANUAL
0 At the top of the stroke, fuel is injected into the cylinder and ignited by the heat of compression to provide power to drive the piston downward until the cylinder wall ports and the exhaust valves again open. The exhaust gases from the cylinders pass through a manifold to drive the turbocharger turbine wheel before flowing out through the exhaust silencer stack. When starting, and at lower power levels, there is insufficient exhaust heat energy to drive the turbine and impeller fast enough to supply all the air needed for combustion. At this time, the engine drives the turbocharger through a gear train, with the available exhaust gases providing some assistance. At high power levels, the heat energy in the exhaust is sufficient to drive the turbocharger without any assistance, and an overrunning clutch in the gear train disengages the mechanical drive from the engine. The air discharged under pressure from the turbocharger assembly is routed through aftercoolers to cool the air, before it enters the airbox, thereby increasing its density for greater combustion efficiency. The engine is equipped with engine mounted gear driven centrifugal water pumps. Coolant is pumped to the engine manifolds connected to the cylinder heads and liner jackets, and to the turbocharger aftercoolers. A coolant return manifold, in the crankcase “V,” encloses the cylinder exhaust ducts (elbows). Heated coolant is piped from the engine through the radiators, and through an oil cooler before it returns to the centrifugal pumps. The entire engine cooling system is pressurized, with pressure level limited by a relief valve in the cap on the water storage tank filler neck. Temperature probes are mounted at the engine water pump inlets to provide engine coolant temperature information to the EM2000 computer. The computer controls engine coolant temperature by independently controlling the speed of each of the two radiator cooling fan motors. Each motor can be “off,” or running at either “slow” or “fast” speed. A positive displacement gear type scavenging pump draws oil from the engine sump, through a strainer, then pumps it through filters and a cooler to a second strainer chamber. A dual oil pump receives oil from the second strainer and delivers it to engine manifolds for engine lubrication and piston cooling. Additional filtration is provided in the circuit delivering oil to the turbocharger. A separate electrically driven pump and filter provide turbocharger lubrication and cooling at engine startup and shutdown. Engine fuel is drawn from the underframe mounted tank through a mesh suction strainer to a gear type DC motor driven pump. The pump forces fuel through a two stage primary filter assembly equipped with a pressure gauge and by-pass valve that functions if the filter becomes clogged. Engine mounted fuel filters provide secondary filtration before fuel reaches the fuel injectors located at each cylinder. Excess fuel that is not injected provides injector cooling before being returned to the fuel tank. Fuel injectors supply a precisely metered quantity of atomized fuel to each cylinder at a precise moment in the firing cycle. The Woodward Governor controls injectors to maintain the proper amount of fuel needed to keep the engine speed at the requested level.
GENERAL INFORMATION 0-13
COMPUTER CONTROL SYSTEM LOGIC CHANNELS The following description provides the reader with a brief explanation of a common logic circuit that is used throughout the locomotive control system. A more detailed discussion of this circuit is supplied later in the manual. The locomotive computer system replaces most of the relay logic found on earlier locomotives. Certain devices in the 74 volt portion of the control system, such as switches, relays, etc., provide inputs to the computer control system through computer DIO (digital input/output) modules. The EM2000 computer also controls relay/contactor pickup and dropout, through the DIOs. Each DIO module input channel, Figure 0-5, is a solid-state circuit that switches “ON” when the 74 V circuit external to the channel is completed, and “OFF” when the external circuit opens .
use F43253
Figure 0-5 EM2000 Computer to 74 VDC System Connections
Each DIO module output channel is a solid-state circuit that conducts when the computer switches it “ON,” and is non-conductive (virtually “open”) when the computer switches it “OFF.” Note that the DIO module output channels do not supply current when ON, they conduct current. The channels conduct current from an external +64 V/74V feed to the 64/74 V common side. In Figure 0-5, when the TEL relay (Tractive Effort Limit Relay ) normally open contacts #1 are open, as shown, the DIO-3 module TEL input channel (CH 13) is off. If the logic computer turns on the DIO-3 module TEL output channel (CH 7), current flows from the +64/74 V source through the TEL coil and through DIO-3 output channel CH 7 to the +64/74V return. TEL therefore picks up. When TEL picks up, its contacts #1 close, completing the circuit to the DIO-3 module TEL input channel to the 64/74 V return.
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ELECTRICAL REFERENCE DESIGNATIONS ABFR - - - - - - - - - - - Air Brake Alarm Relay ABASR - - - - - - - - - - Air Brake Alarm Silence Relay ADA - - - - - - - - - - - Analog to Digital Analog Module AG FLD- - - - - - - - - - Auxiliary Generator Field ALARM- - - - - - - - - - Alarm Bell ALT - - - - - - - - - - - - Companion Alternator AMM BC - - - - - - - - - Ammeter Battery Charging AMBTMP
- - - - - - - - Ambient Air Temperature Probe
AMM TE - - - - - - - - - Braking/ Tractive Effort Meter ASC- - - - - - - - - - - - Analog Signal Conditioner Module ASG- - - - - - - - - - - - Traction Computer AR - - - - - - - - - - - - Alarm Relay AUX GEN- - - - - - - - - Auxiliary Generator AV - - - - - - - - - - - - Governor “A” Solenoid B1, B2, B3, B4- - - - - - - Brake Grid Contactors BATT - - - - - - - - - - - Storage Battery (64 VDC) BATT SW - - - - - - - - - Battery Switch BC ASM - - - - - - - - - Battery Charging Assembly BCU - - - - - - - - - - - Braking Control Unit (Knorr) BKBL - - - - - - - - - - - Brake Blower Motor BKS - - - - - - - - - - - Brake Handle Switch BTA - - - - - - - - - - - Battery Box Temperature Sensor BV - - - - - - - - - - - - Governor “B” Solenoid BWR - - - - - - - - - - - Brake Warning Relay CA__ - - - - - - - - - - - Capacitor CB- - - - - - - - - - - - - Circuit Breaker CCU - - - - - - - - - - - - Cab Control Unit (Knorr Brake Valve) CMPSYN - - - - - - - - - Compressor Synchronization Relay GENERAL INFORMATION 0-15
COM - - - - - - - - - - - - EM2000/TCC’s/Knorr Communication Interface CPU - - - - - - - - - - - - Central Processing Unit CR_ - - - - - - - - - - - - Rectifier CR-AG - - - - - - - - - - Auxiliary Generator Rectifier CR-BC- - - - - - - - - - - Battery Charging Rectifier CRU - - - - - - - - - - - - Computer/Relay Unit CR-GTO - - - - - - - - - - GTO Power Supply Rectifier CT - - - - - - - - - - - - - Current Transformers CV - - - - - - - - - - - - - Governor “C” Solenoid DBGR - - - - - - - - - - - Dynamic Brake Ground Relay DCL - - - - - - - - - - - - DC Link Motorized Switchgear DCR - - - - - - - - - - - - Air Dryer Control Relay DRC - - - - - - - - - - - - Diode-Rectifier-Capacitor DV - - - - - - - - - - - - - Governor “D” Solenoid DVR - - - - - - - - - - - - Digital Voltage Regulator Module EFCO - - - - - - - - - - - Emergency Fuel Cut Off/Engine Stop Switch EFS - - - - - - - - - - - - Engine Filter Switch ENG PU - - - - - - - - - - Engine Speed Magnetic Pick Up ESR - - - - - - - - - - - - Emergency Sanding Relay ETP_ - - - - - - - - - - - Engine Temperature Probe FCD - - - - - - - - - - - - Firing Control Driver Module FCF - - - - - - - - - - - - Firing Control Feedback Module FCF_ - - - - - - - - - - - Fan Contactor, Fast Speed FCS_ - - - - - - - - - - - - Fan Contactor Slow Speed FLSHR - - - - - - - - - - - Flasher Relay FP MTR - - - - - - - - - - Fuel Pump (Motor) FP/ES - - - - - - - - - - - Fuel Pump/ Engine Start Switch FPR - - - - - - - - - - - - Fuel Pump Relay FVS - - - - - - - - - - - - Filter Vacuum Switch 0-16 GT46MAC LOCOMOTIVE SERVICE MANUAL
GEN AUX - - - - - - - - - Auxiliary Alternator/Generator GEN MAIN - - - - - - - - Main Alternator /Generator GFC - - - - - - - - - - - - Generator Field Contactor GFD
- - - - - - - - - - - Generator Field Decay Contactor
GOV - - - - - - - - - - - Engine Governor GR - - - - - - - - - - - - Ground Relay GRT- - - - - - - - - - - - Ground Relay Transductor GTOPS1- - - - - - - - - - Gate Turn-Off Thyristor Power Supply1 GTOPS2- - - - - - - - - - Gate Turn-Off Thyristor Power Supply 2 IB1,IB2 - - - - - - - - - - Grid Current Sensor (Hall Effect) IBKBL - - - - - - - - - - Grid Blower Current Sensor (Hall Effect) IMGF - - - - - - - - - - - Main Generator Field Current Sensor (Hall Effect) IS - - - - - - - - - - - - - Isolation Switch ITCC__ - - - - - - - - - - Inverter Current Sensor (Hall Effects) LR - - - - - - - - - - - - Load Regulator L456 - - - - - - - - - - - DC Link Stabilizer Inductor LOS - - - - - - - - - - - - Low Oil Switch (Governor) LWS - - - - - - - - - - - Low Water Level Switch MCB - - - - - - - - - - - Module Circuit Breaker Relay MRPT
- - - - - - - - - - Main Reservoir Pressure Transducer
MV - - - - - - - - - - - - Magnet Valve MV-EBT- - - - - - - - - - Magnet Valve Electronic Blow Down Timer MV-Horn CE - - - - - - - Magnet Valve-Air Horn Cab End MV-Horn HE - - - - - - - Magnet Valve-Air Horn Hood End MV-CC - - - - - - - - - - Compressor Control Magnet Valve MV-RB - - - - - - - - - - Radar Blower Magnet Valve MV-SH - - - - - - - - - - Shutter Control Magnet Valve MV1SF - - - - - - - - - - Magnet Valve Truck 1 -Sanders, Forward MV1SR - - - - - - - - - - Magnet Valve Truck 1 -Sanders Reverse GENERAL INFORMATION 0-17
MV2SF - - - - - - - - - - Magnet Valve Truck 2 -Sanders, Reverse MV2SR - - - - - - - - - - Magnet Valve Truck 2 -Sanders, Reverse ORS - - - - - - - - - - - - Governor Overriding Solenoid NO DBCO - - - - - - - - - Dynamic Braking Cut Out Switch PCR - - - - - - - - - - - - Pneumatic Control Relay PCS - - - - - - - - - - - - Pneumatic Control Switch PCU - - - - - - - - - - - - Pneumatic Control Unit (Knorr) PDP - - - - - - - - - - - - Power Distribution Panels PD - - - - - - - - - - - - - Power Distribution Plugs (74 VDC) RADAR - - - - - - - - - - Super Series Radar RBL MTR___ - - - - - - - Radiator Blower Motor RDR TST - - - - - - - - - Radar Test Relay RE__ - - - - - - - - - - - - Resistor RE-BC - - - - - - - - - - - Battery Charging Resistor REC - - - - - - - - - - - - Receptacle RE-DB - - - - - - - - - - - Dynamic Brake Rheostat Auxiliary Resistors RE-GRID 1-8 - - - - - - - Dynamic Braking Resistor Grid (1 thru 8) RE-VDCL - - - - - - - - - DC Link Voltage Feedback Resistor REVMG - - - - - - - - - - Main Generator Feedback Resistor RHS-F-R- - - - - - - - - - Reverser Handle Switches Forward - Reverse RHS - - - - - - - - - - - - Remote Headlights Control Switch RH - - - - - - - - - - - - - Rheostat SCR - - - - - - - - - - - - Silicon Control Rectifier (Generator Excitation) SDR - - - - - - - - - - - - Shut Down Relay SM1& 2 - - - - - - - - - - Starting Motor SPR1-2- - - - - - - - - - - SIBAS 16 Traction Con. Comp. Power Relays ST
- - - - - - - - - - - - Starting Contactor
STA - - - - - - - - - - - - Starting Auxiliary Contactor T__ - - - - - - - - - - - - Transformer 0-18 GT46MAC LOCOMOTIVE SERVICE MANUAL
TB - - - - - - - - - - - - - Terminal Board TCC_ - - - - - - - - - - - Traction Control Converter TCC1SS - - - - - - - - - - TCC1 Blower Slow Speed Contactor TCC2SS - - - - - - - - - - TCC2 Blower Slow Speed Contactor TEL - - - - - - - - - - - - Tractive Effort Limit Relay THS_ - - - - - - - - - - - Throttle Handle Switch TLP MTR - - - - - - - - - Turbo Lube Pump Motor TLPR - - - - - - - - - - - Turbo Lube Pump Relay TM AIR - - - - - - - - - - Traction Motor Cooling Air Temperature Probe TM-1to 6 - - - - - - - - - Traction Motor (1-6) TMS- - - - - - - - - - - - Traction Motor Stator Temperature Sensor TM__SPPU - - - - - - - - Traction Motor Armature Speed sensor TURBO PU - - - - - - - - Turbo Speed Magnetic Pickup VCU - - - - - - - - - - - - Voltage Conditioning Unit (Knorr) VDCL - - - - - - - - - - - DC Link Voltage Sensor VPC - - - - - - - - - - - - SIBAS Voltage Protection Contactor WH SLP - - - - - - - - - - Wheel Slip Light WL - - - - - - - - - - - - Wheel Slip Relay
GENERAL INFORMATION 0-19
INTRODUCTION TO KNORR AIR BRAKE SYSTEM This locomotive model is equipped with a Knorr CCB microprocessor (computer) controlled air brake system that has been incorporated into the EM2000 system. The display of pressures uses traditional discreet analog gauges. The Knorr CCB is a computer based electro-pneumatic system providing control of air brakes on locomotives and cars coupled in trains. An overview of this system is provided in the block diagram of Figure 0-5. The overall purpose of using a computer (microprocessor) to control the air brake system is to eliminate as many of the discrete electrical and pneumatic devices as possible thus reducing periodic maintenance and simplifying troubleshooting. The processor controlled air brake is designed to work like a standard 26L mechanical brake system. Because of the reduced components required it allows greater reliability while reducing maintenance cost.
Figure 0-6 Computer Controlled Braking System Overview The function of pneumatic relays and valves is replaced by a Pneumatic Control Unit (PCU) mounted in the cab sub-base. The PCU is a fabricated structure made up of a panel for mounting of pneumatic devices formerly at scattered locations on the locomotive. The PCU is controlled by the CCB air brake computer - it can connect its inputs together in different ways and provides an interface for electrical and pneumatic devices. A Cab Control Unit, located on the top right side of the lower console, houses controls for the automatic and independent brake systems.
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Figure 0-7 Cab Control Unit Block Diagram
AIR BRAKE EQUIPMENT A Cab Control Unit (brake valve) is located on the top of the lower console on both sides of the cab and most brake equipment is mounted on a laminated panel behind an access panel on the front of the locomotive. The electrical Cab Control Unit (brake valve) has two handles -
1. Automatic Brake Valve function 2. Independent Brake Valve function IMPORTANT The following air brake controls on this Locomotive are implemented with discrete air brake components and are also communicated to the EM2000 system. Refer to Figure 6-14 on page 6-26 for set up of these functions.
1. REGULATING VALVE (FEED VALVE) 2. MULTIPLE UNIT VALVE 3. CUT-OFF PILOT VALVE. These devices have been replaced with electrically (computer) controlled equipment. The device that replaces the pneumatic brake valve is described as follows.
GENERAL INFORMATION 0-21
The automatic and independent brake system combines two controls in a single housing, located on the top of the console. Handles are operated in a forward-backward motion, the brakes being released at the backward (towards the operator) position. Operating positions are detented for positive location.
Figure 0-8 Cab Control Unit (replaces brake valve)
INTRODUCTION TO EM2000 LOCOMOTIVE DISPLAY The EM2000 locomotive computer display can be accessed by selecting LOCO DATA from the Main Menu on the display. The EM2000 display panel is made up of a 6 line, 40 column display that is operated with push-button keys. This panel, combined with the locomotive control computer, is referred to as the Display Diagnostic System (DDS) because it can provide locomotive operating, maintenance, and troubleshooting data. The Display Diagnostic System was designed to be “user friendly” for a locomotive operator with little or no computer experience. Do not let the detailed discussion which follows cause undue concern about the complexity of this system - actual DDS use is much easier than the technical details might imply. The Display Diagnostic System is an interactive device that provides an interface between the control computer and the locomotive operator or maintenance person. The user observes the display screen and can input to the computer through the keypad. The computer directs operator input by providing “messages” on the screen. These messages indicate locomotive control and maintenance functions.
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KEYPAD The characterization of the EM2000 uses one on-screen row of 4 spaces which are related to the 4 hard keys under the screen. The following list defines the purpose of each key on the screen keypad area as they are used for the EM2000 display. –F1, F2, F3, F4 are function keys. The term “function” key is used to specify keys that are not defined in the same way for every screen. The purpose of these keys is to provide greater flexibility in menu selection. On any given screen the function keys represent an instruction to the control computer such as, reset a fault, cut out an inverter, request more information about other stored data, etc. The function keys are located under the actual display screen with pointer lines showing which key affects that function. The bottom line on the screen provides the definition for the function keys that are active on that screen. There are 4 function (globally undefined) keys available on the display and 12 dedicated keys. These dedicated keys are defined as follows –Cursor Arrow Keys are used to move the on-screen cursor to a different postion. NOTE The “cursor” on an EM2000 display screen is actually a highlighted box the background behind the area of the selection is reverse colored black/white. –On/Off
turns on or off the display screen
–M MENU
returns screen to main menu in one keystroke.
–CREW
returns screen to crew message function in one keystroke.
–HELP
provides information about the current screen and explains available options.
–SELECT
Select the item highlighted on the screen
–HE POWER
Not used on GT46MAC Locomotive
–SLOW SPEED Not used on GT46MAC Locomotive –BRIGHT/DIM
Controls Screen Brilliance
GENERAL INFORMATION 0-23
BASIC SCREENS When power is first applied to the display (the battery knife switch is closed and the "Computer Control " circuit breaker is closed), the system will do the necessary board level checks on the display. Once this task is completed, a search for archived faults in a temporary fault storage area called the "annunciator" will be conducted. If there are faults stored in the annunciator, the display screen will appear as follows:
f43254
Figure 0-9 Maintenance Information Stored The annunciator is intended to hold recent faults, and it is prudent to clear out the annunciator of any faults before the locomotive is dispatched on a train. In this manner, if any faults do occur while the locomotive is on a current run, the next maintenance area will know that there was a problem during the last run because of the "Maintenance Information Stored" message. We will cover resetting the annunciator and other in-depth use of the display later the course. If there are no faults stored in the annunciator, the display will then search for "Crew Messages", which are messages displayed on the screen with the intent of informing the operating crew of an unusual condition on the locomotive (not necessarily a fault condition). An example of this type of message is shown below:
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F43255
Figure 0-10 Crew Message #2 of 3
NOTE CREW MESSAGES actually display normal operating conditions as well as problems that occur on the locomotive, such as: • engine speedup for low water temperature • locomotive is not properly set up for the current required mode of operation • power is limited • some piece of equipment or system has failed and a protective function is active. If there are no crew messages to display, the display screen then automatically goes to the "Main Menu", which is shown below:
GENERAL INFORMATION 0-25
F43256
Figure 0-11 EM2000 Main Menu Display Other selections off of the main menu can be made by using the four cursor keys in the center of the keypad. Once the desired selection has been highlighted, use the F3 key to SELECT. Once in the desired screen, use the F4 key (except in the Fault Archive) to EXIT and return to the previous screen to make another selection. •Unit Information •Unit number •Software identification number •Ambient air temperature •Barometric pressure •Date •Time
TRACTION CUTOUT This selection replaces the "Traction Motor Cutout" switch on previous locomotives. You must now initiate traction motor cutout or truck disable from this screen.
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SELF TESTS Self load Excitation Load Regulator Wheel Slip Contactors/Relays Cooling Fans Radar Meter Test DCL Shorting Test
FAULT ARCHIVE Display archive faults Send archive faults to RS-232 port Clear the annunciator
RUNNING TOTALS Show running totals on display Transfer data to RS-232 port Start/Stop trip monitor
MAINTENANCE Air Test Setup TE Limiting
ENGLISH/METRIC Allows the user to toggle between both measurement units. The display retains the last selected units until toggled back.
LOCKED WHEEL DETECTION Disable/Enable Locked Wheel Detection
GENERAL INFORMATION 0-27
DATA METERS The purpose of the data meter is to give the user information about the operation of the locomotive and computer in real-time fashion. To make signal selection easy, there are a number of predefined meters. There is also the ability for the user to select individual signals for a personalized meter screen. See the following page for a listing of the available meters.Listing of Available Meters
•Program meter •Dynamic Brake •Starting System •Digital I/O •Power Data •Creep Control •Cooling system All maintenance and operating personnel are encouraged to gain experience on the display system in hopes of working more efficiently with the GT46MAC locomotives and the EM2000. The easiest way to get experience with the system is to "learn by doing". The locomotive cannot be damaged by perusing the screens, however, the novice should first go through the screens with someone knowledgeable about locomotive operation, as selections such as "Load Test" can be made that will set the locomotive into a power generating mode. Also, since pick-up and dropout of a variety of contactors (as well as other duties) can be executed through interface with the display, safe work rules should prohibit casual "browsing" through the display when the unit is "Blue Flagged" as someone may be working in a vulnerable position.
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INTRODUCTION TO FLANGE LUBE SYSTEM Rail lubrication systems are designed to reduce friction between the locomotive’s wheel flanges and the rails by applying a controlled amount of lubricant to the “throat” area of selected wheels during locomotive operation under conditions appropriate for its use. The GT46MAC units #11001 to 11013 are equipped with a TSM rail lubrication system entirely controlled by the locomotive computer EM2000. This system uses a grease/oil type lubricant - propelled, and atomized by the locomotive’s compressed air system.
SYSTEM OPERATION The TSM rail lubrication system consists of 3 major components 1. A reservoir (tank), located in the rear (long hood) end of the locomotive, contains the lubricant supply. The TSM system utilizes a lubricant reservoir which is pressurized by air from the main reservoir. 2.Lubricant spray nozzles (2) are mounted adjacent to (and aimed at) the flange “throat” area of the appropriate wheels. Locomotive compressed air is used to operate (trigger) the nozzles on the systems, and is used as a lubricant propellant (atomizer) on the TSM system. 3. Metering valves and solenoid(s) are used on the systems to control the flow of air and lubricant to the nozzles upon receiving electrical signals from the EM2000. The rail lubrication system is now being controlled by the EM2000, thus eliminating the need and cost of a TSM system controller box. The electrical components of the system are MV-PUMP, MV N0ZF and MV N0ZR. The computer controls these magnet valve using DIO3 output channels 11, 12 and 13. EM2000 will turn on the appropriate output channels RLN0Z 1 (Rail Nozzle Forward) or RLN0Z2 (Rail Nozzle Reverse) every 0.2 seconds every 122 meters (400 feet) if locomotive speed is above 8.1Km/h (5 M.p.h.) and there is no emergency brake application or sand application. To pressurize the lubricant, the computer turns on the output channel (RL PUMP) every10 nozzle spray “shots” so that main reservoir air pressurizes the lubricant. A system self test can be performed using EM2000 display - Select SELF-TEST on the main menu, then flange lube self-test. Follow the instruction displays.
GENERAL INFORMATION 0-29
ALERTER (VIGILANCE) SYSTEM
The vigilance function on the GT46MAC locomotive is performed by EM2000. When the locomotive brakes are released, the computer requests an acknowledgment from the locomotive operator from time to time. The acknowledgment request is never more frequent than once per 60 seconds. If the acknowledgment request is not answered, the locomotive computer initiates a penalty brake application. The acknowledgment requests consists of: 1.Alerter lights flashing for 17 seconds, then 2.ALERTER ALARM sounds for 17 seconds (Lights continue flashing) Pressing either alerter RESET button while the alerter lights are flashing or the ALERTER ALARM is sounding resets the acknowledgment request timing cycle. Using the automatic brake handle to moderately reduce brake pipe pressure also resets the timing cycle. In addition, movement of the throttle handle, independent brake handle, or dynamic brake handle will also reset the timing cycle, as will pressing the HORN or SAND button. If the alerter system request is not acknowledged while the alerter light is flashing or the ALERTER ALARM is sounding, the alarm stops sounding and a penalty brake application occurs. The penalty brake application must be reset before normal train operation can continue.
NOTE
Use of alerter equipment must be in accordance with Railway rules and operating practices The alerter indicator light mounts on the control console instrument panel, below the indicator light panel. The orange alerter RESET push-button mounts on the control console desktop surface, in front of the air brake controller. The audible ALERTER ALARM mounts on the No. 1 electrical control cabinet engine control panel. EM2000 uses : –DIO-3 input channel 9 (ALTRST)to monitor the state of the alerter reset buttons (console #1 and #2). –DIO-3 Output channel 1 (ALT LT) to control the alerter lights (console #1 and #2). –DIO-3-Output channel 3 (ALTBEL) to control the alerter alarm bell.
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SAFETY PRECAUTIONS FOR GT46MAC LOCOMOTIVES INTRODUCTION The GT46MAC is a new locomotive model that has some equipment not found on freight locomotives with DC traction motors. Safety precautions specific to a GT46MAC must be followed before inspecting the equipment. This section provides general safety information and precautions that are necessary before maintenance can be performed on the locomotive.
WARNING
All local safety rules should be observed. This document is designed for use by various customers. It should be used in conjunction with customer specific safety rules.
The output of the TA17-6 main generator is the DC link voltage. A large capacitor rack is located within each of the traction inverters TCC1 and TCC2 to filter main generator voltage before it goes to the traction inverters. These capacitors operate at the DC link voltage between 600 and 3000 VDC. When the locomotive is shut down these capacitors could retain this high voltage causing a possible safety hazard to operating and maintenance personnel. A procedure has been developed to discharge this high voltage into the dynamic brake grids to prevent the possibility of injury.
WARNING
The DC link voltage is present on all equipment connected to the output of the main generator. This includes main generator output terminals and cabling connections, TCC cabinets, Crowbar Inverter Protection Resistors (IPR), DCL switchgear, DCL Reactor and brake grids.
THE LOCOMOTIVE OPERATOR SHALL NOT ACCESS ANY DEVICES WITHIN THE HIGH VOLTAGE CABINET, DUE TO RESIDUAL HIGH VOLTAGE. ACCESS WITHIN THE HIGH VOLTAGE CABINET (HVC) IS LIMITED TO MAINTENANCE INDIVIDUALS THAT ARE KNOWLEDGEABLE OF THE GT46MAC DISCHARGE PROCEDURE. This restriction does not apply to the engine control panel, circuit breaker panel, circuit breaker compartment, and the fuse and switch panel, which may be accessed during normal operation. A drawing on the following page shows the location of the 3 panels and one compartment, which may be accessed by the locomotive operator.
GENERAL INFORMATION 0-31
Figure 0-12 High Voltage Cabinet Upper Half (showing panels accessed by operator)
Figure 0-13 ECC1’s Circuit Breaker Panel
0-32 GT46MAC LOCOMOTIVE SERVICE MANUAL
F42002
Figure 0-14 Circuit Breaker and Voltage Test Panel
F43257
Figure 0-15 Fuse and Battery Compartment Switch
GENERAL INFORMATION 0-33
F42003
Figure 0-16 Engine Control Panel The DC link is discharged automatically by the locomotive operator or maintenance personnel in the normal course of shutting down the unit. Upon engine shutdown, excitation to the main generator is disabled and main generator output voltage will approach zero. In the event of a system failure, even after the engine is stopped, capacitors and phase modules could be at operating voltage. Moving the Isolation switch to ISOLATE causes the DC link voltage to be automatically (by EM2000) connected across the dynamic brake grids causing the DC link energy to be dissipated through the grids. It takes approximately 1 second for the DC link to be discharged in this manner.
WARNING
Even after the automatic shut down, i.e. in case of failure, TCC cabinet components such as DC Link capacitors, snubber capacitors, grounding capacitors, and phase modules may still be charged at hazardous voltage level. Therefore, additional activities have to take place in the TCC in order to make the AC system safe for inspection and maintenance. If a cut out bogie (inverter) cannot be cut in because of a fault in the computer control system, the DC link shorting test cannot be completed. Follow the GT46MAC discharge procedure.
0-34 GT46MAC LOCOMOTIVE SERVICE MANUAL
SECTION 1. ENGINE STARTING AND STOPPING INTRODUCTION The locomotive is equipped with two 64VDC electric motors for starting the diesel engine. When the starting motors operate, their pinions engage the engine flywheel ring gear, and the starting motors crank the diesel engine. Before starting, the diesel engine must be primed with fuel by operating the fuel pump. The fuel pump also operates during engine cranking (starting) and while the engine is running.
STARTING EQUIPMENT STARTING FUSE Battery current flows through a 800 amp rated fuse only during the diesel engine starting process.The fuse should be in good condition and should always be left in place, even though it has no effect on locomotive operation except during engine starting. The fuse may be defective if the starting motors will not crank the engine when the battery knife switch is closed and a starting attempt is made (i.e. FP/ES switch held in ENGINE START position. In that event, EM2000 will display a crew message labeled “NO START - START FUSE IS OPEN OR MISSING”. CAUTION This locomotive is equipped with a 800 amp starting fuse. When replacing the fuse, observe rating marked on the panel. Do not use an incorrectly rated fuse.
FUEL PRIME/ENGINE START SWITCH (FP/ES) The Fuel Prime/Engine Start switch (FP/ES) is the control device used to initiate engine starting on export model units. When the fuel prime/engine start switch is held in FUEL PRIME position and the proper switches and breakers are closed, the fuel pump will operate. This switch has three positions and is used to provide three circuit functions •
FUEL PRIME Position
Holding the FP/ES switch in the PRIME position tells the computer to start the fuel pump motor and pressurize the fuel system for starting. •
ENGINE START Position
Holding the FP/ES switch in the START position provides a start logic signal to the control computer, which in turn picks up the STA contactor. Pickup of STA causes pick up of starting contactor ST which powers the engine starting motors. •
OFF POSITION (not used by EM2000)
ENGINE STARTING AND STOPPING 1-1
FP/ES SWITCH LOGIC To accomplish the 3 functions listed above, the FP/ES switch must be a multi function switch. Below is the logic chart for OFF, START and PRIME positions and a brief explanation of interlock function.
USE f43258
Figure 1-1 Fuel pump engine prime/start logic chart •
Interlock 1-2 closes in PRIME and START tells the computer to start the fuel pump motor
•
Interlock 3-4 & 5-6 closes in OFF position. NOT USED
•
Interlock 7-8 closes in START position, the computer receives a starting request
•
Interlock 9-10 closes in START position to allow pickup of the STA contactor by the computer
•
Interlock 11-12 closes in START position. NOT USED
ENGINE PRIME CIRCUITS (see fig 1-2)
1-2
•
Battery switch and local control breaker closed.
•
Hold FP/ES switch in prime position. Refer to Figure 1-2.
•
Interlock 1-2 close provide a feed to the computer DIO-2(IN)(CH7)(PRIME)
•
The computer activates output channel 2(OUT)(CH11)(FPRLY) which picks up the FPR relay coil
•
EFCO interlock #2 must be closed.
GT46MAC Locomotive Service Manual
DIO-
NOTE The EFCO relay is picked up as soon as the LOCAL CONTROL breaker is closed and the SDR (shut down relay) is not picked up and none of the EFCO switches are pushed. •
When the FPR picks up, its #1 and #2 contacts close to start the fuel pump. The pump will run as long as the FP/ES switch is held in prime.
F43259
Figure 1-2 GT46MAC Engine Prime/Engine Start Circuit. When the FP/ES switch is placed in the start position and the above conditions are met: 1. Interlock 1-2 close to provide a feed to the computer’s DIO-2(IN)(CH7)(PRIME). As in the prime sequence the FPR picks up the fuel pump. 2. Interlocks 7-8 close to provide a feed to DIO-1(IN)(CH1)(START). This provides the computer with the starting input signal 3. Interlocks 9-10 close to complete the circuit to STA coil and DIO1(OUT)(CH16)(STA). This circuit picks up the STA contactor, which in turn picks up the ST contactor to start the diesel engine. ENGINE STARTING AND STOPPING 1-3
ENGINE START CIRCUIT
F43260
Figure 1-3 Engine Start Circuit. The engine start sequence will be allowed to commence only if the following conditions are met: Unit is not already running The computer will not pick up STA if it detects that engine speed is greater than 55 RPM or that companion alternator output voltage is greater than 25 V. To detect engine speed, the computer monitors the frequency of the signal from a magnetic pickup mounted near the engine flywheel. This pickup transmits a pulse each time a flywheel gear tooth moves past. To detect companion alternator voltage, the computer uses the information provided by the panel
mounted module FCF, (Firing Control Feedback) which is connected to the output of the companion alternator through the AC control breaker. Isolation switch is in the START/STOP/ISOLATE position Computer detects this by means of its DIO-2(IN)(CH1)(ISOLATE) input channel. Turbo lube pump is running Computer detects this by means of the DIO-1(IN)(CH24)(TPLR) input channel . No starting abutment Computer detects this condition when it does not receive the feed from starting contactor (ST) auxiliary contacts within 0.3 seconds after starting is initiated. (Indicates that something was preventing a starting plunger from reaching its fully-drawn-in position.) Starting motors SM1 and SM2 are each equipped with a solenoid assembly. Each solenoid assembly has a pickup coil (PU), a hold-in coil (HOLD), and a set of contacts (SM). The PU coil resistance is relatively low; the HOLD coil has many turns of fine wire, and has much greater resistance. 1-4
GT46MAC Locomotive Service Manual
0 When the computer picks up contactor STA, the FR (STA) and BK (STA) contacts close, supplying battery current through the starting motor solenoid PU coils and the starting motors themselves. Energizing a PU coil draws in its plunger, causing the bottom arm of the connecting linkage to push the motor clutch so that it engages the motor pinion gear with the engine flywheel ring gear. As the solenoid plunger nears the end of its travel (near fully drawn in), it closes the solenoid SM contacts. When both solenoid SM contacts are closed, they enable battery power to pick up the main starting contactor ST, through closed STA contacts. The FR (ST) and BK (ST) contacts then close to connect the starting motors (in parallel) across the batteries though the battery switch and the START fuse, and the starting motors begin cranking the diesel engine. When the ST contacts close, the PU solenoid coils are virtually shorted out because the STA contacts are also closed. Therefore, current stops flowing through the PU coils. However, sufficient current flows through the HOLD coils to keep the solenoid plungers drawn in. After the engine has started and the FP/ES switch is released, the computer drops out STA. This causes ST to drop out. With STA and ST both dropped out, all power to the starting motors is cut off, so they stop cranking, and their pinions withdraw from the ring gear.
EFCO SWITCH
F43261
Figure 1-4 GT46MAC EFCO Circuit The Emergency Fuel Cut Off Push-button Switch EFCO is used to drop out the EFCO relay which drops out fuel pump relay FPR and shuts down the engine. The GT46MAC is equipped with 3 EFCO switches. One is on the Engine Control Panel (electrical cabinet) and one is on each side of the locomotive near the fuel filler orifices.
MU ENG STOP SWITCH & SDR RELAY The MU ENG STOP (Multiple Unit Engine Stop) push-button switch, on the #2 control console, is used to activate the Shutdown Relay SDR. Pick up of SDR shuts down the diesel engines of all MU connected locomotive units in a consist.
ENGINE STARTING AND STOPPING 1-5
STARTING PROCEDURES FOR GT46MAC DIESEL ENGINES Perform the following Prestart Inspections before attempting to start the diesel engine.
PRESTART INSPECTIONS Open the doors along the sides of the locomotive long hood to gain access to engineroom equipment. Refer to previous chapter, for equipment location. •
Check air compressor for proper lube oil supply. Add oil, if necessary. Refer to Section 6 for compressor lube oil recommendations.
•
Check level in water level sight gauge; it should be near the FULL (ENGINE DEAD) mark. If water level is low, refer to Section 4 in this manual.
•
Make sure that overspeed trip (OST) mechanism is set, Figure 1-6, page 1-8.
•
Check that the governor low oil pressure trip plunger is set, and that oil is visible in the governor sight glass.
•
Check to be certain that the crankcase pressure and low water pressure detector reset buttons are set (pressed in). (See Figure 1-7.) If either button protrudes, press and hold button for five (5) seconds immediately after engine starts.
•
Make sure that engine top deck, air box, and oil pan inspection covers are in place and are securely closed.
•
Make sure that oil level gauge (dipstick), located on side of engine oil pan, is coated with lube oil.
NOTE A properly filled lube oil system coats the oil gauge above the FULL mark when the engine is stopped. To obtain an accurate check, recheck level when engine is idling and at normal operating temperature. •
1-6
Perform Prelubrication procedures described in “PRELUBRICATION,” on page 1-9, before attempting to start a new engine, or an engine that has been overhauled, or an engine that has been shut down for more than 48 hours.
GT46MAC Locomotive Service Manual
F-EN42790
Figure 1-5 GT46MAC Engineroom Equipment Rack
ENGINE STARTING AND STOPPING 1-7
F29233
Figure 1-6 Govenor Trip Plunger and Engine OST Reset Lever.
F-ES37807
Figure 1-7 Low Water and Crankcase Pressure Detector
1-8
GT46MAC Locomotive Service Manual
PRELUBRICATION It is necessary and important to prelubricate new engines, engines that have been overhauled, and engines that have been inoperative for more than 48 hours. Prelubrication alleviates loading of unlubricated engine parts during the interval when the lube oil pump is filling the passages with oil. It also offers protection by giving visual evidence that oil distribution in the engine is satisfactory. Perform prelubrication as follows: 1. Remove the pipe plug at the main lube oil pump discharge elbow, and connect an external source of clean, warm oil at the discharge elbow. Prelube engine at a minimum of 69 kPa (10 psi) for a period of not less than three and not more than five minutes (approximately 57 liters/min. [15 gpm] using a 1.1 to 1.5 kW [1-1/2 to 2 HP] motor). 2. While oil pressure is being applied, open the cylinder test valves and bar the engine over one complete revolution. Check all bearings at the crankshaft, camshafts, rocker arms, and at the rear gear train for oil flow. Also check for restrictions and excessive oil flow. Check for fluid discharge at the cylinder test valves. If fluid discharge is observed from any cylinder test valve, find the cause and make the necessary repairs. 3. On new or overhauled engines, remove the pipe plug at the piston cooling oil pump discharge elbow and connect the external oil source at that opening. Check for unrestricted oil flow at each piston cooling tube. 4. Disconnect the external oil source and replace the pipe plugs at the pump discharge elbows. Close the cylinder test valves. 5. Raise the top deck covers and pour a liberal quantity of oil over the mechanism above each cylinder. 6. Check oil level in strainer housing and, if required, add oil to strainer housing until it overflows into the oil pan. 7. Replace and securely close all handhole covers and engine top deck covers. NOTE When an engine is replaced due to mechanical breakdown, it is important that the entire oil system, such as oil coolers, filters, and strainers, be thoroughly cleaned before a replacement engine or the reconditioned engine is put in service. A recurrence of trouble may be experienced in the clean engine if other system components have been neglected. In some cases, engines have been removed from service and stored in the “as-is” condition by draining the oil and applying anti-rust compound. When these engines are returned to service, care must be taken to see that any loose deposits are flushed out before adding a new oil charge. The entire engine should be sprayed with fuel to break up any sludge deposits, and then drained, being careful that the drains are not plugged. Fuel should not be sprayed directly on the valve mechanism or bearings, as lubrication will be removed or dirt forced into these areas. The surfaces should then be wiped dry before new oil is added to the engine.
ENGINE STARTING AND STOPPING 1-9
ENGINE STARTING PROCEDURE After the preceding inspections have been completed, the diesel engine may be started. CAUTION Perform the Prelubrication procedures described in “PRELUBRICATION” on Page 1-12 before attempting to start a new engine, an engine that has been overhauled, or an engine that has been shut down for more than 48 hours. If engine temperature is below l0°C (50°F), engine should be preheated prior to any starting attempts. 1. Check engine oil level in strainer housing and, if required, add oil to strainer housing until it overflows into the oil pan. 2. Open cylinder test valves and bar over the engine at least one revolution. Observe for leakage from test valves. Close the test valves. NOTE It is highly recommended that the engine be barred over one complete revolution with the cylinder test valves open before starting. If any fluid discharge is observed from any cylinder, find the cause and make the necessary repairs. This practice should apply particularly to engines that are approaching a scheduled overhaul after several years of service or have had a history of water or fuel leaks. 3. At the fuse and switch panel located outside of the locomotive (left side), verify that the battery knife switch (BATT SW) is closed. Check that the starting fuse is in good condition and has proper rating. At the circuit breaker panel on the electrical cabinet #1 verify that the auxiliary generator (AUX GEN) circuit breaker is closed. CAUTION This unit model is equipped with a 800 ampere starting fuse. Observe markings on panels to avoid interchange of incorrectly rated fuses. 4. On the electrical cabinet at the No. 1 circuit breaker panel and No. 2 circuit breaker and test panel, close all the breakers that are located in the black panel areas. (Breaker is closed when its lever is UP.) At the No. 1 circuit breaker panel, check position of the ground relay cutout switch. This switch is normally kept closed (lever UP) to enable normal locomotive operation. When this switch is open (lever down), as set during certain shop maintenance inspections or procedures, the ground fault detection system is disabled and the locomotive computer prevents both loading (main generator excitation) and throttle response by the diesel engine (engine speed not affected by throttle handle). 5. At the engine control panel, set the isolation switch to the START/ STOP/ ISOLATE position. 6. At the #2 control console, set the generator field switch and engine run switch to the OFF (down) position. Set the control and fuel pump switch to the ON (up) position. 7. At the equipment rack, momentarily hold the fuel prime/engine start switch (FP/ES), Figure 1-9, Page 1-15, in the PRIME position to start the turbo lube oil pump. 1-10
GT46MAC Locomotive Service Manual
0 8. Remove rear oil pan handhole cover and open top deck covers. Check turbo lube pump operation by observing lube oil flow at camshaft gear train. NOTE Observe camshaft bearings. If lube oil flows from camshaft bearings with turbo lube pump running and engine shut down, the turbo filter outlet check valve is defective. Refer to Engine Maintenance Manual.
CT42000
Figure 1-8 Typical Fuse and Switch Compartment.
9. Replace and securely close handhole covers and engine top deck covers. 10. Turn the fuel prime/ engine start switch (FP/ES) to the PRIME position and hold it there until fuel flows in the return fuel sight glass, Figure 1-10, page 1-13, clear and free of bubbles (normally 10-15 seconds).
ENGINE STARTING AND STOPPING 1-11
Figure 1-9 Fuel Prime Engine Start Switch 11. Manually advance injector control lever about 1/3 its travel and turn the fuel prime/engine start switch (FP/ES) to ENGINE START position and hold the switch in this position until the engine fires and speed increases, but not for more than twenty (20) seconds. CAUTION Do not crank engine for more than twenty (20) seconds or “inch” engine with starting motors. After cranking, allow a minimum of two (2) minutes for starter motor cooling before attempting another engine start.
12. Release injector control lever (if advanced) when engine comes up to idle speed. Do NOT advance lever to increase speed until oil pressure is confirmed.
NOTE Engine water inlet temperature should be allowed to reach 49°C (120°F) at idle before moving the throttle handle above TH2 position.
1-12
GT46MAC Locomotive Service Manual
F27505
Figure 1-10 Fuel Oil Sight Glasses 13. Check low water pressure detector reset button after engine starts. If tripped, press button to reset detector. The engine will shut down after a short time delay if the detector is not reset. NOTE If the detector is difficult to reset after engine starts, confirm oil pressure, position the injector control lever (layshaft) to increase engine speed for a short time, and then press the reset button. 14. With engine running at normal operating temperature check A. Coolant level is near the FULL (ENGINE RUNNING) mark on the water level sight glass. B. Lube oil level is near the FULL mark on oil level gauge (dipstick). C. Governor oil level. D. Compressor lube oil level.
ENGINE STARTING AND STOPPING 1-13
STOPPING PROCEDURES FOR GT46MAC DIESEL ENGINES ENGINE STOPPING SYSTEM The normal way to shut down a diesel engine is to cause the engine governor to bring the fuel injectors to the “NO-FUEL” position. (Stopping the fuel pump without first bringing the injectors to the “NO-FUEL” position will also result in stopping the engine, but that method is not recommended.) There are several ways to cause the governor to bring the fuel injectors to the “NO-FUEL” position (to stop the engine), including operating the following switches: • • • •
EFCO/ STOP - the emergency fuel cutoff & engine stop push-button switch, mounted on the high voltage cabinet engine control panel in the cab; EFCO2 - the emergency fuel cutoff push-button switch mounted on the left side of the locomotive just above the fuel tank filler; EFCO3 - the emergency fuel cutoff push-button switch mounted on the right side of the locomotive just above the fuel tank filler; MU ENG STOP - the multiple unit engine stop/run switch mounted on the #2 console. (Pressing the STOP portion of this switch stops all engines in the consist.)
The governor will also bring the fuel injectors to the no-fuel position if any of the following conditions occur: • • • •
Engine lube oil pressure too low. Engine lube oil too hot. Engine cooling water pressure too low. Engine crankcase pressure too high.
MULTIPLE UNIT STOP Pressing the MU ENG STOP switch STOP push-button shuts down all the diesel engines in the consist. This is the result of the pick up of SDR. When SDR is picked up: • • • •
#2 contact opens to drop out emergency fuel cutoff relay EFCO, #4 contact opens to drop out generator field contactor GFC #3 contact opens to block the feeds to all the computer DIO module THS input channels and associated trainlines, #1 contact change position to continue to feed DIO module input channel THST56 and trainline 3T after the above feeds are blocked.
When EFCO is dropped out, its contact #1 closes to provide a direct return path to negative (the contact is installed in parallel with the output channel D VALVE) for the governor DV solenoid. When DV is energized it brings the injector rack to the “NO-FUEL” position.
1-14
GT46MAC Locomotive Service Manual
NOTE Once depressed, the MU engine stop switch remains mechanically latched in until the run portion of the MU ENG stop switch is depressed. The diesel engine cannot be started when the switch is in STOP position. The crew message: MU SHUTDOWN REQUESTED appears on the display screen. Pressing the MU ENG STOP switch RUN push-button drops out SDR. The following results from SDR dropout: • • •
EFCO relay pickup is enabled. GFC contactor pickup is enabled. Normal control of feeds to DIO module THS input channels (by THS switches) is established.
EFCO SWITCH & MU ENG STOP/RUN SWITCH OPERATION Refer to Figure 1-4. When the STOP section of the MU ENG STOP switch is pressed, relay SDR picks up. (The MU ENG STOP switch contacts remain closed, energizing the SDR coil, until the RUN section of the switch is pressed.) When SDR picks up, the normally open No. 1 SDR contact close, providing a feed to trainline 3T (GOV-D) and to the computer DIO module THS 5 6 input channel. In addition, the normally closed No. 3 SDR contacts open, cutting off the feed to all the THS (throttle handle switches with the exception of - THS IDLE switch), which cuts off the feed to the corresponding computer DIO input channels and trainlines, as well as to the computer DIO module main generator field request input channel (GF REQ). In response, on all trainlined units, the computer drops out engine governor A, B, and C governor valves (speed-setting solenoids), and picks up the governor D valve; the governor therefore moves the injector control rack to the “NO-FUEL” position, stopping the engine. The computer also halts main generator excitation. The RUN section of the MU ENG STOP switch must be pressed to drop out relay SDR, restoring normal throttle switch inputs to the computer, to enable the engine to start and run. The normally closed switches EFCO/STOP, EFCO2, EFCO3, and the normally closed contact of SDR relay are connected in series with the EFCO relay coil. In normal operation, all the contacts in the series remain closed, and the EFCO relay stays picked up; note that, the computer DIO module NO EFCO input channel receives a feed that is not affected by the SDR contact. If any EFCO push-button is pressed, the EFCO relay drops out, and if the pushbutton is held pressed for at least 0.5 second, the computer detects that DIO module NO EFCO input channel input feed has been interrupted. If the MU ENG STOP switch, STOP section is operated, the SDR relay is energized which drops out the EFCO relay, without interrupting the feed to the NO EFCO input DIO channel.When the EFCO relay is de-energized, its No. 1 contact closes to provide a direct return path to negative for the governor DV solenoid which, when energized, shutdown the diesel engine.
ENGINE STARTING AND STOPPING 1-15
When the computer senses that the feed to the NO EFCO input channel has been interrupted, it turns OFF the DIO module governor valve output channels AV, BV, CV, and ON the output channel D valve - causing the governor to stop the engine. In addition, the computer drops out the FPR relay, which stop the fuel pump.
NOTE As described in the preceding text, when an EFCO push-button is pressed, the EFCO relay immediately drops out, and, if the push-button is held depressed for at least 0.5 second, the computer reads that the NO EFCO computer DIO module input channel is interrupted. Either occurrence results in the governor bringing the injector rack to the no-fuel position, to stop the engine. Although unlikely, it is possible that someone will press an EFCO push-button when the computer is not operating; the loss of the NO EFCO computer input in these circ*mstances will have no effect on the governor or FPR relay. EFCO relay dropout will still cause the governor to shut down the engine and will still drop out fuel pump control relay FPR, but the EFCO pushbutton must be held down until the engine stops, or the engine will resume running when the push-button is released. (The reason that the engine will resume running is that the EFCO relay will pick up again when the push-button is released.)
Figure 1-11 Engine Fuel Cut Off Circuit.
1-16
GT46MAC Locomotive Service Manual
STARTING MOTOR MAINTENANCE Maintenance should be performed as indicated in the Scheduled Maintenance Program, and may be performed when checks are being made on the motors. 1. Clean the brush holder and commutator area. Remove the most accessible brush inspection plugs from each motor assembly and direct a high pressure air hose at either opening to drive foreign matter out of the other opening. Use only dry air. Reinstall and secure inspection plugs. 2. Saturate the oil reservoirs and wicks at the bearing positions located at the front and rear of each motor assembly. Use only SAE No. 10 oil. 3. Manually press the pinion away from the ring gear to make the overrunning drive spline accessible for oiling. Use only SAE No. 10 oil.
SOLENOID REPLACEMENT PROCEDURE 1. Remove the starting motor guard cover and disconnect all wires to the solenoid after noting location of each wire connection. 2. Remove the solenoid from the motor by removing the four hex bolts. 3. Remove the front inspection cap in the plunger housing. 4. Check the number of threads exposed beyond the plunger stud adjustment nut inside the housing. If more than three threads are visible, hold the plunger to prevent its rotation, then back off the adjustment nut to a threethread exposure plus or minus half a thread. 5. Thoroughly wipe the plunger clean of any surface contaminants, with a clean shop rag. 6. Install new solenoid 1115567 in exact reverse order of removal procedure. CAUTION Three types of starting motor solenoids are presently in use. Part numbers 1115567 and 1115536 may be intermixed on a unit. However, part number 1115515 must be used only with another part number 1115515. 7. Reconnect all solenoid wires. Follow the above steps to renew the second motor solenoid. 8. Replace the guard cover and the ring gear cover. NOTE Refer to Engine Maintenance Manual for further starting motor maintenance procedures.
ENGINE STARTING AND STOPPING 1-17
1-18
GT46MAC Locomotive Service Manual
SECTION 2. FUEL SYSTEM INTRODUCTION A pictorial diagram of the fuel oil system is shown below. Fuel is drawn from the storage tank through a fuel suction strainer by a motor driven positive displacement gear type pump. Some of the fuel is pumped through a preheater, and some is directed through an Amot Mixing Valve. Warm fuel from the preheater goes to the Amot Valve where it is mixed with fuel from the Pump. Fuel, which exits the Mixing Valve, first flows through a strainer and then through the Primary Fuel Filter, and the Engine-Mounted Filters.
use modified F-FU37531
Figure 2-1 Fuel Oil System After passing through the engine mounted dual-element filter, the fuel flows through manifolds that extend along both banks of the engine. These manifolds supply fuel to the injectors. The fuel pump delivers more fuel oil to the injectors than is injected into the cylinders. The excess fuel is used to cool and lubricate the close tolerance injector parts. Fuel returning from the injectors passes through the “return fuel” sight glass and back to the fuel tank. Refer to Figure 2-1. A relief valve at the inlet to the “return fuel” sight glass establishes a fuel back pressure, thus maintaining a positive supply of fuel for the injectors.
FUEL SYSTEM 2-1
A bypass valve and gauge is connected across the primary filters. If the primary filters become plugged, fuel will bypass and impose the total filtering load on the engine mounted dual element filter. As the engine mounted fuel filter elements become plugged, fuel flow to the injectors is limited. A relief valve will open at a preset high pressure to return fuel to the tank, bypassing the fuel injectors.
FUEL SUCTION STRAINER The fuel suction strainer, Figure 2-2, should be cleaned and inspected at the intervals stated in the Scheduled Maintenance Program or at shorter intervals if operating conditions warrant.
CLEANING PROCEDURE 1. Stop the diesel engine and turn the fuel pump circuit breaker OFF. 2. Remove the bolts holding the strainer shell to the strainer cover and remove the shell and strainer from the cover. To prevent loss, thread the bolts with washers into the strainer shell threaded openings. 3. Withdraw the strainer element, discard the oil and sediment held in the strainer shell. 4. Clean the element in a container of clean fuel oil. A brush may be used and a round wooden dowel employed to spread the pleats and determine the degree of cleanliness, but no special tools are necessary.
Figure 2-2 Fuel Oil Suction Strainer. 2-2
GT46MAC LOCOMOTIVE SERVICE MANUAL
CAUTION Chlorinated hydrocarbon solvents and temperatures above 180°F (82°C) will damage the epoxy material bonding the strainer element to the end caps. 5. Clean the shell with fuel oil and wipe clean. Note that the spring in the bottom is spot welded to the shell. 6. Inspect the housing-to-cover “O” ring, and replace it with a new ring if necessary. 7. Place the cleaned strainer element in the shell and reapply the shell to the strainer cover. Tighten firmly into place after making certain the “O” ring is properly seated.
FUEL PUMP AND MOTOR The motor driven fuel pump, Figure 2-3, page 2-3, is mounted on the equipment rack. It is an “internal” gear pump driven by battery power during system priming and by power from the auxiliary generator during operation.
F43262
Figure 2-3 Fuel Pump Cross Section Fuel is drawn into the inlet portion to fill a space created by the gear teeth coming out of mesh. The fuel is then trapped in the space between the gear teeth and carried to the outlet side of the pump where the gears mesh, forcing the fuel from between the gear teeth out through the outlet. The fuel pump and motor need no routine maintenance - the motor and pump should be maintained in accordance with EMD Maintenance Instructions listed on the Service Data page. Maintenance should be performed at the intervals stipulated in the Scheduled Maintenance Program (MI 1777).
FUEL SYSTEM 2-3
FUEL PUMP CIRCUIT After locomotive control circuits are properly established, closing the control and fuel pump switch (on the #2 control console) provides an input to the computer, Figure 2-4, page 2-5, which enables the fuel pump relay FPR, and provides the engineer with the means of shutting off the fuel pump with the switch on this panel. Before the engine is running the fuel pump relay performs no function. With the control circuits established and FPR enabled, rotating the fuel prime/ engine start switch (FP/ES) to FUEL PRIME position provides a signal to the computer which turns on the fuel pump motor. After the system is primed and fuel flows free and clear in the return fuel sight glass, the FP/ES switch is rotated to the START position. This energizes the STA coil causing the cranking motors to turn the engine. The battery continues to power the fuel pump motor until engine speed comes up sufficiently to cause auxiliary generator output voltage to exceed battery voltage. The fuel pump motor will stop if either the fuel pump relay FPR opens or if any of the emergency fuel cutoff switches EFCO open. However, dropout of FPR will not immediately stop the engine. Dropout of one of the emergency fuel cutoff switches EFCO is required for immediate positioning of injector racks to the “NO-FUEL” position on units with a governor to cause engine shutdown. See “EMERGENCY FUEL CUTOFF SWITCHES,” page 2-13.
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GT46MAC LOCOMOTIVE SERVICE MANUAL
use F43263
Figure 2-4 Fuel Pump Circuit.
FUEL SYSTEM 2-5
PREHEATER AND MIXING VALVE The preheater mixing valve assembly uses the hot coolant from the engine to keep the fuel to a constant temperature.
PREHEATER
FU31902
Figure 2-5 Fuel Preheater and Mixing Valve Assembly.
The water flows through a tube inside the cooler. The fuel flows in the shell around the heated tube. The coolant and fuel flow through the cooler in opposite directions to produce the maximum cooling effect. Fuel exiting the preheater goes to the mixing valve.
NOTE:
If water is present in the fuel system, the preheater should be thoroughly checked for possible leakage.
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GT46MAC LOCOMOTIVE SERVICE MANUAL
MIXING VALVE The mixing valve mixes the cold fuel from the pump with the hot fuel from the preheater. The mixing is thermostatically controlled to keep the fuel exiting the valve at a nominal temperature of 35°C (95°F). It is composed mainly of a housing and a thermostatic element. The housing has three Ports, the mixed fuel enters at output Port A, the hot fuel from the preheater enters at Port B and cold fuel enters from the pump at Port C. The thermostatic element keeps the output fuel at the nominal temperature by controlling the quantity of cold fuel to be mixed with the hot fuel.
fu31903
Figure 2-6 AMOT Mixing Valve (Cut Away View).
FUEL SYSTEM 2-7
PRIMARY FUEL FILTER SINGLE CANISTER-TYPE A canister-type primary fuel filter assembly is mounted on the equipment rack under the lube oil cooler assembly. Change the canister filter element at the intervals stated in the Scheduled Maintenance Program or more frequently, if operating conditions warrant.
fu38307
Figure 2-7 Single Canister - Primary Fuel Filter Assembly
FU37790
Figure 2-8 System Diagram: Single Canister - Primary Fuel Filter Assembly
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GT46MAC LOCOMOTIVE SERVICE MANUAL
CLEANING PROCEDURE: 1. Set isolation switch to ISOLATE and stop the diesel engine 2. Place a 5 gallon container to catch fuel under the filter housing and open the filter vent valve at the top of the filter housing. Open the filter drain gate valve at the side of the filter housing bottom, or located near the fuel suction strainer and tagged: “FUEL FILTER DRAIN”. Valve handle is spring loaded and must be held in the OPEN position (handle parallel to drain line) until filter housing is drained. (Note: A helper may be needed for this step.) WARNING If the drain valve is opened shortly after engine shutdown, pressure retained in the system will allow fuel to drain rapidly. Fuel drained from the filter housing is piped back to the fuel tank. 3. Wipe out inside of collar around cover to remove any dirt or contaminants. 4. After enough time has elapsed to allow adequate filter drainage. a. Loosen the hand knob until it contacts the stop nut (approximately 3 turns). Do NOT use a hammer to loosen the hand knob.Place a container for the used filter element at a convenient location. b. Raise and hold safety latch in raised position. Grasp wing grips and rotate cover in slots. If cover sticks, use a screw driver to pry against the cross bar. c. Pull cover outward and engage hinge pin in hinge brackets, then swing cover downward. 5. After an adequate drainage period; A. loosen the 3 cover bolt nuts and swing open the hinged cover. 6. Remove and quickly dispose of the used filter element. NOTE Any fuel spilling from the bottom of the housing will leak into the drainpan. From there it is piped to the oil filter drain pan which in turn is piped to the engine pit drain. 7. Using only clean bound edge towels, wipe out the interior of the filter housing. Clean up the drain pan and surrounding area. 8. Insert a new filter element consisting of part number as shown on the Service Data page. Make certain that the element is fully seated over the standpipe. Note: Be certain to use only approved replacement element. 9. When the filter element is properly inserted, inspect the “O” ring in the circular groove in the housing cover. Replace, if necessary, with part number shown on Service Data page.
FUEL SYSTEM 2-9
10.
a.) Swing cover upward. Grasp wing grips and hold safety latch in raised position, then push cover inward. b.) Rotate cover to engage cross bar securely in slots, then lower safety latch and tighten hand knob until it is hand tight. Do NOT use a hammer to tighten the hand knob.
11. Close the filter drain gate valve and vent valve. 12. Turn fuel prime/ engine start (FP/ES) switch lever to FUEL PRIME position and hold it there until fuel runs free and clear of bubbles through the return fuel sight glass.
PRIMARY FUEL FILTER BYPASS VALVE AND GAUGE This gauge, Figure 2-9, indicates the condition of the primary fuel filter. Increased pressure differential across the primary fuel filter will be indicated by a greater reading on the gauge. Normally, with new primary filters, the gauge should read in the green zone. As the filter element becomes plugged, the indicator will read higher until it reaches the red CHANGE FILTER zone at approximately 30 psi (207 kPa) pressure differential. At this point, the bypass valve will begin to open, allowing the fuel oil to bypass the primary fuel filter. Renew primary fuel filter elements when the indicator reaches the CHANGE FILTER zone.
Fu34996
Figure 2-9 Primary Fuel Filter Bypass Valve and Gauge.
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GT46MAC LOCOMOTIVE SERVICE MANUAL
ENGINE MOUNTED FUEL FILTER ASSEMBLY FUEL SIGHT GLASSES Two sight glasses, Figure 2-10, are located on the engine mounted filter housing to give visual indication of fuel system condition.
F27505
Figure 2-10 Fuel Oil Sight Glass Fuel flowing through the return fuel sight glass (sight glass closest to engine) is the excess fuel that has circulated through the engine without being injected. Upon leaving the sight glass it returns to the fuel tank for recirculation. Upon engine start with governor-controlled engines, the return fuel sight glass will be empty. When the fuel system is primed, turbulent flow will occur as evidenced by bubbles in the sight glass. When the fuel in the glass flows clear and free of bubbles, the engine may be cranked. The engine mounted filter is also equipped with a bypass relief valve and sight glass. This sight glass, farther from the engine, is normally empty. When more than a trickle of fuel is seen in the bypass sight glass, it indicates that the relief valve is open. Fuel will pass through the bypass sight glass and relief valve to bypass the engine and return to the fuel tank when the filter elements become clogged. This condition may become serious and cause the engine to shut down from lack of fuel.
ENGINE MOUNTED (Spin On) FUEL FILTERS The engine mounted spin-on type fuel filters should be changed at the intervals stipulated in the Scheduled Maintenance Program, or whenever fuel appears in the bypass sight glass. . The filter assembly should be maintained in accordance with the instructions in the Engine Maintenance Manual. Refer to the following procedure while changing filter elements.
FUEL SYSTEM 2-11
1. Shut engine down. 2. Unscrew and discard the elements. Use a strap wrench if necessary. 3. Clean the filter and sight glass assemblies. 4. Apply a film of oil to the element gaskets. 5. Apply the elements to the filter body. Hand tighten until the gasket contacts the filter body, then tighten one-half turn. 6. Check for leaks after the engine is started.
DRAINING CONDENSATE FROM THE FUEL TANK Condensate should be drained from the locomotive fuel tank at the intervals as defined in the Scheduled Maintenance Program, or more frequently if conditions warrant. During draining, the locomotive should be placed on an incline with the drain end of the tank facing downhill to ensure condensate accumulation at the water drain valve, Figure 2-1, page 2-1, and adequate drainage without loss of fuel.
fu31766
Figure 2-11 Fuel Filler Assembly.
FILLING THE FUEL TANK The fuel tank can be filled on either side of the locomotive. The fuel tank is equipped with one fuel filler pipe at each side of the locomotive. A short fuel level sight gauge is located next to the fuel filler pipe. This gauge indicates the fuel level from the top of the tank to about 4-1/2 inches below the top and should be observed while filling the tank to prevent overfilling. Figure 2-11 illustrates a fuel filler and cap assembly. Periodically inspect the fuel strainer and check the condition of the filler cap gaskets.
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GT46MAC LOCOMOTIVE SERVICE MANUAL
FUEL STORAGE FACILITIES The presence of slime on fuel filters indicates that bacteria and fungi are present in troublesome quantities. Water in the fuel storage tanks should be kept at the lowest possible level. Contact fuel oil suppliers for recommendations regarding antiseptic treatment of fuel storage facilities.
EMERGENCY FUEL CUTOFF SWITCHES Two emergency fuel cutoff (EFCO) switches, one on each side of the locomotive, are located on the underframe near the fuel fillers, and a third EFCO switch is located on the engine control panel. Operating any of the EFCO push-button switches, even momentarily, opens the line feeding both the computer DIO-2 module NOEFCO input channel and the EFCO relay coil terminal Y.
EFCO relay dropout causes immediate dropout of fuel pump relay FPR, and pickup of governor solenoid DV. These events start the engine shutdown process. As soon as the push button is released, the EFCO relay picks up again. However, if the push button is held in for at least 0.5 second, the computer recognizes that the NOEFCO input is absent. Once the computer recognizes that the NOEFCO input is missing, EM2000 turns OFF the output channels A valve, B valve, and C valve and turns ON the output channel D valve to complete the engine shutdown process, even if the push button is released. When the computer recognizes that the NOEFCO input is missing, it also: • Picks up turbo lube pump relay TLPR for up to 35 minutes, causing the pump to operate for that period of time; • Picks up alarm relay AR to ring the alarm bell and energize trainline 2T, provided that the computer is receiving the ER SW input (ENGINE RUN switch up or trainline 16T energized); and • Displays EMERGENCY FUEL CUTOFF ACTIVATED crew message until next time that Fuel Prime/Engine Start (FP/ES) switch is activated.
FUEL SYSTEM 2-13
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GT46MAC LOCOMOTIVE SERVICE MANUAL
SERVICE DATA - FUEL SYSTEM ROUTINE MAINTENANCE PARTS AND EQUIPMENT FILTERS
Part No.
Primary Fuel Filter Assembly - Two Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10636643 Pleated Paper Element . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40056007 Cover Gasket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40061836 Engine Mounted Filter Assembly, Spin On Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40047323 Filter Element . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8423132 Fuel Filter Body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8479301 Suction Strainer Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8341983 Mesh Element . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9324489 “O” Ring, Housing to Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8343161 Pressure Differential Gauge With Bypass Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10632529 FUEL PUMP
Fuel Pump & Motor Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40037370
SPECIFICATIONS Fuel Tank Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6000 Litres (1585 US gallons)
FUEL SYSTEM 2-15
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GT46MAC LOCOMOTIVE SERVICE MANUAL
SECTION 3. LUBRICATING OIL SYSTEM INTRODUCTION Oil flow through the lubricating oil system is shown in Figure 3-2, “Lube Oil System Diagram” on page 3-2. Oil under pressure is forced through the engine for lubrication and piston cooling by a positive displacement combination piston cooling and lubricating oil pump. After circulating through the engine, the lubricating oil drains into the oil pan. A positive displacement scavenging oil pump draws oil from the sump and strainer housing, then forces it through the oil filter and cooler. From the cooler, the oil is delivered to another compartment in the oil strainer assembly where it is available for recirculation by the combination piston cooling and lubricating oil pump. The lubricating oil pumps are mounted on the front end of the engine and are gear driven by the engine through the accessory drive gear train. The oil strainer housing is also mounted on the front of the engine. The oil cooler and filter assemblies are located on the equipment rack adjacent to the front of the engine at the long hood end of the locomotive.
WARNING Use the dipstick to check oil level rather than removing a handhole cover - in some circ*mstances the oil level may be above the bottom of the oil pan handholes.
OIL LEVEL GAUGE (DIPSTICK) An oil level gauge, Figure 3-1, extends from the side of the oil pan into the oil pan sump. The oil level should be maintained between the low and full marks on the gauge, with the readings taken when the engine is at idle speed and the oil is hot.
F22847
Figure 3-1 Lube Oil Gauge (Dipstick)
LUBRICATING OIL SYSTEM 3-1
LU37628
1) Lube Oil Filter Assembly 2) Lube Oil Cooler 3) Strainer Housing 4) Turbo Lube Pump 5) Soakback Filter 6) Turbo Lube Filter
7) Scavenging Oil Pump 8) Turbo Charger 9) Hot Oil Detector 10) Main Lube/Piston Cooling Pump 11) Oil Pressure Gauge
Figure 3-2 Lube Oil System Diagram 3-2
GT46MAC Locomotive Service Manual
FILLING OR ADDING OIL TO SYSTEM When filling or adding oil to the system, it is recommended that the oil be poured into the strainer housing through the square opening as shown in Figure 3-3. Should it be found more desirable to add oil through a handhole opening in the engine oil pan, it is imperative that the strainer housing be filled before starting the engine. Failure to do this may result in serious engine damage due to the time delay before oil is completely circulated through the system and then to the working parts of the engine. If the system has not been drained, oil may be added to the strainer housing with the engine running or stopped.
WARNING Do not remove the round caps from the strainer housing while the engine is running as hot oil under pressure will come from the openings and serious injury could result.
use 19243 (new EMD TBA)
Figure 3-3 Filling or Adding Oil.
LUBRICATING OIL SYSTEM 3-3
Lu37885
Figure 3-4 Lube Oil System Diagram #2 3-4
GT46MAC Locomotive Service Manual
OIL FILTER INSPECTION AND MAINTENANCE OIL FILTER INSPECTION PROCEDURES The lube oil filter tank cover is equipped with a male quick disconnect fitting, Figure 3-5, to accept a female coupler. The fitting facilitates application of a pressure gauge to monitor filter tank pressure, which indicates the condition of the filter elements.
use 22481 (emd#)
Figure 3-5 Quick Disconnect Fitting. Periodic pressure readings will help prevent undue engine wear by alerting the maintenance crew when filter element plugging and bypass are about to occur. If a locomotive has a short filter element life, there may be water leaks or a heavy dirt load. The engine probably needs maintenance. Lube oil filter pressure checks are to be made WEEKLY OR MORE OFTEN, the engine may be loaded or unloaded. However, the best time to perform these tests is soon after a unit comes in from a run, thereby ensuring an adequately high degree of lube oil temperature. Readings must be taken when lube oil temperature is at least 66°C (150°F). Since there is no convenient gauge to indicate lube oil temperature, perform test when water temperature is at a minimum of 150°F 66°C. Water temperature can easily been seen on EM2000 display. From the MAIN MENU select DATA METER, then COOLING SYSTEM. The water temperature is indicated by ETP1 and ETP2 (Engine Temp. Probes) Filter elements must be renewed if filter tank pressure reaches: •
172 kPa (25 psi) at throttle position No. 8 OR
•
48 kPa (7 psi) at IDLE speed.
Readings taken at throttle No. 8 engine speed are the most reliable. Therefore, if a marginal reading is obtained at idle engine speed, verify filter element condition at No. 8 engine speed.
LUBRICATING OIL SYSTEM 3-5
Oil filter elements, Figure 3-6., “Lube Oil Filter Assembly” on page 3-6, should be replaced with new elements at the intervals stipulated in the Scheduled Maintenance Program. Use only approved elements as indicated on the Service Data page.
OIL FILTER PROCEDURES MAINTENANCE 1. Operate the diesel engine until oil is warm and circulating freely, then stop the engine and remove the starting fuse. 2. Remove the square cap from the engine mounted lube oil strainer housing, Figure 3-3, “Filling or Adding Oil.” on page 3-3.
LU42615
Figure 3-6.Lube Oil Filter Assembly . 3. Raise and latch the strainer drain gate valve handle in the engine strainer housing to drain oil from the filter housing into the engine sump. It is not necessary to move the valve handle that drains the oil strainer housing. NOTE: Depending upon the temperature of the oil and system at the time that the drain valve is opened, adequate drainage of the lube oil filter can take from 1/2 hour for hot oil and a hot system to several hours for a cool system. If the system is fully charged at the time the system is to be drained, the oil level will rise above the bottom of the oil pan inspection covers. 4. After enough time has elapsed to allow adequate drainage and easy handling of the filters, slightly loosen the nuts on the filter housing cover. Oil remaining at the bottom of the housing will leak into the drain pan. From there it is piped to the engineroom drainage sump. 5. Place a container for used filter elements at a convenient location and provide adequate quantities of bound edge towels. 6. After oil has stopped draining from under the flat filter housing cover, loosen the retaining nuts and swing the hinge bolts clear of the cover. Swing the cover open. Remove and quickly dispose of used filter elements. 3-6
GT46MAC Locomotive Service Manual
0 7. Using only clean bound edge towels, clean out the interior of the filter housing. Clean up the drain pan and surrounding area. 8. Insert a set of five (5) new filter elements of 15 inches long, consisting of part numbers shown on the Service Data page. Make certain that the elements are fully seated over the standpipes.
NOTE Approved pleated paper elements have a red casing. When the complement of paper elements is used, be certain to replace with only approved elements.
9. When the filter elements are properly inserted, inspect the “O” ring in the circular groove in the housing cover. Replace if necessary. 10. Close the cover. A guide hole in the filter cover must mate with a dowel on the filter housing body before the cover can be closed. 11. Swing the hinge bolts into place and tighten the hold-down nuts, to 81 N⋅m (60 ft-lbs) . 12. At the intervals stipulated in the Scheduled Maintenance Program, remove and inspect the internal filter bypass relief valve assembly, Figure 3-7.. The procedure is detailed in the article entitled “Inspection Of Bypass Valve Assembly”. 13. Close the filter drain gate valve at the oil strainer.
13454
Figure 3-7.Filter Bypass Relief Valve Assembly. 14. Before starting the engine, check the oil level, using the dipstick. Oil level should be above the full mark on the dipstick with engine shut down. Start the engine and allow it to run at idle speed. Check the oil level at the dipstick. Add oil if necessary. See Figure 3-3, “Filling or Adding Oil.” on page 3-3. 15. Replace and tighten down the square cover on the oil strainer. 16. Inspect for oil leaks at the filter housing. Tighten the hold-down nuts as necessary to stop any leaks. LUBRICATING OIL SYSTEM 3-7
BYPASS VALVE ASSEMBLY The internal filter bypass relief valve assembly, Figure 3-7., “Filter Bypass Relief Valve Assembly” on page 3-7, should be removed and checked periodically at intervals stipulated in the Scheduled Maintenance Program or whenever improper oil filtration is suspected. However, operation of the valve assembly cannot be effectively checked on the locomotive. For this reason it is recommended that qualified spare assemblies be available for exchange during maintenance procedures. A bench test and inspection may then be performed in accordance with the appropriate Maintenance Instruction listed on the Service Data page.
REMOVAL 1. After the oil has been drained from the filter housing, the elements removed, and the housing cleaned; remove the hold-down bolts from the bypass valve assembly and remove the assembly. 2. Replace the filter bypass relief valve assembly with a qualified spare. Seat the assembly properly and tighten the hold-down bolts to 33 N⋅m (24 ft-lbs) torque. Tighten the cover hold-down nuts to between 75 to 81 N⋅m (55 to 60 ft-lbs) torque, using standard tightening procedure. If a qualified spare is not available, the valve assembly should nevertheless be removed from the filter housing and cleaned of sludge and varnish by washing in solvent. The assembly should be carefully inspected after cleaning. If the poppet stem or valve body guide is worn, those pieces should be replaced with new pieces.
TEST OF VALVE SPRING If a qualified spare is not available, the valve spring should be tested by compressing it to a specific height. If this requires more or less than the values shown on the Service Data page, the spring should be replaced with a new spring.
OIL COOLER INSPECTION AND MAINTENANCE Major servicing of the oil cooler should not be undertaken until the need for such maintenance is definitely established by unsatisfactory operation, suspected oil cooler core leaks, or wide temperature differential between cooling water and engine oil.
WATER LEAKS There are no simple methods of detecting water leaks to the oil side of the lubricating oil cooler assembly- evidence of water contamination will show up in the routine engine oil samples analyzed as prescribed in the Scheduled Maintenance Program. Any such evidence calls for a close examination of the cooler and inspection of the engine. Maintenance Instructions for cleaning and repair of the lubricating oil cooler are listed on the Service Data page.
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GT46MAC Locomotive Service Manual
QUALIFICATION PROCEDURE Proper lubricating oil temperatures are dependent upon maximum lube oil cooler performance. Operation of the hot lubricating oil detector provides indication that the lube oil cooler may not be functioning efficiently. However, in order to obtain a valid indication of oil cooler performance, the locomotive must be operated at its full rated load and engine speed while the oil and water temperatures are allowed to stabilize. 1. At the right bank engine water inlet elbow, Figure 3-8, “Oil Cooler Qualification.” on page 3-10, fill the thermometer well with oil. Water temperature into the engine will be taken at this point. 2. Using EM2000 display, from the MAIN MENU select SELF TEST then SELF LOAD or set up engine loading apparatus capable of taking the full rated load of the locomotive. Refer to the Load Testing section of the manual for instructions covering the load testing setup.
CAUTION Many standard load boxes are not of sufficient capacity to fully load the locomotive. 3. Remove the square cover from the engine mounted oil strainer and hang a cage thermometer in the overflow oil compartment of the strainer housing, Figure 3-8, “Oil Cooler Qualification.” on page 3-10. (This is oil out of the cooler - oil flows from the oil cooler into the strainer.) Make certain that the thermometer bulb is well below the surface of the oil and is kept submerged when the reading is taken. 4. Insert a thermometer into the well located at the engine water inlet. 5. Operate the engine and apply load. Do not operate above throttle position 2 until water temperature is above 49°C (120°F). Operate at full load and speed until engine water inlet temperature is stabilized. It may be necessary to block the shutters open to maintain a constant temperature.
NOTE Readings taken at 15 minute intervals will indicate when a stable operating condition is reached. 6. Record temperature readings and compare them with performance baseline EE provided in Maintenance Instruction M.I. 928. When oil temperature for a given water temperature is higher than limit indicated, oil cooler should be serviced in accordance with Maintenance Instruction listed on Service Data.
LUBRICATING OIL SYSTEM 3-9
F-LU30530
Figure 3-8 Oil Cooler Qualification.
HOT OIL DETECTOR A thermostatic valve, located on the outlet elbow from the main lube oil pump, is calibrated to open when lube oil temperature reaches a nominal 124°C (255°F). At this temperature it is probable that the lube oil cooler is plugged on the water side. When oil temperature causes the valve to open, pressure to the oil pressure detecting device in the engine governor is dumped. The device detects low oil pressure and reacts to shut the engine down. The thermostatic valve is not latching, and it will reset automatically when oil temperature falls.
WARNING If it is determined that hot oil is the cause for engine shutdown, make no further engineroom inspections until the engine has cooled sufficiently to preclude the possibility that hot oil vapor may ignite. When a low oil shutdown occurs, always inspect for an adequate supply of water and oil. Also check engine water temperature. Do not add cold water to an overheated engine.
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GT46MAC Locomotive Service Manual
use LU101e
Figure 3-9 Hot Oil Detector Thermostatic Valve. HOT OIL DETECTOR QUALIFICATION Remove detector from engine and test as follows: 1. Connect air lines to and from valve so that flow is in direction of arrow. 2. Place valve in an agitated liquid bath so that half the valve body is immersed. (Dow glycerine, USP Grade 96% recommended.) 3. Heat the bath. When the bath reaches113°C (235°F), the rate of rise must not exceed 0.6°C (1°F) per minute. 4. Apply 345 kPa (50 psi) air pressure and observe for leaks. Leaks between the valve body and cap are not permissible. 5. At 121°C (250°F) the maximum rate of leakage is 10 SCFH. (Standard cubic feet of air per hour.) 6. Remove air flow to avoid chilling. 7. Raise temperature to 126°C (258°F). 8. Turn on air. Minimum rate of flow to be 20 SCFH.
LUBRICATING OIL SYSTEM 3-11
TURBOCHARGER Turbocharger lubricating oil is obtained from the engine lubrication system. A separate automatically started motor driven turbocharger lube oil pump is used to supply oil to the turbocharger prior to starting the engine and whenever the engine is shut down. The motor is timed to operate approximately 35 minutes after each time it is started. Oil circulation through the turbocharger is necessary prior to starting the engine and during the period when the engine oil pressure is building up to provide proper lubrication. After the engine is shut down, continued oil circulation is necessary to remove residual heat from the turbo and return the hot oil to the oil pan sump. Pump operation requires the main battery knife switch, the computer and the turbocharger pump circuit breaker to be closed (main battery knife switch may be opened after engine shutdown). Turbo lube pump timing after shutdown is based on the Highest throttle position attained in the previous sixty minutes. Throttle position is logged by the computer. If throttle remains in position for 2 minutes or more the timing is as follows.
Throttle Position (at or below)
Time
TH 1
15 Mins
TH 2
20 Mins
TH 3
25 Mins
TH 4
30 Mins
TH 5 (or higher)
35 Mins
The turbocharger lube oil pump draws oil from the oil pan sump. Discharge oil from the pump is then filtered and fed into the head assembly of the main turbocharger oil filter. This head assembly contains the check valves required for proper lube oil flow. Oil from the filter head assembly is then directed to the turbocharger.
TURBOCHARGER LUBE PUMP CIRCUIT The turbo lube pump motor (TLP) must be operated before engine start to prelube the turbocharger bearings. The turbo lube pump motor is controlled by the turbo lube pump relay TLPR circuit which is enabled by the control computer when these conditions are satisfied: • • • •
BATTERY SWITCH closed COMPUTER CONTROL circuit breaker closed. TURBO. circuit breaker closed. LOCAL CONTROL circuit breaker closed.
When the fuel prime/engine start (FP/ES) switch is held in the FUEL PRIME position, an input signal PRIME is sent to the computer through DIO-2 (IN) (CH7).
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GT46MAC Locomotive Service Manual
0 The Computer then sends an ouput signal through D1O-2(OUT) CH23 to energize the TLPR relay. TPLR interlocks #2 close and the turbo lube oil pump starts . D1O-1(IN) channels 23 & 24 tell the computer that the turbo CB is closed and the TLPR interlocks are closed.
use modified F-Lu37886
Figure 3-10 Lube Pump Circuit/Engine Prime.
LUBRICATING OIL SAMPLING AND ANALYSIS A lubricating oil sample should be taken for analysis at the intervals stipulated in the Scheduled Maintenance Program. The sample should be submitted to a competent laboratory to monitor the suitability of the oil for continued use. Obtain the sample in the following manner.
WARNING Under some conditions the oil level may be above the bottom of the oil pan handholes, so care must be taken when the oil pan handhole covers are removed. 1. Run the engine long enough to ensure thorough circulation. 2. Shut the engine down and remove the starting fuse. 3. Obtain the oil sample (normally 0.5 liter (1 pint)) at the center of the oil pan halfway between the surface and the bottom of the pan.
NOTE Inconsistent sampling techniques will produce inconsistent results.
LUBRICATING OIL SYSTEM 3-13
PRELUBRICATION OF ENGINE Prelubrication of a new Engine, an Engine that has been overhauled, or an engine which has been inoperative for more than 48 hours, is a necessary and important practice. Prelubrication alleviates placing a load on unlubricated engine parts during the interval when the Lube Oil Pump is filling the passages with oil. It also offers protection, by giving visual evidence of satisfactory oil distribution in the Engine. Perform the prelubrication as follows: 1. Remove the pipe plus at the main Lube Oil Pump discharge elbow, and connect an external source of clean, warm oil at the elbow. Prelube the Engine at a minimum of 10 PSI, for a period of not less than three, and not more than five minutes. This amounts to approximately 15 GP-M, when using a 1.5 to 2 HP motor. 2. As the oil pressure is being applied, open the cylinder test valves, and bar the Engine over one complete revolution. Check for an oil flow at all crankshaft bearings, at camshafts, rocker arm , and at the rear gear train. In addition, check for restrictions and excessive oil flow. Check for fluid discharge at the cylinder test valves. If fluid discharge is observed from any cylinder test valve, investigate the cause, and make the necessary repairs. 3. On new or overhauled Engines, remove the pipe plug at the piston Cooling, Oil Pump discharge elbow, and connect the external oil source at that opening. Check for unrestricted oil flow at each piston cooling tube. 4. Disconnect the external oil source, and replace the pipe plugs. Close the cylinder test valves. 5. Pour a liberal amount of oil over the rocker arm cylinder mechanism of each bank. 6. Check the oil level in the strainer housing. If required, add oil to the strainer housing until it overflows into the oil pan. 7. Replace, and securely close, all handhole covers and the Engine top deck cover.
NOTE When an engine is replaced due to mechanical breakdown, the entire oil system, (such as oil coolers, filters, and strainers), should be thoroughly cleaned before a replacement engine, (or the reconditioned Engine), is placed in service. If other system components have been neglected, a recurrence of trouble may be experienced in the clean engine. In some cases, by draining the oil and applying an anti-rust compound, engines have been removed from service and stored in the "as is" condition. When these engines are returned to service, and before adding oil and prelubing the engine, loose deposits must be flushed out. To break up any sludge deposits, the entire engine should be sprayed with fuel, and then drained. Care must be taken that the drains do not plug. Fuel should not be sprayed directly on the valve mechanism or bearings. Since lubrication will be removed, dirt might be forced into these areas. The surfaces should then be wiped dry, before new oil is added to the engine.
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GT46MAC Locomotive Service Manual
SERVICE DATA - LUBRICATING OIL SYSTEM ROUTINE MAINTENANCE PARTS AND EQUIPMENT Pleated Cotton-Paper Elements (5 per housing). . . . . . . . .9545152
NOTE Filter changeout recommendation will be found in the applicable Scheduled Maintenance Program. “O” Ring Seals (Lube Oil Inlet/Outlet) . . . . . . . . . . . . . . 9557674 “O” Ring Seal (Cover) . . . . . . . . . . . . . . . . . . . . . . . . . . . 40065194 Hot Oil Detector - Thermostatic Valve . . . . . . . . . . . . . . 8427032 Hot Oil Detector Gasket . . . . . . . . . . . . . . . . . . . . . . . . . . 40034621
NOTE It is recommended that qualified spare bypass valve assemblies be kept available for scheduled maintenance replacement. Quick Disconnect Male Fitting. . . . . . . . . . . . . . . . . . . . . 9321340 Quick Disconnect Female Fitting . . . . . . . . . . . . . . . . . . . 9321341 Lube Oil Tank Pressure Test Kit (0-100 psi gauge, hose, and female quick disconnect fitting) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9325061
SPECIFICATIONS Oil Pan Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 950 liters (251 gal)
NOTE A weight of between 191 and 227 kg (420 - 500 lbs) is required to compress filter bypass valve spring to a height of 92 mm (3-5/8 in).
LUBRICATING OIL SYSTEM 3-15
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GT46MAC Locomotive Service Manual
SECTION 4. COOLING SYSTEM INTRODUCTION The engine-mounted water pumps, draw cooling water from the expansion tank and lube oil cooler assembly, and pump it into the engine. The heated water leaves the engine, and flows through two radiator assemblies where it is cooled. The cooled water then returns by way of the oil cooler to repeat the closed-loop cycle. Part of the water from the water pumps is piped to the air compressor. There are no valves in this line, air compressor cooling is provided whenever the engine is running.
F43264
Figure 4-1 Cooling System Diagram Two electronic temperature sensing probes (ETP1-2) are located in the water line from the oil cooler to the inlet of the water pump on the engine left side, near the water temperature gauge. Temperature probe readings are converted by ADA Module (analog to digital to analog) to digital signals used by the EM2000 to control all cooling functions. If the EM2000 computer detects that either temperature probes has failed, it sends a crew message ENGINE TEMPERATURE FEEDBACK FAILURE to the EM2000 display screen and also stores the message in Archive memory. If it detects that both probes have failed, it ignores both probe signals, fans remain in last operations status, engine speed goes back to idle and the following message is stored in archive memory, NOT LOADING-ENGINE TEMP FB FAILURE.
COOLING SYSTEM 4-1
RADIATORS AND COOLING FANS During circulation through the diesel engine, air compressor and oil cooler, the coolant picks up heat which must be dissipated. Water temperature is controlled by means of radiator banks and AC motor-driven cooling fans. Refer to Figure 4-2, “Radiator, Cooling Fan, and Shutter Arrangement” on page 4-2 and Figure 4-3, “Two Speed Cooling Fan AC Motor Circuit.” on page 4-5.
F-26660
Figure 4-2 Radiator, Cooling Fan, and Shutter Arrangement The radiators are located in a hatch at the top of the long hood end of the locomotive. The hatch contains the radiator assemblies, which are grouped in two banks. Each radiator bank consists of two quad length radiator core assemblies, bolted end-to-end. Headers are mounted on the radiator core to form the inlet and outlet ends of the radiator assembly, a bypass line is provided between the inlet and outlet lines in order to reduce velocity in the radiator tubes. The cooling water from the engine is piped to the headers of each radiator bank. The discharge from the radiators enters the oil cooler. From there, the water returns to the water pumps for recirculation.
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GT46MAC LOCOMOTIVE SERVICE MANUAL
0 Two 8 blade 52” cooling fans, which operate independently, are located under the radiators in the long hood carbody structure. They are numbered 1, and 2, with the No. 1 fan being closest to the cab. For fuel efficiency, each cooling fan is driven by a two-speed AC motor, which in turn is powered by the companion alternator. As the engine coolant temperature rises, the fans are energized in sequence by the control computer (slow speed). As additional cooling is required, the fans switch to full speed in progression as coolant temperature rises. As coolant temperature drops, the fans switch off one at a time. The cooling fans are controlled by the computer which act on the contactors. The computer also controls the fan sequencing duty cycle and speed (low or high) to ensure even fan and contactor wear. The two-speed cooling fan system consists of two full speed contactors (FCFA and FCFB) and one slow speed contactor (FCS) per cooling fan motor. The system maintains the coolant temperature within a predetermined range of from 79º C to 85º C (175º F to 185º F).
COOLING FAN TWO-SPEED AC MOTOR CONTROL Each fan motor circuit consists of one slow-speed, and two fast-speed contactors that are located in the AC cabinet. The following circuit description concerns only fan motor No.1, with associated slow-speed contactor FCS1, and fast-speed contactors FCF1A and FCF1B. The circuits for fan motors 2 operates in a similar manner. The J-K interlocks of FCF1A and FCF1B, in series with the FCS1 coil, ensure that FCS1 cannot be picked up unless FCF1A and FCF1B are both dropped out. If thus enabled, the computer FCS1 output channel 1 (DIO-2 OUT) picks up FCS1 by completing the circuit to negative. If FCS1 is picked up, the J-K interlocks of FCS1 prevent the pickup of FCF1A and FCF1B. When the computer picks up FCF1A, the FCF1A E-F interlocks close to pick up FCF1B without requiring a separate FCF1B output from the computer. When FCS1 is picked up, its L-M contacts close. This provides a multiplexed feedback signal to computer FCS1 input channel 6 (DIO-2 IN). In a similar manner, when both FCF1A and FCF1B are picked up, their closed contacts provide a feedback signal to computer FCF1A/B input channel 7 (DIO-1 IN). In this way, the computer monitors fan contactor status. Figure 4-4, “Radiator Fan Control Circuit” on page 4-6, illustrates how the main contacts of FCS1, and FCF1A/B control the speed of the No. 1 fan motor. The pickup of FCS1 connects the No. 1 fan motor stator windings in series-wye configuration across the AC power from the companion alternator. This causes the cooling fan to rotate at slow speed. FCF1A and FCF1B pickup connects the No. 1 fan motor stator windings in parallel-wye configuration across the AC power from the companion alternator. This causes the cooling fan to rotate at full (fast) speed.
COOLING SYSTEM 4-3
When coolant temperature exceeds the operating range upper limit, the computer begins turning fans ON. The fans will continue to turn ON until the temperature has dropped back within the operating range. Any fans that were ON when the operating temperature range was entered, will remain ON as long as the coolant temperature stays within this range. If the temperature continues to drop, and goes below the lower limit of the operating temperature range, any fans that were ON will begin to drop out. Fans will continue to be dropped out as long as the engine temperature stays below the operating range. If the temperature jumps back into the operating temperature range, the fans that are still ON will remain ON for as long as the temperature stays in this range. All fans will be picked up in sequence, starting with the slow speed mode. There is a 20 second interval between fan energizations. Twenty seconds after the last slow speed fan was energized, the fans will then be picked up at fast speed, as required. There will still be a 20 second interval between pickups, in the same order as slow speed. Once a fan is turned ON, it must remain ON for at least 2 minutes before it will be stepped down from fast to slow, or slow to OFF. The only exception is if the engine temperature dropped below 66°C (150°F) (possibly during the turbo cooldown cycle). In this case, all fans will be turned OFF instantly. This will minimize the possibility of the water temperature decreasing to excessively low levels, which in turn could cause the engine to exhaust white smoke. The fans will be dropped out in the same order that they were picked up, starting with the fast speed fans in 20 second intervals, and followed by the slow speed fans in 20 second intervals. The next time it becomes necessary to pick up the fans, (once the fans have dropped out), the first fan to start up will be the fan in the next position, with respect to the fan that was started first the previous time. For example, if fan #1 was the first to be picked up in a sequence, fan #2 would be the first one picked up. This is done to even out fan usage and contactor wear.
RADIATOR FAN MOTOR FUSES Fan fuses and contactors are mounted in the AC cabinet Zone 80. Each fan circuit is protected by two fuses, which are designed to open and protect the cooling fan system. The fuses are of the bolted-lug type, with fusible elements within a reinforced melamine cylinder. In order to absorb arc energy when the fuse opens, the cylinder is sand-filled. The fusible elements cannot be renewed. A blown fuse must be discarded. A spring-loaded indicator is connected in parallel with the main fuse element. When the main element opens, the indicator also opens, and a small rod protrudes from the end of the indicator. If fuses open, inspect the fan motor and circuits before installing new fuses. If inspection reveals a single blown fuse, always renew BOTH fuses in the motor circuit. This is required because the second fuse, while perhaps good in appearance will in all probability be degraded and will open next time the fan is called upon to start. Whenever fuses are removed during maintenance, always remove both fuses in the circuit. This ensures that the motor is completely isolated.
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GT46MAC LOCOMOTIVE SERVICE MANUAL
use F43279
Figure 4-3 Two Speed Cooling Fan AC Motor Circuit.
COOLING SYSTEM 4-5
use modified F-CL36726
Figure 4-4 Radiator Fan Control Circuit
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GT46MAC LOCOMOTIVE SERVICE MANUAL
OPERATING TEMPERATURE RANGE AND TURBOCHARGER COOLDOWN CYCLE The cooling system is designed to normally maintain an operating temperature of 79×C - 85×C (175×F - 185×F). However, in order to better lubricate the turbocharger bearings at low engine speeds, a special turbo cooldown cycle is activated under the following circ*mstances: If the throttle handle is moved below the throttle #2 position (after loading in throttle 2 and above), the temperature range is set at 71×C - 77×C (160×F 170×F) for a 20 minute period, or until the throttle is moved to, or above, position 2, whichever occurs first. The engine will also run at throttle-2 speed until the water temperature reaches 71ºC (159ºF), or the 20 minute timer has expired, whichever occurs first. All cooling fans shall be dropped out without time delay, if the water temperature drops below 68× C (155× F).
SPEEDUP DUE TO COLD ENGINE DURING ENGINE IDLE CONDITIONS If the engine water temperature probes, ETP1 & ETP2, detect that temperature is below 115×F, the engine speed will be raised to TH 2. The engine will continue to run at TH 2 for as long as the temperature stays below 125×F. Once the temperature goes above 125×F, the engine speed will again be reduced to IDLE. The isolation switch must be in RUN position for this speedup to occur. The reason for this speedup will be displayed to the crew as ENGINE SPEED INCREASE - LOW WATER TEMPERATURE.
INSPECTION AND CLEANING OF RADIATORS Periodic inspection and cleaning of the radiators, including the inlet screens in the headers, should be performed at the minimum intervals called for in the scheduled maintenance program, at more frequent intervals as determined by operating conditions, or when trouble is suspected. Since this closed-loop system will rarely require the addition of water, any progressive lowering of the water level indicates that an inspection should be made. Check carefully for small leaks (“weep”), at the junction of the radiator tubes and headers. Normally, applying clean dry compressed air to radiator top surfaces cleans both radiator cores and radiator compartments satisfactorily. NOTE: During locomotive operation, the access covers on both sides of the carbody between the Fan room and the radiator compartment must be securely bolted in place. If a swing-out cover is not in place, improper circulation of cooling air will result.
COOLING SYSTEM 4-7
HOT ENGINE CONDITION The engine cooling water temperature is sensed at the water pump inlet. When the temperature becomes excessively high, the computer will display the HOT ENGINE - THROTTLE 6 LIMIT message. In addition to the message, the computer will limit engine loading when operating in throttle position 7 or 8. This condition will remain in effect until the temperature returns to a safe limit. If operating in throttle position 6 or lower, engine load will not be reduced during a hot engine condition. However, the return to full power can only be accomplished by reducing cooling water system temperature to normal. The reduction of power assists in cooling down the engine. The reduction of engine speed minimizes the possibility of cavitation at the water pumps. The engine water temperature may be readily checked by using EM2000 display: : Select DATA METER from the main menu then, select COOLING SYSTEM a temperature gauge is also located on the inlet line to the water pump. The gauge is color-coded to indicate COLD (blue), NORMAL (green), and HOT (red). A more accurate check of engine water temperature may be obtained by placing a thermometer in the thermo-well, located in the right bank engine water inlet. A hot oil detector is located on the outlet elbow of the main Lube oil pump. If, in the unlikely event that the computer failed to reduce engine temperature, and a boiling condition created a pressure that would prevent the low water detector from tripping, the temperature of the lube oil would increase. As a result, the thermostatic valve in the hot oil detector will dump oil pressure in the line to the governor low oil pressure detector, and consequently, the diesel engine will shut down. The thermostatic valve will be automatically reset after the hot oil cools. However, until a thorough engine inspection has been completed, no attempt should be made to restart the engine after a hot oil shutdown. WARNING To prevent hot oil vapor ignition, allow sufficient time for the engine to cool down. Do not, under any circ*mstance, remove engine oil pan covers, air box covers, or open the top deck, for at least two hours following an emergency engine shutdown.
COOLING SYSTEM PRESSURIZATION The cooling system is pressurized to raise the boiling point of the cooling water. This in turn permits higher engine operating temperatures, with a minimal loss of coolant due to boiling. Pressurization also ensures a uniform water flow, and minimizes the possibility of water pump cavitation during transient high temperature conditions. A pressure cap, which is located on the water tank filler pipe, opens at approximately 20 PSI. By relieving excessive pressure, this prevents damage to cooling system components. The pressure cap is also equipped with a vacuum breaker. This minimizes the possibility of system damage, which could be caused by pulling a vacuum on the system as the system cools.
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GT46MAC LOCOMOTIVE SERVICE MANUAL
0 The pressure cap is equipped with a handle that aids installing and removing the cap. The most important feature of the pressure cap handle, however, is that it interlocks with the fill/relief valve handle, ensuring system pressure release (through fill/relief pipe) before pressure cap is loosened for removal. WARNING Always relieve system pressure before attempting to remove the pressure cap or the water tank plugs.
1
2
F29236
3 1. Filler/Relief Valve Handle (Pull Down To Open 2. Pressure Cap 3. Filler Pipe Connector
F29236
Figure 4-5 Pressure Cap and Filler/Relief Arrangement PRESSURE CAP AND FILLER NECK The pressure cap and filler neck should be inspected, tested, and replaced at intervals indicated in the scheduled maintenance program.
INSPECTION AND REPLACEMENT 1. If the pressure cap bell housing or other metal surfaces are bent, replace the entire cap with a new one. 2. If the filler neck sealing surface is damaged or distorted, replace the neck assembly with a new one. Use a new tank-to-neck gasket. 3. If seals are hardened or damaged, replace the pressure cap with a new one. 4. Perform a pressure test to qualify the pressure cap and filler neck. NOTE Rebuilding of Pressure caps is not recommended.
COOLING SYSTEM 4-9
COOLING SYSTEM PRESSURE TEST Quick disconnect fittings are provided on the water tank, and in the air system piping at the Equipment Rack. A locally fabricated testing apparatus can be used to pressurize the cooling system with main reservoir air. This test can be performed while the diesel engine is running, and the cooling water system is at its normal level.
F-CL32892
Figure 4-6 Cooling System Pressure Test. WARNING
Do not subject the water tank to pressures greater than 50 PSI. 1. Using the test apparatus, operate the ball valve to gradually pressurize the cooling system to approximately 25 PSI. Tolerances for the 20 PSI pressure cap are as follows: • Minimum Opening Pressure: 19 PSI • Maximum Opening Pressure: 21 PSI 2. Close the ball valve and observe the pressure gauge. The pressure should drop slowly, until the pressure cap closes. The pressure should then remain constant. Gauge pressure (PSIG) is the cap-opening pressure. 3. If the cap-opening pressure is not within the allowable tolerance, replace the cap with a new cap, and repeat the test.
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GT46MAC LOCOMOTIVE SERVICE MANUAL
0 4. If the gauge pressure does not remain constant, and falls below the allowable minimum, perform the following: a. Place a container of water at the discharge end of the water tank overflow pipe. The water level should be above the end of the pipe. Check for air bubbles. The presence of air bubbles indicates a defective cap. Relieve the system pressure, replace the cap with a new cap, and repeat the test. b. Place a container of water at the intake end of the water fill pipe, so that the water level is above the end of the pipe. Check for air bubbles. The presence of air bubbles indicates a defective fill/relief valve. Relieve the system pressure, replace the valve with a qualified valve, and repeat the test. 5. If above Steps, (4.A) and (4.B), do not detect or eliminate leakage, as indicated by a continuous drop in gauge pressure, inspect filler neck assembly and gasket, radiators, and cooling system piping connections.
OPERATING WATER LEVEL A water level instruction is located next to the water level sight glass. It indicates LOW (MINIMUM) and FULL (MAXIMUM) water levels, with ENGINE RUNNING, or DEAD (STOPPED). The water level should not be permitted to go below the applicable LOW level mark. Progressive lowering of water in the sight glass indicates a leak in the system. This should be corrected immediately. A low water level switch (float type) is installed in the cooling system water tank. This switch is connected to DIO 1 input channel 7 labeled NO LWL (no low water level). While the engine is running, if the low water level switch opens (Low Water Condition) for 10 seconds a crew message “LOW ENGINE WATER LEVEL DETECTED” will be displayed and the alarm bell will ring for 60 seconds to alert the crew and the fault will be archived if the low water level condition is detected while the engine is shutdown. The engine will not be allowed to start and a crew message “ENGINE WILL NOT START - LOW ENGINE WATER LEVEL DETECTED” will be displayed for 60 seconds. With the exception of extended intervals, it should not be necessary to add water to a sealed, closed-loop cooling system under normal operating conditions.
COOLING SYSTEM 4-11
C L 31900
Figure 4-7 Water Tank Instruction Plate and Level Gauge
FILLING THE COOLING SYSTEM Water used in the engine cooling system should be made up and tested in accordance with the Maintenance Instruction listed on the Service Data page. CAUTION If a hot engine has been drained, allow sufficient time for cooling before refilling its cooling system. The cooling system should be filled in accordance with the following instructions:
NORMAL FILLING: Do not remove the pressure cap! Attach a hose to the filler pipe connector and hold the fill/relief valve open. Observe the water tank sight gauge. Do not overfill the system.
FILLING A DRY SYSTEM: 1. Hold the fill/relief valve open, until the system pressure is completely vented. 2. Remove the pressure cap, and fill the system through the opening. Observe the water tank sight gauge. CAUTION Do not overfill the tank. Overfilling may create a hazard to personnel.
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GT46MAC LOCOMOTIVE SERVICE MANUAL
0 3. After filling a dry, or nearly dry, system, the engine should be run with the filler cap removed, or with the fill/relief valve opened. This will eliminate air pockets in the system. After running the engine, check the water level. If necessary, add more water to the system. When the filling operation is complete, hold the fill/relief valve open, and replace the pressure cap. NOTE The low water shutdown device will normally be tripped on a drained cooling system. Therefore, after the cooling system has been filled, the low water reset button must be pressed before the engine can be started.
OBTAINING AN ENGINE WATER SAMPLE Water samples should be taken in a clean container, with the engine warm, and running. The sample should be collected from a point where the water flow is normally turbulent. Prior to taking a sample, allow the water to flow for a few seconds. This will drain off accumulated d sediment, and minimize the possibility of a contaminated sample.
DRAINING THE COOLING SYSTEM To drain the cooling system: 1. Open the manual engine drain valve located at the sump between the engine and the equipment rack. 2. Loosen pressure cap on expansion tank. Once the pressure on the system has been released, the water tank filler cap may be removed to allow faster draining.
COOLING SYSTEM 4-13
SERVICE DATA - COOLING SYSTEM ROUTINE MAINTENANCE PARTS AND EQUIPMENT PART NO. Engine Temperature Sensor ............................................................................................................... 40029233 Water Tank Pressure Cap Assembly, 20 PSI........................................................................................ 9323490 Water Tank Pressure Relief Assembly ................................................................................................. 9330855 Filler Neck Assembly........................................................................................................................... 9323491 Tank-to-Neck Gasket ........................................................................................................................... 8424925 Female Coupling .................................................................................................................................. 9321341 Male Fitting.......................................................................................................................................... 9321340
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GT46MAC LOCOMOTIVE SERVICE MANUAL
SECTION 5. FORCED AIR SYSTEMS INTRODUCTION This section of the Locomotive Service Manual covers the forced air systems, the components of which are located in, or connected to a compartment, Figure 5-1. This compartment is located on the locomotive behind the TCC’s (Traction Control Cabinets) and in front of the engine compartment. A partition at the rear of the TCC#2 cabinet makes up the front wall of the air compartment. The back wall is made up of a partition fitted around the main generator. There are two openings in this rear wall, one between the engine air filters and the turbocharger, and one for the auxiliary generator drive shaft. The carbody hood side, roof, and the generator pit complete the central air compartment. Ambient air is drawn into the compartment through the inertial air filters located on either side of the locomotive. Air that is drawn into the compartment is primarily used to supply a. b. c. d. e.
Combustion air for the diesel engine; Cooling air for the main generator and companion alternator; Cooling air for the traction motors Cooling air for the traction inverter equipment; Pressurization of electrical cabinets.
FORCED AIR SYSTEMS 5-1
use CA42328 + Fr view of TM Blower from F43265
Figure 5-1. Central Air System
5-2 GT46MAC Locomotive Service Manual
INERTIAL AIR FILTERS Two inertial air filter panels, one mounted on either side of the locomotive, are made up of a series of tubes designed to produce a cyclonic action, Figure 5-2.
F43266
Figure 5-2. Inertial Air Filter Tube. Each tube contains specially designed vanes that induce a spinning motion to the contaminated incoming air. The demands of devices that air from the central compartment create a depression within the compartment which draws outside air rapidly through the tubes. Dirt and dust particles, because they are heavier than air are thrown to the outer wall of the tube and carried to the bleed duct where it is removed by the scavenging action of the filter blower and expelled through the roof of the locomotive. The resulting clean air continues on through the smaller diameter portion of the tube and into a second tube where the air is again caused to swirl by internal vanes. The particles are carried to the bleed duct and the resulting clean air enters the central air compartment. Approximately two-thirds of the filtered air goes to the generator and traction motor blowers to provide cooling air to the generator, inverters, and motors. Supplementary use is also made of traction motor cooling air for the following purposes: 1. To provide pressure to counteract the depression in the central compartment and enable an aspirator, Figure 5-4. on page 5-7, to drain water from the generator pit. 2. To provide filtered air under pressure to the electrical cabinet.
FORCED AIR SYSTEMS 5-3
MAIN GENERATOR BLOWER The Main Generator Blower and Traction Motor Blower share a common housing mounted on the front side of the auxiliary generator, see Figure 5-1. Although the blowers are both mounted on the auxiliary generator shaft, an internal partition separates the two blower portions. Air is drawn from the central air compartment into the generator blower (closest to the auxiliary generator) and passed through a duct to the main generator airbox. Air from the generator blower first cools the main generator rectifier banks, then passes internally through the generator and companion alternator to the engine room. This creates a slight positive pressure to keep dirt from entering the engine room. This filtered air is also used by the air compressor, reducing the load on its own filter assembly.
TRACTION MOTOR BLOWER The front blower mounted on the auxiliary generator, See Figure 5-1, supplies air for traction motor cooling, generator pit aspirator operation, main electrical cabinet pressurization and traction computer cooling. Air is drawn through a moveable inlet guide vane, through the blower, and delivered into a duct to the traction motors. A portion of this air is diverted through a set of filters for delivery to the computer module portion of traction inverter cabinets for module cooling. Another set of filters cleans the air used to pressurize the main electrical cabinet.
TRACTION MOTOR BLOWER INLET VANE OPERATION The reduction of traction motor blower load is dependent upon the request of the traction control computers (Siemens). This load reduction is accomplished by controlling the amount of air at the blower inlet. A moveable circular inlet vane acts like a shutter to limit the amount of air drawn into the blower consequently reducing the work done by the blower. The inlet vane is actuated by an air cylinder positioning the vanes to either full air or half air. It is held in the partly closed portion (half air) by air but is spring loaded to full open in case of a fault in the compressed air system. The air to the actuating cylinder is controlled by a magnet valve, MVTS. When MVTS is energized compressed air is supplied to the actuating cylinder to move the vanes to the half air position. The inlet guide vane shutter is spring loaded to the full open position. A +74 VDC signal (TMSGTR) from the computer to a magnet valve (MVTS) is required to close the guide vanes. The inlet guide vanes are closed by means of energizing the TMSHTR computer output. The inlet guide vanes are opened by means of deenergize the TMSHTR computer output.
5-4 GT46MAC Locomotive Service Manual
NOTE
“Closing” The guide vanes does not completely shut off the traction motor cooling air supply. It results in limiting the volume of cooling air to the motors to about one half of the full air supply. POWER MODE The guide vanes are under the indirect control of the TCC computers (a.k.a. the ASG’s). They will request operation based on the throttle position, TCC temperatures, capacitor temperatures and motor stator temperatures and the LCC will drive the DIO-3 output channel 6 (THSHR) accordingly. Generally, the ASG computers never ask for the shutters to be closed unless the locomotive is in throttles 6, 7 or 8. This is due to concerns for proper cooling of TCC capacitors and other internal components. If the shutters are closed (i.e. TMSHTR in ON) and HIGH_TM_TEMPERATURE IS GREATER THAN 149°C, then the TMSHTR output is set to FALSE to open the shutters. If the hottest traction motor temperature is less than 139°C, then the TMSHTR output is set to TRUE to close the shutters.
DYNAMIC BRAKE MODE The guide vanes are to remain opened during all dynamic brake operation.
LOAD TEST MODE The guide vanes are to remain closed during all load test operation, unless open operation is requested by the TCC’s on AC locomotives.
IDLE The guide vanes are to remain closed during all idle operation, unless open operation is requested by the TCC’s.
FORCED AIR SYSTEMS 5-5
F43267
Figure 5-3. Traction Converter Cabinet views.
TCC BLOWER The TCC cabinets mount 180° opposite each other. Air is taken from the central air compartment by the TCC electronic blower (located in the central air compartment) which is driven by an AC motor powered by the companion alternator output. This air is used for cooling and pressurizing in some (but not all) parts of the inverter cabinet. This air keeps dirt from contaminating areas containing DC Link Capacitors, Gate Units and Traction computers. Because the source is the central air compartment, the air has already been inertially filtered. In addition to this filtering, a paper filter for each cabinet located under the cabinet just below the phase modules serves to clean the supply an extra step. This air supply is not the same as that used for phase module cooling. The TCC electronics blower motor is powered as soon as there is an output from the companion alternators, assuming that the TCC Electronic Blower motor circuit breaker is closed. Air for the phase module and cabinet cooling comes directly from the ambient supply. A blower in each cabinet driven by its own 3-phase AC motor (powered by the companion alternator) draws the air in across the modules and expels it across the R 2-snubber resistor. Since the cabinets mount opposite each other, air draws in on the engineer’s side of the locomotive for TCC #1, and in on the conductor’s side for TCC#2. 5-6 GT46MAC Locomotive Service Manual
0 The initial command for blower operation comes from traction control computers. EM2000 executes the request by turning on the DIO-2 output channel 7 (TCC1SS) and DIO-2 output channel 8 (TCC2SS).
INSPECTION AND MAINTENANCE OF THE CENTRAL AIR SYSTEM COMPARTMENT INSPECTION If any leaks exist in the central air compartment, then unfiltered air will enter. This may be caused by any of the following defects: 1. 2. 3. 4.
Access panel bolts missing. Access panel gaskets or seals not properly applied. Compartment door not tightly closed. Engineroom partition and attached cover plates not properly applied and sealed. 5. Generator pit aspirator not properly connected.
ASPIRATOR INSPECTION At the intervals stipulated in the Scheduled Maintenance Program, inspect the main generator pit aspirator, Figure 5-4., as follows: 1. Check aspirator drain holes for obstructions. 2. Check that traction motor cooling air is exhausting from the aspirator tube causing venturi action at the aspirator drain holes.
F-CA30821
Figure 5-4. Generator Pit Aspirator. FORCED AIR SYSTEMS 5-7
INSPECTION OF INERTIAL FILTER (BLEED) BLOWER OPERATION The efficiency of the inertial carbody air filters will be significantly reduced if the inertial filter blower is faulty. If the blower is not operating, unfiltered air will be drawn in through the inertial filter blower exhaust stack, or if improper electrical connection is made, the blower may run backward with a resulting large drop in blower effectiveness. Either of the aforementioned conditions will cause an excessive amount of dirt to be blown into the generator and traction motor ducts. The engine filter will effectively clean the air taken in by the engine, but the added burden placed upon the engine filter may bring about the need for early filter element renewal. Proper operation of the inertial filter blower can be easily verified in the following manner. Open the filter blower motor circuit breaker mounted on the high voltage cabinet circuit breaker panel. If the engine is running, allow time for the blower to coast to a stop. Go under frame of the locomotive and observe the squirrel cage blower through the exhaust filter compartment. Have someone close the filter blower motor circuit breaker and start the engine, if not already running. As blower starts it will be possible to see which direction it turns. The blower vanes should move down, toward the observer. NOTE It is not sufficient merely to check that air is exhausting from the bleed blower duct of an already running engine. The squirrel cage blower, if running backward, exhausts air, but at a greatly reduced volume.
INSPECTION OF CARBODY INERTIAL FILTERS When dirt accumulates on the inertial filter tube vanes, the pressure drop across the filter increases, thus increasing the depression inside the filter compartment. As depression increases, the carbody inertial filter becomes less efficient, but this in itself is not critical, since the efficiency of the engine filter may not be affected. However, as filter compartment depression increases, the traction motor and generator blowers, which take their air from the compartment, will put out less cooling air. When the pressure differential between ambient and the filter compartment reaches the maximum value stipulated on the Service Data page, cooling air flow is insufficient and damage to the main generator and traction motors is possible. It is not possible to determine by a visual inspection whether the carbody filters are sufficiently clean or are plugged to the maximum allowable limit. It is possible for the filters to appear very dirty and still provide adequate filtration and adequate cooling air. If dirt on the filters is evenly distributed, it has no adverse effect upon filtration except for the resulting increased pressure drop that the cooling blowers must work against. However, if dirt is unevenly distributed, filtering efficiency can be reduced without an increase in pressure drop. It has been determined from experience that inertial filters should be removed from the locomotive and cleaned whenever compartment depression exceeds the value shown on the Service Data page.
5-8 GT46MAC Locomotive Service Manual
ENGINE INTAKE AIR FILTERS Additional filtration is required for air used by the engine. The engine intake air filter uses a fiberglass bag filter element, Figure 5-5.
18029 at 2+1/4i
F18029
Figure 5-5. Engine Air Filter - Fiberglass Bag The engine air filter assembly is equipped with pressure switches, Figure 5-6., that sense the differential between ambient pressure and pressure at the turbocharger inlet. The switches are located inside of the electrical cabinet, and connected by tubes to the turbo inlet side of the engine air filter, and to ambient. As the filter elements become restricted a depression is created within the filter housing. When the differential between the filter housing and ambient reaches 356 mm (14 in) H2O the filter vacuum switch FVS will trip closed. FVS closing feeds a signal to the computer. The DIO-2 input channel 2 (FVS) turns on and the display message will read FILTER VACUUM SWITCH TRIPPED after the FVS has been active for some time, indicating excessive restriction of air to the engine. Filter elements should be checked at this time. Refer to Checking Air Filters And Filter Compartment.
21482 at 3+1/2i
F21482
Figure 5-6. Filter Safety Switches FORCED AIR SYSTEMS 5-9
If the filter elements become so restricted that the differential reaches 610 mm (24 in) H2O the engine filter switch EFS (located in the high voltage electrical cabinet) will trip closed. EFS closing provides a signal to the computer through DIO-2 input channel 2 (EFS) which results in reduced engine speed and load. The display message will read “ENGINE AIR FILTERS DIRTY”. If throttle is above 6, the display shows “ENGINE AIR FILTERS ARE DIRTYCHANGOUT REQUIRED, POWER MAY BE LIMITED TO THR 6.”. Engine speed will be reduced to 730 RPM (TH6) and loading will be reduced to a maximum of 1820kw (turbo off gear train) or 1550kw (turbo on gear train.) 1500 HP (1120 KW). Filters should be changed at the earliest opportunity. The fault message will remain on display until the menu program is started, and will reappear after the menu program is ended, unless the fault is corrected. The fault is archived. Hose stems located on the front of the electrical cabinet, Figure 5-7., provide a convenient place to take manometer readings of pressure drops across the inertial air filter, the engine plus inertial air filters, and the electrical cabinet filter.
29256 at 1.8i
F29256
Figure 5-7. Filter Test Hose Stems CHECKING AIR FILTERS AND FILTER COMPARTMENT Filter compartment depression may be checked when operating conditions or the appearance of the filters seem to warrant such a check. Perform the following: 1. Connect a flexible tube to the INERTIAL FILTERS hose stem, Figure 5-7. Connect the other end of the tube to a U-tube manometer. Vent other end of manometer to atmosphere. 2. Make necessary preparations to start engine. Start engine and allow it to idle until warm. With reverser handle in NEUTRAL position and GENERATOR FIELD and DCL CONTROL circuit breakers OFF (open), place throttle in RUN 8 position. Loading is not necessary. 3. If filter compartment depression is less than the minimum stipulated in the Service Data, make certain that all central air compartment panels, partitions, and cover plates are properly applied and that no air is bypassing the carbody filters.
5-10 GT46MAC Locomotive Service Manual
0 4. When the filters are clean, the central air compartment depression should be near the value stipulated in the Service Data. Depression readings greater than the maximum stipulated are cause for immediate cleaning of the carbody inertial filters. NOTE If depression readings are taken on an annual basis, a reading of more than 3.5 in (89 mm) is indication that the inertial filters can be expected to plug within 12 months. 5. Connect the measuring device to the ENGINE + INERTIALS hose stem. If the reading is less than the minimum stipulated in the Service Data, and the inertial filter reading previously taken was satisfactory, the engine air filters should be checked for bypassing. Tears in the paper media, improper element seating, a loose connecting boot to the engine, and loose or broken pressure lines leading to the manometer hose stem or pressure switch are possible causes for such readings. If the reading is greater than the maximum stipulated in the Service Data, the engine air filters must be renewed. NOTE If, after lengthy service, the pressure drop remains low, similar to new (clean) filters, or is decreasing rather than increasing, the air filters should be checked for bypassing. If the inertial filter reading is near the maximum, cleaning of the inertial filters may extend the useful life of the paper filters somewhat. 6. Connect the measuring device to the ELECTRICAL CABINET hose stem. Make certain that all cabinet doors are securely latched. If static pressure is less than the minimum stipulated in the Service Data page, renew all electrical cabinet filter elements.
CLEANING THE CARBODY INERTIAL AIR FILTER The only approved and recommended method of cleaning the carbody filters is immersion in a hot detergent bath followed by a cold wash. The filters should be removed from the locomotive and cleaned if filter compartment depression exceeds the maximum value shown on the Service Data pages.
REMOVAL AND CLEANING PROCEDURE In order to facilitate inertial air filter cleaning and changeout, a spare set of filters should be available for rapid exchange with dirty filters. This practice will allow proper cleaning and maintenance of the filter assemblies without causing unnecessary delay. To remove the inertial air filter assemblies from the locomotive, perform the following: 1. At the filter compartment perform the following: A. Loosen the hose clamps and slide the rubber ducts clear of the inertial filter assemblies. B. Disconnect the dust bin drain line. C. Disconnect the blower motor electrical cable from receptacle on the partition between the dynamic brake and central air compartments.
FORCED AIR SYSTEMS 5-11
2. Remove all bolts holding the roof of the filter compartment to the carbody structure, Figure 5-8. on page 5-12. 3. Attach an overhead crane to lifting eyes provided, and raise the roof and filter blower assembly clear of the carbody. 4. At the inertial filter assemblies, perform the following: A. B. C. D. 5.
6. 7. 8.
Disconnect inertial filter drain pipes. Remove bolts at the flanges of the filter assemblies. Slide the filter assembly inward on structural members. Attach lifting device to four lifting eyes provided and raise the filter assembly out of the filter compartment. Place the entire filter assembly in a hot caustic or detergent bath until clean. The time required for cleaning will depend upon the type of bath used, its temperature, and the condition of the filter. When the filter is removed from the caustic bath it should be given a clear wash. Dry and inspect the filter flange for cleanliness and smoothness. Inspect the gasket material on the carbody structure where it mates with the inertial filter flanges. Replace any damaged portion of the gasket with material listed in Service Data.
F-CA30822
Figure 5-8. Inertial Filter Cross Sectional View 5-12 GT46MAC Locomotive Service Manual
0 9. Brush or wash corrugated filter compartment intake screen. It is not necessary to remove this screen from the locomotive carbody at any time during inertial filter removal and washing. 10. Reinstall the cleaned filters, and reconnect the filter drain pipes. 11. Reinstall the hatch roof by performing the following: A. Inspect the gasket material on the underside of the roof where it mates with the carbody structure. Repair damaged gasket as required. See Service Data for material. B. Inspect carbody structure where it mates with the roof hatch. Make certain that it is clean and smooth. C. Position the hatch roof, and secure all roof bolts. D. Connect rubber ducts between the filter assemblies and dust bin. Make certain hoses are correctly fitted before tightening the hose clamps. E. Reconnect dust bin drain pipe. F. Reconnect blower motor plug with receptacle.
CHECK AND ADJUSTMENT OF PRESSURE DIFFERENTIAL SWITCHES Switches EFS and FVS sense pressure differential between two sources, therefore their calibration can be checked by either increasing the pressure at the “high” (atmosphere) port or by lowering the pressure at the “low” (engine air inlet) port.
Switch Trip Values Switch
Part No.
Pressure Differential At Trip
FVS
8465021
14 in +/− 2 in (356 mm +/- 51 mm)
EFS
8466230
24 in +/− 2 in (610 mm +/- 51 mm)
1. Connect a voltmeter across the NO and C terminals of switch to be tested. With battery switch and local control circuit breaker closed, voltmeter should indicate up scale. NOTE If voltmeter does not indicate up scale, recheck voltmeter connections to switch. Switch is defective if voltmeter does not indicate up scale in Step 1. 2. Connect a flexible tube to the atmospheric pressure reference port. Connect a “tee” fitting, a short piece of tubing, and a manometer as shown in Figure 5-9. on page 5-14.
FORCED AIR SYSTEMS 5-13
F-CA33746
Figure 5-9. Testing Filter Safety Switches 3. Apply low pressure air to the short tube by blowing into it. 4. Note manometer reading when voltmeter indication goes to zero (switch closes). If manometer reading is within limits shown in Switch Trip Value chart, switch is operating normally. 5. If the switch does not operate within the +/- 2 in (+/- 51 mm) H2O limits, the switch should be adjusted to within +/- 0.5 in (+/- 13 mm) H2O limits. Turn the calibration screw, Figure 5-10., clockwise to increase the trip value, or counterclockwise to decrease the trip value.
F-CA30824
Figure 5-10. Filter Safety Switch 5-14 GT46MAC Locomotive Service Manual
NOTE Occasionally a filter light indication is reported, but manometer checks indicate clean filters and satisfactory switches. Such transient indications can be caused by wet filter elements or by snow plugged inertial filters.
Tests on switches may be performed with the engine running or shut down. If the tests are performed with the engine running, the slight depression produced by the engine at idle must be added to the pressure found necessary to trip the switch. Refer to Checking Air Filter And Filter Compartment portion of this section to measure air inlet pressure to engine.
CAUTION If a switch is removed from the locomotive and is to be calibrated at a bench, it is important to position the switch so that the diaphragm is in the vertical plane (which is the plane of mounting on a locomotive).
FORCED AIR SYSTEMS 5-15
SERVICE DATA - CENTRAL AIR SYSTEM ROUTINE MAINTENANCE PARTS AND EQUIPMENT PART NO. TM Blower Compartment.......................................................................................................... 10647162 Engine Air Filter Element Fiberglass Bag Type (4 Required)............................................................................................. 8470903 Electrical Control Cabinet Air Filter (#1 and #2) Pleated Cotton - Paper Elements............................................................................................... 9330535 Fiberglass/Dacron (optional)...................................................................................................... 8402068 #3 Electrical (AC) Cabinet Air Filter Pleated Cotton - Paper Elements (1 Required) .......................................................................... 8402068 TCC Cabinets Filters.................................................................................................................. 909358
FILTER SAFETY DEVICES PART NO. Filter Vacuum Switch (FVS) 356 +/- 51 mm (14" +/- 2") H2O .............................................................................................. 8465021 Engine Filter Switch (EFS) 610 +/- 51 mm (24" +/- 2") H2O............................................................................................... 8466230
SPECIFICATIONS Inertial Filters (Central Air Compartment) Minimum Depression.............................................................................................................76 mm (3”)H2O Maximum Depression ......................................................................................................... 178 mm (7”)H2O Combination Engine Plus Inertial Minimum Depression..........................................................................................................127 mm (5”) H2O Maximum Depression ......................................................................................................... 356 mm (14”)H2O Electrical Control Cabinet Filters Minimum Static Pressure .................................................................................................... 13 mm (0.5”)H2O AC Cabinet Minimum Static Pressure .................................................................................................... 2.6 mm (0.1”)H2O
5-16 GT46MAC Locomotive Service Manual
SECTION 6. COMPRESSED AIR SYSTEMS INTRODUCTION Compressed air is used for the locomotive brake system as well as for auxiliary systems such as sanders, bell, horn, windshield wipers, rail lube systems, and radar head air cleaner. WARNING Compressed air can be very dangerous if not handled properly by trained and qualified people. Before attempting to service any components in a compressed air system, isolate the component by closing the appropriate cut out valves. Vent any contained pressures before breaking seals or opening lines
F-CP31186 mod
Figure 6-1 WLNA9BB Air Compressor
COMPRESSED AIR SYSTEMS 6-1
WLNA9BB AIR COMPRESSOR The WLNA9BB three cylinder air compressor is a two stage (low-pressure and high-pressure) compressor. Water-cooled and shaft driven, the WLN is equipped with a shallow sump. The air compressor is mechanically driven by a driveshaft from the front or accessory end of the locomotive engine. This driveshaft is equipped with flexible couplings, which require periodic inspection and replacement. Part numbers and specifications are given at the end of this section, in “Service Data”. The compressor is equipped with its’ own internal oil pump and pressure lubricating system, as well as an oil filter. The oil level is checked running using the dipstick mounted on the side of the compressor crankcase. When adding oil, the compressor (and therefore the engine) must be shut down. At idle, with the oil at normal operating temperature, oil pressure should be between 124-149 kPa (18-25 psi). A plugged opening is provided for installation of an oil pressure gauge. The compressor is equipped with three cylinders, two low pressure and one (the center cylinder) high pressure. Air is pulled through two dry Pamic type air filters, into and compressed by the two low cylinders, and then passed through a pressure relief valve equipped intercooler to lower compressed air temperatures. After this the compressed air moves on to the high-pressure cylinder where it is compressed to main reservoir pressure.
F-13522
Figure 6-2 Pamic type compressor air filter.
6-2 GT46MAC LOCMOTIVE SERVICE MANUAL
AIR COMPRESSOR MAINTENANCE The compressor oil level should be checked regularly using the dipstick, and the oil level should be kept at the full mark. The compressor oil and compressor oil filter should be changed at the scheduled maintenance intervals. The compressor air filters should be changed out at the scheduled maintenance intervals. Remove the filters by first removing the nuts attached to the clamps on the filter housing. Swing the clamps to the side and remove the retainer screen. The filter housing and screen should be cleaned whenever the filter elements are change out. When the application of test gauges are required for maintenance ensure that the gauges are removed and the proper sized plug inserted and tightened before returning the locomotive to service. Air compressor change out and overhaul should be done at the scheduled maintenance intervals. For detailed rebuild instructions see the appropriate vendors’ instructions.
WARNING Although the three-cylinder air compressor is equipped with lifting eyeholes, it is not the recommended lifting procedure. The proper technique is with lifting straps of the proper rating wrapped around each exit manifold from the low-pressure cylinders If lifting eyes must be used, a spreader bar is required to minimize side loads on the eyeholes and lifting eyes.
AIR COMPRESSOR CONTROL The standard air compressor on a GT46MAC locomotive is coupled directly to the diesel engine through a driveshaft and when the engine is running, the air compressor is being driven. Therefore an unloader assembly, mounted on the compressor, is required to control when the compressor is actually pumping air. The intake or suction valves of the compressor contain unloaders that block the valve open when pneumatically activated. With the intake valves blocked open the compressor is incapable of compressing, whether it is rotated or not. These unloaders are controlled pneumatically, through the unloader magnet valve. This valve is called the MV-CC, or Magnet Valve Compressor Control. The locomotive computer, the EM2000, controls the MV-CC in turn. When the locomotive is started, the computer picks up the MV-CC, allowing main reservoir air through to activate the unloaders. When the computer, monitoring main reservoir pressure, notes that the pressure is below the required pre-programmed maximum pressure it drops out the MV-CC. This releases the unloaders causing the compressor to load.
COMPRESSED AIR SYSTEMS 6-3
MAIN RESERVOIR PRESSURE TRANSDUCER The EM2000 reads main reservoir air pressure from the main reservoir pressure transducer, or MRPT. This pressure is read between the number one and number two air reservoirs. The transducer itself is located inside the AC cabinet at the right rear side of the locomotive. The signal from this transducer, MR-PRESS, is sent to the EM2000. If the pressures of the main reservoirs are below 9.14 kg/cm² (130 psi) in lead, 9.49kg/cm² (135 psi) in trail, the EM2000, using the same circuit as compressor synchronization, drops out the MV-CC and activates the compressor. When the main reservoir pressure reads 9.84kg/cm² (140 psi) in lead, 10.19kg/cm² (145 psi) in trail, the EM2000 will shutoff the output signal for the CMPSYN circuit, causing the COMPSYN relay to drop out. With the COMPSYN contacts open (1 and 2 for redundancy), the CRL signal from 25T trainline and the DIO input is removed. When EM2000 sees this combination of factors, MV-CC is picked up, allowing MR air through to actuate the unloaders and prevent the compressor from loading.
MV-CC MAGNET VALVE MAINTENANCE If MV-CC magnet valves are suspect, check the position of the manual override “T” handle. When the handle is in the normal (up) position, and the valve coil is not energized, the valve should be closed. This should disable the unloaders, allowing the compressor to load. Conversely, if the “T” handle is held in the down and locked position, the compressor unloaders will be held open and prevent the compressor from loading. Ensure all pneumatic connections are tight and free of leaks. Check all electrical connections for proper contact and placement.
6-4 GT46MAC LOCMOTIVE SERVICE MANUAL
COMPRESSOR UNLOADER PANEL The MVCC itself is mounted on the compressor unloader panel. The panel is located inside the long hood, next to the AC compartment, at the right rear of the locomotive.
F-CP42612
?
Figure 6-3 Compressor unloader panel. COMPRESSOR SYNCHRONIZATION GT46MAC locomotives have a computer-controlled circuit for full compressor synchronization with any other EM2000 equipped locomotives that are trainlined. When main reservoir air pressure is below the low-pressure limit (called P LOAD), the EM2000 sends a signal out CH 14, DIO-3 which causes pick up of the compressor synchronization relay, CMPSYN. This provides a “compressor request to load” signal (CRL) to the EM2000 (CH 18, DIO-3) as well as trainline signal (25T) to activate any trailing unit compressors. In addition, CMPSYN provides the compressor synchronization relay verification input signal (CH 12, DIO-3). After a programmed period of time, the computer drops the output signal (which is CH 14, DIO-1), dropping out MV-CC. This causes the compressor to load, including when MV-CC fails. Note that when the locomotive is in trail, the input signal CRL is activated via the 25T input and the TLF. This singular input also tells the EM2000 that it is in trail and should load the compressor, providing that the MRPT setting on that particular trailing locomotive is below the low pressure limit.
COMPRESSED AIR SYSTEMS 6-5
F43268
Figure 6-4 Compressor synchronization circuit. When coupled to locomotives not equipped with synchronization, the CCS (Compressor Control Switch) will automatically start the compressor pumping when low main reservoir pressure is sensed.
6-6 GT46MAC LOCMOTIVE SERVICE MANUAL
MAIN RESERVOIRS To store the compressed air for use by the various systems, the locomotive has two main reservoirs (tanks) each with 492 liters (30,000 cubic inches) capacity. The reservoirs, designated number one and number two Main Reservoirs, are interconnected and furnished with various filtering and drying devices, check valves and liquid drains. Main reservoirs are equipped with safety drillings to prevent catastrophic rupture.
Figure 6-5 Main Reservoir System.
COMPRESSED AIR SYSTEMS 6-7
COMPRESSED AIR FILTERS AND DRAINS The compressed air system on the GT46MAC is equipped with various devices for the filtration and drying of the air produced by the compressor. These are discussed in this section.
MAIN RESERVOIR FILTERS The GT46MAC locomotive can be equipped with either 824 and 814 filters or 975 filters. In the case of the India Railways locomotive, the filters are 975 type. There are two identical filters, one for auxiliary air filtration and one for brake system filtration. Each filter has a canister type desiccant filter element inside it, which must be changed as per the scheduled maintenance instructions. The filters are also equipped with a bottom mounted drain valve.
(Illustration #6) CP37935
Figure 6-6 975 Air Filters
MAIN RESERVOIR FILTER MAINTENANCE To eliminate contaminants, open the manual drain valves at the bottom of the filter housing each day. Change the main reservoir filter elements every two years.
MAIN RESERVOIR SYSTEM SAFETY VALVE A safety valve rated at 10.6 kg/cm² (150 psi) connects to piping on the output side of the Number One Main Reservoir.
6-8 GT46MAC LOCMOTIVE SERVICE MANUAL
MAIN RESERVOIR DRAIN BLOWDOWN VALVES Number one and two reservoirs are equipped with bottom mounted Salem 580H automatic drain blowdown valve. These are used to remove condensate from the main reservoirs. The valves are normally air actuated, and operate each time the unloader valves on the compressor cycle. The airline that connects magnet valve MV-CC to the unloaders also branches off to the main reservoir drain valves. When there is air pressure in this line, (when the compressor is unloading), the drain valves actuate.
(Illus
Figure 6-7 Automatic Blowdown Valve The EBT or Electronic Blowdown Timer can also activate the drain valves. This is simply another magnet valve piped into the drain valve pneumatic control circuit. The EM2000 computer controls this magnet valve using DIO-3 output channel 3 (EBT). The blowdown valves will either operate automatically or the main reservoirs can be manually drained (using the same valves). To manually drain the main reservoirs, use the control valve on the end of the blowdown valve. Turning the handle on the valve clockwise until it stops will close the valve. Turning the valve counter clockwise until the valve stops will position the valve for automatic drain. Midway between these two positions is manually open.
MAIN RESERVOIR DRAIN BLOWDOWN VALVE MAINTENANCE
WARNING Close cutoff valve (co*ck) to isolate a blowdown valve or drain valve before attempting any disassembly, service or repair. Failure to cutoff air pressure to valve before starting any repair may result in injury. All valves should be regularly inspected. All main reservoirs should be manually drained on a regular basis and automatic operation confirmed. When working on standard or automatic type valves remember to use a good grade of air brake grease. COMPRESSED AIR SYSTEMS 6-9
1. Close main reservoir drain shut off valve to isolate automatic drain valve from system. 2. Remove cap, exposing disc and seat area. 3. Remove any foreign material from seat are, and from the inlet and exhaust area of the valve body. Clean the disc, seat area, and cap using a soft cloth and solvent or alcohol. 4. Reinstall the disc with the smooth side out (facing the cap), and replace the cap hand tight. Turn on the air by opening the manual drain valve, and note that the valve has resumed normal cycling. If the valve is functioning properly, torque the cap to 122 N.m (90 ftlbs.). To recondition a valve, the following procedure should be followed. NOTE It is recommended that the automatic drain valve be removed from the locomotive before reconditioning. Ensure that the main reservoir drain manual shut off valves and filter cutout valves are closed before removing the automatic drain valve.
1. Remove cap. 2. Remove and discard existing disc. 3. Clean cap and body thoroughly. Steam cleaning or an equivalent method can be used. 4. Inspect the body seat area. The seat area must be clean and free from any scratches or damage. Wear patterns should be even and polished. If not, the face can be reconditioned by lapping. A. Use a flat plate and lapping compound equal to 240 grit boron carbide (Norbide), or equivalent. B. When lapping the body seat, use a figure eight motion to maintain a square seta surface. Continue the operation until a 50-micro inch finish is achieved. Up to 0.010 inch can be removed from the body seat without affecting the operation of the valve. 5. Apply a new disc. See service data at the end of the section for the part number. 6. Reinstall cap. Torque cap to 122 N-m (90 ft-lbs.). 7. Reinstall valve on to locomotive. Charge the locomotive air system to operating pressure. Check for leaks and proper cycling of the valve.
6-10 GT46MAC LOCMOTIVE SERVICE MANUAL
FINAL AIR FILTERS The GT46 MAC is equipped with a KNORR/NYAB CCB 1.5 brake system. This system incorporates final air filters on the PCU (Pneumatic Control Unit). See the CCB 1.5 section
FINAL AIR FILTER MAINTENANCE See the KNORR/NYAB CCB 1.5 system maintenance section.
DRAINING THE COMPRESSED AIR SYSTEM DAILY
NOTE The manual drain valves for the main reservoir filters should be opened at least once a day to ensure proper operation.
GRAHAM WHITE TWIN TOWER AIR DRYER AIR DRYER CONTROL The compressed air from the air compressor contains moisture which can be detrimental to the air system components. India Railway choose to use a combination filter/air dryer to remove the condensate. The dryer has two identical “tower” elements, one which is actually drying the compressed air while the other element is being regenerated. The operation of the dryer is controlled by EM2000 computer. The computer controls the operation, the dryer is operated by DIO-3 output channel 11 (DCR) to pick up relay DCR, which energizes the dryer. When the DCR is energized, internal timing circuits in the air dryer alternate the compressed air from one tower to the other. As the regeneration process consumes compressed air, DCR is turned off to save compressed air when it is determined that no other compressed air is being used by the locomotive. The DCR relay is energized whenever the air compressor is pumping or when the engine speed is greater than 430 rpm. The DCR relay is turned off when the compressor in not pumping and the engine speed is below 420 rpm.
COMPRESSED AIR SYSTEMS 6-11
AIR FILTER DRYER ASSEMBLY The air filter dryer assembly on the GT46MAC is a Graham White twin tower type. The dryer cleans and dries air for use by the air brake equipment and auxiliary pneumatic devices. It connects between number one and number two reservoirs.
CP37934
Figure 6-8 Location of air dryer. The air filter assembly includes a precoalescer filter section, twin coalescer-dessicant towers, an electronic control circuit (including a timer and a relay), various valves and a pressure sensor. When the air compressor is pumping and main reservoir pressure is below 7.03 kg/cm² (100 psi), the precoalescer and both towers operate. Once main reservoir pressure is above 7.03 kg/cm² (100 psi) and the air compressor is pumping (or the throttle handle is in position three or higher), the precoalescer and only one tower at a time will function. The other tower will regenerate (dump the collected impurities). At approximately one-minute intervals, the towers will switch functions. That is, the tower that was regenerating will filter, and the tower that was filtering will regenerate. Each time the towers switch functions, the precoalescer purges itself.
6-12 GT46MAC LOCMOTIVE SERVICE MANUAL
CP37933
Figure 6-9 Air Dryer.
PRECOALESCER SECTION The precoalescer protects the filter dryer towers against contaminants (primarily oil) which can cause premature desiccant failure. The precoalescer is a cylinder containing a changeable borosilicate element. Droplets of contaminant form on the element as pressurized main reservoir air flows through it. These droplets drip down to the precoalescer sump. When the tower filters switch functions, the precoalescer drain valve is activated, purging the sump.
TWIN TOWERS Each tower consists of a two piece (upper and lower) cylinder shell, a desiccant canister, a renewable metallic coalescer element, an air operated desiccant compactor, inlet and outlet check valves, outlet solenoid valve, and an air operated electrically heated tower sump purge valve.
DEHYDRATION FUNCTION When the control circuit sets up one of the towers for dehydration, air flows into the inlet check valve near the top of the tower. From there it flows through an internal passageway that spirals downwards, circling outside the desiccant canister shell until it reaches the coalescer. This spiraling movement uses centrifugal force to drive the larger particles out and down along the tower housing, until it reaches the sump. COMPRESSED AIR SYSTEMS 6-13
The air flows through the coalescer, where the metallic mesh traps oil and other liquid contaminants. These contaminants drip from the mesh down to the sump. The air then flows upward, through the desiccant beads, which absorb humidity. The air then exits the tower, exits the dryer assembly, and flows through the silencer.
REGENERATION FUNCTION When the dryer control circuit first sets up for regeneration, both the inlet and outlet check valves are forced closed. Momentarily trapping the air in the tower. Next, the tower sump purge valve opens, and air pressure in the tower forces the collected impurities out of the sump. The sudden drop in pressure within the tower causes moisture to be released to the surface of the desiccant beads. Then, while the tower purge valve is still open, a small flow of dry air from the other tower is ducted to the top of the regenerating tower. The dry air flows down through the desiccant beads and out of the purge valve, drying off the beads.
HUMIDITY INDICATORS A humidity indicator monitors the air at each tower outlet check valve. These indicators reveal the air humidity level by means of color changes within the indicators. Blue, as seen through the sight glass, indicates dry air. Lavender indicates a deteriorating condition, and yellow/white indicate wet or contaminated air.
AIR FILTER DRYER MAINTENANCE Monthly: 1. Check condition of humidity indicators. 2. Ensure towers are cycling. 3. Ensure precoalescer drain valve and sump purge valves are functioning.
EACH 90 DAYS: 1. Check humidity indicators. Blue indicates proper functioning. White indicates unsatisfactory operation, and requires further inspection. 2. Check tower purge valves and precoalescer drain valve: A. Listen for slight, continuous air exhaust from the purge valve at one dryer tower and no air exhaust from the other dryer tower. B. Approximately one minute later, you should hear a loud, short air discharge from the second dryer tower, followed by the sound of slight, continuous air exhaust from the second dryer tower.
6-14 GT46MAC LOCMOTIVE SERVICE MANUAL
0 C. Approximately one-minute later steps A and B should repeat. Purge valve exhaust reversal once a minute indicates proper filter dryer assembly cycling. D. Listen to the precoalescer drain valve. It should exhaust each time that the purge valves reverse exhaust. If the filter dryer assembly does not cycle properly, if either dryer tower purge valve fails to discharge, or if the precoalescer drain valve fails to discharge: 1. Reaffirm that the main reservoir system air pressure is at least 7.38 kg/cm² (105 psi) and that the compressor is pumping. (Filter dryer assembly internal pressure switch closes at 7.03kg/cm² +/- 0.35 kg/cm² (100 psi, +/- 5). 2. If neither tower purge valve produces exhaust, connect a jumper across the pressure switch terminals. If connecting the jumper causes a short, loud exhaust noise followed by a continuous relatively quiet exhaust sound, the pressure switch is defective and should be replaced. 3. If the air dryer towers do not cycle (reverse functions) while the compressor is pumping, make sure that air is flowing into the tubing that connects the solenoid valve, the inlet check valve, and the purge valve. If air flows into the tubing at one tower and then switches to the other tower, the timing circuit is operating correctly. If no air flow is present, check the electrical connections to the dryer assembly. If the electrical connections are correct, and no air is flowing, replace the dryer assembly circuit board. 4. If actuating air is not present in the tubing between the inlet check valve and the purge valve during the regenerate cycle, check the solenoid valve electrical terminals to see if they are being energized. If the solenoid is energized, but air flow is not present in the tubing, inspect the solenoid valve plunger for proper seating. If the plunger binds in the coil, renew it. 5. Check the inlet and outlet check valves for proper seating while the tower is in regenerating mode by listening to purge valve exhaust. If the loud discharge of air does not quickly decrease to a slight discharge, check for foreign matter lodged under the inlet and/or outlet valve seat. Clean or replace the seat as required. 6. Inspect each tower while it operates in dehydrating mode. There should be no exhaust of air at the purge valve. If air is exhausting at the purge valve, the purge valve is not seating properly. It must be inspected and repaired with a new seat, seals, and packing cup. 7. Inspect the precoalescer drain valve. It should exhaust each time the dryer towers reverse functions. If the drain valve does not exhaust, inspect the actuating lines from the adjacent towers’ purge valves, and then follow steps 3 and 4 again.
COMPRESSED AIR SYSTEMS 6-15
8. Check the timer memory circuit by first unloading the compressor while the locomotive is running. (Locomotive should not be MU’ed for this test.) The air dryer should stop regenerating. Load the compressor. The same dryer that stopped should begin to regenerate at the same point in the cycle where it stopped. (In relation to regenerating time already expended in the cycle.)
ANNUAL MAINTENANCE Repeat the 90 day maintenance and: 1. Remove and replace the precoalescer borosilicate coalescing element. 2. Inspect the regenerating orifice and it’s operation. Do this by first pushing in the orifice plunger. If the plunger will not push in, wait for the dryer assembly to switch tower functions, and then push in the plunger. At the next tower function switch, the plunger should automatically return to the extended position. If the plunger does not return to the extended position, remove the regenerating orifice and apply maintenance kit.
BIANNUAL MAINTENANCE Repeat the 90 day maintenance and: 1. Check the humidity indicators. If they are white, inspect the desiccant beads. If the beads are contaminated with oil and water, change out the desiccant canisters. Ensure that new desiccant canister seals and gaskets are used. 2. Remove and replace the precoalescer borosilicate coalescing element.
TRIANNUAL MAINTENANCE Completely overhaul the filter dryer assembly, renewing or replacing: 3. 4. 5. 6. 7. 8. 9. 10.
All seals, gaskets and seats. Desiccant canisters. Tower purge valves. Precoalescer drain valve. Inlet and outlet check valves. Solenoid valve. Regenerating orifice. Desiccant compactor.
After reassembling the filter dryer assembly, perform the 90-day maintenance procedure to verify control circuit operation. If a malfunction occurs, replace the circuit board.
6-16 GT46MAC LOCMOTIVE SERVICE MANUAL
KNORR/NYAB AIR BRAKE SYSTEM (CCB 1.5) INTRODUCTION GT46MAC locomotives are equipped with a KNORR/NYAB CCB (Computer Controlled Braking) 1.5 system. This system is an electro-pneumatic microprocessor based system with 30A CDW type desktop controls. An overview of this system is provided in the following block diagram.
GM# GI42639
Figure 6-10 Block Diagram Of GT46MAC CCB 1.5 System. This system eliminates many of the discrete electrical and pneumatic controls and connections, thereby simplifying troubleshooting and reducing periodic maintenance. NOTE CCB 1.5 system information is presented here for reference purposes only. See system specific manual or contact NYAB representative for details.
AIR BRAKE EQUIPMENT The CCB 1.5 system on the GT46MAC is mounted on a brake rack. This is located in the short nose at the front of the locomotive, on the right side.
COMPRESSED AIR SYSTEMS 6-17
Figure 6-11 General Layout, showing location of brake rack.
6-18 GT46MAC LOCMOTIVE SERVICE MANUAL
1) Air Brake Rack 2) Engineers Control Console 3) Cab Door 4) Traction Control Cabinets 5) Inertial Air Filters 6) TCC Electronics Blower\ 7) Engine Air Filter
8) Radiators 9) Engine 10) AC Auxiliary Generator 11) Inertial Filter Dust Bin Blower and Motor 12) Electrical Control Cabinet 13) Cab Seat
0 This brake rack consists of a VCU (voltage conditioning unit), CRU (computer relay unit), PCU (pneumatic control unit), regulator, and a KE valve. Inside the cab, mounted on the consoles, are the rest of the components, such as the BVC (brake valve controller), gauges, and emergency brake handles.
GM# F41967 and CT42492
Figure 6-12 Control Stand And Emergency Brake.
All air brake pressures are monitored by console mounted analog gauges, and set up functions are controlled by switches mounted to the right of the brake valve controller.
COMPRESSED AIR SYSTEMS 6-19
SYSTEM DESIGNATIONS AND ABBREVIATIONS AB Automatic Brake ABCB Air Brake Circuit Breaker AD Analog to Digital AE1 Automatic Emergency Switch 1 (normally closed) AE2 Automatic Emergency Switch 2 (normally open) AP Automatic Variable Handle Potentiometer AR Automatic Release Switch (normally open) AW4 – ER Analog Converter Equalizing Reservoir AW4 – 16 Analog Converter 16 Pipe AW4 – 20 Analog Converter 20 Pipe (BCEV) BAN Battery Negative BAP Battery Positive BC Brake Cylinder BCCO Brake Cylinder Cut-Out Pressure Switch BCEP Brake Cylinder Equalizing Pipe BCEV Brake Cylinder Equalizing Valve BCT Brake Cylinder Transducer BEA Binary Input Output BO1 Bail Off Switch, Automatic BO2 Bail Off Switch, Independent BP Brake Pipe BPA Brake Pipe Flow Indicator, Port 2 BPCO Brake Pipe Cut-Off Valve BPDE Brake Pipe Dead Engine BPG Brake Pipe Gauge Port BPPS Brake Pipe Pressure Switch BPT Brake Pipe Transducer BVJ1 Brake Valve External Connector 1 BVJ2 Brake Valve External Connector 2 C1 Choke C2 Choke CCB Computer Controlled Brake COC Cut-Out co*ck COMM Communications CONT Controller COR Cut-Out Relay CP Central Processor CRU Computer Relay Unit DB1 Magnet Valve Driver Board DC Direct Current DCV Double Check Valve DI Diagnostic Printed Circuit Board ELV Emergency Limiting Valve EMER Emergency EPA1 Automatic Application (Equalizing Reservoir) Control Printed Ciruit Board EPA2 Control Pipe (Brake Cylinder) Control Printed Circuit Board EPA3 Direct Brake Control Printed Circuit Board ER Equalizing Reservoir ERG Equalizing Reservoir Gauge Port 6-20 GT46MAC LOCMOTIVE SERVICE MANUAL
0 ERT ES EX EXH FIG FLT FOJ1 FOJ2 FOP FOR FS Ft-lbs. FVG IB IBS ID IM I/O IPS IP IR J1 to J11 K1ES K2IBS K3BCPS K4RLIS K5COR K6SPOT K7BOBU K12VA KE KN L Lbs. mm. MIN MR MRDE MREP MRET MVBP MVEM MVER MVEREX MVLT MV16T MV20E MV20S MV20M 20T MV53 N Nm.
Equalizing Reservoir Transducer Emergency Sand Exhaust Exhaust Magnet Valve Figure Flow Transducer Automatic Fiber Optic External Connector Independent Fiber Optic External Connector Fiber Optic Fiber Optic Receiver Full Service Foot Pounds Flow Indicator, Port 1 Independent Brake Independent Brake Switch Inner Diameter Independent Maximum Applied Switch (normally open) Input/Output Iron Pipe Size Independent Variable Handle Potentiometer Independent Release Switch (normally open) Printed Circuit Board Connectors Emergency Sand Relay Extended Dynamic Range Cut-Out Relay Dynamic Brake Cut-Out Relay (spare) Rail Lubrication Relay PCR Cut-Out Relay Spotter Relay Bail Off Back Up Relay Brake Failure Alarm Relay Distributor Valve Kilo Newtons Liter Pounds Millimeter Minimum Main Reservoir Main Reservoir Dead Engine Main Reservoir Equalizing Pipe Main Reservoir Equalizing Pipe Cut-Off Transducer By-Pass Magnet Valve Magnet Valve Emergency Equalizing Reservoir Default Magnet Valve Equalizing Reservoir Default Magnet Valve Exhaust Lead-Trail Magnet Valve 16 Pipe Default Magnet Valve Independent Application & Release Exhaust Magnet Valve Independent Application & Release Supply Magnet Valve Independent Application & Release Maintaining Magnet Valve Direct Application Pipe Transducer Brake Pipe Cut-Off Magnet Valve Newtons Newtons Meters COMPRESSED AIR SYSTEMS 6-21
OD PARA PCB PCU Pg. Psig PVBIT PVBC PVBP PVEM PVERI PVLT Qty R1 R2 REL RES SC1 SC2 SS9A SS9B SUP SVJ SV2 TJB TPBC TPBP TPER TPMR TP16 TP20 V VA VCU VDC VOL 16 RES 16E 16S 16T 20CP 20F 20R 20T
Outside Diameter Paragraph Printed Circuit Board Pneumatic Control Unit Page Pounds Per Square Inch Gauge Pneumatic Break In Two Valve Pneumatic Valve Brake Cylinder By-Pass Pneumatic Valve Emergency Pilot Air Valve Equalizing Reservoir Pneumatic Interlock Lead-Trail Pneumatic Valve Quantity Resistor Resistor Release Reservoir Signal Conditioning Printed Circuit Board Signal Conditioning Printed Circuit Board Digital Input/Output Printed Circuit Board Digital Input/Output Printed Circuit board Supply Magnet Valve Computer Power Supply Computer Power Supply Transducer Jumper Board Brake Cylinder Test Port Brake Pipe Test Port Equalizing Reservoir Test Port Main Reservoir Test Port 16 Pipe Circuit Test Port 20 Pipe Circuit Test Port Volts Air Brake Alarm (Visual Alarm) Voltage Conditioning Unit Volts Direct Current Volume 16 Reservoir 16 Circuit Exhaust Magnet Valve 16 Circuit Supply Magnet Valve 16 Circuit Transducer 20 Circuit Control Portion 20 Circuit Trainline Filter 20 Circuit Relay Valve 20 Circuit Transducer
6-22 GT46MAC LOCMOTIVE SERVICE MANUAL
BRAKE VALVE CONTROLLER The automatic and independent (direct) brake system controllers, located to the right on the desktop of the consoles, are combined into a single unit called the Brake Valve Controller (BVC). Each handle is attached to a variable potentiometer that provides input signals to the CP (Central Processor) in the CCB computer. The handles are operated front to back so that the brakes are released when the handle is closest to the operator. The operating positions of the handles are detented for positive location.
CT42495
Figure 6-13 Illustration Of BVC AUTOMATIC BRAKE HANDLE The automatic brake handle controls the application and release of both the locomotive and train brakes. The brake valve functions as a pressure maintaining type, which will hold brake pipe reductions constant against normal brake pipe leakage. The brake handle operates through the following detented control positions and zones. 1. Release Position-used for fast recharge/overcharge-5.7kg/cm² (80 psi) maximum, plus 0.5 kg/cm² (7.1 psi) for overcharge 2. Run Position-normal BP release position, ER and BP at 5.2 kg/cm² (74 psi) 3. Minimum Reduction Position- minimum train brake, ER/BP reduce to 4.7 kg/cm² (67 psi) 4. Service Zone-from Minimum Reduction to Full Service 5. Full Service-maximum train brake, ER/BP reduce to 3.4 kg/cm² (48 psi) 6. Emergency Position-ER reduces to 0 kg/cm², BP reduces to less than 1 kg/cm² (14 psi)
COMPRESSED AIR SYSTEMS 6-23
NOTE A companion’s emergency brake valve is provided at the lower left of each console.
INDEPENDENT (DIRECT) BRAKE HANDLE The independent or direct brake is directly to the right of the automatic brake handle on the BVC. This handle provides independent control of the locomotive brakes irrespective of train braking effort. The brake function is self-lapping and will hold the brakes applied. The brake handle operates through four positions or zones. There is an additional bail off or actuate function provided by lifting a ring mounted below the handle knob. The four positions or zones are as follows: 1. Release Position- 0kg/cm² 2. Application Zone-Release position to Full Application position 3. Full Application Position-5.2 kg/cm² (74 psi). Note that BCEP pressure is 3.7 kg/cm² (53 psi). 4. Bail Or Actuate Position-vents any train brake application on MU’ed locomotives.
DEAD ENGINE CUT-OUT co*ck A dead engine cut-out co*ck, located at the lower left corner of the Pneumatic Control Unit (PCU), is used to limit braking effort on a locomotive being hauled dead in a train. When the cutout co*ck is set for a dead locomotive, the pressure regulator will charge the main reservoir at 1.76 kg/cm² (25 psi). This will limit brake cylinder pressure to 1.76 kg/cm² (25 psi) as well. Note that both BCEP and MREP cut-off end co*cks must be opened. Brake Pipe hoses must be connected and BP end co*cks opened, and Brake Cylinder co*cks must be open as well. Air Brake Circuit Breaker (ABCB) must be opened.
AIR BRAKE SET UP The micro air brake circuit breaker is wired to the load side of the locomotive battery switch, consequently the air brake system is not powered even with the battery knife switch open. The CCB system performs the same functions as a 26L-type brake system, but uses front-end electrical and electronic control instead of pneumatics. CCB is equipped with a pneumatic back-up system that operates in parallel with the computer control and is always active. Upon power up, the CCB system will not allow the operator to take control until certain brake system conditions are met. Until that time the system is strictly under pneumatic (back-up) control.
6-24 GT46MAC LOCMOTIVE SERVICE MANUAL
POWER-UP PENALTY Whenever the ABCB is first closed, the CCB system applies a penalty brake application. Brake Cylinder (BC) and Brake Cylinder Equalizing Pipe (BCEP) will be pressurized to 3.57 kg/cm² (50 psi). To recover the power up penalty, the automatic brake handle should be moved to the Full Service (FS) position. The handle must remain in this position for ten seconds (in addition to the initial thirty seconds of the penalty) to reset the system. When Brake Pipe (BP) pressure increases to 2.9 kg/cm² (41 psi), move the automatic brake handle to the Run position. This will fully recharge the BP system. The computer will not take control of the system until Brake Cylinder (BC) pressure falls to zero. This ensures that a complete penalty brake application occurs.
MULTIPLE UNIT OPERATION Setting up the locomotive for LEAD/CUT-IN, LEAD/CUT-OUT, and TRAIL, is accomplished through the three-position switch mounted on the lower right of the console.
SET UP FOR INITIAL LEAD/CUT-IN OPERATION 1. Place the automatic brake handle in Full Service (FS) position. 2. Place the independent (direct) brake handle in the Full position. 3. Close the Battery Knife switch. Ensure all breakers for normal locomotive operations are closed (computer breaker last). 4. Close the Air Brake Circuit Breaker (ABCB). The current air brake pressures and brake system status will be shown on the console gauges. Set-up air brake system for lead cut-in, using the Lead/Trail set-up switch.
COMPRESSED AIR SYSTEMS 6-25
Air Brake Set-up Table In absence of specific railroad instructions, the following table may be used for the most commonly encountered brake equipment operation. SERVICE
AUTOMATIC BRAKE HANDLE
INDEPENDENT BRAKE HANDLE
CUT IN/ CUTOUT
DEAD ENGINE CUTOUT co*ck
LEAD OR TRAIL
SINGLE LOCOMOTIVE Leading
Release
Release
Cut In
Out
Lead
Shipping Dead in Train
Handle Off Position
Release
Cut Out
In
Lead (Open all IND and ACT end connection COC’s.)
LOCOMOTIVE IN MULTIPLE UNIT CONSIST Leading
Release
Release
Cut In
Out
Lead
Trailing
Handle Off Position
Release
Cut Out
Out
Trail
Shipping Dead in Consist w/ MU Hoses Connected & End Connection co*cks Open
Handle Off Position
Release
Cut Out
Out
Trail
Shipping Dead in Consist w/Mu Hoses Not Connected
Handle Off Position
Release
Cut Out
In
Lead (Open all IND and ACT end connections COCs.)
Figure 6-14 Brake Equipment Set-up Table.
6-26 GT46MAC LOCMOTIVE SERVICE MANUAL
POWER LOSS/PNEUMATIC BACK-UP As a loss of power to the CCB system could occur, there is a pneumatic back-up system. The following conditions will occur: power loss, air brake fail alarm on the affected unit, along with a trainlined alarm. 1. AIR BRAKE FAIL alarm, on the affected unit, along with a trainlined alarm. 2. Immediate power and dynamic brake knockdown. 3. Equalizing Reservoir reduces to zero at a service rate. 4. Brake Pipe is vented to 0.7 kg/cm² (10 psi) at a service rate. 5. Brake Cylinder pressure developed by back-up system to 3.8 kg/cm² (54 psi). 6. Trailing units will receive pressure equal to BC via the Brake Cylinder Equalizing Pipe. Note that if power cannot be restored to the brake system, the unit must be used as Trail or Dead. After power is restored, there will be another Power-up Penalty, which will have to be recovered as above (see Power-Up Penalty).
E.S.D PRECAUTIONS The CRU box protects the internal components against damage from Electro Static Discharge (ESD) damage in normal operation. During normal maintenance procedures and inspections, no special ESD precautions are necessary, provided that the covers of the system enclosure box remain closed. If welding or performing high potential testing on the locomotive, special precautions must be taken. See the section on “Protecting Sensitive Equipment When Welding Or High Potential Testing”. If it becomes necessary to open the cover of the CRU, or to remove any electrical portion of the system, use a wrist strap as described under “How To Use Electrostatic Discharge Systems”. All power must be shut off when working on any electrical air brake systems, and care should be taken not to physically damage any components or the housing itself.
COMPRESSED AIR SYSTEMS 6-27
CCB FINAL FILTER MAINTENANCE The CCB system is equipped with two different types of air filters. These are mounted on the Pneumatic Control Unit (PCU), and consist of one MR filter (mounted on the rear of the PCU) and three identical filters for BCEP, MREP, and BP (mounted on the front of the PCU). All main reservoir air for the PCU flows through the MR filter. The filter is a canister type with an internal element, which must be replaced as per the scheduled maintenance requirements. To remove the MR filter from the PCU manifold and change the filter element: 1. Remove the two hex head screws, lock washers and flat washers holding the assembly to the PCU manifold. 2. Remove the filter assembly from the PCU manifold. 3. Remove and discard the two “O”ring gaskets from the filter assembly. 4. Secure the filter head in a vise and use an oil filter wrench or similar tool to unscrew the housing from the head. 5. Unscrew the locknut from the rod and remove the retainer. 6. Remove and discard the filter element from the filter assembly. 7. Install new filter element into filter assembly 8. Reverse process. 9. Replace all “O”rings with new, remembering to lubricate lightly before reinstallation. 10. Torque mounting hex head screws to 40.7 Nm. +/- 4.07 Nm. (30 +/3 ft.lbs.) – dry torque. Note that the automatic drain valve inside the filter assembly should not be removed unless it is defective. The other types of filters on the PCU are LF-19-T filters. There are three of them, all of which are identical. The LF-19-T filters are designed to be removed, disassembled, cleaned, and reapplied during maintenance. To remove LF-19T filters from PCU manifold and disassemble:
1. Remove the two mounting hex nuts. 2. Remove filter from manifold. 3. Remove and discard the two “O”rings from filter assembly. 4. Remove retaining ring and cover from filter housing. 5. Remove and discard “O”ring from housing. 6-28 GT46MAC LOCMOTIVE SERVICE MANUAL
0 6. Remove the spring, support ring, and filter from housing. 7. Wash all parts in suitable solvent. (i.e. mineral spirits) 8. Blow dry parts with clean, dry, compressed air. 9. Replace any components that are worn or damaged. 10. Lubricate all “O”rings with number two silicone grease before assembly 11. Insert cleaned filter, support ring, and new spring into housing. 12. Insert new, lubricated cover “O”ring into housing. 13. Insert cover and retaining ring into housing. 14. Install new housing “O”rings before remounting filter assembly to PCU manifold. 15. Reinstall hex nuts and torque to 16.3 Nm. +/- 1.4 Nm. (12 +/- 1 ft.lbs.) - dry torque.
92 DAY MAINTENANCE Inspect air brake system equipment and perform functional brake test. Drain moisture from all reservoirs. Replace any damaged components.
ANNUAL MAINTENANCE Perform 92 day maintenance and; clean and replace all CCB air filters as per previous instructions.
5 YEAR MAINTENANCE Overhaul brake controller (pneumatic portion only) as per NYAB instructions. Overhaul PCU as per NYAB instructions.
COMPRESSED AIR SYSTEMS 6-29
SANDING SYSTEM Sanding on the locomotive is controlled in two ways. Either manually by the operator, or automatically by the control system. Technically, however, both methods are actually controlled by the EM2000 computer. When activated by manual switches, a sanding request signal is sent to the computer, which then initiates the sanding process. In automatic mode, the request comes from the traction or braking systems. The sanding process itself, remains the same for either option. The exception to this is when an emergency braking sequence is initiated. Under those circ*mstances sanding is initiated by the brake system, but the control signals still work through the EM2000.
GM# CP39988
Figure 6-15 Sand Magnet Valves. Gravity feeds sand from the sand reservoirs to the sand traps. Energizing a sanding magnet valve causes it to open, sending compressed air through a pair of sand traps. Air flowing through a sand trap picks up sand as it passes through. The air/sand mixture exits the trap through the attached sand hose, and blows down onto the rail.
GM # F31173
Figure 6-16 Sand Traps.
6-30 GT46MAC LOCMOTIVE SERVICE MANUAL
0 Manual Sanding is cutout when the locomotive is operating in power/wheel creep mode, and moving at speeds above 19.4 km/h (12 mph). If a wheel creep equipped locomotive is MU’ed in consist with an older EMD locomotive, a trainlined signal will initiate sand on the older units.
MANUAL SANDING The locomotive operator initiates sanding by operating one of the non-latching sanding switches mounted on the consoles. This will apply sand to the leading axle (wheelset) on each truck depending on locomotive direction.
Manual Sanding Switch
GM # F41970
Figure 6-17 Manual Sanding Switch. When the sand switch is closed, a signal is sent to the DIO module on the computer. The computer responds by energizing the correct magnet valves and turning on the sand indicator light on the consoles. As well, the computer will energize the 23T trainline to cause sanding on any trailing units. Note that while manual sanding is available in dynamic braking at all speeds, when motoring at speeds above 19.4 km/h (12 mph) or in Super series mode manual sanding is cutout on this locomotive.
AUTOMATIC SANDING The locomotive computer initiates automatic sanding when it detects that sand is required to maintain or increase wheel to rail adhesion. Such automatic sanding may occur when in controlled wheel creep operation. The computer also uses automatic sanding to correct undesirable wheel slip during initial start up from a standstill, and if wheel slip occurs when Super Series is disabled. In addition, the computer will use automatic sanding to correct wheel slide when in dynamic braking. As when the manual SAND switch is operated, the computer automatically energizes the sanding magnet valves appropriate to the direction of locomotive travel. Automatic sanding is inoperative if the generator field contactor GFC is de-energized. COMPRESSED AIR SYSTEMS 6-31
EMERGENCY SANDING Emergency brake applications and brake pipe breaks (break in two) will cause brake pipe pressure to drop quickly. The air brake system’s computer monitors this time frame/pressure drop. The CP (Central Processor) in the CCB (Computer Controlled Braking) system will command a relay to energize, and this signal will energize the ESS (Emergency Sanding Switch). At the same time, a signal will be forwarded to the EM2000 locomotive computer, which will then initiate the sanding process. In the case of emergency sanding the computer will also control the time duration of sanding (60 seconds). For more detailed information of the interaction of the CCB system and emergency sanding, see the CCB section.
SANDING SYSTEM MAINTENANCE EMD recommends checking the manual sanding system before each trip. With the locomotive set-up for power operation, and the diesel engine idling, proceed as follows: 1. Set the reverser handle in FORWARD or REVERSE. 2. Operate the SAND switch. Unit should sand the rails in front (or behind) of each truck, as determined by the reverser setting. Sand light should illuminate at operator’s console. 3. Release the SAND switch. Sanding should cease. 4. Move the reverser to the opposite setting. Sanding should switch to opposite end of locomotive. Sand light should illuminate at operator’s console.
MAGNET VALVE MAINTENANCE There are two sanding magnet valves at each end of the locomotive. Of the two magnet valves on one end of the unit, one controls forward direction sanding and one controls reverse direction sanding. Each magnet valve controls two sand traps at one end of the truck, one on each side.
6-32 GT46MAC LOCMOTIVE SERVICE MANUAL
Figure 6-18 Sand Magnet Valves. If faulty magnet valve operation is suspected, make sure all electrical connections are tight. Ensure air line are not leaking. Each valve is equipped with cleanout jets. To operate the jets, push in the plungers located on each side of the valve. The plungers reset automatically at the beginning of the sanding cycle. If further service is required, remove the valve and replace with a qualified rebuilt or new valve.
SAND TRAP MAINTENANCE Eight sand traps are on the locomotive. A pair of sand traps is provided for each side of each truck. One trap in each pair sands at the leading end of the truck and one at the trailing end.
GM # 13573
Figure 6-19 Sand Trap. Gravity feeds sand from the sandbox to the sand shutoff at the top of the sand trap. Unless the sand shutoff is closed, sand fills the cavity in the trap and spills into the horizontal passage in the sand delivery flange.
COMPRESSED AIR SYSTEMS 6-33
.
GM # CP 35663 and 13988
Figure 6-20 Sand Trap Details. The setting of the sand control paddle controls the rate at which the sand spills into the passage. If sand is not removed from the horizontal passage, it stops flowing there. Pressurized actuating air from the sanding magnet valve enters the trap and blows through the horizontal passage where it mixes with the sand. The air/sand mixture exits the trap assembly and flows down to the rail through the trap outlet pipe, the sander hose, and the sander nozzle. Sand exiting the trap is replaced by sand flowing into the top of the trap. A sand shutoff is provided for cutting out a particular sand line, or to enable maintenance work on a sand trap. Setting the shutoff lever OPEN opens the shutoff, admitting sand into the trap. The shutoff lever CLOSED position is approximately 45° counter clockwise from the vertical. Raised letters on the body casting of the trap assembly indicates both settings. Setting the shutoff lever in the CLOSED position closes the shutoff, blocking sand entry into the sand trap, but not preventing sand already in the trap from blowing out. CAUTION Before performing any work on a sand trap, set the shutoff lever to the CLOSED position. Condensation may cause moisture in the trap. To clean out the trap, remove the pipe plug in the bottom of the trap casting, using the provided handle. For more thorough cleaning, also remove the outlet flange and pipe. After cleaning reinstall the pipe plug and outlet flange. The trap sand delivery is set at 425 to 567 grams (15 to 20 oz.) per minute at the factory. 6-34 GT46MAC LOCMOTIVE SERVICE MANUAL
MISCELLANEOUS COMPRESSED AIR EQUIPMENT THE RAIL LUBE SYSTEM The GT46 MAC locomotive is equipped with a TSM rail lube system. The control of this system is the EM2000 computer. There is a magnet valve mounted on the unloader panel for compressed air supply for the rail lube system. For more information see the Rail Lube System section.
WINDSHIELD WIPER ASSEMBLIES Wiper assemblies are provided for each windshield in front and behind the operator’s consoles. Each windshield wiper assembly is driven by an air operated motor and controlled by individual hand operated air valve. The air motor assemblies consist of four moving parts, including a rack and pinion power train and simple internal valving with reversal provided by pneumatic mechanical action. Valve parts are of a material that is very durable and resists the effects of contamination. Therefore, very little maintenance is required. If a windshield wiper motor is not operating correctly, make sure that the air connections to the motor are tight and that they do not leak. If necessary, remove the air connections to inspect for signs of foreign particles that may have settled on air motor valve seats. If such is not the case, disassemble the motor further to check for broken or jammed components, or plugged air ports. Check the air motor internal air flow by removing the air connections and valve chamber, then blowing out the ports. Also, blow into the exhaust port to ensure it is not plugged. If the motor still doesn’t work properly, replace it with a new or qualified motor. To remove the wiper connecting arm from the air motor shaft, remove the acorn nut from the end of the shaft and pull the connecting arm off the splined shaft. When reassembling the connecting arm to the shaft, be careful not to over tighten the acorn nut. The wiper assemblies are designed to operate at a maximum speed of 60 to 80 cycles (120 to 160 strokes) per minute.
COMPRESSED AIR SYSTEMS 6-35
AIR HORN The locomotive operator, through a switch-activated circuit that energizes the MV-AH magnet valve controls the air horn. There are two controls for the air horn on the GT46MAC locomotive, one on each operator’s console. To inspect and clean an air horn diaphragm, remove the back cover bolts, the back cover, the diaphragm ring screws, the diaphragm ring, and finally, the diaphragm itself. Whenever removing an air horn back cover, blow out the air lines and clean out the orifice dowel pin. This can be done by fully opening the air horn valve while the air line to the valve is at full operating pressure (with the air horn back cover removed).
MAGNET VALVE RADAR BLOWDOWN To assist in keeping the locomotive radar transceiver clean during less than optimum conditions, the radar wipe system automatically and periodically blasts the transceiver faceplate with compressed air.
GM # CP38171
Figure 6-21 Radar Head Transceiver The system consists of an air supply line from the main reservoir, radar blowdown magnet valve (MV-RB), and a pipe assembly that aims the air blast at the radar face plate. The computer sends an output signal (RADBLW, on DIO-3 output channel 18) to the MV-RB, energizing the magnet valve which allows compressed air to pass through to the pipe assembly. Compressed air will blow on the faceplate for 2.6 seconds out of every 25 seconds, providing all of the following conditions are met: a. b. c. d.
Diesel engine is running The reverser handle is not in neutral The LOCAL CONTROL circuit breaker is closed The locomotive computer is powered up, battery knife switch is closed, and COMPUTER CONTROL breaker is closed.
6-36 GT46MAC LOCMOTIVE SERVICE MANUAL
MAGNET VALVE TRACTION MOTOR BLOWER On the GT46MAC locomotive, the traction motor blower is equipped with an air-actuated cylinder. This cylinder controls (through a linkage) a circular inlet vane assembly. The inlet Guide vane is spring loaded to the full open position. MVTS needs to be energized to partially close the shutters. Even if EM2000 controls MVTS through DIO-3 output channel 6 (TMSHR), the request for shutter operation comes from the Traction Control Computers TCCs which monitors traction motor temperature. When hottest traction motor temperature is less than 139°C, shutters are partially closed. When hottest traction motor temperature is greater than 149°C, the shutters are fully open. Restricting unnecessary cooling air reduces the mechanical load on the traction motor blower, thus improving fuel economy and increasing traction motor blower life.
GM # CA30825
Figure 6-22 Traction Motor Blower. COMPRESSED AIR SYSTEMS 6-37
See “Forced Air Systems” for more information. To check linkage adjustment, all the following conditions must apply: 1. There is a 1/32” gap between the restrained vane and the full open stop block. (See TM Blower illustration, part A.) Measure this at the closest point between the block and the vane. 2. A threaded rod length of at least 3/8 “ must be screwed into the ball joint barrel. Check this by measuring the length of exposed threads on the rod. There should be no more than 5/8” of thread exposed below the jam nut. (See TM Blower illustration, part B.) 3. The ball joint bolts at the ends of the rod should be wrench tight into the air cylinder plunger and actuator arm nut. 4. The jam nut should be wrench tight against the barrel. 5. The restrained vane does not hit the half-flow stop block during operation. To adjust the linkage: 1. Tighten the ball joint bolts into the actuating arm nut and air cylinder plunger (hold the plunger fixed). 2. Back off the jam nut on the rod, and turn the rod to get the vanes away from the full open stop block. 3. By using a feeler gauge in your left hand and turning the rod with your right hand, adjust the gap so that there is 1/32” clearance at the tightest spot. (See part A of TM Blower illustration.) 4. With the feeler gauge still in place, use a wrench to tighten the jam nut against the barrel. Do not allow the rod to move when tightening the nut because the vane will move closer to the block. 5. Now check for proper thread engagement. There should not be more than 5/8” thread showing. If there is less than 5/8” tread showing, proceed to step 9. If there is more than 5/8” thread showing, proceed to step 6. 6. While holding the plunger fixed, remove the ball joint from the cylinder plunger. 7. Add another nut to that ball joint bolt, and tighten it up against the collar. 8. Replace the bolt and nut in the plunger, tighten, then repeat steps 2 through 4. 9. Recheck gap with feeler gauge.
6-38 GT46MAC LOCMOTIVE SERVICE MANUAL
Insert CP42608 11 x 17
Figure 6-23 Piping Schematic.
COMPRESSED AIR SYSTEMS 6-39
6-40 GT46MAC LOCMOTIVE SERVICE MANUAL
SERVICE DATA – COMPRESSED AIR SYSTEM ROUTINE MAINTENANCE PARTS AND EQUIPMENT PART NO. AIR COMPRESSOR: .....................................................................WLNA9BB Air Filter Element .................................................................................... Pamic Oil Filter Element ................................................................................ 9311037 MAIN RESERVOIR FILTER.............................................................. 9559346 Filter Element .................................................................................... 40028168 Seal, Sump Bowl................................................................................ 10530737 AIR FILTER DRYER (Twin Tower) ................................................. 10629715 Desicant Recharge Kit ....................................................................... 10520364 Self Actuating Drain Valve ................................................................ 10569213 Drain Valve Repair Kit ...................................................................... 10565990 Coalescar Element Kit ....................................................................... 10565991 Inlet Check Valve Repair Kit ............................................................. 10520365
SPECIFICATIONS AIR COMPRESSOR LUBE OIL
NOTE Compressor lube oil must be SAE 30 weight turbine type oil containing anti-rust, anti-oxidation, and anti-foam inhibitors and should possess the following properties: Viscosity-Saybolt Universal (ASTM D88 or D2161) @ 38°C (100°F) seconds – 130 to 180 @ 99°C (210°F) seconds – 42 to 45
Pour Point (ASTM D97 Degrees Minimum) - -18°C (0°F) Rust Distilled Water (ASTM D665) – No Rust
DEAD ENGINE PRESSURE REGULATOR Set @ - 172 +/- 10 kPa (25 +/- 1.5 psi)
COMPRESSED AIR SYSTEMS 6-41
6-42 GT46MAC LOCMOTIVE SERVICE MANUAL
SECTION 7. HTSC BOGIE INTRODUCTION The GT46MAC locomotive is equipped with an HTSC (High Tensile Steel Cast) truck or bogie. This truck/bogie assembly supports the weight of the locomotive and provides the means for transmission of power to the rails. Unlike conventional rigid trucks/bogies, in which axles are held in parallel with each other, the HTSC truck/bogie is designed as a powered "bolsterless" unit. Although the bogie or truck frame itself is rigid, the design allows the end axles to move or "yaw" within the frame. This movement will allow the wheels to position themselves tangent to the rails on curves for reduced wheel and rail wear. Traction loads are transmitted from the truck or bogie to the locomotive underframe through the carbody pivot pin assembly. The truck/bogie is designed for extended maintenance intervals with lateral thrust pads and plates at the journal bearings and brake rigging being the only friction wearing components on the truck/bogie requiring periodic replacement. At truck/bogie overhaul suspension shock absorbers are replaced and linkage bushings are inspected for reuse or replacement. The trucks/bogies are equipped with three AC power traction motors. The traditional rubber suspension spring "nose packs" on the motors are replaced with nose link assemblies (dogbones) that increase ease of disassembly and lowering of traction motor/wheel sets for maintenance.
HTSC BOGIE 7-1
FTR43208
Figure 7-1 HTSC Truck/Bogie. 7-2
GT46MAC LOCOMOTIVE SERVICE MANUAL
0 These three traction motors in each truck/bogie convert the electrical energy into locomotive tractive effort. The motors are geared to the driving axles, which in turn apply rotational force to the rail through the wheels. The driving force is transmitted to the bogie frame through tractive rods attached to the journal bearing adapter and the frame. From the truck/bogie frame the driving force is transmitted to the locomotive carbody through the carbody pivot pin. The unsprung weight of the locomotive carbody is transferred directly to the truck/bogie frame through four rubber "compression" spring assemblies. These four spring assemblies are located at corner positions formed on the truck/bogie where the side beams and cross beams intersect, thus providing the yaw stiffness for tracking stability. These relatively stiff secondary spring suspension limits weight transfer between axles during adhesion as all traction motor nose positions are on the same side of each axle within the truck/bogie frame. (All the traction motors are arranged within a truck/bogie in one direction, providing good motor accessibility and adhesion characteristics.) The soft primary suspension, made up of twelve single coil journal springs (two at each journal), is designed to provide ride quality and equalization of wheelset loads for operation over track irregularities. Shock absorbers are used between the truck/bogie frame and locomotive underframe to damp the lateral movements of the bogie for stability at higher road speeds. The truck/bogie frame is equipped with lateral stops at the center axle position to limit the lateral movement between it and the locomotive underframe. Vertical stop clearance is established between the truck/bogie frame and the underframe at 15.9 +/- mm (0.62" +/- 0.12") using shims under the four rubber compression springs and at locations inward of the lateral stops at the center axle position. All shims are tack welded in place. There are also "safety" links installed by these lateral stop locations on each side of the center axle between the truck/bogie frame and the locomotive underframe.
HTSC BOGIE 7-3
F43281
Figure 7-2 Lateral Shock Absorbers And Safety Links.
7-4
GT46MAC LOCOMOTIVE SERVICE MANUAL
0 These safety links serve to prevent separation of the truck/bogie assembly from the locomotive in case of derailment and to provide a means of lifting the truck/bogie assembly along with the carbody. The journal bearing adapters transmit the vertical load from the springs to the axles. Rubber deflection pads on the adapters and nylon wear plates on the frame control the lateral thrust loads of the axles within the truck/bogie frame. These pads and wear plates are renewable and provide the means by which the lateral clearances can be maintained within limits. These limits are 15.9 mm (0.62") for the center axles and 10.4 mm (0.37") for the end axles. Air brake cylinders and brake rigging mounted on the truck/bogie are used to apply retarding forces to the wheels to slow and stop the locomotive. A single shoe system is used which provides a single composition type brake shoe at each wheel.
F43280
Figure 7-3 Brake Cylinder Mounting.
HTSC BOGIE 7-5
fTR43221
Figure 7-4 Brake Rigging.
7-6
GT46MAC LOCOMOTIVE SERVICE MANUAL
ROUTINE MAINTENANCE AND INSPECTION The following paragraphs contain information necessary for performing routine truck/bogie maintenance adjustments, and inspection while the locomotive is trucked/bogied.
LUBRICATION Periodic lubrication of the truck/bogie is not required. However, depending on the type of traction motor gear and axle assemblies used, the following lubrication schedule can be followed;
ROLLER SUPPORT BEARINGS (BTR), GREASE LUBRICATED: 375,000km (250,00 miles) or at wheel change, whichever comes first.
OIL LUBRICATED GEARCASE: 46 days or as required by locomotive service demands. In addition, the brake slack adjusters should be checked at every inspection, and if found to be dry and/or dirty should be cleaned and lubricated.
fTR43220
Figure 7-5 Carbody pivot pin Nylon bushing halves.
The carbody pivot pin assembly is another item that requires regular inspection. The pivot pin assembly is lined with two Nylon bushing halves. The pivot pin is to be sprayed with a bonded type spray lubricant any time the truck/bogie is overhauled or the locomotive carbody is lifted from the truck/bogie. No additional oil, lubricant, or grease is required during normal operational service.
HTSC BOGIE 7-7
FTR42793
Figure 7-6 Carbody pivot pin, safety links, compression springs, and secondary yaw dampers. Note that special care should be taken with the rubber deflection pads on the journal adapters, the Nylon wear plates on the truck/bogie frame and the brake levers, and the rubber compression spring assemblies in order to keep them as free from oil or grease contamination as possible.
TRUCK/BOGIE CLEANING Truck/bogie assemblies should be cleaned periodically to eliminate any accumulations of oil, sand, dust, dirt, etc. Any buildup of these contaminants will increase wear as well as detract from the appearance of the assembly. There are two methods of cleaning are suggested. The first method is used when the truck/bogie assemblies are still in position under the locomotive. The second method is used when facilities are available for removing the truck/bogie from the locomotive and it is disassembled.
UNDER LOCOMOTIVE: When using this method, run the engine to supply pressurized air to the traction motors. Air discharged from the traction motors will help to prevent overspray from entering and contaminating the motors. Using water and an alkaline solution cleaner, spray the truck/bogie. Be careful to direct the spray away from the traction motor openings to avoid wetting them.
7-8
GT46MAC LOCOMOTIVE SERVICE MANUAL
0 Let the cleaning solution remain on the truck/bogie for 10 to 15 minutes. Then, using steam and the alkaline solution in a mixing gun, thoroughly spay the truck/bogie assembly. Again, be careful of the traction motor openings. Rinse the truck/bogie with hot water as required.
TANK IMMERSION: When the truck/bogie assembly is removed from the locomotive, the traction motors (including wheels, gears and axles), journal bearing adapters, rubber compression springs, shock absorbers (all types), brake cylinders, and all the Nylon or rubber deflection, snubbing, wear plates, bushings, or pads should be removed before immersion. Again the preferred cleaning agent is an alkaline solution. Once all damageable components are removed, the truck/bogie assembly may be immersed in the cleaning solution. Allow sufficient time for removal of all foreign material and then remove the assembly and rinse with hot water. Brake slack adjuster rods and tubes as well as brake lever connection joints should be immediately lubricated to prevent seizing.
TRUCK/BOGIE FRAME The truck/bogie frame is a one-piece high tensile steel casting (Hence the acronym, HTSC). It has been designed to hold all the major components of the truck/bogie assembly. During inspection; check for loose or broken equipment and integrity of components. Inspect all truck/bogie frame members for cracks or breaks. Check all worn areas. Worn spots can be repaired by building up the effected area with weld and then grinding the area back to its original form.
VERTICAL STOP CLEARANCE The vertical stop surfaces on the side of the truck/bogie frame are designed to mate with similar surfaces (vertical stops or shims) on the tack welded beneath the carbody underframe. Clearance is provided between the bogie vertical stops and the carbody underframe vertical stops (shims0 during normal operation. These stops are designed to prevent the excessive tilting or leaning of the locomotive. These stops are not designed to carry a continuous load. The vertical stop clearances are (on a new assembly); 16 mm +/- 3.2 mm (0.62" +/- 0.12").
HTSC BOGIE 7-9
F43269
Figure 7-7 Vertical Stop Clearances. CARBODY PIVOT ASSEMBLY Vertical stop wear that is close to the limit can be an indication of wear at the carbody pivot assembly Nylon wear ring and pin bushing halves. This can also indicate relaxation of the rubber compression spring assemblies. The condition of the wear ring and pin bushing halves should be checked whenever accessible and replaced if worn excessively or damaged.
7-10
GT46MAC LOCOMOTIVE SERVICE MANUAL
Figure 7-8 Carbody pivot pin and bushings. JOURNAL BEARINGS The GT46MAC locomotive is equipped with cartridge type grease lubricated journal bearings. These cartridge type bearings are self-contained, preassembled, pre-adjusted, pre-lubricated, and completely sealed. The bearings are applied and/or removed without exposing the bearing elements, seats, or lubricant to contamination or damage.
HTSC BOGIE 7-11
F29102
Figure 7-9 Journal Bearing (Partial exploded view). The bearing element assembly is pressed on the axle as a completely sealed unit. It is retained on the axle by one end cap, which in turn is secured to the axle by three cap screws and a locking plate. A journal bearing adapter is used to locate the bearing assembly within the truck/bogie frame. The bearing adapter uses a full bore housing which must be clean and free of any dust, dirt, metal chips, and foreign material which could otherwise interfere with the proper seating of the bearing within the adapter.
F43270
Figure 7-10 Journal Bearing Adapter Assembly. The adapter serves to position the journal springs between the truck/bogie frame and the axle to transmit the vertical loads. It also provides the means to position and control the axle laterally within the frame, as well as longitudinal control through the attached traction rod.
7-12
GT46MAC LOCOMOTIVE SERVICE MANUAL
0 Roller bearings should be given a visual inspection for the following; •
Signs of overheating
•
Excessive lubricant leakage
•
Broken, loose, or missing parts (such as loose cap screws, etc)
•
Loose or defective seals
•
Cracked or broken cups, end caps, or adapters, etc
If a seal can be removed with a suitable probe, the bearing must be removed from the axle for inspection and possible repair. Under normal operating conditions, running temperatures of approximately 56° C (100° F) may be expected. In this range simply placing a bare hand on the journal adapter can check the temperature. If the bare hand cannot be kept on the adapter for more than a few seconds, and if the bearing feels noticeably warmer than other bearings on the locomotive, the bearing should be checked further. This is accomplished by checking the outside face of the adapter with a temperature indicating crayon of 93° C (200° F) or with a direct reading pyrometer. If the bearing temperature is in excess of these figures, the bearing should be removed from service for closer examination. In the event that one or more bearing end plate retaining cap screws are found loose or missing, the wheel, gear, axle and journal adapter should be removed form the truck/bogie assembly. The bearing should then be removed from the axle and a full inspection made to determine the cause and possible damage. A small amount of bearing grease leakage around the seals may be expected during an initial run-in period. This leakage will eventually be reduced to a more normal "weeping". However, if a bearing appears to be leaking excessively, check for loose or damaged seals. Distorted, cracked, or damaged end caps should be replaced, and the damaged end caps should be scrapped. When locomotives equipped with cartridge type roller bearings are placed in storage, the hand brake should be set or the wheels should be chocked to prevent movement. It is not necessary to periodically move the locomotive to distribute the lubricant over the bearing surfaces as with older types.
HTSC BOGIE 7-13
AXLE LATERAL THRUST CLEARANCE Each journal bearing adapter assembly, when installed on the end of an axle in the truck/bogie assembly, has a bracket section (or lug) that is positioned in (engages) a spring pocket of the truck/bogie frame.
F43271
Figure 7-11 Journal bearing adapter spring and pocket. A rubber deflection pad is bolted to the bracket and a corresponding Nylon wear plate is mounted in the spring pocket
F43272
Figure 7-12 Axle lateral thrust clearance, wear plate and deflection pad shown. 7-14
GT46MAC LOCOMOTIVE SERVICE MANUAL
0 The renewable rubber deflection pads and Nylon wear plates provide for control of the axle lateral thrust clearance. Clearance limits between these lateral wear surfaces are such that in normal operation, the clearance will not exceed the maximum limits in the scheduled period between truck/bogie reconditioning. The maximum limits are 7.87 mm (0.31") per side on the middle axles and 4.75 mm (0.187") per side on the end axles. If the clearances are beyond the maximum limits at any time, the wear plates and deflection must be replaced. If wear plates are to be reused, they must be given a visual inspection for possible cracks or excessive wear. The clearance between the deflection pads and Nylon wear plates can be measured using feeler gauges. These feeler gauges should be approximately 25.4 mm (1.00") wide and 305 mm (12.00") long. When using these feeler gauges, make sure that they are inserted adequately into the clearance at the wearing area, so that as true a reading as possible is obtained.
NOTE No attempt should be made to shift the journal bearings from the position they are in when the locomotive is stopped, and the weight of the locomotive is supported by the bearings.
HELICAL COIL SPRINGS Locomotive truck/bogie frame to axle journal primary suspension is provided by steel helical coil springs. Single coils are used that provide for large amounts of deflection. This assists in wheel load equalization, and improves ride quality over rough sections of track. It also aids in allowing yaw movement of the traction motor/axle wheel assemblies within the truck/bogie. Helical coil springs are specifically designed for various weight ranges, and provide the optimum suspension system for each range of locomotive weights. Periodically the coil springs should be thoroughly inspected for signs of fatigue or degradation, as follows; Inspect the coils for breaks or surface cracks. Springs with any indication of surface cracks should be scrapped. Check for any surface nicks. Deep sharp surface nicks can cause failure of a spring and their presence should be cause for rejection. Hand wash or shot blast the coil to remove any surface rust. "Pickling" of the spring is to be avoided. If the cleaning operation removes all indication of surface rust, and does not reveal any corrosion pitting, the spring is acceptable for requalification. If any corrosion pitting is visible after cleaning, scrap the affected coil. Smooth any worn spots on the coil, which were caused by rubbing. Do not condemn a coil for these. However it must still pass the other qualification criteria.
HTSC BOGIE 7-15
COIL SPRING SEATS In order to secure the coil springs on the journal spring adapters, spring pilot tubes are used along with pilot wear plates between the springs and the adapter. Spring pilot pins and shims are also located in the truck/bogie frame spring pockets to perform the same function.
Figure 7-13 Spring Pilot Tubes And Pins. The pilot plates and shims are chosen to maintain the 434.8-mm (17.12") installed spring length. These, along with the shims used between the underframe and the rubber compression secondary springs, serve to maintain the proper locomotive height for clearance from the rail to the underframe. As well, this will maintain the proper coupler height and distribute equal axle loads.
WHEEL AND AXLE INSPECTION Wheels should be inspected for any visible defects before and/or after each trip. Wheels are periodically checked for wear, sharp flanges, shelling, cracks, and flat spots to see that they are within limits. Use the following guidelines when determining wheel and axle condition; • Minimum wheel diameter after last truing operation. • Maximum diameter mismatch of two wheels on a common axle. • Maximum diameter mismatch between wheels on one axle compared to those of any other axle. This includes wheels on the same truck/bogie as well as wheels on whole locomotive. • Minimum rim thickness, as specified by railroad or government regulation. • Axle longitudinal limits. • Circumferential defects on or below the axle surface. • Axle runout.
7-16
GT46MAC LOCOMOTIVE SERVICE MANUAL
SHOCK ABSORBERS The GT46MAC truck/bogie is equipped with vertical primary shock absorbers and lateral secondary shock absorbers for high-speed operation. Partial failure of locomotive shock absorbers is a comparative rarity. Normally, when one fails there is no resistance to movement in compression or rebound. A simple manual test will usually detect these failures. If a shock absorber is new or has not been used (in storage, for example) for some time, it must be cycled to obtain consistent motion before being checked for control. Resistance developed during testing is proportional to the velocity of the test stroke. In other words, the harder and faster the shock is cycled, the more it will resist movement. Shock absorbers contain a reserve of hydraulic oil, and allow seepage to lubricate the shock's piston rod. A light film of oil is normal and is not a cause for rejection. However, as the remaining oil in the shock cannot be ascertained, any heavy leakage is cause for replacement of the shock. Periodic inspection and maintenance of shock absorbers is required. Use the following easily performed Periodic Checks and Manual Qualification procedures. Perform the following at wheel truing or when loss of damping action is suspected;
PERIODIC CHECKS Check for leaking fluid. Make sure that oil has not been deposited from some other source. Check the shock absorber per the Manual Qualification procedures before condemning. Inspect bushing integrity. Bushings should not permit gross vertical or lateral movements of the shock absorber.
NOTE If a failed vertical primary shock absorber is detected, inspect the journal springs, lateral thrust pads, and wear plates at each journal bearing adapter. If a failed lateral secondary shock absorber is detected, check the same items as noted for a failed vertical primary shock absorber, as well as the carbody pivot assembly and rod assembly bearings and bushings. In addition, check the four rubber secondary spring assemblies.
HTSC BOGIE 7-17
MANUAL QUALIFICATION PROCEDURES
NOTE Shocks, which are found to be reusable, should never be disassembled using a flame-cutting device. The high temperatures will damage the bushings. GO/NO GO TEST: This is a quick and easy test that can be performed without completely removing the shock absorber from the locomotive. One end of the shock absorber is unbolted and the shock is cycled manually. If there is resistance to the force applied in both compression and rebound, the shock absorber is acceptable. If control is gone in either direction, replace the shock with a new or qualified shock absorber. If there is any indication of internal looseness, replace the shock regardless of control condition.
NOTE .Vertical shock absorbers must be tested in the normal vertical position. Precautions must be taken to avoid damaging the shock absorber bushings during the testing or during wheel maintenance (whenever the shocks are partially disconnected or removed). For standard bolt mount shock absorbers, the upper mounting bolts must be loosened before the shock is tilted away from the journal bearing adapter bracket. Tilting the shock without providing enough free movement by loosening will result in damage to the bushing. Shocks using bar mounting or Huck bolt fasteners must not be tilted or rotated under any circ*mstances. If necessary, the entire shock absorber should be removed during testing or maintenance. Use the following steps to qualify vertical (primary) shock absorbers; Unbolt the shock absorber from the journal bearing adapter bracket. Loosen the upper mounting bolt. Manually stroke the shock absorber while retaining the normal vertical position. Renew the shock absorber as required. If the shock tests acceptably, reapply the mounting bolts and torque to 366 Nm (270 ft-lbs.). Lateral shock absorbers are used to provide stability during higher speed locomotive operation. The shock absorbers are similar in appearance to vertical shock absorbers, however they are not interchangeable.
NOTE Each lateral or vertical shock absorber has a label mark "L" or "V". This further identifies them for lateral or vertical operation. Vertical and lateral shock absorbers also differ significantly in size. Use the following steps to qualify lateral (secondary) shock absorbers; Disconnect the outer end of the shock assembly only. 7-18
GT46MAC LOCOMOTIVE SERVICE MANUAL
0 Manually stroke or cycle the shock absorber. The same qualification conditions apply as with vertical shock absorbers. Replace the lateral shock as required. Torque the mounting bolts to 366 Nm (270 ft-lbs.). Inspect the lateral shock absorber mounting brackets on the underframe for fatigue cracks at the welds. If any cracks are present, rework the brackets to a full 13-mm (0.50") weld as specified for this application.
MANUAL COMPARISON TEST A wall-mounted fixture has been designed to test and compare used shock absorbers with new shock absorbers of the same type. A torque wrench is used with the fixture. Work Sketch # 41089 is available upon request from any EMD regional office. A shock absorber tested in this fixture can be reused if the torque reading at the same stroke velocity is 75% of the reading for a new shock absorber.
BRAKE RIGGING Inspect the brake rigging to ensure that the brake pins, bushings, levers, and brake shoes are reusable. The wear surfaces of the brake rigging are equipped with replaceable hardened bushings, pins, and bolts. Any of these connecting parts that are worn more than 1.6 mm (0.06") from new should have both parts replaced. Never use an old pin with a new bushing or the reverse. Cylinder levers and brake levers that are slightly bent can be reused, provided that they are restored to their original shape without damage. Bolts and nuts that are not subject to wear can be reused if they are not damaged, but cotter pins should always be replaced with new. To adjust pin type slack adjusters, unlock the pin retaining lever and remove the pin. Move the rod assembly in or out until the brake shoes clear the wheels by at least 15.9 mm (0.62") with single wheel slack adjusters, and between 19.1 mm (0.75"0 to 31.8 mm (1.25") total clearance for two wheel slack adjusters. Align the pinholes in the rod and tube or bracket assemblies and reinstall the pin. Turn the pin retaining lever to the locked position. Brake cylinder piston travel should be set between a minimum of 50.8-mm (2.00") to a maximum of 165.1 mm (6.50").
HTSC BOGIE 7-19
FTR43222
Figure 7-14 Brake slack adjusters.
BRAKE SHOE GUIDES Brake shoe guides are provided on the underside of the truck/bogie frame at each brake lever location. Each brake lever is equipped with a steel stabilizing bar. A 19.04-mm (0.75") steel wear plate is attached to each brake lever, which mates to the steel stabilizing bar. Each live brake lever uses a guide bracket that straddles the stabilizing bar to maintain brake shoe to wheel alignment. A "U" shaped bracket that straddles the lever pivot bracket near the top of the truck/bogie frame affords the same function. The stabilizing bars are bolted to brackets under the truck/bogie frame. The wear plates should be replaced when the thickness is half of the original thickness, or 9.52-mm (0.375"). Transverse alignment of the stabilizing bars should be checked periodically and maintained as per original measurements.
7-20
GT46MAC LOCOMOTIVE SERVICE MANUAL
fTR43223
Figure 7-15 Brake Shoe Guides.
HTSC BOGIE 7-21
TRACTION MOTORS The GT46MAC truck/bogie is equipped with three alternating current (AC) traction motors.
FTR43216
Figure 7-16 AC traction motor.
7-22
GT46MAC LOCOMOTIVE SERVICE MANUAL
0 Each traction motor is hung on an axle-wheel set. The power from the traction motor is directly transmitted to the axle-wheel set through a pinion and axle (bull) gear assembly. A gear case protects the pinion and axle gears from contaminants and contains the gear lubricant.
FTR43217
Figure 7-17 Typical axle-wheel set.
HTSC BOGIE 7-23
GEAR CASES The gear case is mounted to the traction motor, thereby becoming an integral part of the traction motor assembly.
FTR43218
Figure 7-18 Gear Case Assembly. The case is made up of two close fitting halves with seals to provide a complete oil tight enclosure. The lower half of the gear case is equipped with access plugs or caps to fill and/or drain the lubricant. When a gear case is removed from the traction motor/axle-wheelset assembly, the case should be thoroughly cleaned and the old seals or sealing material removed completely and discarded. Seal retainers and all parting lines should be free of dirt, gasket sealing compound, or any foreign material. Always visually inspect the case halves for damage such as cracks, perforations, or deformities. Reapply gear case halves using new seals and/or sealing compound.
7-24
GT46MAC LOCOMOTIVE SERVICE MANUAL
GEAR CASE MOUNTING PROCEDURE 1) Prepare gear cases for application by thoroughly cleaning interior and exterior of all foreign material such as dirt, oil, or old sealing material. Ensure that all traces of oil have been removed from all gear case sealing surfaces and mating motor seals. 2) Install breather pipe (if removed) into top case half, using Loc-tite thread sealing compound. Install filter and vent cap to breather pipe. 3) Wipe all seal surfaces on the gear case halves and the motor/axle assembly with a lint free cloth to remove any oil residue. Apply three continuous ¼" diameter beads of RTV sealant to the motor and axle assembly adjacent to the seal tongues. 4) Apply ¼" diameter sealant beads at each of the half bores in both the top and bottom case halves. Note that these beads are always applied outboard of the tongue or groove. 5) Apply a 1/8" diameter bead of sealant on either the upper or lower case parting line flange segment. Form the beads continuously and surround each hole with a ring of sealant. 6) Install lower case half to motor and apply hand tight two 1-1/8-7 bolts and washers with Thread-Tex. Install upper half onto motor and apply 3/8-16 parting line bolts. 7) Torque parting line bolts to 35 ft/lbs. Torque 1-1/8-7 bolts to 990 ft/lbs. 8) Place motor assembly in normal operating position. Ensure drain plug is secure. Add lubricating oil through fill plug on side of lower case half. Fill to level inside elbow. 9) Verify gearcase lubricating oil level when motor/axle assembly is applied to locomotive.
HTSC BOGIE 7-25
TRACTION MOTOR REMOVAL Whenever a traction motor-wheelset assembly needs to be removed, the following basic procedures should be used: Support the weight of the traction motor-wheelset assembly with an appropriate hydraulic jack or lifting device. Disconnect the nose link rod (dogbone) from the traction motor at the lower connection. If Huck bolts were used in the original assembly, they will have to be cut off using a cutting torch (burned off), or Huck collar splitter.
CAUTION Use care when removing any Huck bolts with a torch in order to avoid damage to the surrounding truck/bogie frame, linkages, and bushings.
F43282
Figure 7-19 Traction Motor Nose Link and Huck Bolt Assembly Remove the retainer bar from the bottom of the journal bearing adapter. Disconnect all electrical cables and any other hardware attached to the motorwheelset or truck/bogie frame that could interfere with the removal. This includes, but is not limited to, the wheel flange lubrication nozzles and the sanding nozzles. Undo the brake slack adjusters and back the brake shoes away from the wheels. In some instances, complete removal of the brake shoes may be required. Secure all cables and hardware in a manner, which places them safely out of the way of the removal process. Pull the nose link (dogbone) away from the traction motor-wheelset assembly. 7-26
GT46MAC LOCOMOTIVE SERVICE MANUAL
0 Lift the locomotive or lower the drop table, rolling the traction motor in a manner that will disengage the motor assembly from the truck/bogie frame limit stops. Move the motor-wheelset out from beneath the locomotive.
NOTE If new Huck bolts are not available for reassembly of the nose link, they may be replaced by 38.1 mm (1.5") diameter bolts torqued to 814 Nm (600 ft-lbs.). Replace the traction motor-wheelset under the locomotive. Reconnect all hardware and lower the locomotive or raise the drop table. Readjust the brake slack adjusters.
TRUCK/BOGIE REMOVAL The truck/bogie assemblies may be removed from the locomotive by using an overhead crane or jacks to raise the locomotive. Alternatively, a drop table of sufficient capacity to handle one entire truck/bogie assembly may be for removal. The bogie safety links must be removed before any attempt can be made to separate a truck/bogie assembly from the locomotive underframe. Two of the safety links are bolted to the underframe and the truck/bogie immediately above the center axle position on either side of the locomotive. Unbolt and remove the pivot pin lock plate and wear ring. Remove all other physical connections between the truck/bogie and the underframe; including the air brake connections, the handbrake chain, sanding hoses and flange lube system connections, cables from the traction motors, and any speed recorder or axle generator connections. Secure all cables, hoses, and all other hardware in a manner, which places them safely out of the way during the truck/bogie removal. Unbolt and remove the two lateral shock absorbers attached between the truck/bogie and the underframe. Their removal is suggested in order to prevent damage to the end bushings or hydraulic mechanisms. This could occur if the shock absorbers were left hanging with one end unsupported.
NOTE When lifting or jacking a locomotive to remove one or both truck/bogie assemblies, all four corners of the unit should be raised equally to a height which will permit end removal (roll out) of the complete truck/bogie assembly. The locomotive should be supported on solid blocking located under the center sills near the jacking pads, if it is to held in a raised position for any length of time. Reinstallation of the truck/bogie assembly is simply reversal of the removal process.
HTSC BOGIE 7-27
TR42792
Figure 7-20 Safety Link Location.
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GT46MAC LOCOMOTIVE SERVICE MANUAL
F43273
Figure 7-21 Carbody Pivot Pin
F43274
Figure 7-22 Pivot Pin and Socket
HTSC BOGIE 7-29
WHEEL FLANGE LUBRICATING SYSTEM INTRODUCTION TO FLANGE LUBE SYSTEM Rail lubrication systems are designed to reduce friction between the locomotive’s wheel flanges and the rails by applying a controlled amount of lubricant to the “throat” area of selected wheels during locomotive operation under conditions appropriate for its use. The GT46MAC units #11001 to 11013 are equipped with a TSM rail lubrication system entirely controlled by the locomotive computer EM2000. This system uses a grease/oil type lubricant - propelled, and atomized by the locomotive’s compressed air system.
SYSTEM OPERATION The TSM rail lubrication system consists of 3 major components 1. A reservoir (tank), located in the rear (long hood) end of the locomotive, contains the lubricant supply. The TSM system utilizes a lubricant reservoir which is pressurized by air from the main reservoir. 2. Lubricant spray nozzles (2) are mounted adjacent to (and aimed at) the flange “throat” area of the appropriate wheels. Locomotive compressed air is used to operate (trigger) the nozzles on the systems, and is used as a lubricant propellant (atomizer). 3. Metering valves and solenoid(s) are used on the system to control the flow of air and lubricant to the nozzles upon receiving electrical signals from the EM2000. Each shot of air through the lube valves to the nozzles allows a predetermined amount of lubricant to shot at the wheel flange. The rail lubrication system is now being controlled by the EM2000, thus eliminating the need and cost of a TSM system controller box. The electrical components of the system are MV-PUMP, MV N0ZF and MV N0ZR. The computer controls these magnet valve using DIO3 output channels 11, 12 and 13. EM2000 will turn on the appropriate output channels RLN0Z 1 (Rail Nozzle Forward) or RLN0Z2 (Rail Nozzle Reverse) every 0.2 seconds every 122 meters (400 feet) if locomotive speed is above 8.1Km/h (5 M.p.h.) and there is no brake application or sand application. To pressurize the lubricant, the computer turns on the output channel (RL PUMP) every10 nozzle spray “shots” so that main reservoir air pressurizes the lubricant. A system self test can be performed using EM2000 display - Select SELF-TEST on the main menu, then flange lube selftest. Follow the instructions shown on the display.
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NOTE Flange Lubrication is provided during power operation only. EM2000 turns off the system while in braking or super series operation. To fire the nozzles at the proper times and rates, and to stop the nozzles from firing at inappropriate times, the computer receives and processes the following information : •
• •
A directional (reverser) signal is needed to determine the direction of travel (forward or reverse), AND; A speed signal is needed to determine the firing rate, AND; Inhibit signals are needed to stop (interrupt) the system when application of lubricant would be inappropriate.
The inhibit signals are: -Brake cylinder pressure is higher than 138 Kpa (20psi) -Main reservoir pressure is lower than 69 Kpa (10psi) -Wheel creep operation -Sanding Operation -Dynamic braking operation -Locomotive speed under 8.1Km/h (5 MPH)
HTSC BOGIE 7-31
MAINTENANCE REFILLING RAIL LUBRICATION SYSTEM The TSM rail lube system supply reservoir (tank), may be refilled (recharged) as follows: 1. Turn handles of the ball valves (cutout co*cks) at the air control panel (2) and at the lube outlet assembly on the tank (1) to the OFF (closed) position (handles perpendicular to the lines). 2. Remove dust caps from the quick disconnect fittings on the lube tank (one near the top and the other at the lube outlet assembly at the bottom). 3. Connect vent hose (with 3/8" quick disconnect fitting) to the quick disconnect fitting at the top of the tank. Open small vent on top of the lubricant drum and run the 3/8" vent hose from the tank to the drum. 4. Connect pump hose (with 1/2" quick disconnect fitting) to the quick disconnect fitting on the lube outlet assembly at the bottom of the tank.
CAUTION Relieve pressure in the lubricant supply hose before connecting it to the quick disconnect fitting on the tank. Air supply pressure to the lube supply pump must be limited to keep the pump OUTLET pressure below 1 379 kPa (200 psig). 5. Start and run the lube pump. 6. When the lubricant begins to come out of the vent hose from the tank to the drum, stop the pump.
CAUTION Relieve the pressure from the lubricant supply hose before disconnecting it from the quick disconnect fitting on the tank. 7. Disconnect the lubricant supply hose. 8. Disconnect the vent hose from the tank and from the drum. 9. Replace the dust caps on the quick disconnect fittings at the top of the tank and at the lube outlet at the bottom. 10. Turn handles of the ball valves (cutout co*cks) at the air control panel (2) and at the lube outlet assembly (1) to the ON (open) position (handles parallel to the lines).
QUALIFYING RAIL LUBRICATION SYSTEM Electro-Motive recommends qualifying a rail lubrication system at intervals stipulated in the Scheduled Maintenance Program or whenever system malfunctioning is suspected.
CAUTION Do NOT high potential (hi-pot) or continuity test TSM system electrical components with a test light as equipment damage could result. Use meter only for all electrical tests. Refer to for electrical qualification procedures.
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GT46MAC LOCOMOTIVE SERVICE MANUAL
QUALIFICATION TEST PREPARATIONS : NOTE: Start locomotive as described in Engine Starting section.
1. Apply locomotive handbrake. 2. Assure that there is an adequate supply of lubricant in the lubricant reservoir (tank). (Refer to See “REFILLING RAIL LUBRICATION SYSTEM” on page 32. for refilling procedures.) 3. Release the air brakes, and assure that no penalty application exists. 4. Close battery knife switch and computer control circuit breaker. 5. Check to be certain the WHEEL FLANGE LUBE circuit breaker on the main circuit breaker panel is in the ON (up) position.
6. Place throttle/ dynamic brake handle in the IDLE position. NOTE The engine does not have to be running to conduct these tests. However, if engine is running, be certain throttle is in the IDLE position. 7. Place directional (reverser) handle in the FORWARD position. 8. Check main reservoir air pressure which should be at least 689.5 kPa (100 psi) in order to conduct the test. 9. Check to be certain all hose connections are tight (air and lube). Tighten any loose connections before proceeding.
WARNING System air lines are pressurized at main reservoir pressure or 689.5 to 1 034 kPa (100 to 150 psi) and lubricant lines at 124 to 138 kPa (18 to 20 psi). Tests run with any loose hose connections can result in injury to personnel. 10. Open ball valve (cutout co*ck) in air supply line to air control panel (handle parallel to line). 11. Open air distribution ball valve (cutout co*ck) on air control panel (handle parallel to line). 12. Assure that lube tank pressure on control panel gauge is in the range of 110 to 138 kPa (16 to 20 psi). If the pressure is above or below this range, check pressure regulator setting on the air control panel and readjust as necessary. (Tank is filled with lubricant - before it is pressurized with air. 13. Open ball valve (cutout co*ck) on lube outlet assembly at base of lubricant reservoir (tank). Handle should be parallel with lube pipe when open.
NOTE Do NOT disconnect the lube hoses or pipes in order to purge air from the lube distribution system. Disconnecting the lines may cause intermittent or faulty operation of the system due to changes in back pressure to the meter valve. Repeated actuation of the Wheel Flange Lube Test on the display unit may be used to purge the lubricant distribution lines, if necessary.
HTSC BOGIE 7-33
Flange Lube Priming /Test: In order to be able to prime or test the wheel flange lubrication system, a display driven self-test feature is provided. From the display self test menu select “FLANGE LUBE’. The entry conditions to the test are: The locomotive is not moving and the reverser handle is not centered. Once the conditions are fulfilled and the start command is activated the following events occur. A. A time delay of 20 seconds permit the operator to exit the locomotive to observe nozzle operation. B. The appropriate nozzle output channel is operated for 10 cycles with an “ON” time of 0.2 seconds and an “OFF” time of 1.0 seconds C. If appropriate, the RL PUMP output channel will be energized for 0.4 seconds by the computer. Testing of the opposite direction wheel flange lubrication is done by changing reverser handle position and operating the test from the display a second time.
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LU33741
Figure 7-23 TSM System Rail Lube Tank & Components (Schematic Diagram)
HTSC BOGIE 7-35
CP32979 at 5i
Figure 7-24 Desired Lubricant Pattern To test the nozzle functions, perform the following: Note: The EM2000 display provides a flange lube self test which is helpful for verifying functionality and proper aiming of nozzles 1. Wipe the wheels clean in the area of the nozzles, then start the selftest on the EM2000. System should cycle 8 to 10 times, spraying lubricant on the wheels. 2. Observe the location of the lubricant on the wheel(s), which should be at the “throat” of the flange, as shown in Figure 7-24. 3. If the lubricant pattern is not correct, re-aim the nozzle(s) in accordance with Figure 7-25, “Typical Nozzle Aim Adjustment” on page 7-37 and the following instructions: 4. Wipe the lubricant from the wheels and nozzles. 5. Loosen all of the adjusting bolts. 6. Place the aim gauge in the flange throat as shown. 7. Slide the bracket snugly up against the aim gauge and tighten all of the adjusting bolts.
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GT46MAC LOCOMOTIVE SERVICE MANUAL
CP32980 at 5i
Figure 7-25 Typical Nozzle Aim Adjustment
HTSC BOGIE 7-37
SERVICE DATA - HTSC BOGIE ROUTINE MAINTENANCE EQUIPMENT DESCRIPTION Lifting fixture traction motor, axle and wheel assembly File Drawing No. 288* Wall mounted fixture to test shock absorbers Work Sketch No.41089*
NOTE File drawings and work sketches are available from the EMD Service Department. These drawings include construction details of tooling that can be manufactured. *NOTE: File drawings and work sketches are available from the EMD Service Department. These drawings include construction details of tooling that can be manufactured.
PART NUMBERS For part numbers for all components referenced in this section, see the appropriate EMD parts manual.
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GT46MAC LOCOMOTIVE SERVICE MANUAL
SECTION 8. ELECTRICAL EQUIPMENT INTRODUCTION This section describes electrical equipment used on GT46MAC locomotives. Changes to the locomotive that occur after this manual is printed may be covered in later editions or revisions. This section is organized, in a general way, according to power generation and distribution through the locomotive. The equipment is presented with an initial emphasis on larger (major) assemblies. Moving through the section, larger assemblies are broken down into smaller assemblies or devices, and the focus on operation becomes more specific. Electrical cabinets are listed by location, starting from the front of the locomotive. Refer to Figure 8-1, and Figure 0-1, Figure 0-2 and Figure 0-3 in the General Information section at the beginning of this manual.
ELECTRICAL EQUIPMENT 8-1
Figure 8-1 Location of Major Electrical Assemblies
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GT46MAC Locomotive Service Manual
1) Air Brake Rack 2) Engineers Control Console 3) Cab Door 4) Traction Control Cabinets 5) Inertial Air Filters 6) TCC Electronics Blower\ 7) Engine Air Filter
8) Radiators 9) Engine 10) AC Auxiliary Generator 11) Inertial Filter Dust Bin Blower and Motor 12) Electrical Control Cabinet 13) Cab Seat
MAIN GENERATOR A diesel electric locomotive uses a main generator to convert the mechanical power developed by the diesel engine into electrical power. This main generator, Figure 8-2, is a three phase alternator equipped with two independent and interwoven sets of stator windings and a rotating field common to the windings.
NOTE In order to provide a higher main generator output voltage, both halves of the generator are permanently connected in series.
Figure 8-2 TA-17/CA6B Main Generator The output from the series connected windings is supplied to two air cooled rectifier assemblies in an airbox that is an integral part of the main generator. The rectifier assemblies consist of high current, high voltage silicon diodes in threephase, full wave rectifier circuits. The circuits have delta connected resistors and capacitors for suppression of commutation transients, and are provided with fuses for automatic isolation of failed diodes. Each fuse has a spring loaded indicator that protrudes when a diode failure causes the fuse to blow. Windows for fuse inspection are located in the airbox. The main generator is an assembly made up of the main generating device and its excitation source; the companion alternator. These air cooled, 3-phase, electrically independent generators are mechanically coupled on the same shaft. The companion alternator will be discussed later in this section and the major components of the main generator are shown in Figure 8-4 on page 8-5.
ELECTRICAL EQUIPMENT 8-3
The main generator consists of 10 field poles and the required stator windings for generating three phase AC power. The AC power is rectified by two banks of air cooled silicon diodes that are an integral part of the TA-17-CA6B main generator assembly. The resulting DC power is applied to the DC link circuit.
Figure 8-3 Locomotive Power Distribution Diagram
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GT46MAC Locomotive Service Manual
F17533 F21452 F20824
Figure 8-4 Main Generator Assemblies: Rotor, Stator, Rectifier Banks.
The operating principle of the TA-17-CA6B main generator is illustrated in Figure 8-2. Direct current from silicon controlled rectifier assembly SCR is applied to the rotating field through a pair of slip rings. The magnetic lines of force developed by the rotating field induce voltage in the stationary stator windings as the rotor turns.
EE30831
Figure 8-5 Main Generator Pictorial Diagram
ELECTRICAL EQUIPMENT 8-5
One three phase group of armature windings and a three phase waveform are shown in Figure 8-5. There are ten groups of these “wye” connected armature windings distributed around the circumference of the stator. Five of the groups are connected to the left bank of rectifiers and the other fivegroups are connected to the right bank of rectifiers .
EE37954
Figure 8-6 Main Generator Physical Schematic (Viewed Facing Slip Ring End) 8-6
GT46MAC Locomotive Service Manual
0 A separate positive and negative bus is provided for each bank of rectifiers. A simplified schematic diagram of the stator windings, bridge rectifiers, and DC buses is provided in Figure 8-7
EE37955
Figure 8-7 Main Generator Electrical Schematic ELECTRICAL EQUIPMENT 8-7
Figure 8-8 illustrates rotor pole position at an instant called “V”. Pole position is with respect to a single stator winding group. By applying the right-hand rule for generators, current flow in the stator windings can be determined, and conditions existing at a given point of time determined. Note that the phase A winding is centered over the poles (point of greatest flux density) and is at negative potential. Note also that the potential at phase C is decreasing while the potential at phase B is increasing. At the moment depicted, the potentials at C and B are equal and positive. Therefore, current at equal potential flows to the rectifier bridge, and two diodes at the positive side of the bridge conduct. Total current then flows through the load and from there through a single diode back to the phase A winding, which is at negative potential.Generator potential can also be observed at the waveform in Figure 8-8.
EC35560
Figure 8-8 Main Generator Current Flow At Instant V 8-8
GT46MAC Locomotive Service Manual
0 At instant “W”, Figure 8-9, the alternator rotor has turned nominally 20 electrical degrees. Phase A is still negative, but of decreasing potential. Phase B is now more positive than phase C. The change in potential has turned off the phase C diode, and no current flows in the phase C winding. Total current at potential slightly greater than that at instant “V” now flows out of phase B winding, through the load and back to the phase A winding which is still negative.
EE30834
Figure 8-9 Main Generator Current Flow At Instant W
ELECTRICAL EQUIPMENT 8-9
At instant “X” in Figure 8-10, the alternator rotor has turned about 60 electrical degrees. Phase C and Phase A are at equal negative potential, and phase B is at positive potential. The direction of current flow in the C winding has reversed, and since potentials at the negative side of the rectifier bridge are equal, both the phase A and phase C diodes conduct. Total winding current at potential equal to that at instant “V” now flows out of phase B winding through the load and back through two diodes at the negative side of the rectifier bridge.
EE30835
Figure 8-10 Main Generator Current Flow At Instant X
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GT46MAC Locomotive Service Manual
0 At instant “Y” Figure 8-11 the alternator rotor has turned about 100 electrical degrees. Phase C is now more negative than phase A. The change in potential has turned off the phase A diode at the negative side of the bridge, and no current flows in the phase A winding. Total current at potential slightly greater than that at instant “V” now flows out of phase B winding, through the load, and back to phase C winding which is negative.
Figure 8-11 Main Generator Current Flow At Instant Y
ELECTRICAL EQUIPMENT 8-11
In Figure 8-12, the alternator rotor has turned 120 degrees. Phases A and B are at equal positive potential, and phase C is negative. Since potentials at the positive side of the rectifier bridge are equal, both the phase A and B diodes conduct. Total winding current at potential equal to that at instant “V” now flows out of the phase A and B windings, through the load, and back through the phase C diode at the negative side of the bridge.
EE30837
Figure 8-12 Main Generator Current Flow At Instant Z
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GT46MAC Locomotive Service Manual
COMMUTATION TRANSIENT VOLTAGE SUPPRESSION During commutation voltage transients are produced. The action of diodes switching from a conducting to a blocking state in the TA-17-CA6B generator is called commutation. During commutation high reverse current flows in the diodes for a few microseconds, after which time the value of reverse current flow in the diode suddenly drops to almost zero. The rate at which current flow changes from a high value to almost zero, multiplied by circuit inductance determines the magnitude of the transient voltage spike. If this transient voltage exceeds the reverse rating of the diode, the diode will immediately fail. The TA-17-CA6B generator is provided with a system for capacitive storage of energy from circuit inductance during commutation. The system is called the commutation transient voltage suppression system. It utilizes a total of six 2 microfarad capacitors and six 5 ohm resistors. The resistors and capacitors are connected in delta fashion, Figure 8-13, between the “A,” “B,” and “C” phase paralleling bars on both left and right banks of the generator.
Figure 8-13 Delta Connected Suppression Circuit
ELECTRICAL EQUIPMENT 8-13
COMPANION ALTERNATOR The companion alternator is physically connected to but electrically independent of the traction alternator. The companion alternator rotor (rotating field) is excited by low voltage current from the auxiliary generator through a pair of slip rings adjacent to the slip rings for the main generator. The 3 phases AC output of the companion alternator comes from the stationary armature (stator). There are no controls in the companion alternator excitation circuit, thus it will be excited and developing power whenever the diesel engine is running. Output voltage will vary with speed of rotation, alternator temperature, and load. The companion alternator, Figure 8-14, is a variable frequency, variable voltage, three phase, wye connected AC generator with a rating of 250 KVA at 0.8 power factor. Nominal output is 230 volts at 120 cycles per second when the diesel engine is rotating at a speed of 900 RPM. The companion alternator/main generator rotating assembly is directly coupled to the crankshaft of the diesel engine The companion alternator provides power for the inertial filter blower motor, radiator blower motors, traction inverter blower motors, TCC electronics blower, excitation for the main generator, and for various control circuits.
F27969
Figure 8-14 Companion Alternator
The maximum output of the companion alternator is approximately 19 amperes for each ampere of field excitation. The auxiliary generator provides approximately 31 amperes of field excitation current to the companion alternator when the field is hot. The 31 amperes of field excitation current is determined by dividing the nominal output voltage of the auxiliary generator (74 volts) by the nominal hot resistance of the companion alternator field (2.40 ohms). The companion alternator can provide an output of approximately 600 amperes with the 31 amperes of field excitation.
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GT46MAC Locomotive Service Manual
AC AUXILIARY GENERATOR The AC auxiliary generator, Figure 8-15, consists of a three-phase pilot exciter assembly and a three-phase AC auxiliary generator field and armature assembly.
Figure 8-15 Auxiliary Generator
The nominal output rating of the AC auxiliary generator is 18 kW at 55 VAC. The three-phase 55 VAC output is used to power the 2 GTO power supplies and the computer panel mounted module FCD (Firing Control Driver) and is also applied to a full-wave three-phase rectifier assembly to obtain 74 VDC output for battery charging, companion alternator excitation, and low voltage DC control power. The three-phase pilot exciter assembly consists of a stationary field, a rotating armature, and a rotating rectifier assembly. The AC auxiliary generator has a rotating field and a stationary armature. The pilot exciter rotating armature and rotating rectifier assembly and the AC auxiliary generator rotating field are installed on a common shaft. During start up, residual magnetism of the pilot exciter stationary field induces voltage in the pilot exciter rotating armature. This AC voltage is rectified by the pilot exciter rotating rectifier assembly and applied to the AC auxiliary generator rotating field. This rotating field induces voltage in the AC auxiliary generator stationary armature. The small AC output voltage of the auxiliary generator is applied to the DVR (Digital Voltage Regulator Module). This low AC signal is used by DVR to determine if the Aux. Generator does turn. If it does, DVR will allow current from the batteries to flow in the exciter field of the Aux. Generator in order to produce the 3 phases 55 VAC output required. A description of the DVR (Digital Voltage Regulator Module) is provided in Section 9.
ELECTRICAL EQUIPMENT 8-15
Figure 8-16 Auxiliary Generator Cross Section
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GT46MAC Locomotive Service Manual
C1-8: DC LINK INVERTER INPUT CAPACITORS These eight capacitors are used to filter the DC link voltage before it is applied to the traction inverters. The TCC cabinet, Figure 8-17, contains eight (8) 550 microfarad capacitors totalling 4400 microfarads, rated at a nominal 2600 VDC.
F73276
Figure 8-17 DC Link Capacitors
ELECTRICAL EQUIPMENT 8-17
DCL123, DCL456: DC LINK SWITCHGEAR These motor driven not-ganged switches separately connect the DC link to the two traction inverters. Refer to Figure 8-18
F43277
Figure 8-18 DC Link Switchgear
TRACTION MOTORS Electrical power from the inverters is distributed to traction motors mounted in the trucks. Each motor, Figure 8-19, is geared to a pair of wheels with the gear ratio (90:17) selected for the intended service.
F32793
Figure 8-19 AC Traction Motor
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GT46MAC Locomotive Service Manual
The motors are cooled by means of an external blower attached to the Auxiliary Generator and directly driven by the diesel engine. 3 phase AC motors for traction provide the high starting torque required for locomotive service. Each traction motor is equipped with a TM armature speed probe and a TM stator temperature probe. Both probes give feedback information to TCC computers. Refer to Section 9 for AC motor operation.
NOTE Motor direction is changed by reversing the phase rotation (two phases) of the 3 phase AC input voltage. In dynamic braking, the traction motor energy is converted back into DC by the traction inverters (TCC1,TCC2) and applied to the DC link. The energy in the DC link is then applied to the brake grids (resistors). The maximum continuous tractive effort rating of the traction motors is applicable only when operating at throttle No. 8 engine speed. This rating decreases as engine speed and cooling air is decreased.
RADIATOR COOLING FAN MOTORS These motors, Figure 8-20, are of the inverted squirrel cage induction type and are an integral part of the cooling fan assembly. The term “inverted” indicates that they differ from the conventional squirrel cage motor in that the rotor is located outside of the stator.
F15369
Figure 8-20 Radiator Fan Motor Two 52” cooling fans (8 blades), which operate independently, are located in the hood under the radiators and blow the cooling air upwards through the radiator cores. They are numbered 1, and 2, with the No. 1 fan being closest to the cab. For fuel efficiency, each cooling fan is driven by a two-speed AC motor, which in turn is powered by the companion alternator. As the engine coolant temperature rises, the fans are energized in sequence as determined by the computer control system. The cooling fans are powered through contactors which are controlled by the EM2000 program. The system is designed to maintain engine cooling water temperature between 79º C to 85º C (175º F to 185º F). Refer to Section 4 “Cooling System” for more detailed information. ELECTRICAL EQUIPMENT 8-19
DYNAMIC BRAKE GRID BLOWER ASSEMBLY Each dynamic brake grid cooling blower assembly, consists of a 48 inch, 10 blade fan powered by a series wound direct current motor. During dynamic braking the locomotive traction motors operate as generators supplying AC generated power to the traction inverters. The inverters convert the AC power into DC power which is applied back to the DC link for each grid paths (2). A portion of the electrical current from the traction motors is shunted around one of the resistor grids and used to power the grid blower motor (36 HP). Air driven by the grid blower drives grid heat to atmosphere.
F23903
Figure 8-21 Dynamic Brake Grid Blower motor
TURBO LUBE PUMP MOTOR The turbo lube pump motor, is a 3/4 Hp ,1200 RPM, 64 - 74 VDC motor assembly, coupled directly to a lubricating oil pump and mounted on the engine crankcase on the left side of the locomotive. At engine start-up the pump provides lubrication for the turbocharger bearings and at shutdown the computer (EM2000) continues pump operation to carry away residual heat from the turbocharger bearings.
FUEL PUMP MOTOR The fuel pump motor, is a 3/4 Hp ,1200 RPM, 64 - 74 VDC motor assembly directly coupled to the fuel pump. The fuel pump motor assembly is mounted on the equipment rack. During engine operation the pump supplies fuel oil for combustion and injector cooling. A bypass valve at the primary fuel filter protects the motor against overloading due to filter plugging.
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GT46MAC Locomotive Service Manual
STARTING MOTORS AND SOLENOIDS The starting motor solenoids, mounted on the starting motor housings, Figure 822, contains concentrically wound coils PU (pickup) and HOLD. When energized, by the pick-up of STA contactor the low resistance PU coil drives the starter motor pinion into place (engaged with the engine ring gear). The starting contactor (ST) then shorts out the PU coil and the high resistance HOLD coil has sufficient energy to hold the pinion engaged. When the cranking signal is removed, the starting contactors drop out and the starting motors pinions disengage from the engine ring gear. The diesel engine is equipped with two 64VDC motors (connected in parallel) for cranking. Power circuits to the motors are interlocked so that the pinions of both starting motors must be engaged with the engine ring gear before cranking power can be applied.
F14024
Figure 8-22 Engine Starting Motor
ELECTRICAL EQUIPMENT 8-21
CAB EQUIPMENT Most operating equipment is located on the engine control panel and the control consoles. The No. 1 control console is shown below. The No.1 control console (left side) faces forward. The No. 2 control console (right side) faces rearward. Most gauges, controls, indicator lights, and switches used by the locomotive operator during normal operation are located on both control consoles.
Figure 8-23 #1 Control Console CONTROL CONSOLES The majority of the locomotive operator control equipment is located on the following sections of the control consoles. Refer to Figure 8-23 and Figure 8-24 LEFT SIDE SWITCH PANEL CONTROL AND OPERATING SWITCH PANEL (#2 CONSOLE ONLY) CONSOLE DESKTOP FRONT INSTRUMENT PANEL 8-22
GT46MAC Locomotive Service Manual
F41967
Figure 8-24 #2 Control Console
LEFT SIDE SWITCH PANEL A switch panel,Figure 8-25, is located at the left lower section of both operator’s control consoles and contains the following devices:
Figure 8-25 Left Side Switch Panel ELECTRICAL EQUIPMENT 8-23
GAUGE LIGHTS Switch Gauge lights will be ON when the toggle switch is UP.
CONSOLE LIGHTS DIMMER Rheostat This dimmer rheostat is used to control the intensity of the gauge lights and the illuminated switches on the console.
ATTENDANT CALL Switch The attendant call push-button is used to sound the alarm bell in all units coupled in consist.
CAB LIGHTS Switch This switch is provided for cab area lighting, Lights are on when the toggle switch is in the UP position.
FLASHER LIGHTS Switches Two toggle switches control the short and long hood flashers units.
CAB FAN Switch Fans, are self contained units mounted in the cab room to provide air circulation. Each Fan is provided with an ON/OFF control switch.
CONTROL & OPERATING SWITCH PANEL (#2 Control Console only)
F41970
Figure 8-26 #2 Control Console and Operating Switch Panel
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GT46MAC Locomotive Service Manual
ENGINE RUN Switch This slide-button switch must be ON to obtain throttle control of engine speed. If the engine run switch is in the OFF position, the engine will run at idle speed regardless of the throttle handle position (except in self load test).
GENERATOR FIELD Switch The generator field slide-button switch must be ON to enable traction motor excitation. If the switch is in the OFF position, the main generator is still excited but the motors will not develop power.
NOTE AC traction technology uses the main generator to power the DC link rather than the traction motors directly. This difference alters the operating definition of the generator field that we are normally accustom too
CONTROL AND FUEL PUMP Switch The control and fuel pump slide-button switch provides power to the low voltage control circuits. The switch must be ON to start the engine and operate the electric fuel pump.
NOTE Engine Run, Generator Field and the Control and Fuel Pump operating switches in the center of the panel must be set in the ON position when the unit leads in a consist, and set in the OFF position if the unit is trailing or dead in a consist. The switches snap into the ON position when moved upward.
DYN BRK CONT CB Circuit Breaker This circuit breaker protects against a faulty operating or test setup. The circuit breaker should be in the ON (up) position for normal operation. A tripped circuit breaker generally indicates that, during dynamic brake testing, more than one dynamic brake handle in a consist was out of OFF position.
MU ENG STOP (Multiple Unit Engine Stop) Push-Button Switch This push-button switch is used to stop all engines in a consist. It is a PUSH ONPUSH OFF switch mounted on the right side of the number 2 control console above the control and operating switch panel. Pressing the red STOP section will shut down all units in a consist, providing that they are in RUN with throttles in IDLE position. During normal operation, or to restart engines, depress the black or green section identified as RUN. Refer to the Engine Starting and Stopping Section for detailed operation.
ELECTRICAL EQUIPMENT 8-25
CAUTION The locomotive controller on this locomotive model does NOT have a STOP position for the THROTTLE/DYNAMIC BRAKE handle and consequently no multiple unit (MU) engine stop function.
Figure 8-27 Consoles Desk Top Equipment DESK TOP EQUIPMENT LOCOMOTIVE CONTROLLER The locomotive controller, at the left side of the console top surface, Figure 828, has two operating handles which control three different functions. The handle to the left, called the DIRECTIONAL HANDLE or REVERSER, controls the direction in which the locomotive will move. The handle located on the right side, called the THROTTLE/DYNAMIC BRAKE, controls the throttle and dynamic brake responses.
DIRECTIONAL HANDLE The directional (reverser) handle, Figure 8-28, has three detent positions; NEUTRAL (centered), FORWARD, and REVERSE (backward).
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Figure 8-28 Directional (Reverser) Handle When the handle is moved forward toward the short hood end of the unit, circuits are set up for the locomotive to move in that direction. When the handle is moved backward toward the rear (long hood) end, the locomotive will move in that direction when power is applied. With the handle centered, mechanical interlocking prevents movement of the THROTTLE/ DYNAMIC BRAKE handle to a dynamic braking position, however, it can be moved to a throttle position. In such a case, power will not be applied to the traction motors. Note: Mechanical interlocking assures that the directional handle can be moved only when the THROTTLE/DYNAMIC BRAKE handle is in the IDLE position.
CONSISTS WITH DC UNITS Damage to traction motors in trailing DC units may occur if the directional handle is moved from forward to reverse or reverse to forward while the locomotive is in motion - the handle position should be changed only when the locomotive is completely stopped. The directional handle is centered and removed from the controller to lock the THROTTLE/DYNAMIC BRAKE handle in the IDLE position. Note: Directional handle must be removed when the locomotive is in trailing position.
THROTTLE/DYNAMIC BRAKE HANDLE The throttle/dynamic brake handle has two control areas or sectors labelled THROTTLE and DYNAMIC BRAKE divided by a gate. Refer to Figure 8-29. To move the handle from throttle to dynamic brake or from dynamic brake to throttle, the handle has to be passed through the gate, i.e., push handle to the right, then straight, then back to the left. An illuminated window to the right of the handle indicates the handle position.
ELECTRICAL EQUIPMENT 8-27
CONSISTS WITH DC UNITS During transfer from power operation to dynamic braking, the handle must be held in IDLE for 10 seconds before moving it to the SET-UP position to eliminate the possibility of a sudden surge of braking effort with possible train slack run-in or DC traction motor flash-over.
Throttle Sector : The throttle sector has nine detent positions; IDLE, and 1 through 8 power positions. From the IDLE position, against the gate, the handle is pulled backward to increase engine speed and locomotive power.
Figure 8-29 Throttle/Dynamic Brake Handle NOTE Mechanical interlocking assures that the handle can be moved from throttle IDLE position to a position in the dynamic brake sector only when the directional handle is positioned for either FORWARD or REVERSE operation.
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Dynamic Brake Sector: The dynamic brake sector has one detent position; SET-UP, and an operating range 1 through 8, through which the handle moves freely without “notching.” From the SET-UP position, against the gate, the handle is pushed forward to increase dynamic braking. MECHANICAL INTERLOCKS ON THE CONTROLLER :The handles on the
controller are interlocked so that: 1. With directional handle in NEUTRAL (centered) a. Throttle/Dynamic Brake handle can only be moved to a position in the throttle sector. b. Dynamic brake sector not accessible. c. Directional handle can be removed from controller if THROTTLE/DYNAMIC BRAKE handle is in IDLE position of the throttle sector. 2. With directional handle removed from controller a. Throttle/Dynamic Brake handle locked in IDLE position of the throttle sector. b. Dynamic brake sector not accessible. 3. With directional handle in FORWARD or REVERSE a. Throttle/Dynamic Brake handle can be moved to any position in the throttle or dynamic brake sectors. The design of the controller, however, is such that only one sector can be engaged at a time. b. Throttle/Dynamic Brake handle in dynamic brake sector, Directional handle is locked in either FORWARD or REVERSE. c. Throttle/Dynamic Brake handle in throttle sector, Directional handle is locked in either FORWARD or REVERSE. d. Throttle/Dynamic Brake handle in IDLE position of throttle sector, Directional handle can be moved to FORWARD or REVERSE position, or if centered in the NEUTRAL position, handle can be removed which will lock Throttle/Dynamic Brake handle in IDLE position.
HEADLIGHT SWITCHES In multiple unit consists the lead unit controls the headlights. Headlight control switches in trail units must be properly positioned. Two rotary switches provide independent control of the front and rear headlights HDLTS-Cab End and HDLTS L/H Ends. The switches have 4 positions: OFF, DIM, MED, and BRT positions.
ELECTRICAL EQUIPMENT 8-29
ALERTER RESET PUSHBUTTON The locomotive control computer EM2000 provides the vigilance function. When locomotive brakes are released, the system requests an acknowledgment from the locomotive operator from time to time. The acknowledgment request consists of : 1) Alerter light (located to the right of the front instrument panel) flashing for 17 seconds. 2) Alerter alarm (located on the engine control panel) sounds for 17 seconds. (Lights still flashing). Pressing the alerter alarm reset button, resets the acknowledgment request timing cycle. If the alerter system request is not acknowledged during the alarm cycle, the alarm stops sounding and a penalty brake application occurs.
MANUAL SANDING SWITCHES Manual sand is cut out when the locomotive is operating in power mode at speeds above 19.4Km/h or when the unit is in wheel creep mode below the speed of 19.4 Km/h. If a wheel creep equipped locomotive is in a multiple unit consist with older units, pressing the manual sand switch will supply a trainlined signal to the older units and sand will be applied. Manual sanding is available in dynamic braking at all speeds. Activation of sand switches also reset the locomotive vigilance system The amber colored non-latching push-button switch on each of the control consoles provide a signal to the sanding input of the EM2000 control computer and causes the amber light to turn on. The computer determines which direction the locomotive is moving and directs the trainlined signal to the appropriate (forward or reverse) sanding magnet valves.
HORN PUSH-BUTTON SWITCHES There are two (2) non-latching blue colored push-button devices provided on each of the control consoles to activate the unit’s front or rear air horns. These horns are individually controlled by pressing the button of choice, causing the locomotive horn to sound and the blue light to turn on until the button is released.
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CONSOLE FRONT INSTRUMENT PANEL The front instrument panel is located on the front “vertical” center section of the two lower control consoles. It includes two window wiper controls, five gauges, an alerter light and an indicator light panel.
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Figure 8-30 Tractive Effort and Speed Meter TRACTIVE / BRAKING EFFORT METER On both consoles contain dual scaled analog meters that provide the tractive effort indications when in power mode and the braking effort in dynamic braking. The tractive effort can be read as the indicating needle moves from the center Zero (0) point towards the right of the gauges scale. Alternately when the locomotive is in dynamic braking the indicating needle will move to the left side of the scale from the common Zero (0) point of the gauge.
SPEED INDICATOR The analog speed indicator provides a true ground speed reference of the locomotive via the radar input.
ELECTRICAL EQUIPMENT 8-31
AIR PRESSURE GAUGES To the left of the console two (2) dual indicating air brake gauges are provided on each console. One of the gauges provides “independent brake system” information for the locomotives main reservoir and the locomotives brake pressure. The other “automatic brake system” provides brake pipe pressure and equalizing pressure for the train consist.
Figure 8-31 Pressure Gauges
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AIR FLOW GAUGE The air flow indicator provides the crew with air leak information in the train braking system
Figure 8-32 Indicating Lights Panel INDICATING LIGHTS PANEL This indicating light panel is mounted on the far right side of the instrument panel. It has lights that indicate operation of various locomotive systems
NOTE Each of the following indicator lights has the push -to-test feature, which allows testing the light circuit alone. This test determines if the light circuit is working properly. Pressing the lens cap applies supply voltage to the light circuit . After a one second delay the light should switch on, TE LIMIT Light - Indicates tractive effort limiting function has been activated from the EM2000 display on this locomotive or on another that is trainlined with this one. SAND Light - Indicates that a sanding request has been made to the locomotive computer by means of a SAND switch actuation on this locomotive or on any locomotive trainlined to this locomotive. Other sanding requests are made by the automatic sanding function (to help wheel creep or wheel slip control) and the emergency air brake applications. WHEEL SLIP Light- Four conditions cause the wheel slip light to switch ON. One of these, Locked Wheel, is dangerous, and requires immediate action by the crew. The others do not require immediate crew action. These four conditions are listed as following.
ELECTRICAL EQUIPMENT 8-33
NOTE Wheel slip annunciation is trainlined. Anything that causes a wheel slip warning on any trainlined locomotive causes the WHEEL SLIP light to switch ON on this locomotive. 1. LOCKED WHEEL CONDITION
NOTE Refer to, and follow Indian State Railways regulations concerning Locked Wheel faults. Locomotive computer immediately lights WHEEL SLIP indicator and drops load when Siemens system detects locked wheel. After 10 second delay, (20 if air brakes are applied), locomotive computer sets fault, sounds alarm bell, continues WHEEL SLIP light, and displays following message: #nLOCKED WHEEL - STOP TRAIN AND THEN CHECK IF THE WHEELS TURN FREELY. Fault indications above continue until the driver uses locomotive computer display panel to reset fault .
WARNING Locked wheels on moving locomotives are very dangerous. If locked wheel is indicated, perform the following steps. a. Stop train and set throttle handle in IDLE. b. Find the locomotive with the Locked Wheel indications . c. Slowly roll the unit with indication past an observer watching for sliding wheels and listening for unusual noises from traction motors and gearcases. Are any wheels sliding and/or traction motors or gear cases making unusual noises? Yes - Go to step d No - Go to step e d. Take appropriate action specified by Indian State Railways rules and regulations concerning Locked Wheel.
WARNING Do not, under any circ*mstances tow a locomotive having sliding/locked wheels, or move such a locomotive in tandem..
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0 e. Reset fault by pressing RESET key on locomotive computer display (Locked Wheel fault message screen). f. Has this fault occurred previously and no problem was found? Yes - Go to Step g. No - Go to Step h. g. On the locomotive computer display, disable Locked Wheel detection for the faulty axle(s). h. Continue monitoring for Locked Wheel fault reoccurrences. Report or shop locomotive at the next maintenance point for Locked Wheel system problem. (End of Locked Wheel Procedure) 2. WHEEL SLIP CONDITION - While starting a train when rail conditions are exceptionally poor, an occasional flash of the light indicates normal wheelslip control. Automatic sanding may also occur. Do not reduce throttle setting unless severe lurching threatens to break train.
NOTE: When rail conditions are poor and the locomotive is operating in power above 2.4Km/h (1.5MPH), occasional, irregular WHEEL SLIP light flashing may indicate a wheel creep system failure. Operation may continue, but report condition to authorized maintenance personnel. 3. WHEEL SLIP CONDITION ON OTHER LOCOMOTIVE - If another locomotive in tandem, connected by MU jumpers to this locomotive, detects any condition that causes it to light its WHEEL SLIP indicator, it energizes the trainline that lights the WHEEL SLIP indicator on this locomotive. 4. WHEEL OVERSPEED CONDITION - The indicator light flashes ON and OFF to indicate wheel (and traction motor) overspeed, which can be caused by excessive track speed or by simultaneous slipping of all locomotive wheels. In either case, the system automatically corrects by adjusting traction alternator output. FLSHR LAMP Light - flashes On/Off when either outside flasher lamp (at cab end or at long hood end) is flashing, provided that outside flasher lamp is not burned out and LIGHTS circuit breaker is closed. Flashes at the same rate as the outside flasher lamp PCS OPEN Light - The Knorr air brake system de-energizes locomotive control system pneumatic control relay PCR whenever it initiates a safety control or emergency air brake application. When PCR trips, it switches On the PCS OPEN light, and EM2000 turns off the excitation, interrupting locomotive power/dynamic brake operation.
ELECTRICAL EQUIPMENT 8-35
To restore locomotive power after safety control or emergency brake conditions end, reset PCR: set throttle handle in IDLE, then set automatic brake handle in EM (Emergency) for 60 seconds, them move it to REL (Release). BRAKE WARN Light - The BRAKE WARN indicator lights turn on whenever this locomotive, or another locomotive in tandem (MU jumpers connected) is generating excessive dynamic braking current, regardless of tractive effort meter reading. If the light switches On, act to make sure that it does not remain On longer than a few seconds.
CAUTION Failure to reduce dynamic braking current when the BRAKE WARN indicator has been On for more than a few seconds can result in major equipment damage and electrical fires The locomotive computer recognizes whether this locomotive originated the BRAKE WARN indication, or whether it came from another trainlined locomotive. If the warning is coming from a trainlined locomotive, EM2000 displays a message stating that fact. If BRAKE WARN indications are repeated, determine which locomotive is at fault, and take it out of dynamic braking service by setting its DYN BRAKE switch (on engine control panel) in CUT OUT. That locomotive then can operate normally under power, but cannot produce dynamic braking. If the faulty dynamic brake system is not cut out, and excessive braking effort continues for an extended period, automatic dynamic brake lockout will occur.
ALERTER LIGHT EM2000 controls the alerter awareness lights and cab buzzer. There are two (2) lights, one on each of the control consoles. The lights turn “on” when EM2000 request an acknowledgment from the locomotive operator.
CONTROL CONSOLES INTERNAL EQUIPMENT RE DB41 thru 46 & RE DB51 THRU 56 These devices are dropping resistors used in conjunction with dynamic brake rheostats RH40 & RH50 to provide a progressively higher brake reference voltage as the dynamic brake handle is moved to a higher position.
RE CTLR41 & RE CTLR 51 These 1.5 K ohm dropping resistor are used for the controller lights for each of the respective consoles.
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RH GA41 & RHGA51 These potentiometers provide dimmer control for the gauge light circuits for each of the respective consoles.
RE GA41-A1 thru GA41-B3 & RE GA51-A1 thru RE GA51-B3 These 275 ohm dropping resistor are used in the gauge light circuits.
TB50 51,52,53,54,55: Terminal Boards These terminal boards are used to connect the control console equipment to the locomotive electrical system
RHS - Reverser Handle Switches RHS-R (Reverse) and RHS-F (Forward) switches are mechanically activated by the locomotive operator when he moves the reverser handle. RHS-R switches contacts C-D of both consoles are connected to DIO-2 input channel 11 (RHSW R). RHS-F switches contacts C-D of both consoles are connected to DIO-2 input channel 10 (RHSW F). Contacts A-B of all four RHS switches (RHS-F#1, #2 and RHS-R #1, #2) are connected in parallel to DIO-1 input channel 18 (LD unit) so that EM2000 can recognize if the locomotive is in TRAIL or LEAD position
THS - Throttle Handle Switches The throttle handle switches 1 thru 8, idle, 5-6, 3 thru 8, 5 thru 8 and 2-4-6-8, are mechanically attached to the throttle handle. These switches are connected to the locomotive computer (EM2000) through the use of input channels to determine throttle handle position in power mode.
BKS - Braking Handle Switches The braking handle switches BKS-B and BKS-BG are mechanically activated by the throttle handle when it is placed in the braking section of the controller. BKS-B switch contacts C-D closes as soon as the throttle handle is put into the “SET-UP” position, 74VDC is applied to M.U. receptacles pin 17 and to the Dynamic Brake rheostat assembly. BKS-BG switch contacts A-B closes when the throttle handle is pushed out of the set up position to the Dynamic Braking section, the output of the rheostat (depending on the position) is applied to MU receptacles pin 24 and to the computer ASC (Analog Signal Conditioner) module. This signal represents the Dynamic Braking power level requested by the operator.
ELECTRICAL EQUIPMENT 8-37
ELECTRICAL CONTROL (#1) CABINET EQUIPMENT WARNING High voltage and current are present within this cabinet. Do NOT open a cabinet door except to access the Circuit Breaker panels. Refer to SAFETY PRECAUTIONS FOR GT46MAC LOCOMOTIVES in Appendix C. The electrical control cabinet, Figure 8-34, houses some of the electrical and electronic equipment needed to power and control the locomotive. This equipment includes principally EXTERNAL •
The No. 1 Circuit Breaker Panel -
•
The Engine Control Panel
•
The No. 2 Circuit Breaker and Test Panel
•
The locomotive Computer Display
INTERNAL
8-38
•
Locomotive Control Computer (EM2000) Chassis
•
Computer Power Supply Chassis
•
Computer Panel Mounted Modules (ASC, FCF, FCD,TLF)
•
Digital Voltage Regulator Module (DVR)
•
4 Braking Contactors (B1, B2, B3, B4)
•
DC Link Transfer Switch (DCL 123, 456)
•
Silicon Controlled Rectifier (SCR) Assembly
•
Battery Charging Rectifier (BC) Assembly
•
GTO Power Supply (GTOPSI, GTOPS2)
•
Current and Voltage Transducers
•
Contactors and Relays
GT46MAC Locomotive Service Manual
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Figure 8-33 #1 Electrical Control Cabinet Equipment (Front View)
ELECTRICAL EQUIPMENT 8-39
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Figure 8-34 #1 Electrical Control Cabinet Equipment (Back view)
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Figure 8-35 #1 Circuit Breaker Panel
NO. 1 CIRCUIT BREAKER PANEL The No. 1 circuit breaker panel, Figure 8-35, contains circuit breakers and switches used in the control and protection of diesel engine and electrical systems. The circuit breakers can be operated as switches but will trip open when an overload occurs. The following paragraphs describe the function of the equipment on this panel. The circuit breaker portion of the panel is divided into sections. Breakers in the shaded section must be ON (lever up) during locomotive operation. Breakers in the unshaded section are to be used as conditions require.
LIGHTS C.B. This double pole 30A circuit breaker provides power and protection to the locomotive +74 VDC switch controlled light circuits, including the maintenance, cab, hood, flashers, classification and gauge lights.
HDLTS (headlights) This 35A circuit breaker provides power and protection to the front and rear headlights circuits.
ELECTRICAL EQUIPMENT 8-41
RADIO This 15A circuit breaker is installed, between the radio base and the locomotive battery, it protects the radio communication equipment
EVENT RECORDER This 3A circuit breaker provides power and protection to the event recorder circuit.
CAB FANS This 15A circuit breaker provides power and protection to the cab fan motors and control circuit.
AIR DRYER This 15A circuit breaker provides protection for the air dryer system.
A.C. CONTROL This double pole 15A circuit breaker protects the part of the ground relay system (GRT and T2) connected to the companion alternator output, as well as the AC input to FCF (Firing Control Feedback) module. EM2000 can monitor the status of the circuit breaker using the contact assembly of the A.C. control C.B. connected to DIO-2 input channel 1 (AC CNTL) of the computer multiplex circuit.
CONTROL This 40A circuit breaker sets up the fuel pump and control circuits used for engine starting. The control circuits are fed by battery power through the battery knife switch before an engine start. Once the engine is running, the auxiliary generator supplies power through this breaker to maintain operating control. A set of contacts belonging to the control circuit breaker is connected to DIO-1 input channel 5 (CNTL CB) of the computer multiplex circuit.
LOCAL CONTROL This 30A circuit breaker establishes “local” (not trainlined) control with power from the locomotive battery to operate heavy duty switchgear, magnet valves, contactors, governor solenoids, wheel flange lube system, and the DIO computer input/output modules. A set of contacts is part of this circuit breaker assembly. It is connected to DIO-2 input channel 18 (LC BAT) of the computer multiplex circuit.
DCL CONTROL This 3A circuit breaker protects the DC Link (DCL) transfer switch motor and control circuits. A safety guard is applied over this breaker to avoid inadvertent actuation.
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FILTER BLOWER MOTOR This 30A circuit breaker protects the inertial filter blower motor circuit. The blower is used to evacuate dirt laden air from the central air compartment inertial filters. A set of contacts is part of this circuit breaker assembly. It is connected to DIO -1 input channel 3 (FLBWCB) of the computer multiplex circuit. If this breaker trips open or is inadvertently left in the OFF position, then a FILTER BLOWER MOTOR CB OPEN message will appear on the EM2000 display panel. NOTE: If the filter blower motor breaker is tripped open (OFF), operation may continue to the nearest maintenance point.
AC GTO #1 PWR SUPPLY This double pole 15A circuit breaker is installed between the 55VAC 3ø output of the auxiliary generator and the GTO power supply - PS GTO1 that provides the 24 VDC supply input for the #1 inverter (TCC1).
AC GTO #2 PWR SUPPLY This double pole 15A circuit breaker is installed between this 55VAC 3ø output of the auxiliary generator and the GTO power supply - PS GTO2 that provides the 24 VDC supply input for the #2 inverter (TCC2).
AUX. GEN. FLD This 10A circuit breaker protects the auxiliary generator field circuit and the digital voltage regulator module (DVR). A contact being part of the circuit breaker closes the circuit between the DC output of the auxiliary generator and the DVR module. A trip coil, also part of C.B. assembly may be energized by DVR if an overvoltage condition is detected. If the breaker is tripped, then auxiliary generator output to the low voltage (+74 VDC) system is eliminated. No auxiliary generator output causes the fuel pump to drop out - the diesel engine goes to idle and eventually shuts down. A FUEL PUMP NOT RUNNING: FORCED IDLE and a NO LOADING- NO CA6 OUTPUT message appears on the EM2000 display panel.
AUX. GEN. F.B. This 10A circuit breaker provides power and protection to the firing control driver (FCD) module.
FUEL PUMP This 30A circuit breaker protects the fuel pump motor circuit.
ELECTRICAL EQUIPMENT 8-43
TCC1 COMP This 10A circuit breaker provides power (74VDC) and protection to the #1 truck traction control (TCC1) computer and associated circuits. This circuit breaker has a contact installed in series with DIO-2 input channel 4 (TC1 BKR) of the computer multiplex circuit. A safety guard is used over this breaker to avoid inadvertent actuations.
TCC2 COMP This 10 A circuit breaker provides power (74VDC) and protection to the #2 truck traction control (TCC2) computer and associated circuits. This circuit breaker has a contact installed in series with DIO-2 input channel 4 (TC2 BKR) of the computer multiplex circuit. A safety guard is used over this breaker to avoid inadvertent actuations.
TURBO This 30A circuit breaker provides power and protection to the turbo lube pump motor. It must be in ON position (lever up) before diesel engine start for prelube and after diesel engine shutdown (to remove residual heat from the turbo bearings). If the diesel engine is running and this circuit breaker is OFF (lever down), then a TURBO CIRCUIT BREAKER DOWN message will appear on the EM2000 display panel. A protection cover is used over this circuit breaker to avoid inadvertent actuation.
COMPUTER CONTROL This 15A circuit breaker provides breaker provides power and protection to MCB relay and to EM2000 Power Regulator PRG.
CAUTION Both the COMPUTER CONTROL and TURBO circuit breakers must remain ON (lever up) after engine shutdown. This allows continued operation of the turbo lube pump to cool down the turbocharger bearings. The battery knife switch can be open immediately after diesel engine shutdown .
TCC ELECT BLOWER MOTOR This 30A circuit breaker is used to protect the TCC electronics blower motor, located in the inertial filter compartment. This blower supplies cooling air to the electronics in both TCC #1 and #2 cabinets
MICRO AIR BRAKE This 15A breaker provides power from the locomotive battery to the Knorr Air Brake computer relay unit/voltage conditioning unit.
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GROUND RELAY CUTOUT Switch This double pole toggle switch disconnects the ground protection relay GR from the locomotive high voltage electrical circuits for maintenance inspections or troubleshooting. When this double pole switch is open, one contact cuts out the ground relay and the other contact connected to DIO-1 input channel 2 GRNTCO turns off this input channel. EM2000 will not allow main generator excitation. This switch is normally locked in the closed (lever up) position by a pin which is safety wired to a switch guard bracket. In this position, the Ground Fault Protection System is armed.
ENGINE CONTROL PANEL Various switches and controls used in the operation of the locomotive are mounted on the engine control panel, Figure 8-36, A brief description of each device follows:
Figure 8-36 Engine control panel
ISOLATION Switch This rotary type switch can be used to isolate the locomotive from other units in consist and has two operating positions - RUN and START /STOP/ ISOLATE which are described as follows:
ELECTRICAL EQUIPMENT 8-45
RUN Position This position puts the locomotive on line after an engine start - the unit will load and respond to throttle control in a normal manner.
START/STOP/ISOLATE Position The isolation switch must be in this position to start the diesel engine. The engine starting switch (FP/ES) is cut out unless the isolation switch is in START/STOP/ISOLATE. This position also isolates the locomotive, therefore, the unit will not develop power - the diesel engine runs at idle speed in all throttle positions. This position will also silence the alarm bell in a no power condition, but not for a hot engine alarm.
NO DBCO (Dynamic brake CUT-OUT switch) When this slide switch is moved to CUT-OUT or OFF position (down), the locomotive will not operate in dynamic brake. The locomotive will operate in power with normal air braking and no other units in consist are affected. The switch can be used to limit the number of units in a consist that operate with dynamic braking or to cut out a unit with defective dynamic brake system while allowing it to operate in motoring. This switch is normally safety wired in the CUT-IN or ON position to avoid inadvertent actuations
EXTERIOR LIGHTS Switch (Rear Platform & Fuel Station) This slide switch is used to provide ON/OFF control of the platform and fueling station lights at the left and right side fueling areas. With the slide-button in the ON (up) position, power is supplied to these lights, provided that the battery knife switch is closed and the LIGHTS breaker is in the ON (up) position.
MAINTENANCE (Engineroom) LIGHTS Switch This slide switch is used to provide ON/OFF control of the engineroom and inertial filter compartment maintenance lights. With the slide-button in the ON (up) position, power is supplied to these lights, provided that the battery knife switch is closed and the LIGHTS breaker is in the ON (up) position.
EFCO (Emergency Fuel Cutoff) / STOP Switch The diesel engine will stop whenever this engine stop push-button switch is pressed and held in for approximately one (1) second. It need not be held in until the engine stops: however, holding the button in for one (1) second ensures that the computer recognizes the switch actuation as a proper shut-down signal.
BATTERY CHARGING Ammeter The battery charging current ammeter indicates the status of charge on the batteries (either charging or discharging). The battery charging ammeter does not indicate the auxiliary generator output, or the engine cranking current during startup.
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CLASS LIGHTS Switch This rotary switch has three (3) positions; LONG HOOD FORWARD, OFF, and CAB END FORWARD. The function of these positions are as follows: CAB END FORWARD Position •
Illuminates cab end classification lights
OFF Position •
Turns off classification lights
LONG HOOD FORWARD Position •
Illuminates long hood end classification lights
WARNING Locomotive operating personnel are not to access any devices within the high voltage areas of the Electrical Control Cabinet due to the presence of residual high voltage. Access within these areas of the cabinet is limited to maintenance personnel that are knowledgeable of the DCL discharge procedures. This restriction does not apply for access to electrical panels used in normal operation.
ELECTRICAL EQUIPMENT 8-47
NO. 2 CIRCUIT BREAKER AND TEST PANEL
Figure 8-37 No.2 Circuit Breaker Compartment The No. 2 circuit breaker compartment, Figure 8-37, has provisions for circuit breakers as well as a test panel intended for use by maintenance personnel during maintenance and testing procedures. All three circuit breakers must be ON (lever up) during locomotive operation.
TEST PANEL This panel is used by maintenance personnel to measure main generator field voltage (DC), companion alternator voltage (Max 230VAC), load regulator voltage(DC) and battery voltage (DC).
GENERATOR FIELD CIRCUIT BREAKER The main generator receives excitation current from the companion alternator through silicon controlled rectifiers (SCR). This 90A circuit breaker protects the silicon controlled rectifiers, the main generator field and the associated circuitry. A current overload in the main generator field is normally detected by EM2000 circuit causing an EXCESSIVE GENERATOR FIELD CURRENT message to appear on EM2000 display screen. The message will disappear when field current drops to a safe level.
NOTE This breaker trips to the CENTER position. Wait for the generator field to cool before resetting the breaker. Reset by moving the breaker lever down to full OFF before raising it to ON.
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TTC1 BLWR CIRCUIT BREAKER This triple pole circuit breaker is used to protect the Traction Control Converter (TCC) Cabinet #1 blower motor. The circuit breaker has a contact assembly connected to DIO 2 input channel 4 (TC1BKR) of the computer multiplex circuit.
TTC2 BLWR CIRCUIT BREAKER This triple pole 30A circuit breaker is used to protect the Traction Control Converter (TCC) Cabinet #2 blower motor. The circuit breaker has a contact assembly connected to DIO 2 input channel 4(TC2BKR) of the computer multiplex circuit.
MAIN CONTROL PANEL Many smaller electrical devices such as relays and resistors are mounted on the main control panel, Figure 8-38, which is located inside the Electrical Control Cabinet across the top back wall. These devices are listed, starting at the top right corner looking into the front (cab side) of the cabinet.
ELECTRICAL EQUIPMENT 8-49
.
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Figure 8-38 Top Half Of Main Control Panel RE HDLT DIM A & DIM B These 3.75 ohms dropping resistors are used to provide proper voltage for the headlights in the dim position.
RE HDLT CE A - CE B & RE HDLT HE A - HE B These 16 ohms dropping resistors are used to provide proper voltage for the headlights in bright position.
PD1, 2, 3, 4 - POWER DISTRIBUTION CONNECTORS Each of these three Power Distribution connectors provide 36 common connected sockets. They are used to distribute low voltage DC (74VDC Pos. and/or Neg.) from circuit breakers to the computer multiplex circuit and output channels. 8-50
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CMU1, 2, 3 CONNECTORS - MULTIPLEX CIRCUITS These multiplex plugs and connectors are used in computer DIO module input channel multiplexing circuits. Each CMU connector has several groups of electrically commoned terminals with each group isolated from the others. Within a common group, one pin connects (through the mating CMU plug) to a DIO module input channel, and the others connect (through the same CMU plug) to the various circuits being monitored by that DIO input channel. Each CMU connector is assigned to a group of 4 multiplexed input channels.
DIP- DIODE INPUT PANELS 30, 31, 32 These Diode Input Panels are used to connect a single DIO output channel to as many as eight different DIO module inputs (including external devices being monitored) for multiplexing purposes. They consist in 24 sets of two diodes in series for each input line to prevent backfeeding electrical noise from one DIO input channel to another.
TB BAR This terminal board provides the interface between the barometer signal and the EM2000 locomotive computer by way of the Analog/Digital/Analog (ADA) module. The barometer is also provided +5 VDC input power through TB BAR from the Analog Signal Conditioner (ASC) module.
BAROMETER The barometer senses atmospheric pressure in the #1 electrical cabinet and provides an analog voltage signal representing absolute air pressure to the EM2000 locomotive computer through the ADA module. Maximum barometric air pressure output is approximately +5 VDC.
RE AG FIELD A-B These 5.7 ohms resistors are connected in series between input terminal F-J & LN of the DVR module and the field winding of the AC auxiliary generator. Its purpose is to limit current to DVR controls circuits and auxiliary generator field winding.
SPR1, SPR2 - SIEMENS PROTECTION RELAYS Each coil is connected into the Siemens computer starting circuit module. Under the right conditions, the starting circuit module completes the circuit to the coil, and allows the relay to pick up, thus providing power to the computer. This relay is used to temporarily disconnect the traction computers (Siemens) from the battery voltage during engine startup when the battery voltage drops.
ELECTRICAL EQUIPMENT 8-51
MCB-EM2000 COMPUTER CONTROL RELAY This relay is controlled by the COMPUTER CONTROL circuit breaker. (The former name of the breaker was MODULE CONTROL, which is the basis for the MCB designation.) MCB picks up when the COMPUTER CONTROL breaker closes, provided that either the battery knife switch is closed or the turbo lube pump relay (TLPR) is picked up. MCB drops out if the COMPUTER CONTROL breaker opens. When MCB drops out, #1 contact closes to keep the fuel pump relay FPR energized (Bypass the FPRLY output channel), provided that all four following conditions are met: 1. 2. 3. 4.
Battery knife switch is closed. LOCAL CONTROL breaker is closed. No emergency fuel cutoff (EFCO) switch is operated. Shutdown relay SDR is not picked up.
#2 contact opens the circuit between DIO-2 output channel 6 (TEL LED) and the Tractive Effort Reduction LED(AMM TM 1 and 2). #3 contacts closes to discharge the PRG (Computer Power Regulator) capacitors.
TEL - TRACTIVE EFFORT LIMITING RELAY This relay is energized by EM2000 when the operator selects the traction effort limit function on the display screen (T.E. Limit can be reduced to 294Kn (66 140 Lbs). When this relay is energized, #1 contact closes the circuit to DIO-3 input channel 13 (TEL) this is the TEL relay status feedback to EM2000. The #2 contact closes to feed M.U. receptacles pin#14. (all EM2000 controlled units in the consist will also reduce their tractive effort), the traction effort limit indicator lights on each of the control consoles and the DIO-3 input channel 19 (TE TEL).
BWR - BRAKE WARNING RELAY This relay is picked up when the computer senses a grid overcurrent condition. When BWR picks up, dynamic braking operation cuts out, and the BRAKE WARN indication appears on the consoles. The coil of BWR is energized by the EM2000 computer through DIO-1 output CH4 (BWR). BWR #1 contact provides a BWR pickup input signal (DIO-2 input, CH2) to EM2000 and BWR #2 contact energizes the 20T trainline and turns on the DIO-2 input channel 22 (BW 20T) and the brake warning indicator lights on the control consoles. EM2000 displays a brake warning indication.
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EFCO - EMERGENCY FUEL CUTOFF AND ENGINE STOP RELAY The EFCO relay is held picked up in normal operation - the EFCO is energized when emergency fuel cutoff is not requested. Momentary pressure on EFCO/STOP, EFCO2, or EFCO3 turns off the EFCO relay coil and disables the DIO-2 (IN)(CH18) NOEFCO signal to the computer. Dropout of the EFCO relay energizes the D valve in the Woodward governor causing the fuel injectors to go to the no fuel position and the engine to shut down from lack of fuel. EFCO/STOP switch is located on the engine control panel of the electrical cabinet. EFCO2 and EFCO3 switches, are located at the locomotive underframe near each fuel filling stations.
PCR - PNEUMATIC CONTROL RELAY The red PCS OPEN indicator light on the control console comes on to indicate a safety control or emergency air brake application. In normal operation, PCR is picked up. The +74 VDC is supplied on 13T through PCR #3 (NO) contacts to power throttle handle switches and turn on DIO-2 input channel 9 (PCS). PCR #1 (NO) contacts #1 provide 13T voltage, through Knorr CRU (Computer Relay Unit) K5 relay contacts, to hold PCR picked up when the throttle is moved out of idle position. PCR #2 (NC) contacts turns on the PCS OPEN light when PCR is not energized. When a safety control or penalty brake application occurs, the Knorr air brake system CRU (Computer Relay Unit) opens the feed to PCR. PCR contacts #2 close to turn on the PCS OPEN indicator lights. PCR #3 contacts open to turn off the PCS input (CH9) signal to the EM2000 computer and de-energize the throttle handle switches as well as the trainlined throttle signals. The computer then acts to cut off main generator/traction motor power, reduce engine speed to TH1, and display a NO LOAD-PCS OPEN message on the EM2000 screen display. To restore locomotive power (to re-energize PCR) set the throttle handle in IDLE, then set automatic brake handle in EMERGENCY for 60 seconds. Then move it to RELEASE.
TLPR - TURBOCHARGER LUBE PUMP RELAY TLPR energizes the turbocharger auxiliary lube oil pump at engine start and shutdown, and prevents engine start until TLPR is picked up. TLPR is picked up by EM2000 computer through DIO-2 (OUT)(CH23). Contacts energize the turbocharger auxiliary lube oil pump at engine start, and shutdown. Refer to Section 3 “Lubricating Oil System” for detailed operation.
WL - WHEEL SLIP LIGHT RELAY This relay is energized when the computer senses a wheel slip, wheel overspeed, ELECTRICAL EQUIPMENT 8-53
or locked powered wheel condition. Pickup of the WL relay turns on the WHEEL SLIP light on the control consoles . The WL relay is picked up by the EM2000 computer through DIO-1 (OUT) (CH3). WL relay N.O. contact #1 is connected to DIO-2 input channel 2 (WH SLP) of the multiplexing circuit (Relay Status Feedback). The N.O. contact #2 is used to feed M.U. receptacles pin 10T, the wheel slip lights on the control consoles and turn “on” DIO-2 input channel 21 (WL 10T)
VPC - VOLTAGE PROTECTION CONTACTOR The power supply starting circuits for the Siemens inverter computers and the voltage protection contactor (VPC) protects computers against overvoltage conditions and does not allow the TCC computers to start up unless all modules are in place. The contacts #1 and #2 of the Voltage Protection Contactor (VPC) are open during (and for a short period after) engine starting in order to allow the DVR to gain proper control of the Aux. Gen. output. Immediately following engine starting, the output of the DVR module can momentarily overshoot its controlling voltage of 74 volts to a point that can cause damage to the GTO circuitry. VPC contact #3 is connected to DIO#1 input channel 2 (VPC) of the multiplexing circuit (contactor status feedback).
SDR - SHUT DOWN RELAY Pressing the MU Engine Stop Switch on the #2 control console picks up SDR. SDR pick-up results in an immediate engine shutdown of all locomotive coupled in the consist. Refer to Section Engine Starting and Stopping for detailed operation.
AR - ALARM RELAY The alarm circuit alerts the operator of abnormal conditions or protective device activity. The relay (AR) is de-energized and the alarm bell rings whenever the attendant call push-button is pressed, or through software - whenever the computer senses various operating conditions. The AR coil is connected to DIO-1 module output CH1 (NO AR) of the EM2000 computer. When the computer de-energizes AR relay, the contact #2 closes to connect 74 VDC control voltage to: Trainline 2T, the alarm bell and the DIO #1 input channel 9 (ALARM).
FPR - FUEL PUMP RELAY The fuel pump circuit provides the locomotive operator with the means of shutting off the fuel pump from a switch on the Left Side CB/Switch Panel on the lower control console #2.
FPR relay is normally energized by EM2000 through DIO-2 output channel 11 (FPRLY). If the computer control circuit breaker is opened while the engine is running, the MCB interlock will prevent the engine shut down by keeping FPR 8-54
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0 energized. An emergency fuel cut-off request or MU (Multiple Unit) shut down request de-energizes the FPR. Contacts #1 and #2 are in series between the fuel pump circuit breaker and the fuel pump motor. Refer to section “Fuel System” for more detailed operation.
CAUTION The control and fuel pump switch must always remain in the ON position while the engine is running. If an engine shuts down from lack of fuel, damage to the engine fuel injectors is possible.
CMPSYN - COMPRESSOR SYNCHRONIZATION RELAY CMPSYN relay is picked up by DIO-3 output CH14, based on the EM2000 compressor loading software routine. An air compressor load request signal is sent to trainline 25T, when CMPSYN is picked up
DBGR - DYNAMIC BRAKING GROUND RELAY This relay is used to connect the dynamic brake grid to the locomotive ground detection system. During normal operation, (both TCC’s are cut-in), DBGR coil is not energized and its contacts connects grid path #2 to the ground relay system. Remember that in dynamic braking, when both trucks are CUT-IN, the two grid paths are connected in parallel so that the ground relay (GR) will pick up if there is a high voltage ground on either grid path. In the case where a TCC (TCC1 or TCC2 ) need to be cut out, EM2000 disconnects grid path #2 and uses grid path #1 to connect the remaining TCC during dynamic braking opeation. When this event occurs, DBGR coil is energized through B2 and B4 contactors interlocks and DBGR contacts move to connect grid path #1 only to the ground relay circuit.
CAUTION In the event of a grid path#1 failure such as open/shorted grid, open/seized Blower Motor, EM2000 will switch automatically to grid path#2 when only one TCC is cut in.
RE PRG- RESISTOR, POWER REGULATOR MODULE (EM2000) This resistor is used to discharge the PRG capacitors when the computer control circuit breaker is turned off.
DCR - DRYER CONTROL RELAY The DCR relay controls the electronic timer “memory” of the air filter/ dryer, which permits the unit to regenerate only when the locomotive is in motoring or dynamic braking, or when an air compressor on any locomotive in a multiple unit consist is loading (pumping), in order to conserve additional air. The DCR relay is controlled by EM2000 through DIO 3 output channel 5 (DCR). Refer to Section 6 Compressed Air system for more detailed information.
DRC - DIODE RECTIFIER CAPACITOR ASSEMBLY This is a Diode Rectifier Capacitor Suppression device used to protect relay pickup coils such as GFD from transients when contacts paralleling DRC are ELECTRICAL EQUIPMENT 8-55
opened.
CR ST Prevents backfeed from batteries through starting circuit string and battery positive string when battery knife switch is open and TLPR relay is picked up.
CR BRK 1, 2, 3, 4 These rectifiers prevents backfeed between the B1, B2, B3, B4, through the negative feeds to the IS switch.
CR PCS Prevents backfeed of PCR reset control circuit into EM2000 locomotive input/output computer circuits.
CR TC1 - CR TC2 Smooth voltage spikes caused by dropout of SPR relay(s)
Z1 - ZENER DIODE This zener diode is used to ensure that the auxiliary generator output voltage regulated by DVR is above a certain limit before the computer DIO 2 input channel 23 (AGENON) turns “on”.
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F43285
Figure 8-39 Top Left Half Of Main Control Panel RE GR1 & RE GR2 RE GR1 and RE GR2 are each dual resistors used in the ground relay (GR) circuit. Four 10 ohms resistors - RE GR1A, RE GR1B, RE GR2A, and REGR2B are wired in series to form one leg of a bridge circuit for the ground relay circuit which is tied between the two series connected main generator halves.
RE GR 3 & RE GR4 RE GR3 and RE GR4 are each dual resistors used in the ground relay (GR) circuit. Four 10 ohms resistors - RE GR3A, RE GR3B, RE GR4A, and RE GR4B are wired in series and connected to the dynamic brake grids and to one leg of the bridge circuit for the ground relay circuit.
ELECTRICAL EQUIPMENT 8-57
RE VDCL This 200 k ohms resistor is used to limit current going through the DC link voltage transducer VDCL. The resistor tolerance value is from 198 KΩ to 202 KΩ
RE GNR A, B, C This resistor assembly (RE GNR-A, GNR-B, GNR-C) consist in three 100 ohms resistors connected between the 3 phase output of the main generator right stator half and GRT (ground relay transductor). These are current limiting resistors for the main generator phase imbalance detection circuit.
RE GNL A, B, C This resistor assembly (RE GNL-A, GNL-B, GNL-C) consist in three 100 ohms resistors connected between the 3 phases output of the main generator left stator half and GRT (ground relay transductor). These are current limiting resistors for the main generator phase imbalance detection circuit.
VDCL: DC LINK VOLTAGE SENSOR This hall effect voltage transducer measure the DC link voltage (main generator output). PDP2 (Power Distribution Panel) supply the ±15 VDC required for the transducer operation and provides the connections between VDCL and ADA (Analog to Digital to Analog) module. VDCL is connected in series with a current limiting resistor directly across the main generator. The output signal from VDCL is from the “M” fast on connection point and is in milli amps. The input voltage vs output current ratio is 40.3 VDC/M.A.
GR: GROUND RELAY The ground relay is part of the circuit that shuts down the main generator if any of the following faults occur:
1. A failed group of rectifying diodes - This results in loss of an output phase and potential generator damage. 2. Development of a positive or negative high voltage path to ground - This is a potential fire hazard. GR is normally de-energized - it is picked up when GR pick-up coil current exceeds 750-875 milliampere. The ground relay is held in its tripped position by a mechanical latch in the relay and is reset by the EM2000 computer. The EM2000 provides a reset lockout function that prevents further resetting after a specific number of resets within a given time period. A ground relay lockout can be reset through EM2000 display. Eliminate the cause of the ground relay fault, to prevent a repeat ground relay lockout condition.
GRT: GROUND RELAY TRANSDUCTOR This transductor contains several control windings which act on a single output winding. The control windings are connected in circuits which sense faults that are potentially dangerous to the main generator.
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CR GNL 1, 2, 3 Used in the ground relay transductor (GRT) circuit to prevent AC voltage from the main generator from being applied to the negative DC generator bus output.
CR GNR 1, 2, 3 Used in the ground relay transductor (GRT) circuit to prevent AC voltage from the main generator from being applied to the positive DC generator bus output.
RE GRT This 190 ohms resistor is connected in parallel with the primary winding of transformer T2, and in series with the primary winding of Ground Relay Transductor GRT. It is used to shunt voltage spikes that occur across T2.
T2: GROUND RELAY TRANSFORMER Provides supply voltage to ground relay GR pickup coil circuit.
CR GR1 THRU 8 These rectifiers make up the ground relay (GR) bridge circuit and protect the ground relay coil circuit from voltage spikes.
CA GR1 THRU 6 These capacitors are used to filter out the high frequency “noise” coming to GR as induced by the “capacitor” formed by the AC motor frame and stator windings (approx. 40 NF) at high speed (high frequency).
ELECTRICAL EQUIPMENT 8-59
MODULE COMPARTMENT The module compartment houses several replaceable modular devices used for various locomotive system requirements. A brief description of each module is provided here with a more detailed explanation provided in Section 9.
F43286
Figure 8-40 Module Compartment (front view)
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PANEL MOUNTED MODULES
F43287
Figure 8-41 Arrangement/ Location of Panel Mounted Modules, Power Chassis and Diagnostic Panel
DVR300 : DIGITAL VOLTAGE REGULATOR The DVR module regulates auxiliary generator output by controlling auxiliary generator field current. The auxiliary generator ouput voltage can vary from 72.5V to 77.5 V depending on battery box ambient temperature. Refer to Section 9 for more detailed information.
FCD300: FIRING CONTROL DRIVER The FCD module amplifies the SCR’s gate signals from the EM2000 CPU. The Green LED on the module faceplate must be “ON” during normal operation. Refer to Section 9B for more detailed information.
FCF300: FIRING CONTROL FEEDBACK MODULE The FCF module provides feedback from the CA6A companion alternator to the EM2000 CPU. This module contains the zero cross detection circuit which tells the CPU when each of the companion alternators phase crosses from the negative half cycle to the positive half cycle. Refer to Section 9B for more detailed information.
ASC300: ANALOG SIGNAL CONDITIONER MODULE The ASC module converts and conditions analog feedback signals into DC voltage signals that are suitable for the Analog to Digital to Analog module ADA. Refer to Section 9B for more detailed information.
ELECTRICAL EQUIPMENT 8-61
TLF301: TRAINLINE FILTER MODULE The TLF module converts the +74 VDC trainline signals from older model locomotives into a form that can be processed by the EM2000. Refer to Section 9B for more detailed information.
COMPUTER CHASSIS (Refer to Section 9B for Detailed Information) The EM2000 computer chassis is equipped with the following modules:
F43288
Figure 8-42 Arrangement /Location of EM2000 Computer Chassis
DIO300: DIGITAL INPUT/OUTPUT MODULE The digital inputs and outputs to and from EM2000 are handled by the 3 DIO modules. Each DIO module has 24 input channels and 26 output channels. The DIO modules act as an interface between the locomotives 74VDC systems and the computer 5 VDC system.
ADA305: ANALOG TO DIGITAL TO ANALOG The ADA module converts analog input signals (Pressure-Temperature-VoltageCurrent-Speed) into digital signals for the computer and converts digital computer output signals into analog signals. (Speed indicators, tractive effort meter)
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CPU302: CENTRAL PROCESSING UNIT The CPU module contains the central processing unit which performs the actual computing operation.
MEM300: MEMORY The MEM module is the archive memory that remembers the dynamic locomotive parameters and archive fault and operational data that is required when all power has been removed from the EM2000 system.
COM301: COMMUNICATIONS The COM module provides an interface for communication between the EM2000 locomotive computer, the SIBAS traction inverter computers and the Knorr air brake system computer.
POWER CHASSIS
F43289
Figure 8-43 PRG 300
The EM2000 control system requires DC power supplies of various ranges. Specifically, the chassis uses +5VDC, +12 VDC & -12 VDC. Many feedback devices called Hall Effect Transducer Devices as well as the RADAR Transceiver and magnetic speed pick-ups require + 15 VDC and - 15 VDC.
ELECTRICAL EQUIPMENT 8-63
PRG 300 POWER REGULATOR The PRG 300 is the power conditioner for the PSM modules. It received its input from the Aux. Gen./Battery circuitry and will function properly when the input voltage is between 20 and 95 VDC. When the input is between 25-63 VDC , the PRG boosts the output voltage to 64-73 VDC. This boosting operation can continue for a limited time before thermal overload occurs. Boost time depends on the amount of boost required. With an input above 63 VDC, the PRG active boost circuitry turns off, and the PRG acts as a low pass filter with the output just lower than the input by approximately 1 VDC. The PRG also acts as a power dissipating resistor when input is too high. The resistive circuitry activates at approximately 80 VDC. 1. The green LED on the faceplate indicates operation of boost mode. This is not a fault condition an is no cause for concern considering the modules. It is, however, a warning that battery voltage is too low for continuous computer operation without output from Aux. Gen. The boost mode will work for about 20-30 minutes. 2. The red LED for input fault will illuminate when the input voltage rises above 93 VDC or falls below 22 VDC. When this LED is on, the PRG300 is disabled. To reset, the breaker must be cycled and remain in the off position for at least 20 seconds as noted on the faceplate. 3. The red LED for output fault will turn on if greater than 7 A of output current is detected. The module interprets this as a short circuit and shuts down boost operation lighting the output fault LED. The LED goes off when the overcurrent condition is removed. Four test points on the module allow for the measurement of + & -74 VDC input as well as output. Notice that the 74 VDC negatives are not common
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PSM 300 POWER SUPPLY MODULE The PSM 300 steps down the 74 VDC input from the PRG 300 to +5 VDC and distributes the power to the computer chassis. Notice that this system does not use a negative 5 VDC supply. The PSM 300 must receive an input between 55 and 90 Volts from the PRG 300 in order to function properly.
F43290
Figure 8-44 PSM 300 PSM 310 POWER SUPPLY MODULE The PSM 310 steps down the 74 VDC input from the PRG 300 to +/- 12 VDC and distributes the power to the computer chassis. The PSM 310 must receive an input between 55 and 90 Volts from the PRG 300 in order to function properly.
F43291
Figure 8-45 PSM 310
ELECTRICAL EQUIPMENT 8-65
PSM 320 POWER SUPPLY MODULE The PSM 320 steps down the 74 VDC input from the PRG 300 to +/- 15 VDC and distributes the power to the PDPs (Power distribution panels) and the computer display screen. The PSM must receive an input between 55 and 90 volts from the PRG 300 in order to function properly.
F43292
Figure 8-46 PSM 320 PSM Module Test Points and LEDs Each of the PSM modules has 4 LEDS (3 on PSM 300) on the faceplate. 1. The green LEDs (only one on the PSM 300) indicate operation within the specified 2.5% of the supply’s rated output voltage. 2. The red input LED indicates a transient in the input line exceeding the input range of 55-90 VDC. This is not necessarily a fault. 3. The red fault LED indicates that the output current from the module is out of the specified range. All three modules have +&- 74 VDC input test points. Test points to measure the module output voltages are also provided. The PSM300 has +5 VDC and a common; the PSM 310 has + & - 12 VDC and a common; and the PSM 320 has + & - 15 VDC and a common.
DIAGNOSTIC PANEL The diagnostic panel consist in 4 communication ports that give access to the TCC1 and 2 computers, the air brake computer and the event recorder (when applied). These communication ports allow maintenance people to download information (fault events, operational data) and perform certain tests.
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F43293
Figure 8-47 Module Compartment Rear View. PDP1-2 - POWER DISTRIBUTION PANEL These panels are used to distribute the ± 15 VDC needed to power the current and voltage hall effect transducers and the radar transceiver. Most of the signals coming in or going out of ADA (Analog to Digital Analog) module goes through the Power Distribution Panels. ELECTRICAL EQUIPMENT 8-67
FC DIS BOX - FIRING CIRCUIT DISTRIBUTION BOX This distribution box is used to connect the computer to the Panel Mounted Modules FCF (Firing Control Feedback) and FCD (Firing Control Driver).
SIG DIS BOX - SIGNALS DISTRIBUTION BOX This distribution box connects the COM301 (Communication) module to the traction control computers (TCCs) and to the air brake system computer (Knorr).
RDRTST - RADAR TEST RELAY This relay is picked up by EM2000 when performing the radar self test. RDRTST contacts provide +15 VDC to the radar transceiver.
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ELECTRICAL CABINET - LOWER PORTION GFC: GENERATOR FIELD CONTACTOR
F43294
Figure 8-48 Electrical Cabinet Bottom Section - Front View The normally-open main contacts of this device are located in the AC supply from the companion alternator to the main generator excitation rectifier, SCR. The contactor picks up when circuits are complete for power operation, dynamic braking, or load testing. The GFC contactor is controlled by the EM2000 and picks up when circuits are complete for power operation, dynamic brake, or load testing. Moving the throttle handle into a power position, with other circuit logic conditions satisfied, provides a generator field pick up signal DIO-1 input channel 15 (GF REQ) to the EM2000. With the Isolation Switch in RUN, GFD picked up and no engine shutdown request, EM2000 turns on DIO-1 output channel 2 (GFC) to pick up GFC. ELECTRICAL EQUIPMENT 8-69
GFD: MAIN GENERATOR FIELD DECAY CONTACTOR If a ground fault causes the ground relay GR to pick up the normally closed GR contact, J-K opens to de-energize GFD coil which contact 2B opens to dropout GFC (Generator Field Contactor). GFD main contacts open to insert resistor RE2 in series with the generator field discharge circuit, thereby increasing the field decay rate by limiting circulating current.
IMGF: GENERATOR FIELD CURRENT TRANSDUCER This hall effect current transducer is in the Main Generator Field circuit between the SCR (Silicon controlled Rectifier) assembly and the slip rings. IMGF provides EM2000 with an accurate field current measurement . The PDP 2 (Power Distribution Panel) supplies the ±15 VDC required for the transducer operation and provides also the connections between IMGF and ADA (Analog to Digital to Analog) module.
B1, B2, B3, B4: DYNAMIC BRAKE CONTACTORS In dynamic brake operation the DC link energy from the traction motors is applied to the grids, through the braking contactors, and dissipated as heat. Brake contactors B1 and B2 connect grids 1,2,3, and 4 (RE GRID 1,2,3,4) to the DC link with B1 at the positive side of the link. Brake contactors B3 and B4 connect grids 5,6,7, and 8 (RE GRID 5,6,7,8 ) to the DC link with B3 at the positive side of the link. Two contactors operate together to connect three 1.251 ohm and one .687 / .626 ohm taped blower grid resistance to the DC link circuit. The grids are connected in series arrangement that increases the overall resistance when two brake contactors are closed. This brake grid resistance allows current flow at high level as locomotive speed decreases.The DC Grid blower fan speed will be directly proportional to the grid current. The pickup of contactors B1 and B3 coils is controlled by the EM2000 computer and contactors B2 and B4 are picked up by B1 and B3 relay logic. Refer to Section 9 for more detailed information. Each contactor is rated to carry 1200 amperes continuously and is equipped with arc chutes that contain, expand, and extinguish arcs by action of an intermittent duty blowout coil structure.
DCL123/R1, DCL456/L1: DC LINK SWITCHGEAR The inverters are connected to the power circuit by a new set of switchgear called DCL switchgear. The motor used to drive the switchgear is driven directly from the EM2000. The normal position of the switchgear is closed which connects the inverters to the power circuit. A few conditions will cause the switchgear to open:
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Inverter cutout is requested.
•
As required by DCL shorting Self Test.
•
Load test is requested.
•
Excitation self test is requested.
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0 •
The engine is not running (based on CA frequency).
•
Various inverter and RS-485 serial link faults.
•
Battery knife switch is opened.
•
Unit is placed in isolate for more than 20 seconds.
When the transfer switches do change state, they actually motor over to a “shorted position”. Rather than leave the switch fingers in the centered position, they make contact with the “front” tips on the switch module, which are connected to a shorting bar. This bar will short all capacitors in the inverter to prevent accidental/incidental charging of the capacitors during normal maintenance routines. A ground wire runs from the shorting bar to the ground relay cutout switch to allow for meggering of the inverter or motors while TCC capacitors remain shorted. The shorting bars can be seen in Figure 8-18 as it is mounted on the front side of the switchgear. The switchgear is located in the center portion of the High Voltage Cabinet just above floor level. Like all other types of switchgear, the DCL transfer switches are not designed to break a load. Doing this will certainly cause arcing and destruction of the contact tips since cycling through a complete transfer can take anywhere from 3 to 7 seconds. For this reason, several conditions must be met before the switches can change state, among them, DC Link voltage and current must be below 50 volts and 50 amps respectively. Operation of the DCL switchgear requires that the DCL Control circuit breaker be closed. In order to insure that the DCL transfer switches make it to their shorted position in the event that someone were to isolate the unit, shut down engine, and pull the knife switch in rapid succession, the breaker has been wired ahead of the battery knife switch on the “hot” side.
F43277
Figure 8-49 DCL Switchgear
ELECTRICAL EQUIPMENT 8-71
SCR: SILICON CONTROLLED RECTIFIER AC power from the companion alternator is rectified and applied to the main generator in controlled amounts by this rectifier assembly. The locomotive control computer (EM2000) determines how much power the SCR conducts to the generator field. Refer to Section 9 -Electrical Control for detailed information
PS GTO1-2 A set of wires run from the Aux Gen. 3 phase AC output to the GTO Power Supply boxes. These devices receive 3 phase AC power from the Aux. Gen. and produce a 24 VDC output to be used by the Gate Units in each TCC. The transforming devices are located in the lower portion of the #1 High Voltage Cabinet below the cab floor on the engineer’s side. Should the DC output voltage stray from the specified input range, the entire locomotive will drop load momentarily, operation of the inverter affected may cease if the proper 24 VDC supply cannot be provided consistently. The faceplate of each device has four LEDs.
F43295
Figure 8-50 GTO Power Supply Devices. The green +24 V LED (top) indicates that the power supply is producing output within its specified tolerance. The red OVERVOLTAGE and OVERLOAD LEDs (second & third from top respectively) indicates those fault conditions. The green INHIBIT LED (lower most) indicates that EM2000 has requested that the supply momentarily stop producing output. Whenever the supplies are receiving 55 VAC input, they ought to be producing output unless the EM2000 sends the inhibit signal. Each faceplate has also five test points. Three of the test points are black and provide a place to measure the 55 VAC input coming from the Aux. Gen . The other two points (red and blue) provide a place to measure the 24 VDC output from the device.
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F43296
Figure 8-51 Electrical Cabinet Bottom Section Rear View
ELECTRICAL EQUIPMENT 8-73
TCC 1 SS-TCC 2 SS - TRACTION CONVERTER CABINETS BLOWER SLOW SPEED CONTACTORS These contactors are controlled by EM2000 through DIO-2 output channel 7 (TCC1SC) and DIO-2 output channel 8 (TCC2SC). The main contacts of these contactors connects three phase AC from the companion alternator to the TCC’s blower motors. Each contactor has an auxiliary contact connected to EM2000 multiplexing circuit to provide contactor status feedback.EM2000 controls the contactors based on the traction control computer request.
IBKBL1-2 - GRID BLOWER MOTOR CURRENT TRANSDUCER These hall effect current transducers measure grids blower motor current. The PDP2(Power Distribution Panel) supplies the ±15 VDC required for the transducers operation and provides the connections between 1BKBL1-2 and ADA (Analog to Digital to Analog) module. This information is used by EM2000 to detect open/shorted motor condition and seized bearings. The 1BKBL1-2 output signal is in volts DC, the input current vs output voltage ratio is 25A/VDC.
1TCC 1 AND 2 - DC LINK CURRENT TRANSDUCERS These hall effect current transducers measure the DC Link current to each inverter. PDP1 (Power Distribution Panel) for the 1TCC 1 and PDP2 for TCC2 supplies the ±15 VDC required for the transducers operation and the connections between the 1TCCs and ADA (Analog to Digital to Analog) module.
CAUTION During replacement of a Hall Effect Current Transducer, care must be taken about current flow direction. An arrow on the device housing indicates current flow direction. Always refer to the proper schematic during repairs or replacement activities. TMA - TRACTION MOTOR AIR TEMPERATURE SENSOR This thermistor (Resistor which resistance value changes with temperature) is connected to the computer ADA module through PDP2 (Power Distribution Panel). EM2000 uses that information to determine Traction Motor overheating conditions.
1B1-2 - GRID PATH #1 AND #2 CURRENT TRANSDUCERS These hall effect transducers measure current in both grid paths. PDP2 supplies the ±15 VDC required for the transducers operation and provides the connections between the grid current transducers and ADA (Analog to Digital to Analog) module. EM2000 uses that information to control dynamic braking effort and current. The 1B1-2 output signal is in volts DC, the input vs output voltage ration is 200A/VDC.
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EFS: ENGINE FILTER SWITCH EFS senses the pressure drop across the inertial plus the engine air filters. When the pressure drop across the combined filters reaches 24 inches of water, the switch will trip closed. EFS closing provides a signal to the computer which results in reduced engine speed and load. The display message will read EFS: PLUGGED ENGINE FILTERS: TH6 LIMIT. Speed and loading will be reduced to TH6 limit.
FVS: FILTER VACUUM SWITCH This switch senses the pressure drop across the inertial plus the engine air filters. When the pressure drop across the combined filters reaches 14 inches of water, the switch will trip closed. FVS closing feeds a signal to the computer. The display message will read ENGINE AIR FILTER DIRTY after the FVS has been active for some time, indicating excessive restriction of air to the engine.
RE MG1: GENERATOR FIELD DECAY RESISTOR This 4.8 ohm resistance is inserted in series with the main generator field to increase the rate of field decay when power is removed from the field.
RE MG2: SUPPRESSION RESISTOR With CA MG this 35 ohms resistor act to suppress voltage spikes at the SCR assembly.
CA MG: CAPACITOR When controlled rectifier SCR is turned on, this 5 MFD capacitor, in conjunction with RE MG2, suppresses the voltage spike that occurs when the “free-wheeling” diode around the generator field is turned off.
OTHER DEVICES IN THE ELECTRICAL CABINET HOSE STEMS FOR MANOMETER CONNECTION Three hose stems are provided at the front of the electrical cabinet.
AIR FILTERS - ENGINE PLUS INERTIAL This opening is piped to the outlet side of the engine air filter. It is used to measure the pressure drop across the carbody mounted inertial filters plus the engine air filter.
ELECTRICAL CABINET This hose stem opens directly to the inside of the electrical cabinet. It is used to measure the pressure drop across the electrical cabinet filters.
ELECTRICAL EQUIPMENT 8-75
INERTIAL FILTERS This opening is piped to the central air compartment. It is used to measure the pressure drop across the carbody inertial filters.
TB31V-A, B, C, D, E, F, G, H, I, J, K, L, M: TERMINAL BOARDS These computer cable terminal boards connect the control computer to the traction inverter cabinets.
TB30-A, B, C, D, E, F, G, H, J, K, L: TERMINAL BOARDS These terminal boards are used to connect the #1 electrical cabinet with the other locomotive systems.
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FUSE AND SWITCH COMPARTMENT The fuse and switch compartment, Figure 8-52 is located on the L.H. side of the locomotive above the battery box. It contains the following components:
Figure 8-52 Fuse And Switch Compartment STARTING FUSE The 800 Amp starting fuse is in service only when starting the diesel engine. Battery current is applied through the fuse, to the starting motors. In this way, the starting fuse protects the motors from a current overload. Although this fuse should be in good condition and always left in place, it has no effect on locomotive operation other than for engine starting. A defective fuse will be detected by the computer when attempting to start the engine. The DIO-1 input channel 20 (ST fuse) is turned off when the starting fuse is open. In that event, the computer will display the following crew message: “NO STARTSTART FUSE IS OPEN OR MISSING.”
BATT SW (Battery Knife Switch) This switch is used to connect the batteries to the locomotive low voltage (64/74 VDC) electrical system. This switch should be kept closed at all times during locomotive operation.
ELECTRICAL EQUIPMENT 8-77
F43297
Figure 8-53 #2 Electrical Cabinet
The #2 Electrical Cabinet is located on the right side of the locomotive, under the locomotive underframe, between the No. 1 Bogie and the fuel tank. It contains the following components.
RE ST1, RE ST2: These 0.16 ohm resistors are connected across starting solenoids SM1 and SM2 to increase current through the starting motors during engagement. This increase in current is sufficient for positive engagement of pinion gear with ring gear.
STA - AUXILIARY STARTING CONTACTOR When the FUEL PRIME/ENGINE START switch is placed in the engine start position and DIO 1 output channel 18 is turned “ON” by EM2000 (if software conditions are fulfilled) STA main contact closes to apply battery power to the “pick up” solenoids that are part of the starting motors assembly. The solenoids drive the cranking motor pinions in, to mesh with the engine ring gear. Refer to section Locomotive Starting and Stopping for detailed operation.
ST - STARTING CONTACTOR The cranking motor assemblies are equipped with heavy duty contact tips. These tips make contact when the starting solenoid has operated to engage the cranking motor pinion with the starting gear. Such contacts are normally used to carry current to the cranking motors. However, to ensure reliability of the cranking devices, the locomotive uses the solenoid operated contacts to pilot a still heavier duty Starting Contactor, ST. The use of this Starting Contactor also ensures the engagement of each of the paired cranking motor pinions, before power is applied to the cranking motors.
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BC ASM: BATTERY CHARGE ASSEMBLY Battery charge assembly BC ASM is made up of battery charge current limiting resistor RE-BC, battery charge rectifier CR-BC, and auxiliary generator rectifier assembly CR-AG. CR-BC consists of a pair of heat sink mounted silicon diodes in parallel with a selenium suppression rectifier that protects the silicon diodes from high voltage spikes. This rectifier prevents battery current from flowing through the field windings of the CA6B companion alternator when the diesel engine is stopped. RE BC protects the auxiliary generator and battery charging circuit against high currents if the battery has a very low charge. CR-AG is the auxiliary generator rectifier section. It consists in two matched sets of silicon diodes (three per set) mounted on heat sinks.
CB AUX GEN - AUXILIARY GENERATOR CIRCUIT BREAKER This 250A double pole circuit breaker is installed between the 55 VAC output of the auxiliary generator and the auxiliary generator rectifier CR-AG. It must be “ON” for normal operation.
TB 61A-62A - TERMINAL BOARDS These terminal boards connects the electrical cabinet #2 components to external components/systems.
ELECTRICAL EQUIPMENT 8-79
AC (#3) CABINET The AC cabinet is located on the right side of the locomotive near the equipment rack. It contains equipment described as follows:
F43298
Figure 8-54 AC Cabinet RADIATOR FAN MOTOR FUSES These 300 ampere bolted lug-type fuses protect against the following: 1. Locked motor rotor due to bearing seizure or jammed fan blades. 2. Single phased motor windings. 3. Faulty fan contactors. 4. Faulty electrical plugs or cables. A small indicating fuse is affixed to the main body of each fuse, and is connected in parallel with the main fuse element. When the main element opens, the indicator link also burns open, and a spring loaded indicator pin protrudes. If an inspection reveals a single blown fuse, remove and discard both fuses used to protect the motor. This should be done because the second fuse, while not blown, will in all probability be degraded and will blow at the next fan start attempt.
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GT46MAC Locomotive Service Manual
CAUTION When working on a fan motor circuit always remove BOTH fuses to isolate the motor.
FCF1A, FCF2A,, FCF1B, FCF2B, FCF1A, FCF2A, FCF1B, and FCF2B are the fast speed cooling fan contactors for fans 1, and 2. These contacts configure the connections of the AC cooling fans motors to the companion alternator 230 VAC, 3-phase output to operate the cooling fan motors at the fast speed. Refer to section Cooling System for detailed information.
FCS1, FCS2 FCS1, FCS2 are the slow speed fan contactors for cooling fans 1 and 2. These contactors configure the connections of the AC cooling fans motors to the companion alternator output to operate the cooling fan motors at the slow speed. Refer to section Cooling System for detailed information.
TB80, 83A, 83B, 83C: TERMINAL BOARDS These terminal boards are used to connect the locomotive electrical system to the electrical devices in the AC cabinet.
MRPT - MAIN RESERVOIR PRESSURE TRANSDUCER This capacitive type pressure transducer monitors Main Reservoir pressure. PDP2 (Power Distribution Panel) supplies the ±15 VDC required to the transducer operation and provides the connection between MRPT and the EM2000 ADA (Analog to Digital to Analog) module. EM2000 uses that information to control the compressor unloader valves through MVCC. (Magnet Valve Compressor Control). Refer to section Compressed Air System for detailed operation.
DIP 80 - DIODE INPUT PANEL This diode input panel is used to connect single output channels to as many as 8 input channels for multiplexing purposes. This panel consists in 24 sets of two diodes in series for each input line to prevent backfeeding electrical noise from one DIO input channel to another.
CMU4 - CONNECTOR, MULTIPLEX CIRCUIT This connector is used in the computer multiplexing circuit. Each CMU connector has several groups of electrically commoned terminals with each group isolated from the others. Within a common group, one pin connects (through the mating CMU plug) to a DIO module input channel, and the others connect (through the same CMU plug) to the various circuits being monitored by that DIO input channel. Each CMU connector is assigned to a group of 4 multiplexed input channels.
ELECTRICAL EQUIPMENT 8-81
MISCELLANEOUS LOCOMOTIVE EQUIPMENT CABLE CONNECTIONS BETWEEN COMPUTER CHASSIS The cables between computer chassis must be connected for correct operation of the computer. Each cable has a specific unique jumper arrangement inside its plug. All cables are identified and computer plugs are keyed to prevent wrong connections.
ETP1, ETP2: ENGINE TEMPERATURE SENSING PROBES These two electronic temperature sensing probes (ETP1, ETP2) supply temperature data to the computer. They consist in a thermistor device which resistance value changes with the temperature. The probes are connected to ADA module, where their feedback is converted to a digital signal for the computer. EM2000 uses the highest temperature feedback signal to control all cooling functions. In the event of one probe malfunction, the second probe provides backup data.
Temperature vs. Resistance Table F° C° OHMS -58 -50 803.1 -40 -40 842.7 -22 -30 882.8 -4 -20 921.6 14 -10 960.9 32 0 1000.0 50 10 1039.0 68 20 1077.9 86 30 1116.7 104 40 1155.4 122 50 1194.0 140 60 1232.4 158 70 1270.7 176 80 1308.9 194 90 1347.0 212 100 1385.0 230 110 1422.9 246 120 1460.6 266 130 1498.2 284 140 1535.8 302 150 1573.1 * Interpolate for intermediate values
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GT46MAC Locomotive Service Manual
MV-H - MAGNET VALVES, HORN The horn Magnet Valves are picked up by the operator horn push-button switches on each Console. The magnet valve for the cab end horn is located in the short hood, zone 10. The magnet valve to the hood end is located in the long hood, zone 20.
MV-CC - MAGNET VALVE, COMPRESSOR CONTROL When the compressor control magnet valve is de-energized, the air compressor unloader valve opens and the compressor begins to pump. The magnet valve is controlled by EM2000 through DIO1 ouput channel 14 (MVCC). EM2000 controls this magnet valve based on information from MRPT (Main Reservoir Pressure Transducer) and trainlined units requests. A manual means in also provided to keep the air compressor unloaded. MV-CC can be held open by moving the manual override T handle into the locking position.
MV1 SF, MV1 SR, MV2 SF, MV2 SR - MAGNET VALVES, SANDING The computer controls the sanding magnet valves. Refer to section 6 - Compressed Air System for operation and Section 9J -Adhesion for sanding control.
TPU - TURBO MAGNETIC PICK UP The ADA module receives a square wave feedback signal from a magnetic pickup mounted in the right hand side of the turbocharger impeller housing (left hand side of the locomotive). This signal is used by the computer to protect against turbocharger overspeed. The magnetic pickup counts the number of impeller blades, and if the feedback frequency exceeds the limits established in software, the computer reduces main generator excitation. This in turn reduces exhaust gas temperature to slow down the turbocharger.
MV-RB - MAGNET VALVE RADAR BLOW OFF This magnet valve is used to blow air on the faceplate of the radar transceiver every 23 seconds. EM2000 controls this magnet valve using DIO-1 output channel 18 (RADBLW).
MV-TS - MAGNET VALVE TRACTION MOTOR BLOWER INLET SHUTTER This magnet valve is used to control the shutters on the air inlet of the traction motor blower. When the magnet valve MVTS is de-energized, the shutters are fully open, when energized shutters are partially closed thus restricting cooling air to the Traction Motors and reducing also the load on the diesel engine (fuel saving) when not needed. EM2000 controls this magnet valve using DIO-3 output channel 6 (TMSHTR). Refer to Section 5 -Central Air System for detailed operation.
ELECTRICAL EQUIPMENT 8-83
MV-EBT - MAGNETIC VALVE ELECTRONIC BLOWDOWN TIMER This magnet valve is used to blow off the moisture/water trapped into the compressed air system centrifugal filter assembly. The computer controls this magnet valve using DIO-3 output channel 3 (EBT). Refer to Section 6 Compressed Air System for detailed operation.
RE-GRID - DYNAMIC BRAKING RESISTANCE GRIDS (GRID1 - 4, GRID 5- 8) These grids absorb power generated by the traction motors in dynamic braking or by the main generator is self-load test. Each set of grids consist in 3 resistor grids of 1, 251 ohms in series with a 0.687/0.626 ohms tapped grid on which a blower motor is connected. The blower dissipates the heat from the resistor grids.
EPU The engine speed pickup feeds back into the ADA as a 5VDC square wave signal. There are no test points to qualify. The unit does not require engine speed pickup to run, as the computer senses that the engine is running by looking at Companion Alternator output. For a proper feedback from the probe, it must be mounted correctly. Set the mounting gap as shown in Figure 8-55. The tolerance is .025" +/- .005". Be sure the spacing over the top of the ring gear teeth is properly set. If a .030" feeler gauge is not available, use a credit card or a 6 inch steel pocket ruler. They are both about .030" thick.
F43299
Figure 8-55 Engine Speed Probe
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GT46MAC Locomotive Service Manual
MRPT - MAIN RESERVOIR PRESSURE TRANSDUCER. The compressor control system uses MRPT to monitor main reservoir pressure. However, this pressure transducer does not control directly the operation of the unloader Magnet Valve.(MV-CC), but acts as an input to the control computer (through ADA module). Operation of MV-CC is controlled by EM2000 DIO-1 ouput channel 14 (MV-CC) based on feedback from MRPT and trainlined units requests. Refer to Section 6 Compressed Air System for detailed operation.
ELECTRICAL EQUIPMENT 8-85
SERVICE DATA PARTS
Part No.
TA17-CA6 B RECTIFIER BANK DIODESRectifier Bank: Diode (Positive) White . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40029132 Diode (Negative) Pink. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40029131 Fuses & Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8407729 TA17 Brush . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40034666 CA6B (Grade AY). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8413190
Main Generator Brushes Min Length . . . . . . . . . . . . . . . . . . . . . 19mm (3/4 “) CAG Brushes Min. Length
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SECTION 9A. ELECTRICAL CONTROL SYSTEM This section describes in general terms the electrical control equipment used on GT46MAC locomotives.
OVERVIEW The GT46MAC locomotive was designed and constructed to provide specific traction and braking characteristics required by the railroads. The primary control system device is the EM2000 locomotive control computer (LCC). Locomotive operating controls provide inputs to the control computer which then directs electrical power equipment and the diesel engine to operate within the constraints of the power and brake requirements. This section provides information about individual electrical and electronic control systems that make up the overall locomotive control system. The GT46MAC locomotive has a 16 cylinder diesel engine that produces a nominal 4000CV (3939HP). This mechanical power is converted to electrical AC power by the TA17-CA6B main generator, converted to DC by two internal rectifier banks, and applied to the DC link. The DC link couples the major components of the GT46MAC locomotive power system together. Refer to Figure 9A-1 below. These main components are: • • • •
MAIN GENERATOR - TA17-CA6B TWO TRACTION INVERTERS - TCC1,TCC2 SIX TRACTION MOTORS - TM1,TM2,TM3,TM4,TM5,TM6 DYNAMIC BRAKE GRIDS - RE GRID 1, 2, 3, 4, 5, 6, 7 & 8
ELECTRICAL CONTROL SYSTEM 9A-1
Figure 9A-1 Power Distribution Diagram
MAIN GENERATOR The TA17-CA6B main generator produces output power based on its excitation current and the speed that the diesel engine drives it. section on page 3 correlates throttle position to diesel engine speed, approximate main generator excitation current, and output power. The DC power output of the main generator is applied to the DC link circuit.
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GT46MAC Locomotive Servive Manual
0 .
Diesel Engine/Generator Power Data Throttle Position
Engine Speed (RPM)
Maximum Voltage Limit
Excitation Current Limit (A)
Power Limit (KW)
IDLE - GFC↓
200
IDLE - GFC↑
269
620
79
-
TH1
269
620
79
133
TH2
343
880
79
294
TH3
490
1295
95
665
TH4
568
1540
99
945
TH5
651
1760
102
1253
TH6
729
2130
105
1820
TH7
820
2430
107
2400
TH8
904
2600
109
2757
NOTE The TA17-CA6B main generator has two sets of stator windings externally connected in series to provide a higher output voltage.
DC LINK EQUIPMENT The DC Link is a common bus or interface between devices that generate DC power and devices that consume DC power - it "links" these devices together. The output of the main generator is supplied to the DC link transfer switch DCL. DCL is an 8 pole motor driven transfer switch that is used to apply DC power produced by the main generator to the inverters. The DC link voltage provided by the main generator is a result of diesel engine speed and excitation current from the companion alternator. The Table on page 3 shows DC link voltage as a function of throttle position.
ELECTRICAL CONTROL SYSTEM 9A-3
NOTE Main generator output voltage is always the DC link voltage except in dynamic brake where the traction motors could generate an increased voltage
DC Link Voltage Throttle Position
DC Link Voltage
Throttle Position
DC Link Voltage
1
600
5
1600 - 1700
2
850
6
1600 - 1900
3
1200 - 1250
7
1800 - 2250
4
1400 - 1500
8
1800 - 2600
DC link voltage is applied to the traction inverters in power, or back through the traction inverters to the braking grids in dynamic brake. DC LINK VOLTAGE RANGE DC link voltage varies between 0 to 2700 VDC within these operating mode limits: TRACTION POWER -
minimum = 600 VDC maximum = 2600 VDC
DYNAMIC BRAKE -
minimum = 600 VDC maximum = *2700 VDC
* In dynamic brake main generator voltage is controlled to a maximum
of 600 VDC by the EM2000 computer. Because the traction motors are being used as generators the actual DC link voltage could be as high as 2700 VDC.
INVERTERS - IN GENERAL NOTE Although these terms are used synonymously, the term converter is for a device that can change either AC to DC or DC to DC. The term inverter is used to describe a device that changes a DC voltage into an AC voltage. There are two main types of DC Link/Inverter configurations:
1. Constant current DC Link with Current Source Inverters (CSI). CSI inverters are characterized by a series connected inductor. 2. Constant voltage DC Link with Voltage Source Inverters (VSI). VSI inverters are characterized by a parallel connected capacitor.
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GT46MAC Locomotive Servive Manual
GT46MAC INVERTERS The GT46MAC locomotive uses two voltage source inverters - one for each of the two traction inverters: TCC1 and TCC2. Voltage source inverters require a constant voltage supply on the DC link. These inverters control the output voltage and frequency to the AC traction motors by means of pulse-width modulation. The appeal of this system has increased with the development of solid state GTO (Gate Turn-Off) devices and microprocessor technology. NOTE The traction inverters TCC1 and TCC2 function as inverters (DC to AC) in power and as converters (AC to DC) in dynamic brake. In other words, the traction motors function as induction motors in propulsion and induction generators in dynamic brake. There is a capacitor filter across the input of each of the two inverters to smooth the output voltage from the main generator and for energy storage use in dynamic brake. Each filter is made up of 8 large capacitors mounted in each of the Traction Control Cabinets (TCC).
NOTE On type 2 inverters that will be applied to the locomotives assembled in India the 8 DC Link capacitors are being replaced by a single capacitor which carries the capacitance valve of the type 1 inverter 8 DC link capacitors. Each traction inverter inverts the DC link voltage into a variable-voltage, variable-frequency AC voltage which is applied to a parallel set of three traction motors. An increase in DC link voltage causes an increase in inverter input voltage which should cause an increase in power to the traction motors if the control computer is asking for it with the throttle setting.
AC MOTORS - IN GENERAL An AC motor running with no load has no induced voltage or current in the rotor the rotor is turning at the same speed as the magnetic field in the stator windings caused by the applied AC voltage. Applying a load causes the rotor to slow down. Slowing down the rotor causes the rotor RPM to fall below the rotating speed of the stator magnetic field. This difference in rotating speed is called SLIP. This slip between the rotating stator magnetic field and the rotor causes more flux lines to be cut thereby inducing a voltage in the rotor circuit. This induced voltage causes a current to flow in the rotor windings that counteracts the current induced in the rotor by the load trying to slow down the rotor. Load current opposes the induced rotor current. The rotor creates torque in trying to make the rotor current equal to the opposing load current thus attaining a new synchronous speed. When the motor RPM reaches the speed and torque necessary to support the load, then induced voltage in the rotor drops back to zero.
ELECTRICAL CONTROL SYSTEM 9A-5
CONTROL COMPUTERS GT46MAC locomotives are equipped with four interrelated computers to provide electronic control of the various functions involved in locomotive operation. Refer to Figure 9A-1. These individual computers are:
•
The locomotive control computer, designated EM2000, controls traction power, monitors main generator feedback, limits main generator excitation levels, and control diesel engine support systems.
•
The Knorr CCB computer controls the air brake system based on control inputs from the electrical brake valve and feedback from the active brake elements.
•
The two Siemens SIBAS 16 monitors feedback signals and protective functions for each Traction Control Converter (TCC1, TCC2). Each SIBAS 16 uses an Intel 8086 microprocessor with an Ultra-Violet Erasable/Programmable Read Only Memory (UVEPROM).
use EC38020 (see corrections)
Figure 9A-1 EM2000 Interaction
EM2000 LOCOMOTIVE COMPUTER The EM2000 locomotive computer controls:
9A-6
• •
Generation of traction and brake reference signals Display/Diagnostic System (computer display)
•
Locomotive Cooling System - cooling fans, radiator shutters
•
Diesel Engine - governor speed settings, turbo. lube pump, fuel pump
•
Engine Starting Circuit
•
Dynamic Brake System -braking contactors/braking effort
•
Excitation - monitors companion alternator (CA6B) output and controls main generator excitation
•
Vigilance and wheel flange lubrication systems
GT46MAC Locomotive Servive Manual
INPUT/OUTPUT DEVICES The term input/output devices applies to input and output signals to the computer (input) or from the computer (output) to other equipment. An input/output device is necessary to change the signal level from one system to another for example; from the +74 VDC locomotive system (relays, switches, etc.) to the +5 VDC computer system or from the computer +5 VDC system to the +74 VDC locomotive system. This locomotive model is equipped with combination input/output modules designated as DIO(Digital Input/Output Modules), used for both inputs and outputs. For example: DIO2 is an input/output module that provides output signals from the EM2000 to pick up cooling fan contactors and input signals to the EM2000 when these contactors have picked up.
ELECTRICAL CONTROL SYSTEM 9A-7
use EC41588 w/ corrections
Figure 9A-2 EM2000 Block Diagram.
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GT46MAC Locomotive Servive Manual
SUMMARY The EM2000 exerts overall control over the individual systems computers that make up the total locomotive. The other three computers are in some way dependent or subservient to the EM2000. EM2000/SIBAS - The EM2000 manages the GT46MAC traction system through an RS-485 serial link to the traction control converters (TCCs). EM2000/CCB - The Knorr CCB system air test set up and self test is initialized through the EM2000 computer display screen.
ELECTRICAL CONTROL SYSTEM 9A-9
Figure 9A-3 SIBAS Computer Module Block Diagram 9A-10
GT46MAC Locomotive Servive Manual
TRACTION CONTROL CONVERTER COMPUTERS -SIBAS TCC1,TCC2 Each TCC computer is basically the same device - a SIBAS 16 that is modified for different applications on this locomotive. The SIBAS 16 is a 16 bit computer based on an INTEL 8086 microprocessor running at 5.6 Mhz. These two computers are dedicated to the two traction inverters; one controls the #1 inverter (TCC1) and the other one controls the #2 inverter (TCC2). The EM2000 locomotive computer controls the main locomotive functions based on inputs from the two traction computers. Refer to the Figure 9-5 on the previous page for a SIBAS block diagram.
PULSE WIDTH MODULATION Pulse width modulation (PWM) is used to control the output waveform from the traction inverters to the traction motors by varying the frequency and amplitude of the inverter output voltage. The traction motors require an increase in frequency to increase the speed of the traction motor and a proportional increase in voltage to maintain motor torque. Pulse width modulation is accomplished with a network of electronic switches (GTOs) that are controlled by the inverter computer to vary inverter output voltage and frequency. Refer to Pulse Width Modulation later in this section.
GATE TURN-OFF THYRISTORS Gate turn-off thyristors (GTOs) are solid state switches that allow the inverter output waveform to be closely controlled. Previous thyristor and SCR design allowed the gate signal to be turned ON with a gate but the device could not be turned OFF with the device. One way to turn off the device is to remove the supply voltage which would of course de-energize the circuit. A GTO has a gate that can turn it ON and OFF. The development of high power turn-off semiconductor devices permit pulse width modulation to control both the amplitude and frequency of the traction inverter output voltage thereby making AC motor control a reality for locomotive drive systems.
LOCOMOTIVE LOAD CONTROL SYSTEM A simplified diagram of the locomotive load control system is shown in Figure 9A-4.
ELECTRICAL CONTROL SYSTEM 9A-11
F43300
Figure 9A-4 Locomotive Load Control System 9A-12
GT46MAC Locomotive Servive Manual
POWER SYSTEM VARIABLES Figure 9A-5 below illustrates the range of system variables that can be encountered during normal operation of the locomotive power system. NOTE The presence of any system variable assumes that the circuit is connected at that point - contactors, switches, relays, etc. are closed.
use F3301
Figure 9A-5 Operating Parameters
ELECTRICAL CONTROL SYSTEM 9A-13
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GT46MAC Locomotive Servive Manual
SECTION 9B. EM2000 LOCOMOTIVE COMPUTER INTRODUCTION This section covers the GT46MAC locomotive computer system and the computer modules. NOTES 1. The phrase “locomotive control computer” is often abbreviated “locomotive computer” or “computer” in this manual. 2. In the text of this manual, many words, phrases, and abbreviations appear in a special typeface - “MG V” for example. Such expressions usually are taken from the computer display or from locomotive electrical schematics. For definitions of the schematic expressions, see the “Electrical Reference Designator Definitions” list in the General Locomotive Information section at the front of this manual. Certain other all-caps expressions are taken directly from device nameplates.
HANDLING ELECTRONIC EQUIPMENT - GENERAL WARNING Electrostatic discharge often damages electronic components and assemblies. Prevent electrostatic discharge around electronic equipment by adhering to the instructions that follow. Electronic components and assemblies that are sensitive to electrostatic discharge damage should display a warning label to alert personnel that special handling is required. Figure 9B-1 illustrates some common electrostatic discharge warning labels.
ELECTRONIC DEVICE
CAUTION!
CAUTION OBSERVE PRECAUTIONS FOR HANDLING
ELECTROSTATIC SENSITIVE DEVICES
SUBJECT TO DAMAGE BY STATIC ELECTRICITY HANDLING PRECAUTIONS REQUIRED ELECTRO-MOTIVE DIVISION GENERAL MOTORS CORPORATION LA GRANGE, ILLINOIS USA PLACE REMOVED DEVICE IN THIS BAG AND BOX TO RETURN TO EMD. USE LABLE INSIDE BAG TO RESEAL BAG.
THIS DEVICE IS ELECTROSTATIC DISCHARGE SENSITIVE!
F33637
Figure 9B-1 Electrostatic Discharge Warning Labels, Typical To help prevent electrostatic discharge damage, Electro-Motive ships new and Utex electronic equipment (including computer modules) in electrostatic discharge-protected bags and cushioned cartons, as shown in Figure 9B-2. Electronic equipment should remain in electrostatic discharge-protected bags until installed. Before electronic equipment is returned for repair, it must be placed in the bags, and the bags must be correctly re-closed (see next paragraph).
EM2000 LOCOMOTIVE COMPUTER 9B-1
Bag material is dark-colored, but transparent: serial numbers are legible through the bag. A disposable grounding wrist strap is included with each Electro-Motive electrostatic discharge-protected electronics package. Printed instructions for use appear on the grounding wrist strap envelope. To prevent trapping moisture within an electrostatic-protected bag, fold over the bag at the opening, and apply an adhesive-backed “Caution” label to secure the folded-over flap. Do NOT close the bag by means of heat sealing. An additional Caution label is included within each bag, for re-closure.
29629
Figure 9B-2 Properly Bagged Module in Cushioned Box, Box and bag are electrostatic-discharge protected.
9B-2
GT46MAC Locomotive Servive Manual
HANDLING PRECAUTIONS - SPECIFIC WARNING Grounding cords and wrist straps do not protect users against electric shock. When using disposable wrist straps or grounding cords and wrist straps, follow normal precautions against electric shock:
- If the equipment being handled has a grounding-type plug, make sure equipment is actually grounded. - Do not touch or contact grounded objects other than equipment connected to wrist strap. •
Appropriate grounding procedures prevent electrostatic charge buildup. When working on computer equipment, ground yourself by means of a disposable grounding wrist strap, or by means of a grounding cord and wrist strap. Wear the wrist strap and connect it to the “3042” grounding terminals in the No. 1 electrical control cabinet computer compartment, or to other convenient chassis ground points, such as computer chassis or chassis holddown hardware.
•
Electrostatic discharge-protected bags should be available at all test, storage, and shipping facilities.
•
Bring enough electrostatic discharge-protected bags to locomotive to protect all modules that will be removed during troubleshooting.
•
Bagged modules must be stored or shipped with electrostatic dischargeprotected cushioning. Do not use expanded polystyrene contoured packing or “popcorn.” Where possible, retain fiberboard cartons for storage and shipment.
The following list provides EMD part numbers for various electrostatic discharge protection items. Item
EMD Part No.
7" x 11" Electrostatic Discharge-Protected Bag
40000012
14" x 18" Electrostatic Discharge-Protected Bag
9575502
18" x 18" Electrostatic Discharge-Protected Bag
9575501
Caution Label
9576500
EM2000 LOCOMOTIVE COMPUTER 9B-3
HOW TO USE ELECTROSTATIC DISCHARGE PROTECTION ITEMS When working at or near the No. 1 electrical cabinet computer compartment, use a disposable grounding wrist strap or a grounding cord and wrist strap until all work is completed, as directed below. CAUTION Wrist straps and grounding cords may loose conductivity through use. Make sure the ones you are using have been checked out recently. 1. Set all switches and circuit breakers to electrically isolate all circuitry in computer compartment.
2. Open computer compartment door, then follow either A or B, below. A. Use disposable wrist strap, if available. When new or replacement equipment is involved, a disposable wrist strap is supplied in equipment box. Proceed as follows: 1) 2) 3) 4) 5)
Unroll two folds of the strap. Wrap length of strap around your wrist, adhesive side to skin. Unroll the remainder of the strap. Peel off the protective liner from copper foil at strap free end. Press adhesive side of copper foil onto bare metal surface in computer compartment, such as side of computer chassis.
3. If disposable wrist strap is not available, use standard (non-disposable) wrist strap with grounding cord and alligator clip. 4. If wrist strap, grounding cord, and alligator clip are not already assembled, snap them together. 5. Slip wrist strap on. Strap (band) should fit snugly to ensure good electrical contact to skin. 6. Attach alligator clip at other end of grounding cord to convenient bare metal protuberance or edge in computer compartment. You can clip cord to any computer chassis mounting bolt, or to any of three brass air fittings on front of cabinet just above computer compartment, or to either “3042” grounding terminal in computer compartment. 7. Open computer chassis for access and remove module and/or component. 8. Take “new” (or Utex) module/component out of box and electrostatic discharge-protection bag, and install it. 9. Put module/component removed from chassis into electrostatic dischargeprotected bag, fold over end of bag, and apply Caution label to hold bag closed. 10. Put bagged module/component into electrostatic discharge-protected box. 11. Disconnect grounding cord or disposable wrist strap from grounding point. 12. Close chassis and compartment door.
9B-4
GT46MAC Locomotive Servive Manual
EM2000 LOCOMOTIVE CONTROL COMPUTER This section describes how the main computer on the GT46MAC works. We now need to see how the EM2000 accomplishes its task, and find out what each module in the system is used for. Figure 9B-3 shows a block diagram of the EM2000 control. As stated before, the modules are housed in two separate areas depending on their function or type of signals processed. All communication with the EM2000 is through the keypad on the display panel mounted on the high voltage cabinet.
COMPUTER FUNCTIONS On the EM2000, there is only one computer system controlled by one CPU module. The functions that the computer is responsible for are as follows: 1. Excitation - Controls Main Generator output in motoring and dynamic brake by varying the timing of the gating pulses to the SCR assembly. These pulses control the strength of the main generator field. EM2000 provides also the torque reference to the inverters. 2. Logic - Monitors the position of control devices in the cab (throttle position and switch position), and monitor and control on/off devices on the locomotive (e.g.. governor speed solenoids, contactors, relays, and magnet valves). It controls also the vigilance system and the wheel flange lubrication system. 3. Display - accepts inputs from the display panel, record data in archive memory, display information on the display screen and initiate diagnostic information on the display screen and initiate diagnostic functions through the display panel.
EM2000 LOCOMOTIVE COMPUTER 9B-5
F43302
Figure 9B-3 EM2000 Block Diagram with AC Traction 9B-6
GT46MAC Locomotive Servive Manual
Grounding Receptacles
DIO#1
F43288
DIO#2 DIO#3
Figure 9B-4 Arrangement / Location of EM2000 Module Cabinet COMPUTER CHASSIS The computer chassis houses the following modules: 4. CPU302 (Central Processing Unit). 5. DIO300 (Digital Input/Output). 6. ADA305 (Analog to Digital to Analog). 7. MEM300 (Archive Memory). 8. COM301 (EM2000/SIBAS® Interface via RS-485 serial link). Figure 9B-4 shows the chassis with all modules in place. A metal partition separates the chassis into two separate sections. The sections exchange data over a bus contained within the backplane of the chassis. The left side holds the analog and digital Input/Output modules. The right side holds the high speed data modules such as CPU, MEM, and COM. A special service module called the Master Memory Board (MMB) also inserts to this side of the chassis when used
NOTE Notice the grounding receptacles on the left portion of the power chassis (arrow to the right of the computer chassis in Figure 9B-4). Always follow proper static precautions when handling any printed circuit boards, including: power supplies and panel mounted modules. A grounding wrist strap should be included in packaging with each new or UTEX module. The disposable strap plugs into the jack provided on the power supply chassis. EM2000 LOCOMOTIVE COMPUTER 9B-7
CPU302 CENTRAL PROCESSING UNIT The CPU302 module is the brain of the entire computer system. Housed on the CPU302 module is a Motorola 68020 microprocessor. The 68020 is a 32 bit, 16 MHz microprocessor. A math co-processor is present to further enhance the speed and efficiency of information processing.
F43303
The module includes programmable memory facilities to store operating routines and locomotive characterization data. Characterization data describes locomotive model and order specific characteristics and specifications pertinent to the operating routines. The CPU uses random access memory (RAM) on the module for “scratchpad” (temporary storage) purposes during operations. The EM2000 utilizes state of the art memory storage called “Flash PROM”. This memory can be easily reprogrammed in the field with the aid of a laptop computer communicating through an RS-232 cable or through a special module called MMB (Master Memory Board). This module is restricted to use by GMLG personnel only. The time required to reprogram the Flash PROM from a laptop computer connected to the RS-232 port on the front of the CPU module is approximately 15 minutes.
Figure 9B-5 CPU302 Faceplate The time required to load a program from the MMB is approximately 15 seconds. On the front of the CPU as well as on the DIO, ADA, MEM, COM are Fault LED’s. All of the modules in the computer chassis have LEDs mounted on the faceplate, and upon power-up, they will illuminate for a couple of seconds as part of the power-up diagnostic routine. The CPU Fault LED can be tripped by watchdog timer faults, data bus errors, or through certain conditions satisfied in software.
9B-8
GT46MAC Locomotive Servive Manual
COM301 EM2000/TCC /KNORR COMMUNICATIONS INTERFACE All four computers on board the GT46MAC need some way of communicating. The two traction computers, each called an ASG or SIBAS® Computer 16, talk to each other and to the EM2000 via RS-485 serial link. The Knorr system CRU (Computer Relay Unit) is also linked to EM2000 via RS-485 serial link. The link carries all sorts of data ranging from torque requests and feedbacks to contactor requests and acknowledgments to fault annunciation. The RS-485 is just one of the many industry standard serial interface configurations.
The module contains dual port memory for exchanging information between the control systems. A central processor on board the COM module supervises operation of the dual port memory. Exchange of information takes place at a rate of 250 kilobaud (much faster than the common 9.6 kilobaud of modems for use in personal or laptop computers).
F43304
EPROM chips, containing the program on which the on board CPU operates, are located inside the module as well. These chips are programmable, as the name implies. Unlike the EPROM chips found on 60 Series locomotives and in the Traction computers, those found on the COM301 are not intended to be changed out during the module's service life. The program burned into the chip may vary slightly from one locomotive order to the next possibly causing some operational difficulties, however, this would be noted by a different part number on the module's faceplate.
Figure 9B-6 COM301 Faceplate If a COM301 failure is suspected after troubleshooting the affected circuits, the best and perhaps only way to verify that such is the case is by swapping the module with a known good piece. Be sure to observe proper static precautions when handling modules. As always, the suspected bad order module should be tagged before swapping, and of course taken out of service if found defective.
EM2000 LOCOMOTIVE COMPUTER 9B-9
DIO300 DIGITAL INPUT/OUTPUT MODULE The digital inputs and outputs to and from the EM2000 are handled by the DIO modules, of which there are three. Each DIO module has 24 input channels and 26 output channels. The DIO modules act as an interface between the locomotive’s 74 VDC control system and the computer’s 5 VDC system. The DIO modules are not numbered externally. To facilitate system expansion the module slots on the left side of the computer chassis are numbered from left to right. DIO modules 1 to 3 occupies slots 1 to 3 respectively (See Figure 9B-4). Furthermore, using the electrical schematic, we can also see that the number designation of the connectors (i.e. 1A, 1B, 1C, 2A, 2B) to the input/output channels also identifies the DIO slot number. F43305
A large number of the inputs are “multiplexed” (Muxed). The multiplexing allows the computer to sample groups of 16 inputs each software loop (100 milliseconds). This configuration allows a significant reduction in the number of input channels required, as each muxed input channel can support up to six inputs. In other words, what can be used to take 96 input channels can be handled with 16 input channels. We will discuss this topic later in the text.
Figure 9B-7 DIO300 faceplate It is important to remember what types of devices are inputs and outputs to/from the control system. DIO input channels - These signals are either +74 VDC or 0 VDC signals that come through switches or relay/contactor interlocks, so they are used to determine switch status (open or closed) or whether a relay/contactor is picked-up or dropped out. There is approximately 10K ohms resistance and one diode drop across an input channel terminals. DIO output channels - These signals are either +74 VDC or 0 VDC across a relay or contactor coil, so the relay/contactor is either picked-up or dropped out.
9B-10
GT46MAC Locomotive Servive Manual
DIO OPERATION BASIC INPUT - Non Multiplexed Let us look at an example of the trainline wheel slip input to the system to see how the DIO and the CPU interact. 1. When positive 74 VDC comes on the line from either the trainline or from battery positive via the WL interlock, this potential seeks a negative anywhere it can find one. In this case the only available negative to seek is through the WL 10T input channel to the computer. This signal comes in on DIO #2 input channel #21. 2. As current flows through the DIO input channel, it lights an LED on the opto-isolator which then biases (turns on), and allows current to flow through the computer’s 5 VDC circuit. Completion of this circuit then tells the CPU that the trainline 10T has gone high indicating that a unit in the consist is experiencing uncontrolled wheel slip. The communication between the DIO and the CPU does NOT show up anywhere in the schematic.
F43306
Figure 9B-8 DIO Input Channel for WL Trainline Input EM2000 LOCOMOTIVE COMPUTER 9B-11
BASIC OUTPUT Let's examine the operation of the engine governor's D Valve. The CPU energizes the coil for D Valve by completing the circuit through the coil. In order for this to happen, the computer closes the 5 VDC circuit to bias the transistor of the opto-isolator. This will then complete the circuit on the negative side of the D Valve coil, through DIO#2 output channel 16. There is also a +74 VDC feed coming into the output channel. This exists to supply gating power to the F.E.T. (Field Effect Transistor), that actually completes the circuit on the negative side of the coil.
F43307
Figure 9B-9 DIO Output Channel for Governor D Valve 9B-12
GT46MAC Locomotive Servive Manual
NOTE Do not use 74 VDC test lights, bell ringers, or analog meters to check the function of output channels directly! The rush of current through the channel to such devices will damage or destroy the module. The use of a digital volt meter is suggested.
MULTIPLEXING
F43308
Multiplexing is a process through which several inputs may be monitored through the use of only one input channel. In simple terms, selective monitoring makes this possible. In other words, not all inputs need to be monitored constantly, just periodically. After gathering these inputs in groups of 5, the CPU looks at the first signal for 10 milliseconds, the second for 10 milliseconds, and so on until it has seen all 5 inputs from the group. Once all five inputs have been checked, the CPU looks at the first signal again and repeats the loop.
In order to understand this in a more detailed fashion, lets start from ground zero and build up. One very important fact must be understood. Output channels have always been used in only one capacity in the past, which was to drive devices such as relays and coils. Now though, six output channels are used for completing paths to negative through input channels.
Figure 9B-10 Standard Input Method Figure 9B-10 shows a typical method of monitoring the status of a device (picked up or dropped out) via interlocks. In this example, once the interlock has closed, current may flow through the input channel and complete its path to negative.
EM2000 LOCOMOTIVE COMPUTER 9B-13
F43309
Figure 9B-11 shows the same configuration with one exception; an output channel is placed in the path between the interlock and battery negative. In this example, two conditions must be satisfied for current to flow through the input channel and complete its path to negative. 1.the interlock must close. 2.the output channel in the path to negative must be energized.
Figure 9B-11 Input interrupt via output
Here lies the secret to how many inputs can be read using only one channel. Understanding this point is very important in comprehending the operation of the multiplexing circuit.
F43310
Figure 9B-12 Representation of muxed inputs.
9B-14
GT46MAC Locomotive Servive Manual
0 Figure 9B-12 shows a representation of the wiring connections associated with DIO #1 input channel #4. This representation cannot be seen directly in the schematic but its existence can be deduced. By looking to the same DIO-1 input channel 4 found under the column E of Schematic pages 41, 42, 43, 44, 45, and 46. Wires from the interlocks on all four B contactors run to a common point called a CMU plug before reaching the chassis connection. The CPU controls which device is providing feedback into the system by energizing different output channels. To see the input from B1, the CPU must energize DIO #1 output channel #21. To see the input from B2, the CPU energizes DIO #1, output channel #22, and so on. The timing of output channel activation is controlled by a clock in the CPU.
F43311
Figure 9B-13 CMU plugs
MULTIPLEX CLOCK: 100MS/CYCLE NOTE: “CH” MEANS DIO OUTPUT CHANNEL
F43312
Figure 9B-14 Multiplexing Software Clock.
EM2000 LOCOMOTIVE COMPUTER 9B-15
The CPU looks at the input from each device for a 10 millisecond duration. Software programmed into the memory of the CPU runs a simulated clock to time each sample. Figure 9B-14 shows a representation of such a clock. The first 5 portions of the clock are for reading system feedbacks. For each of these 5 segments, the CPU energizes a different output channel as illustrated. Based on pre-programmed software, the CPU knows that when DIO #1 output channel #21 is on, the feedback on DIO #1 input channel #4 must be from B1. If some other interlock were connected in the place of B1 without changing the software respectively, then the status of that new interlock would be read as the status of B1. The 6th and 7th portions function in a diagnostic capacity. The remaining three portions of the clock serve no purpose.
F43313
Figure 9B-15 Schematic Diagram: Multiplex Circuit Representation As shown in Figure 9B-15, up to 16 inputs share a common output channel to complete paths to negative. So when looking at page 41 of the schematic, all inputs shown on the page will be read through their respective channels, when DIO #1 output channel #21 is turned on. When output channel is not turned on, the inputs on the page cannot be read since they have no way of completing a path for current to negative. Likewise, should output channel #21 fail in an open status, none of the inputs on page 41 could be read. This condition would be detected by EM2000 through constantly running automatic diagnostic routines.
9B-16
GT46MAC Locomotive Servive Manual
0 The 6th and 7th portions of the 100 ms clock mentioned previously serve a diagnostic function. During the 6th portion, the CPU turns on DIO #1 output channel #26 shown on page 46 of the schematic. When this occurs, all of the muxed input channels should see current flow through them indicating all “high” inputs to the CPU. During the 7th loop, output channels 21 through 26 are turned off meaning that the CPU should read all “low” for muxed inputs. If either of these two diagnostic routines fail, the computer logs a fault displays “MULTIPLEX CIRCUIT FAILURE” and disregards any inputs seen from these channels.
DIODE INPUT PANELS All examples so far ignore the presence of a vital component, the diode input panels or DIPs as shown on Figure 9B-16. These diodes prevent interlocks from providing paths to negative for other portions of the MUX circuit. Why are two diodes provided in series if one would do the job, one might ask? Simple, if a diode fails shorted, the unit fails on the road, placing an extra ten cent diode in the circuit provides cheap but reliable insurance against road failure.
CMU DIP
Figure 9B-16 Diode Input Panels
EM2000 LOCOMOTIVE COMPUTER 9B-17
MULTIPLEXED INPUT CHANNEL CHART. DIO #1 OUTPUT CHANNEL 21
DIO #1 OUTPUT CHANNEL 22
DIO #1 OUTPUT CHANNEL 23
DIO #1 OUTPUT CHANNEL 24
DIO #1 OUTPUT CHANNEL 25
DIO #1 INPUT CHANNEL 1
START
ST
SPARE
SPARE
SPARE
MXON01 MXOF01
DIO #2 INPUT CHANNEL 1
ISOLAT
RUN
SPARE
ACCNTL
SPARE
MXON09 MXOF09
DIO #1 INPUT CHANNEL 2
GRNTCO
VPC
GFC
GFD
SPARE
MXON2 MXOF2
DIO #2 INPUT CHANNEL 2
EFS
FVS
BWR
WH SLP
DBNTCO
MXON10 MXOF10
DIO #1 INPUT CHANNEL 3
FLBWCB
SPARE
SPARE
TCC2SC
SPARE
MXON03 MXOF03
DIO #2 INPUT CHANNEL 3
DCCL
DCOP
SPARE
TCC1SC
SPARE
MXON11 MXOF11
DIO #1 INPUT CHANNEL 4
B1
B2
B3
B4
SPARE
MXON04 MXOF04
DIO #2 INPUT CHANNEL 4
TC1BKR
TC2BKR
GTOPS1
GTOPS2
SPARE
MXON12 MXOF12
DIO #1 INPUT CHANNEL 5
TI1CO
TI2CO
SPARE
CNTLCB
SPARE
MXON05 MXOF05
DIO #2 INPUT CHANNEL 5
GRD RLY
SPARE
SPARE
SPARE
SPARE
MXON13 MXOF13
DIO #1 INPUT CHANNEL 6
SPARE
SPARE
SPARE
SPARE
SPARE
MXON06 MXOF06
DIO #2 INPUT CHANNEL 6
FCS1
FCS2
SPARE
SPARE
SPARE
MXON14 MXOF14
DIO #1 INPUT CHANNEL 7
FCF1AB
FCF2AB
NO LWL
LOS
SPARE
MXON07 MXOF07
DIO #2 INPUT CHANNEL 7
SPARE
SPARE
SPARE
SPARE
SPARE
MXON15 MXOF15
DIO #1 INPUT CHANNEL 8
SPARE
SPARE
SPARE
SPARE
SPARE
MXON08 MXOF08
DIO #2 INPUT CHANNEL 8
MXSEL1
MXSEL2
MXSEL3
MXSEL4
MXSEL5
MXON16 MXOF16
Figure 9B-17 Multiplexed Input Channel Chart
9B-18
GT46MAC Locomotive Servive Manual
DIO #1 OUTPUT CHANNEL 26
DIO INPUT/OUTPUT CHART LISTING Figure 9B-18 show the inputs and outputs from the digital I/O locator chart on page 9 of the schematic. The chart serves as a reference for determining input/output channels when the chart on page 12 of this module is not available. This information may come in handy if trying to confirm the existence of a bad input or output channel. If a bad channel is suspected, swap the suspected bad channel with another module that has an open channel, or contains a device input/output that is of lesser priority.
F43647
Figure 9B-18 DIO Input and Output Channel Chart EM2000 LOCOMOTIVE COMPUTER 9B-19
SHARED POSITIVES AND NEGATIVES Certain output channels share module borne 15 VDC power supplies. Also, non-multiplexed inputs and many outputs are grouped to share negative feeds on the module boards. In the schematic, a dotted line to -74 VDC indicates where a wire would normally need to provide a negative feed, but since a connection to negative exists on the module board, a wire is not needed. In the case of shared 15 VDC power supplies for outputs, the schematic does not even show a dotted line; these module borne connections are "understood." As explained in the section of this module on output channel operation, each channel needs a +15 VDC power supply to bias its opto-isolator when called to do so by the CPU. Rather than have each channel generate its own +15 VDC source, groups of channels share a single source. In other words, one +15 VDC supply can provide power to many channels. Figure 9B-19 shows page 49 of the schematic which represents cooling fan control circuitry. DIO #2 output channels 1-4 are all shown on this page. Only channel 1 has a non-interlocked +74 VDC feed. This channel uses the noninterlocked +74 VDC to create a +15 VDC supply which is then shared with the other channels of its group. The shared connection does not show up in the print because it is internal to the module. Should the connection inside the module fail, one or more channels would lose their +15 VDC supply and cease operation. Should wire PA125 fail to open, all channels of the group would cease to function. A few module borne defects may occur that affect the operation of output channels in a group. First, if the 15 Volt power supply being generated by channel #1 should fail, all channels of the group will now lose their ability to drive devices. Second, a faulty connection in the string carrying 15 Volt power to the base of the F.E.T. for each channel would result in the loss of one or more channels of the group. As a side note, the groups are kept to relatively small numbers of included channels in this instance, as well as those to be described in the following text. This is done with the intention of sharing load currents. The "weak link" in the circuit supplying the 74 volts to each 15 volt source is the connector pin on the rear of the module. This can withstand only a few milliamps of sustained current flow. The same holds true for the connector pins linking 74 VDC negatives (to be described next) to "sharing" points on the module boards.
9B-20
GT46MAC Locomotive Servive Manual
F43315
Figure 9B-19 Shared 15 Volt Power Supply Understood connection to shared 15 VDC power supply on module board! 15 VDC supply is created from 74 VDC on channel 1, then shared with channels 2, 3, & 4.
EM2000 LOCOMOTIVE COMPUTER 9B-21
F43316
Figure 9B-20 Input Channel Shared Negatives 9B-22
GT46MAC Locomotive Servive Manual
0 The output channel groups are as follows.
Output Groups The output channel groups are as follows •
1-6
•
7-10
•
11-14
•
15-18
•
19-20
•
21-22
•
23-24
•
25
•
26
These same groups also share 2 x 74 VDC negative wires on the board. Should the connection on the board or the negative feed to the group fail, channel operation would follow as described for the similar situations in losing a +15 VDC feed. The shared negative feed is represented on the schematic as a dotted line as also can be witnessed in Figure 9B-19. Non-multiplexed inputs are also grouped into arrangements such that some will share negative feeds on the DIO module. The groups of channels sharing negatives on the board are as follows.
Input Groups The output channel groups are as follows •
1-8 do not apply since they read muxed inputs
•
9-17
•
18
•
19
•
20
•
21-22
•
23-24
Again the same scenario applies as explained before with the loss of continuity in the different connection points. Figure 9B-20 shows page 58 of the schematic which demonstrates the dotted line representing the shared -74 VDC.
EM2000 LOCOMOTIVE COMPUTER 9B-23
NOTE In simple terms, the schematic does not indicate in any way the shared +15 VDC. Dotted lines represent the shared 74 volt negative feeds
ADA305 ANALOG TO DIGITAL TO ANALOG MODULE The ADA modules are responsible for accepting all analog inputs (0 to 10 VDC) into the computer, which it converts into digital representations that the CPU can understand. It is also responsible for converting digital information from the CPU into an analog signal that is required by the receiving device (Tractive Effort Meters and Speedometers). Figure 2.28 shows the analog input/output locator chart from page 9 of the schematic. All of these signals are received by, or are sent from the ADAs except for the SCR outputs (from FCD) and the traction motors speed and temperature feedback signals (to SIBAS computers). In most instances, these signals do not feed directly into the ADA. They may feed through the PDP (Power Distribution Panel or also referred to by some people as the TDP - Transducer Distribution Panel). Some signals are conditioned through the ASC module (Analog Signal Conditioner). The ADA inputs and outputs are shown in the schematic on pages 17 through 22. As with the DIO modules, the ADAs are not numbered externally. Looking at the computer chassis, it is split in the middle by a metal partition. The left side houses the I/O handlers ADA and DIO. The modules have not been numbered for facilitating expansion at a later date. The module slots on the left side are numbered from left to right. DIO modules occupy slots 1, 2, 3 & 4. The ADA module occupies slot 7. A signal that comes into a chassis connector labeled 7A-** (**stands for some letters) runs through the ADA in slot 7 (closest to the CPU.
Figure 9B-21 ADA Faceplate
9B-24
GT46MAC Locomotive Servive Manual
F43318
Figure 9B-22 EM2000 Module Chassis Slots
EM2000 LOCOMOTIVE COMPUTER 9B-25
F43648
Figure 9B-23 Analog Input/Output Locator Chart. 9B-26
GT46MAC Locomotive Servive Manual
ADA SIGNAL CHART ADA Module Signal Designation CA V GBLWZA GRID1A/GRID2A DCLV MGFLD A RADAR ETP1/ETP2 TM AIR EPU RPM TPU RPM LDMETR MG CT A TL 24T
BAR PRS TCC1A/TCC2A MPRES LR SPD METER
Signal Description Companion alternator voltage signal from FCF module. (ADA input) Dynamic brake grid blower current signal from sensor. (ADA input) Dynamic brake grid current signals from sensors. (ADA inputs) DC link voltage signal from sensor. (ADA input) Main generator field current signal from sensor. (ADA input) Speed signal from radar transceiver. (ADA input) Engine temperature signals from coolant temperature probes. (ADA inputs) Traction motor cooling air temperature signal from probe. (ADA input) Diesel engine speed signal from ENG SP MAG PU. (ADA input) Turbo speed signal from TURBO MAG PU. (ADA input) Tractive/Braking Effort signal to load meter. (ADA output) Main generator output current signal from ASC module. (ADA input) Trainline 24T voltage signal from ASC module. (ADA input) Ambient air pressure signal from barometer. (ADA input) DC Link current signals from sensors (ADA input) Main reservoir pressure signal from sensor (ADA input) Load regulator signal from ASC module (ADA input) Locomotive speed signal to speed indicators (ADA output)
EM2000 LOCOMOTIVE COMPUTER 9B-27
MEM MEMORY MODULE
F43319
The memory module is responsible for storing Fault and Running Total data. It has 128K of memory. The memory allows for detailed fault storage. For selected faults, such as ground relay, data is stored from each of the 5 seconds BEFORE the fault occurred. This information will assist shop personnel in determining the cause of defects. The memory module also stores some "operational" data needed by the CPU. For example, the RADAR Recalibration Ratio is calculated only once per day and stored in memory. This signal can only be calculated under a very specific set of operating parameters. If power to EM2000 is lost, this data must be retained so that effective/aggressive wheel slip control can be maintained when the system reboots. Since the CPU cannot write information to memory resident on its board, the data must be stored here. The memory on this module is RAM memory, so it requires battery backup. Lithium batteries are used for battery backup. No part number for the battery has been issued to date. The EM2000 will not operate properly with low or no battery set. When battery voltage does begin to reach a critical level, a fault is logged in the EM2000 archives. As all of the modules are sealed units, there is no provision at this time for field changeout of the batteries. The EM2000 will allow download the data on the MEM module to the MMB module, for in depth analysis by the appropriate personnel. No written procedure is available on this at this time.
Figure 9B-24 MEM300 Faceplate.
9B-28
GT46MAC Locomotive Servive Manual
PANEL MOUNTED MODULES Many more modules belonging to the EM2000 control mount directly to the rear panel of the High Voltage Cabinet. For this reason, they are collectively called "Panel Mounted" modules. These components interface directly with either the "noisy" 74 VDC analog systems, or the high voltage circuits on the locomotive. They mount separate from the chassis for the purpose of voltage and electro-magnetic isolation from the microcomputer. Figure 9B-25 shows the mounting of the panel.
F43287
Figure 9B-25 Arrangement/Location of Panel Mounted Modules.
ASC300 ANALOG SIGNAL CONDITIONER MODULES The ASC serve to condition analog feedbacks into DC voltage signals that can be handled by the ADA. It also serves to provide +5 VDC power to the Barometer.The signals that are conditioned by the ASC are: 1. MG CT A (main generator current transformer amperage). 2. TL 24T (dynamic braking input trainlined on pin 24). 3. LR (load regulator signal).
EM2000 LOCOMOTIVE COMPUTER 9B-29
The faceplate contains test points where scaled/filtered feedbacks can be measured with a hand held meter. The power supply for the barometric pressure transducer can also be checked. The test points are labeled as follows: 1.+5V (check with respect to CGND) - This is the 15 to 5VDC stepped down power supplied to the barometric pressure transducer. F43320
2.+15V and -15V (check with respect to 15 VCOM) This is the power supply for the circuitry that converts the 15 VDC signal to 5 VDC for the barometric pressure transducer. 3.IMG (check with respect to CGND) - This is the rectified signal from the MG current transformers. The scale factor is 756 A/V. 4.24T (check with respect to CGND) - This is the brake handle position. 0 VDC = Min. Brake 9 VDC = Max. Brake. 5.LR (check with respect to CGND) - This is the load regulator feedback. 0 VDC = Max. Field 9 VDC = Min Field.
Figure 9B-26 ASC300 Faceplate
Figure 9B-27 of the following page shows how the ASC300 appears in the schematic connecting to the ADA, barometer, Main Gen. CTs and TL 24T. Notice that the ASC module's only relation with the barometer is for power supply; feedback from the barometric transducer runs straight into the ADA 305.
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GT46MAC Locomotive Servive Manual
F43321
Figure 9B-27 ASC Module in Schematic FIRING CIRCUIT/SCR CONTROL There are two ways to control the output of a rotating machine: 1. Regulate the rotational speed. 2. Regulate the excitation to the machine's field. Since Main Gen. output must vary widely and change within milliseconds, changing the rotational speed of the diesel is not practical. Therefore, the method by which the CPU controls the locomotive's electrical load is by regulating Main Generator field (or excitation) current. Excitation for the Main Generator comes from the Companion Alternator. The Companion Alternator receives its excitation from the Aux Gen. which is 72.5 to 77.5 VDC, depending on temperature only. In other words, the output of the CA cannot be regulated. So, in order to regulate the output of the Main Generator, we find a method to pass a selective amount of power from the CA to the Main Gen. fields. A diesel electric locomotive uses a special type of conductor called a Silicon Controlled Rectifier or SCR to achieve this end.
EM2000 LOCOMOTIVE COMPUTER 9B-31
An SCR is a diode which can be given a signal to conduct. The SCR will not conduct until it receives this signal and will continue to conduct until forward voltage across the circuit element goes to zero or less. Recall that the CA output is alternating current and an SCR placed in its path will conduct only when it is forward biased and the "turn-on" signal has been given. So if we place the SCR in the path of the CA output, then regulate the time past positive-going zero cross of the CA output at which the "turn-on" signal is given to the SCR, we can regulate Main Gen. output. Figure 9B-28 below shows how variable gate signals produce variable amounts excitation for the Main Generator.
F43322
Figure 9B-28 Variable SCR gating RED indicates a low amount of excitation passes by SCRs. GREEN indicates a medium amount of excitation passes by SCRs. BLUE indicates a high amount of excitation passes by SCRs. The CPU must have certain data concerning Companion Alternator frequency in order to perform the task described above, but we cannot bring CA output into the EM2000 chassis because of electro-magnetic interference and other complicating factors. Furthermore, the CPU operates on a low scale nowhere near the power level required to turn on an SCR. For these reasons, two panel mounted modules serve as interface between the excitation circuit components and the CPU. These modules are FCF301 which handles CA frequency data and passes it to the CPU, and FCD300 which takes weak "turn-on" signals from the CPU and amplifies them for use in triggering the SCRs.
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GT46MAC Locomotive Servive Manual
FCF301 FIRING CIRCUIT FEEDBACK MODULE
F43323
The FCF is responsible for providing feedback from the Companion Alternator to the CPU. The information includes per phase output of the CA and the resultant of the 3 phases combined. This module contains the zero cross detection circuitry. This circuitry determines when the sine wave for each companion alternator phase crosses from the negative half-cycle into the positive half-cycle. When the zero line is crossed, the FCF tells the CPU module in the computer chassis that a phase has crossed zero. Based on this signal, the CPU counts the amount of time necessary before generating a weak gate pulse at the proper phase angle for a given load request. The module faceplate has the following test points: 1.CA1, CA2, CA3 (measure with respect to each other) - These represent the phase to phase voltages coming from the CA. 2.GEN A, GEN B, GEN C (measure with respect to 15V COM) - These are 5 VDC square wave pulses generated by the FCF and sent to the CPU each time the respective phase crosses zero.
Figure 9B-29 FCF301 Faceplate 3. CAV (measure with respect to 15V COM) - This is the composite sent to the ADA representing actual CA output. The scale factor is 31 VAC output/ VDC measured. 4. +15V, -15V (measure with respect to 15V COM) - This is the reference voltage for the module's zero cross detection circuitry.
EM2000 LOCOMOTIVE COMPUTER 9B-33
FCD300 FIRING CIRCUIT DRIVER MODULE This module contains the gate amplifier circuitry needed to amplify the weak gate signals that are sent from the CPU module to the FCD. The amplified gate signals are then sent out to the SCR assembly. Power for the gate amplifier circuit is the threephase AC output of the Aux Gen.
F43324
The module face plate bears the following test points: 1.GD1, GD2, GD3 (measure with respect to the corresponding CM test point) - This is the amplified gate signal being sent to each SCR. 2.CM1, CM2, CM3 (see above) - These are the commons for the respective gating signals for each SCR. 3.SCR1, SCR2, SCR3 (measure with respect to the corresponding RTN test point) These are the weak gate pulses sent by the CPU to the FCD still needing amplification. 4.SCR1 RTN, SCR2 RTN, SCR3 RTN (see above) These are the commons for the respective weak gate signals.
Figure 9B-30 FCD300 Faceplate The FCD also has a green LED on its faceplate. This LED illuminates to indicate that gate amplifier power is present. Both the FCF and FCD appear in the schematic in more than one place. The FCD appears with the Aux. Gen circuitry to show the three-phase power connection and also in the SCR gating circuitry with the Main Gen. field. The FCF appears in the CA circuitry where it monitors CA output. Figure 9B-31 shows the FCD and FCF with their connections to CPU, ADA, and power chassis as well as their test points.
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GT46MAC Locomotive Servive Manual
fIG 2.38 STD.TXT
Figure 9B-31 FCF & FCD Interface with EM2000 Chassis TRAINLINE INPUTS
F43325
Figure 9B-32 27 Pin M.U. Receptacle. Inputs into the computer that come through the 27 pin M.U. cable first go through another module called the TLF301 (Trainline Filter Module) mounted on a panel behind the computer chassis. This module merely conditions the trainlined inputs to make the input channel interpret the inputs exactly like an older relay logic-equipped locomotive would. EM2000 LOCOMOTIVE COMPUTER 9B-35
Figure 9B-32 shows the M.U. receptacle pin out. Notice how each row of pins is numbered from left to right just like reading a book. When checking for a signal on the cable with a meter, test light, or other device, place the leads between pin 4 Negative Control (battery negative) and the signal being measured. Some of these signals can also be measured in the High Voltage cabinet at the faceplate of the TLF301 module as explained in the following text.
TLF301 TRAINLINE FILTER MODULE The TLF allows trainlined digital signals to be interpreted by the EM2000 in the same manner as older locomotives.
F43326
On older locomotives, the 74 VDC relays would pick up at approximately 35 VDC. The input channels on the DIO modules will go high (bit status "1" = ON) at approximately 25 VDC. In order for the input channels on the DIO to act like a relay, we need to add the TLF channel to "fool" the DIO into acting like a relay. Inside the TLF is circuitry that lowers the input voltage into the TLF by 10 VDC.
Figure 9B-33 TLF Faceplate So on the positive side of the TLF, if the voltage is 35 VDC, the voltage on the negative side of the TLF channel is 25 VDC applied to the positive side of the DIO. So, this circuitry keeps the DIO channels from going high erroneously if it is MU’d in consist with older power that may have stray voltage on the trainlined circuit. It is important to notice that only some of the trainline inputs to the CPU are filtered by this module. A total of 27 possible inputs exists on locomotives, but only 12 signals are filtered by the TLF. The module has testpoints as outlined in the following table.
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GT46MAC Locomotive Servive Manual
Test Point
Signal Name
Trainline
IN1
Alarm
2T
IN2
D Valve
3T
IN3
Generator Field
6T
IN4
C Valve
7T
IN5
Dir. Contl., = F
8T
IN6
Dir. Contl., =r
9T
IN7
Tractive Effort Limiting.
14T
IN8
B Valve
12T
IN9
A Valve
15T
IN10
Engine Run
16T
IN11
Db Set Up
17T
IN12
Db Excitation
21T
-74V
-74 V Reference
4T
Figure 9B-34 TLF Channels with Test Points.
EM2000 LOCOMOTIVE COMPUTER 9B-37
DVR300 DIGITAL VOLTAGE REGULATOR
F43327
In order to assure a stable output from the Auxiliary Generator, a regulating device controls the amount of excitation current passed to its fields. EMD locomotives built in the past 20 years employed a Dash 2 style voltage regulating module. Variations of this module have included manually adjustable output, output varied based on battery airbox temperature, and narrowing of the tolerable output range. All versions to date have implemented purely analog circuitry. The newest breed of voltage regulators is called DVR (Digital Voltage Regulator). This device is a standard panel mounted module similar to TLF301, ASC300, etc. Internally, the module departs greatly from past VR designs, but externally the module still provides test points to monitor 3 phase Aux Gen. output, battery voltage, battery charging voltage, and Aux Gen. Field voltage.
Figure 9B-35 DVR300 DVR regulates Aux Gen. field based on battery box air temperature. If the 74 VDC system is drawing heavily on the Aux Gen., and DVR cannot supply additional excitation to meet the power demands, DVR requests that EM2000 increase diesel speed by sending a signal to DIO2 input channel 24 (XAGLOD). When cranking the diesel, the DVR receives an “inhibit” signal from EM2000. DVR works with a new battery temperature probe, (BTA) and has the ability to recognize and store faults as well as communicate through a serial port with EM2000 (this potential is not currently utilized). In the event of 74 VDC system overvoltage, the DVR takes several actions to rectify the situation, last of which removes it from the circuit and ceases Aux Gen. excitation by tripping the AUX GEN. FLD circuit breaker. DVR only passes excitation current when the diesel is running, the module watches for 1.5 VAC phase to phase on Aux Gen. output to determine if such is the case. As the Aux Gen. ages, residual magnetism of the machine falls very low meaning that Aux Gen. output may fall below the 1.5 VAC DVR requirement.
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GT46MAC Locomotive Servive Manual
0 If this happens, perform the following steps: 1. With the Locomotive's Isolation Switch in run, "Engine Run" and "Control & Fuel Pump" switch closed (up), "Gen Field" switch open (down), reverser handle centered, advance the throttle handle step by step until the "No Companion Alternator Output" message no longer displays. 2. If the message never goes out when the throttle handle is advanced to TH8, Flash" the field by connecting a 30 watt test light from the negative side of RE4A (Wires AGBI & AGB2) to Battery Negative. Advance the throttle as in Step 1 until the, "No Companion Alternator Output" message no longer displays. 3. If the message does not clear, renew the Aux Gen.
F43328
Figure 9B-36 DVR300 In Schematic EM2000 LOCOMOTIVE COMPUTER 9B-39
VOLTAGE REGULATION The DC voltage on this locomotive will vary from 77.5 VDC at 0°C (32 °F) and fall linearly to 72.5 VDC at 37°C (100 °F). This allows additional charging voltage when the batteries are cold and require it, and keeps from boiling them with excessive charging voltage when they are warm. The DVR module is responsible for regulating the charging voltage depending on the feedback received from a temperature probe called the BTA (Battery Temperature Ambient). Figure 9B-36 shows the BTA input circuitry. Figure 9B-37 shows the probe inside the battery box. The probe looks like a long silver stem protected by a metal shield on three sides.
F43329
Figure 9B-37 BTA In Battery Box This signal is used inside the DVR module circuitry to generate a reference voltage called AGV Ref, which is 1/10 of the charging voltage. The chart in Figure 9B-38 shows the output voltage, and its correlation to BTA probe input and AGV Ref voltage. If the BTA probe fails, it will fail in one of two ways; open or shorted. The DVR will set charging at 74 VDC.
Temperature
BTA probe input voltage
AGV Reference voltage 1/10 of charging voltage
Charging voltage T.P. 1 to 14
37° Celcius
>4.8 VDC
7.2 VDC
72.5 VDC
Figure 9B-38 Aux Gen. Charging Voltage.
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GT46MAC Locomotive Servive Manual
THE EM2000 DISPLAY The Display Diagnostic System (sometimes referred to as DDS or just “display”), was designed to be “user friendly" for operating and maintenance crews having little or no computer experience. The explanations given in this section should not cause concern over complexity of the display. Its use is much easier than details contained in this section might imply.
THE MONITOR The monitor portion of the DDS is a 6 line read out of information and/or instructions for the user. Each line can contain up to 40 characters (letters, numbers, symbols). A timer is built into the software controlling the display. This timer keeps track of how much time has passed since someone has pressed a key. If the timer counts down all the way and no activity on the keys has taken place, the display will “time-out”, or enter its screen saver mode to preserve life. If the display does “time-out,” the information on the screen prior to going blank does not get lost or thrown away. The next interaction with the keypad will immediately restore all data to its original position on the screen. Note that the initial keystroke serves only as a "wake up call" and is otherwise ignored by the display. When first boarding the locomotive, check to see that the computer is turned on. If the display is blank or “asleep” when the EM2000 is on, pressing any key will “wake it up.”
F43330
Figure 9B-39 Diagnostic Display System EM2000 LOCOMOTIVE COMPUTER 9B-41
THE KEYPAD The keypad contains 16 keys in total. Four of these keys, (F1, F2, F3, & F4) called function keys, are used to perform operations shown in the space of the display directly above them at any particular moment. If an option does not appear above that key in a particular screen, then it serves no purpose for that screen. For example, in the Main Menu, the SELECT option corresponds to the F3 key, EXIT goes with F4, and F1 & F2 serve no purpose. In the center of the keypad are four arrow keys (right, left, up, & down). The arrow keys are used to move the cursor (pointer on either side of the item) to different locations on the display. On some screens, the arrow keys will serve no purpose. Two keys (BRIGHT & DIM) can be used to vary the brightness of the display. The illumination can be set to 3 levels, bright, medium, and dim. The brightness can be adjusted at any time in any screen. These keys serve no other purpose. The ON/OFF button is used to turn the display on or off. This can be done from any screen. The screen may turn on by itself if the computer has a Crew Message to send. The HEP button provides information on the Head End Power generating unit. Since this is only used on passenger locomotives, the key serves no purpose on this particular locomotive. The button marked MAIN MENU will automatically send the display back to the “Main Menu” screen from any other screen. This key can come in handy if the user “gets lost” in the display and can’t find home or the Main Menu. Pressing CREW will display any crew messages that are currently active. Only one crew message at a time will be displayed. By doing so, the display can help the user through a fault that requires something to be reset or cut out by tailoring the function keys to the particular message. If more than one message is active, the display will note as such. Some crew messages, such as that demonstrated below, will log faults in the archives along with them. Others, such as “INCREASE ENGINE SPEED - TRACTION MOTOR COOLING” will leave no trace of existence once the condition has subsided.
Crew Message #2 of 3 MESSAGE CODE: 179 NO LOAD - IMPROPER GFC STATUS PREVIOUS I
NEXT I
EXIT I
The HELP key signals the display to provide the user with assistance pertaining to the information currently being displayed. The assistance may be in the form of a more in-depth explanation of the message or a set of directions.
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GT46MAC Locomotive Servive Manual
0 Finally, the SLOW SPEED key will provide further instructions if needed for “Slow Speed” operation, and then initiate the screen needed to operate the locomotive in this mode. Slow Speed is similar to the pace setting devices used at train loading/unloading facilities such as coal mines. The key serves no purpose on this paticular locomotive.
USING THE DISPLAY AS AN EFFECTIVE TOOL To receive the full benefit of built in diagnostics, the user must understand how to efficiently use the interface to the system which, in this case, is the display. Many screens exist inside of other screens, continually branching off much like a tree. For the user, finding his way through the various screens may be quite tedious and confusing, therefore familiarization with the layout and structure of the screens is highly suggested. Once again, familiarization comes through hands on experience. Operators and maintenance personnel alike are strongly encouraged to peruse the screens at their convenience. Below is the Main Menu for the display system. This is essentially the "home base " when operating the system. From here, the screens branch out in various directions to perform different services.
EM2000 LOCOMOTIVE COMPUTER 9B-43
EM2000 MAIN MENU ARCHITECTURE 1st page Data Meter Progam Meter (5) Dyn. Brake Starting System Digital I/O DIO1-DIO2-DIO3 IN/OUT MUX ON/OFF Multiplexer Power Data Creep Control Cooling System Self- Tests
Fault Archive
Air Brake Test DCL Shorting Test Self Load Excitation / SCR W/S Contactors / Relays Cooling Fans Radar Meters Wheel Flange Lube TCC Blowers Display Archive Faults Send to RS232 Clear Annunciator
Running Totals Show on Display Send to RS232 Start / Stop Trip Monitor Traction Cut Out Truck #1 Truck #2 Unit Information English / Metric Locked Wheel Detection 2nd Page Maintenance Air Test Setup TE Li i i 9B-44
GT46MAC Locomotive Servive Manual
All Archives {data packs} Since Annunciator {data packs}
MAIN MENU ITEMS UNIT INFORMATION This screen provides statistical information such as road number, date, time, software ID. #, barometric pressure, etc. If a unit is continually limiting horsepower due to low barometric pressure, this is an easy place to quickly qualify the output from the barometer.
TRACTION MOTOR CUTOUT Prior to the 70 Series locomotives, traction motors could only be cut out singly, or in sets by use of a rotary switch mounted on the Engine Control Panel. With the EM2000 on the GT46MAC, though, three motors at a time must be cut out. This is known also as inverter cutout. As with other units, the amount of power available from the locomotive will be limited approximately proportional to the number of motors cut out. However, the ability for the unit to function in dynamic brake with motors cut out will remain, unlike conventional DC locomotives. When a TCC is cut-out, grid path #1 is the default grid path in use unless there is a problem such as a grid path #1 blower failure, open/shorted grids. In that case, the computer will use grid path #2.
SELF TESTS The Self Tests option is the first example of a sub-menu. Selecting the Self Tests option will give a screen with several new options. Each of these options allows the user to exercise various locomotive subsystems to verify proper function. Many of the tests performed are a simple go/no go evaluation. Tests that can be run include RADAR, contactor/relay, self load, excitation, wheel slip, cooling fans, speed meters, load regulator, and wheel flange lubrication. All tests have an initial screen called “Entry Conditions” telling the user the required status of various switches prior to beginning the test. . -Entry Conditions to Contactor TestReverser handle centered, unit is not moving, engine is not running, C/FPSW switch is up, and all circuit breakers located in the black panel are up. CONTINUE I
I
I
EXIT
For example, to test GFC, the engine must not be running, otherwise the unit will begin loading. The following text will give a short explanation of each test and its intended use.
EM2000 LOCOMOTIVE COMPUTER 9B-45
SELF LOAD Self Load, or Load Test as it is more commonly called, connects the output of the Main Generator across the dynamic brake grid resistors. Self Load provides a quick and easy method of loading a unit without moving it. The test can be a fountain of valuable information revealing engine troubles such as low horsepower, smoke in the exhaust, and hunting under load, as well as some electrical problems. Since Self Load also sets the unit into near operational loading conditions (as far as contactors picked up and where power flows), the test can help troubleshoot electrical problems such as ground relay pick up. During the test, the display provides the user with a default data screen including information such as horsepower, throttle position, load regulator % of maximum field, Main Gen. volts, etc. Screen options available to the user are Load Test #2, Overriding Solenoid energize, and a Meter Menu. CONTACTORS/RELAYS This test will give the user the ability to test all contactors and relays (listed below). They may be checked all at once, each individually, or in individual groups such as switchgear. If a particular test fails, the EM2000 computer will hold its output to energize the device in the “on” or “high” position so that the circuit can be diagnosed further. This is a new feature made possible by the EM2000 computer. Once the user is ready to move on to another test, he can tell the computer by pressing the appropriate button as instructed by the display. At this time, the computer will de-energize the output and resume operation as commanded by the user.
NOTE Note that corrective actions made while troubleshooting a circuit powered from an output being held "high" by the computer will cause devices to pick up. This means that making connections will draw an arc! Granted these voltage levels are relatively low and current flow is not particularly high, the uninformed troubleshooter may get quite a scare if an arc is drawn, while Fast-Ons & terminals may be damaged. It is suggested that the Contactor test be exited before any corrective actions to the defective circuit are made.
Below is a listing of devices checked by the Contactor/Relay Test.
All B contactors
GFC and GFD contactors
BWR relay
All fan contactors
All switchgear
FP relay TLPR relay
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GT46MAC Locomotive Servive Manual
0 EXCITATION/SCR CIRCUIT New for the GT46MAC locomotives is an excitation circuit/SCR Bridge test. The The test actually checks that specified SCR firing angles deliver the appropriate Main Generator field currents. The test can uncover common failure modes such as a bad SCR, incorrect phase rotation, failed gate drivers and wiring errors. The computer actually performs several smaller tests within the greater Excitation general test. The first six of these tests are to check each SCR individually for functionality. When the display says that a particular SCR is turned on, the Main Gen. field current should climb to about 10 Amperes, and gradually fall to zero when the SCR is turned off. When the computer is no longer attempting to hold the SCR gate open, the field is given a few seconds to decay since the machine is highly inductive. Once each SCR has been tested individually in both the on and off states (totaling 6 tests), the computer decides whether or not to proceed with the multiple SCR firing portion of the test based on the results of the first six trials. If any of the first six tests have failed up to this point, the user will be notified accordingly at this time and will be given the option END TEST. During the multiple SCR firing portion of the test (tests 7 through 10), the computer attempts to fire the SCRs at various angles while monitoring the field current produced. As with the first six tests, many opportunities for failure exist. In the event of a failure, the user is notified through the monitor and given a few suggestion for troubleshooting the cause of the failure. Keep in mind that the suggestions provided are just that - suggestions. The computer has no way of knowing whether or not a particular device has failed. Tests 7-10 and expected results are outlined here.
Test 7 8 9 10
Angle 90° 146° Full On Full Off
Field Current 60 Amperes 10.2 Amperes 119.5 Amperes 0 Amperes
% Error Allowed 25% 25% 10% Within 2 Amperes
If the system passes all portions of the test, the user will be notified by a message on the screen.
EM2000 LOCOMOTIVE COMPUTER 9B-47
COOLING FANS The cooling fan test is designed to verify proper operation. The automatic portion of the test turns on each fan at both low and high speed, one after the other, allowing enough time for the operator to visually observe the fans rotating in the various settings. The individual test portion allows the user to test operation of a selected fan and selected speed. Time delays between pick up of the associated contactors is necessary during the automatic portion of the test so the user can verify proper fan rotation, because confirming that a contactor has picked up gives no assurance that the fan is actually running as required. At the completion of any of the tests, the monitor shows a message indicating either a particular fault status or a successful run. RADAR This test will exercise the RADAR transceiver, wiring connections and the computer’s ability to correctly process the RADAR feedback signal. During the test, the transceiver sends the computer a 1000 Hz, 8 VDC square wave which translates to a speed very near 45 MPH (22.2 Hz/MPH). These units come equipped with the new K-band RADAR modules. If the speed signal exceeds 1.5 M.P.H. during the first 5 seconds of the test, the test is immediately ended, and the user is notified of a possible transceiver mounting problem allowing vibration. Upon successful completion of the first portion, the test continues and looks for a stable speed signal between 40 and 50 M.P.H. As usual, the user will be notified of either possible difficulties, or successful operation upon test completion. Note that the mounting angle for the K-Band RADAR Transceiver is 37.5° between the rail (not the underframe of the locomotive), and the module. WHEEL SLIP This test causes the Wheel Slip light on the engineer’s control stand to be illuminated by picking up the WH SLP relay. This test fulfills FRA requirements that a locomotive have the ability to prove that it has a functional wheel slip warning system. When the test is in progress, the display informs the user to check the control stand indicator as the WH SLP relay has picked up. Once operation of the indicator has been checked, the test can be ended as usual by pressing the button assigned by the display. If the user does not manually end the test after 15 minutes, the screen automatically returns to the “Entry Conditions” screen. METERS TEST This test is used to verify speed meters and Tractive / Braking Effort Meter Operation. During this test: The speed meters reading incrments by step up to full meter scale. At first, the Tractive / Braking Effort Meter needle goes to full scale in the tractive effort portion and the Tractive Effort LED comes on, then, the needle goes back to 0 to full scale in the braking portion of the meter.
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GT46MAC Locomotive Servive Manual
0 WHEEL FLANGE LUBE TEST This test is used to verify the wheel flange lubricating system operation. Once the test start button is pressed, the computer sets a time delay to allow the user to go to axles 3 and 4 nozzles. The user can verify that the nozzles do spray lubricant by placing a sheet of paper in front of the nozzles. EM2000 activates the nozzles about 10 times during the test. FAULT ARCHIVE The EM2000 has the ability to record abnormal events during operation. These events are commonly referred to as faults. When a fault occurs, data packs (certain feedback signals to the computer that might help the troubleshooter determine the cause of a fault), are stored in the computer’s battery backed up memory. The memory back up battery is part of the memory board so even if power to the computer is lost, the data in the archive will be protected. The entire archive capacity, the amount of data stored with each fault, and the method in which the data are recorded represent major differences in the archive systems. The EM2000 computer has an archive memory capacity of 128K. This capacity allows for a great number of faults to be stored, and for additional information with each fault. Data is recorded before corrective action is taken. Additionally, certain types of faults will provide data packs at 1, 2, 3, 4, & 5 seconds prior to the fault, as well as at the time of the event. This is made possible by a FIFO (first in first out) data storage buffer.
FIFO#1
Figure 9-40.FIFO Data Storage Buffer The "first in first out" or FIFO data storage buffer is illustrated in Figure 6.2. This particular buffer contains five separate spaces for groups of data. In the illustration, the spaces are labeled A, B, C, D, & E, with space A being the space to always receive new information, and E being the space to always eject old data. Figure 6.3 shows the first set of data being brought into the buffer as it is captured. The data set is placed into space A until a new set takes its place one second later. Before this occurs, though, the data from space A gets bumped to the right one space into B, as shown in Figure 6.4. After a data set has been bumped 4 times, it occupies the E space in the buffer. The next bump will cause the data set to be ejected from the buffer as shown in Figure 6.5. EM2000 LOCOMOTIVE COMPUTER 9B-49
This data is no longer stored in any type of memory anywhere. This bumping continues until a fault condition on the locomotive is detected by the CPU. When a fault condition is detected, all data sets in the buffer as well as the set waiting to enter the buffer, are immediately copied to or "dumped" to the MEM300 archive memory module. This data buffer dump is illustrated in Figure 6.6. It is important to note that the information in the buffer cannot be erased during this process in case one fault were to occur immediately after another.
FIFO2
Figure 9-41.Data Set Moved into FIFO Buffer
FIFO3
Figure 9-42.New Set Bumps Old Set
FIFO#4
Figure 9-43.Data Set Gets Bumped Out After Five Seconds 9B-50
GT46MAC Locomotive Servive Manual
FIFO#5
Figure 9-44.FIFO Data Buffer Gets Dumped to Memory Upon Loco. Fault Detection The computer samples the feedbacks every second. If no faults occur for five seconds, the data recorded five seconds ago is pushed out of the buffer to make room for the data being sampled at the present moment. If a fault condition occurs at this instant, the entire buffer is dumped to the fault archives before corrective action is taken. The archive can be downloaded from the computer to a laptop computer or serial printer.
Information flows through the RS-232 port on the CPU 300 face to the remote device. During this download, the display is not dynamically updated. Because of this, data can be acquired in a timely manner. Also, small groups of data or only particular faults specified by the user may be downloaded. When viewing a particular fault, simply selecting the PRINT option will automatically transfer all fault related information to the device on the other end of the RS-232 interface. Faults will be logged regardless of terminal connection.
EM2000 LOCOMOTIVE COMPUTER 9B-51
In the interest of saving space, redundant faults will not be archived. Once a particular fault has reached its quota of faults for one day (starts at midnight), the computer recognizes the redundancy and no longer records data for the fault. The record of the number of times to date that the fault has occurred, however, will be incremented by one, as usual, for each subsequent event. Up to 999 occurrences can be counted in each day. METHODS OF DISPLAYING THE ARCHIVE When the user selects the archive viewing menu, he is given 4 fault retrieval modes to select from.
fault archive display menu
The first is to review all records in the history beginning with the newest and paging back through time. The second option is to view the faults sorted by class. When recorded, each fault is assigned a class such as Feedback, Ground Relay - Power, Improper Loading, etc. Again, the faults would be viewed in reverse chronological order. Every fault logged is assigned to a particular class. Third is to review all records newest to oldest until the annunciator was last reset. The reset date is defined when the user selects that option from the main archive menu. The annunciator is useful for viewing only those faults which have occurred on a particular trip, or over a certain time period. The final mode consists of a user selectable record. This feature prompts the user for a particular date (providing the last annunciator reset date as a default). Once the date has been entered, the first archive record whose date is equal to or newer than that requested will be retrieved. From this point, the user can begin to scan forward to the newest record. DATA PACKS Many faults recorded in the archives will have a data pack stored along with them. A data pack is a series of values, contactor statuses, etc. associated with an event collected by the computer and stored when the event occurs. If an event has a data pack associated with it, it can be one of two types: a time span collection, or a fault moment collection. A fault moment collection is a single pack of values, each recorded within milliseconds of the other.
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If a user chooses the DATA option when viewing the fault message as shown above, the values will be shown on a screen similar to the following:
Some data packs will include enough values to require two pages or screens. In such a case, the user will be given the NEXT option on page 1, and the PREVIOUS option on page 2 for viewing the alternate screens. A time span collection of data will include data similar to the items listed in the moment collection, however, as the name implies, the data will be recorded over a time span. Specifically, data is recorded at 0, 1, 2, 3, 4, & 5 seconds prior to the fault. Again, some packs will include enough data to require two pages or screens for each second or moment. The time span selection screen will look similar to the screen shown below.
Choosing the NEXT option will show the next screen, allowing selection of fault data 4 and 5 seconds prior to the fault. Pressing SELECT will choose the pack of information highlighted by the cursor (0 seconds in this example). Pressing EXIT will return the user to the screen that initially listed the fault. EM2000 LOCOMOTIVE COMPUTER 9B-53
DATA METER The purpose of the data meter is to give the user information about the operation of the locomotive and the computer in a real-time fashion. The user is able to see various digital I/O, analog feedbacks and computer-derived variables. To make signal selection easy, yet versatile, several predefined meters exist in ROM, which means they cannot be altered by the user. In addition, the user has the ability to compose “custom” meters with the signals he selects.
The next few pages will show the various predefined meters available to the user and explain the use of the Digital I/O and Programmable meter selections.
POWER SCREEN
Note the options at the bottom of the screen. The user has the opportunity to make “screen dumps” to a remote device such as a serial printer or lap top computer that is connected to the serial port of the CPU 300 module. The instant the PRINT key is pressed, the display takes a snapshot of all data on the screen and sends it off to the remote device. Snapshots can be taken nearly as frequently as the user’s finger can press the button. This feature is particularly useful in capturing data leading up to, directly following, or at the instant of a particular event. The following shows examples of some of the other screens.
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0 DYNAMIC BRAKE
CREEP CONTROL
STARTING SYSTEM
COOLING SYSTEM
EM2000 LOCOMOTIVE COMPUTER 9B-55
DIGITAL I/O
This is the menu that comes up when the user selects “Digital I/O” from the meter menu. From this screen, a particular module’s inputs or outputs may be chosen for monitoring. Upon selecting one of the “DIO Inputs” options on this menu, the next menu appears similar to that shown below.
Choosing one of the first three items on this list will yield a screen similar to the one below. Since each input channel can handle up to five variable inputs (plus 2 diagnostic) as explained in the multiplexing section of Module 2, each column of the screen is dedicated to a particular channel. A blank space in any column indicates that the channel monitors no input during that particular snap shot. Choosing the last item on the menu list will show a screen laid out similar to the one shown below, however the signals monitored are those which are “hard wired” into the DIO modules rather than the multiplexed type.
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If the user selects one of the “Outputs” options from the DIO Module Menu, the following screen will appear.
Choosing the first one of the two options available here will yield the next screen shown below. Remember that only certain input signals and no output signals are multiplexed. Since all signals are hard wired, each channel has its own dedicated space on the display. The location of the channels is represented in the example. The layout is similar to the dedicated input channel layout.
EM2000 LOCOMOTIVE COMPUTER 9B-57
RUNNING TOTALS This function of the display stores assorted locomotive performance data in nonvolatile memory. Data stored includes, but is not limited to, distance travelled and time operating at various power levels and operating modes. The information accumulates over the lifetime of the locomotive and can also be reviewed over a shorter time interval such as, since the last overhaul or scheduled maintenance interval. Upon entering the Running Totals option, the user will encounter a screen resembling that below. >Show running totals on display < - Running Totals Transfer dataMenu to RS-232 port >Show running totals on display < Stop/start trip monitor Transfer data to RS-232 port Stop/start trip monitor II SELECT I EXIT II SELECT I EX
Information can only be accumulated in the memory when the engine is running, therefore a unit being towed dead-in-consist will not tally the towed miles. If a serious fault occurs in the data acquisition of running totals, all data will be reset to zero. If this occurs, the service date of the unit should be changed to the date that the reset event occurred. Requesting the “...totals to display” option from the menu will present the following two page screen.
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Choosing the lifetime or trip monitor totals options will display running total data in a format similar to the following.
Choosing any throttle data package presents the data in the following format.
EM2000 LOCOMOTIVE COMPUTER 9B-59
Selection of monthly data packages will show information as below.
ENGLISH/METRIC This function gives the user the ability to display units through the computer read out in either the English or metric numbering system. The computer will remember the last request for units. Therefore, cycling power to the computer in an attempt to “reset” the display to the familiar English units won’t work.
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SECTION 9C. AC MOTOR - THEORY OF OPERATION AC MOTOR POWER OPERATION - NO LOAD A conventional DC motor with a separately connected field and armature winding allows armature current, and consequently motor torque, to be varied independently of flux (field current). Increasing the load will cause an increase in armature current but the field current will not be changed. NOTE DC motors for locomotive traction usually have armature and field windings connected in series which precludes separate field and armature control.
NOTE: AC induction motors have no electrical connections to the rotor and no electrical connection between the rotor and stator - the stator and rotor circuits are magnetically coupled. There is no external electrical connection to the rotor therefore all voltage present on the rotor winding has to be "induced" across the air gap by magnetic fields created by stator current. Because there are three separate stator windings, one for each phase, the effects of each separate winding has to be considered in regard to any inductive effect on the rotor.
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Figure 9C-1 Simplified Diagram Of 3 Phase Induction Motor A three phase induction motor, Figure 9C-1, is constructed of a stator with one electrical winding for each phase placed symmetrically (120°) around its circumference and a rotor with a winding formed into a cylindrical cage (“squirrel cage”). An air gap separates the stator and rotor. The lack of brushes or commutator provides a simple, rugged and maintenance free design. AC MOTOR - THEORY OF OPERATION 9C-1
ENERGY FLOW IN POWER An overall view of the locomotive power system can be obtained with an energy flow diagram. Figure 9C-2 illustrates general energy flow in power operation. Chemical potential energy of the diesel fuel is converted to mechanical energy by the diesel engine to power the main generator. Energy flows from the diesel engine to the main generator to the DC link to the inverters. Traction inverters control energy flow to the traction motors that convert the electrical energy into mechanical energy to do the work of moving the train.
NOTE In dynamic brake the energy flow is essentially reversed in so far as the motors are used as generators drawing rotational energy converted from the kinetic energy of the unpowered moving train. This energy is dissipated on resistive grids. The attendant loss of energy through heat causes the train to slow down.
use F43331
Figure 9C-2 Energy Flow In Power
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GT46MAC Locomotive Servive Manual
INPUT PHASE VOLTAGES When power is applied to the motor, the supply voltage is provided to all three windings at the same instant. The position of the zero starting point of each AC voltage waveform determines when the maximum value (voltage) will occur in relation the other phases. The difference in the zero starting point between phases is called the phase angle and is designated phi φ. The applied voltage V is a three phase source - any given phase occurs 120 electrical degrees (phase angle = 120°) from the phase before and after it. These phases are designated A, B, C, and are shown in Figure 9C-3. A voltage V is applied to each winding and causes a magnetic field to occur around the winding. The AC supply causes a continuous change in polarity of the input voltage and consequently the magnetic field also switches from north to south. The magnetic field radiates outward from the core of the winding and is constantly switching poles at each end of the core from north to south as the supply voltage changes from positive to negative (alternations). The magnetic fields build to maximum value as the supply currents (voltages) go to maximum. NOTE Alternating frequencies are usually expressed in cycles per second such as 60 cycles/second. A conversion to circular units can be made by using radian measure. A radian is the distance around the circumference of a circle that is equal to the radius of that circle. There are two π radians (2π = 6.28 radians) in a circle. Waveforms that are periodic every 360 degrees can be converted to radian units because 2π radians is the same as one complete revolution of a radius vector around a circle. A representation of the input phase voltages applied to the stator windings of a three phase induction motor is shown in Figure 9C-3. Each input voltage cycle is 360° in length - waveforms are periodic in 2π (360°) with each phase occurring 120 degrees apart from the next.
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Figure 9C-3 Induction Motor Input Phase Diagram
AC MOTOR - THEORY OF OPERATION 9C-3
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Figure 9C-4 Phase A Winding Of A Three Phase AC Motor
Phase A voltage rises to +V at 90° and decays to 0 VAC at 180° before going negative. When phase A is at 120° phase B is at 0 VAC. The phase B voltage value is 0 VAC (rising) 120° after phase A voltage is 0 VAC. Phase C voltage similarly lags phase B voltage by 120°.
NOTE The continuous nature of an AC voltage supply requires that we assume an instantaneous starting point as a reference: phase A starting from 0 VAC in winding A at t0 (or 0 °). For simplification, phase voltages V A, VB, and VC are applied to stator windings A, B, and C respectively at the instant that the circuit is powered.
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GT46MAC Locomotive Servive Manual
FLUX WAVE The phasing of the three phase input voltages and the location of the stator windings causes alternating magnetic fields to rotate around the stator windings, in effect, creating a “flux wave”. Refer to Figure 9C-5.
EC31359
Figure 9C-5 Stator Flux Wave
The flux wave, which originates in the air gap between rotor and stator, interacts with the rotor winding and induces a voltage in the rotor circuit. This induced voltage causes a rotor current which sets up a magnetic field that opposes the flux wave created in the stator circuit. Because these magnetic fields are in opposition the rotor is forced to move away from the stator flux wave thereby forcing the rotor to move in the direction of the flux wave. NOTE The complex interaction between 4 poles/phase, 3 phase, varying magnetic fields on the rotor makes an exact representation on a physical level impossible. These illustrations are simplified expressions of the net effect of the magnetic fields on the motor.
AC MOTOR - THEORY OF OPERATION 9C-5
MOTOR START When starting an induction motor, the stator winding is connected to the line and a current flows through the winding and produces a rotating magnetic field that, as long as the rotor is at a standstill, revolves by the conductors at a speed equal to the synchronous speed of the machine. This sets up a heavy current in the rotor’s conductors of a frequency equal to the line frequency. As the rotor comes up to speed, the current and frequency decrease in the rotors conductors until a speed is reached where the current in the rotor is just sufficient to produce the necessary torque to carry the load. This speed must be less than synchronous speed, for if the rotor is made to revolve at the same speed as the magnetic field, it has no voltage generated in its conductors to set up a current to produce torque.
MOTOR REVERSAL Changing the direction of rotation (armature) of a DC traction motor, is accomplished by reversing the direction of current flow through the field. The direction of rotation of an AC induction motor can be changed by interchanging any two phases of the input voltage.
POWER OPERATION - APPLY LOAD SLIP FREQUENCY When a load is applied to the rotor it causes the rotor to slow down below the speed of the flux wave. The difference between the synchronous speed and the rotor speed is called the SLIP of the motor. The slip can be measured as a percentage of the synchronous speed or expressed as the slip frequency - the difference between synchronous speed and rotor speed. Refer to Figure 9C-6. When the rotor reaches the slip speed then the rotating flux wave is turning at the exact same speed as the rotor and therefore no lines of flux are being cut by the single rotor conductor we used in the example - the relative speed of the rotor to the flux wave is constant. Therefore no voltage is induced in the rotor, no current is produced in the conductor, and consequently no force is exerted on the rotor. No force exerted on the rotor means no motor torque is available and the rotor will continue to rotate at the same speed. The frequency of the applied voltage and the number of poles in the rotor determine the speed of the rotating magnetic field as it passes through the rotor conductors. If the rotor is stationary, then the flux wave will generate maximum current at the line frequency in the rotor conductors. Rotor movement will occur until the rotor reaches operating speed. If the rotor was unloaded and could speed up to approach the speed of the stator flux wave, then the lines of force in the rotating stator flux wave will not cut the conductors in the rotor circuit. If the rotor conductors are not under the influence of the flux wave, then no rotor voltage will be induced and, consequently no rotor current or motor torque will be developed. No rotor torque means that the machine will begin to slow down.
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GT46MAC Locomotive Servive Manual
0 If the rotor under load slows down it will reach a speed where the flux wave is again cutting the rotor conductors and torque is produced. This speed must be less than the synchronous speed to maintain constant motor operation - under load the rotor always rotates slower than the flux wave in the stator windings. This difference in rotating speed is called the SLIP. In real applications, this SLIP or difference in speed amounts to from 1 to 20 per cent, depending on motor design. The difference in speed between the magnetic field of the stator and the mechanical speed of the rotor is usually expressed as a percentage.
Mag Fld Spd - Rtr Spd x 100% SLIP = ------------------------------Mag Fld Spd
NOTE Depending on load conditions, the GT46MAC locomotive will operate with a much smaller motor slip at speeds above about 10 MPH.
EC31950
Figure 9C-6 Slip Frequency INCREASE LOAD : If the load is increased on the motor, the rotor decreases in
speed so that a voltage and current will be generated in the rotors conductors to produce the necessary torque to carry the load. If the increase in load is too great, the motor will be stalled. The torque developed when the motor is stalled is known as the pull-out or breakdown torque. Generally an induction motor can develop a torque that is about 1.5 to 2.5 times its rated value before stalling. AC MOTOR - THEORY OF OPERATION 9C-7
The current in the stators windings of an induction motor is limited by both the DC resistance of the winding and the counter-e.m.f. generated in the winding similar to the primary of a transformer. Under normal operating conditions, the current in the rotor conductors is in a direction to have a demagnetizing effect on the stator, so that as the load increases on the rotor, the increased current in the rotor reduces the flux due to the stator current. This in turn reduces the countere.m.f. in the stator, and a greater current is taken from the line to balance the effects of the rotors current.
OPERATING CURVE An operating curve for a simple 3 phase induction motor is shown in Figure 9C7. This curve indicates how the torque of the motor changes with an increase in motor speed.
EC31756
Figure 9C-7 AC Motor Operating Curve
Increasing the supply frequency of the voltage applied to an AC motor causes the motor speed to increase as long as rotor current continues to increase. Motor torque will increase with increasing motor speed until inductive reactance reaches a point where it starts to limit rotor current. A further increase in motor speed (frequency) and consequently inductive reactance, causes rotor current to drop off. As rotor current decreases it causes a drop in motor torque.
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GT46MAC Locomotive Servive Manual
BREAKDOWN OR PULLOUT TORQUE Breakdown or pullout torque is the maximum load torque a motor will produce while running without an abrupt drop in speed and power. Refer to Figure 9C-8. The practical operating range of the motor lies between its maximum torque (min. speed) and minimum torque (max. speed).
EC31768
Figure 9C-8 Traction Motor Operating Characteristics
AC MOTOR - THEORY OF OPERATION 9C-9
INCREASE MOTOR VOLTAGE The torque of a 3 phase induction motor could be increased by raising the supply voltage. This would increase the density of the rotating flux wave which would increase the amount of induced voltage in the rotor circuit thereby raising the induced rotor current. Increased rotor current increases the force on the rotor which is the motor torque. The drawback of this method is that in a short time the limiting value of rotor current is reached and the voltage cannot be increased any further. Refer to Figure 9C-9.
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Figure 9C-9 Increase Motor Voltage
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GT46MAC Locomotive Servive Manual
INCREASE MOTOR SPEED •
If motor input supply voltage is raised, then rotor current will go too high.
•
If frequency is raised, then rotor current goes down due to raising the impedance of the stator windings: XL = 2 π f L. The higher stator impedance causes reduced stator current with the resulting loss in flux density through the rotor.
•
The speed of the traction motor could be increased by raising the frequency of the supply voltage. But raising only the frequency of the supply will cause a reduction in rotor current because the impedance (inductive reactance) of the rotor increases with frequency. This reduction in rotor current is compensated for by increasing rotor current through an increase in supply voltage.
•
The effects of raising the supply voltage/frequency is that the flux wave is rotating at a much higher speed than the rotor and the flux in the rotor will cause the rotor to speed up creating a new synchronous speed. Refer to Figure 9C-10.
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Figure 9C-10 New Synchronous Speed
AC MOTOR - THEORY OF OPERATION 9C-11
INCREASE POWER The overall aim of the control system is to cause the traction motors to operate at a constant output torque level over the required locomotive speed range. Unfortunately, the nature of high power electric motors prevents constant torque at higher speeds. It is possible to maintain fairly constant output torque until maximum applied voltage is reached. After maximum applied voltage is reached, operation at constant horsepower to the maximum motor speed is the best that can be obtained.
INCREASE APPLIED VOLTAGE/FREQUENCY It can be seen that by increasing both the applied voltage and the frequency in the same proportion the motor operating curve will move to the right and the torque peak will be available at a higher motor speed. Refer to Figure 9-11 on this page. The voltage and frequency must be raised proportionally as an increase in motor speed is desired.
EC31772
Figure 9-11 Increase Frequency And Voltage Proportionally
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GT46MAC Locomotive Servive Manual
OPERATION BELOW MAXIMUM APPLIED MOTOR VOLTAGE Motor speed can be increased by raising the proportional value of the applied voltage and frequency until the maximum applied voltage is reached. Refer to Figure 9-12. At the maximum applied voltage value of 2000 VAC, no further increase in voltage is allowed and constant motor torque operation is no longer possible.
EC31773
Figure 9-12 Increase Motor Voltage/Frequency To Voltage Limit
AC MOTOR - THEORY OF OPERATION 9C-13
OPERATION ABOVE MAXIMUM APPLIED MOTOR VOLTAGE Once motor voltage is at maximum, operation at constant horsepower is required to keep the locomotive at its highest operating level. Refer to Figure 913.
EC31775
Figure 9-13 Increase Motor Voltage/Frequency Above Voltage Limit As motor frequency is increased with the same applied voltage (2000 VAC) the inductive reactance of the rotor circuit also increases. The increase in rotor impedance causes rotor current to be reduced and consequently, motor torque also to be reduced - the operating curve moves to the right, with a decreasing motor torque value, to the motor (and locomotive) maximum speed.
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GT46MAC Locomotive Servive Manual
DYNAMIC BRAKE In order to slow down or brake a moving object some means of decreasing its kinetic energy (KE = 1/2mv2) must be provided. Dynamic braking is an electrical method used to brake a locomotive (train) by translating the kinetic energy of the moving train into rotating energy in the traction motors. This mechanical rotating energy is converted to electrical power by using the traction motors as electrical generators. The power generated by these motors can be applied to the resistor grids which dissipate the power as heat to the atmosphere thereby reducing the kinetic energy of the train.
ENERGY FLOW IN DYNAMIC BRAKE Figure 9C-14 illustrates energy flow in dynamic brake operation. The kinetic energy of the moving train is transformed into electrical energy by the rotating traction motors acting as generators. This generated electrical energy is applied to the DC link which supplies the braking grids. The control computer directs energy flow to the brake grids where this excess energy is dissipated as heat.
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Figure 9C-14 Energy Flow In Dynamic Brake
AC MOTOR - THEORY OF OPERATION 9C-15
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Figure 9C-15 Power/Brake Motor Operating Curve NOTE The traction control converters (TCC) have the ability to transfer power generated by the traction motors back into the DC link. This dual capability to convert DC into AC (inverter) and AC into DC (converter) is what makes dynamic brake possible. The AC traction energy is converted to DC, applied to the DC link, then applied to the brake grids.
DYNAMIC BRAKING EFFORT CONTROL It may be desirable from a train control standpoint to provide a specific constant amount of retarding (braking) force for each brake handle position regardless of the speed of the train. This control system attempts to provide that characteristic but is limited at higher track speeds. Traction motors convert mechanical energy into electrical energy. Each traction motor can be considered as an electrical power generator that is loading into the brake grids. In this way, traction motor output can be thought of as providing braking horsepower for the train to the grids. .
Retarding Force (lbs) x Speed (MPH) BRAKING HORSEPOWER = ----------------------------------------------375 where 1/375 converts lbs-mile/hour into horsepower
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GT46MAC Locomotive Servive Manual
0 The dynamic brake system on this locomotive model was designed to provide a constant amount of braking effort for each brake handle position. For a given brake handle position, braking effort will remain constant until the grid power limit is reached. Refer to Figure 9C-16.
B
EC38026
A
Figure 9C-16 Dynamic Braking Effort/Speed Curves OPERATION The total dynamic braking energy must be dissipated on the brake grids. Grid resistance is lowest when grids are cold and highest when grids are hot. Assume that the grids are 1.25 ohms (HOT-) to find the highest value of grid voltage as follows.
NOTE When dynamic brake is initiated, the brake grids will change from COLD to HOT values within 30 seconds of operation. The exact HOT resistance value depends on ambient air temperature and density.
AC MOTOR - THEORY OF OPERATION 9C-17
Maximum power that the grids are able to dissipate is a total of 2940 KW- 2 parallel paths of four grids each (1.25 ohm/grid) for a total resistance of 2.5 ohms. Therefore the DC link voltage must be limited to: P = V x I P = V x V/R P = V2/R V2 = 2940000/2.5 V = 1084.4 VDC
The maximum power rating of the dynamic brake grids is 367.5 KW per grid. The grids should operate at the highest allowed value to provide the most braking effort but DC link voltage is limited at 1055 VDC. The motor must be operated at a reduced maximum voltage in dynamic brake because energy flow in power is from the inverter to the traction motor which requires that the voltage at the motor terminals be higher than the internal motor voltage. Energy flow in dynamic brake is from the traction motor to the inverter which requires that the motor terminal voltage be less than the internal motor voltage. In other words, energy flows downhill - from a higher potential to a lower potential. NOTE Calculations are based on the HOT grid resistance value of 1.25 ohms which will produce the highest power rating for a given applied DC link voltage. With dynamic braking, the electrical braking on the train is limited to the amount of electrical power that can be dissipated by the grid resistors. The GT46MAC locomotive has eight 1.25 ohm (HOT) braking grid resistors each capable of dissipating a maximum of 367.5 KW. Maximum dynamic braking will occur when the most power is being dissipated. The control computer regulates DC link voltage for dynamic braking as the locomotive slows down from higher speed. Along curve C-D on Figure 9C-16, the grids are at the maximum value of dissipated grid power which is about 2940 KW. At speeds above point C (24 MPH), grid resistance is equal to the eight brake grids connected in series-parallel which is 2.5 ohms. The maximum DC link voltage in dynamic brake is limited by the computer so as not to exceed the maximum power rating of the grids.
NOTE Braking power is more than just grid power because there is inverter and cabling losses.
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GT46MAC Locomotive Servive Manual
GRID POWER VS LOCOMOTIVE SPEED At D: Braking effort is at maximum because the traction motors are providing maximum power to the brake grids- the grids are at maximum dissipation. C to D: Constant braking horsepower - braking effort increases as train slows down because each pound of braking force is more effective as speed decreases. B to A: Below 4 MPH the traction motors do not have sufficient rotational energy to provide appreciable braking effort. At higher locomotive speed, the effective value of the power dissipated on the grids becomes less because the overall kinetic energy of the train has increased. In other words, each kilowatt of power that leaves the grids provides less braking on the train as speed increases because the dissipated power is limited by the design of the grid resistors while the energy of the train can continue increasing with speed. In the same way, as the locomotive slows down from a high speed each kilowatt of energy dissipated becomes more effective on braking the train. This process will continue until the train slows to approximately 24 MPH. At 24 MPH braking effort is at a maximum value of about 81,000 pounds of braking force or braking effort. Below this point braking effort is constant to 4 MPH. The 24 MPH break point is not related to the mechanical energy loss capability of the moving train but rather to the decrease in the motor’s efficiency as generators as they slow down. Refer to Figure 9C-16.
AC MOTOR - THEORY OF OPERATION 9C-19
PULSE WIDTH MODULATION TECHNIQUES The ideal power source for an AC motor is a sine wave voltage input. A locomotive AC traction motor has unique requirements from a generation and control standpoint: •
high horsepower output (670 HP max)
•
high power input (500 KW max)
•
high voltage input (2000 VAC max)
•
variable voltage input (0 to 2000 VAC)
•
variable frequency input (0 to 110 Hz)
•
variable operating speed (0 to 3220 RPM)
These special considerations make it too complex and expensive to control the amplitude and frequency of an AC sine wave from a mechanically driven generator or transformer. The GT46MAC locomotive has DC to AC inverters that use solid state electronic devices to synthesize a variable voltage, variable frequency, high power AC sine wave. This method uses the 5 VDC microprocessors of the inverter computers to generate and control a 2000 VAC, 3 phase AC sine wave approximation. The DC link voltage is the input voltage supply for both inverters - traction inverters TCC1 and TCC2. The inverters convert the DC link voltage into variable frequency, variable voltage, 3 phase power for the traction motors. This process is performed in the inverters with some form of pulse width modulation (PWM) that makes use of gate turn-off thyristors (GTO) to control the pulse widths. The GTOs are triggered by the inverter (secondary) computers. Conventional SCRs can be turned on with an electronic gate but can only be turned OFF by removing the supply voltage which eliminates excitation to the circuit. A Gate Turn-Off (GTO) thyristor has an electronic gate that can turn it on and turn it off. This feature allows much more precise control of an output signal without disconnecting the supply voltage from the circuit. The inverters are constructed in a modular design that allows easy service and provides interchangeability. The GTOs and diodes that make up each phase in an inverter cabinet are also packaged in a modular design that is designated a phase module.
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GT46MAC Locomotive Servive Manual
EC32746
Figure 9C-17 Traction Motor Characteristic/Inverter Pulsing
NOTE The GT46MAC locomotive reaches full horsepower at 9.3 MPH. Motor voltage will continue to increase from the start of the constant power region at 9.3 MPH until maximum applied voltage is reached.
This system uses AS (asynchronous) and SS (sinusoidal) modes while operating at constant torque then switches to R (rectangular) and BLOCK (fundamental or input frequency) when the limit of constant torque is reached and the system switches to constant power operation. At the switching point from constant torque to constant power the GTOs have reached maximum frequency so some other means is needed - operation goes into fundamental frequency PWM. All operation above maximum applied motor voltage is by BLOCK (fundamental frequency) PWM.
AC MOTOR - THEORY OF OPERATION 9C-21
LOCOMOTIVE OPERATING CHARACTERISTICS The ideal locomotive would supply constant tractive effort over its entire speed range of operation. High tractive requirements make it impractical for the power equipment to fulfill this condition at higher locomotive speeds. At higher speeds the control system regulates at a constant kilowatt level (or horsepower) being delivered to the traction motors over the remaining speed range. The main limitation on constant tractive effort delivery is that the traction motors are unable to provide a constant motor torque over their operating speed range. Maximizing motor torque results in maximum tractive effort. To provide the most torque from the traction motors at all times, the control system attempts to keep the motors operating at the torque peak as long as possible - constant torque is provided; then, from the point of maximum applied voltage the control system will maintain constant horsepower. Constant horsepower operation produces a continual lowering of the torque peak which lowers tractive effort and produces the traction motor operating curve shown in Figure 9C-18.
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Figure 9C-18 Traction Motor Operating Values NOTE In actual locomotive operation, full horsepower (constant power) is available at 9.3 MPH and applied voltage continues to rise to maximum as speed increases. The torque of the traction motor is applied to the wheel through the wheel/axle gear ratio. This gear ratio changes the torque value that is applied to the wheel. Traction motors can operate at high speed but provide little torque. At the locomotive wheel, what is needed is lots of torque with little speed. The locomotive gear ratio converts the speed of the motor into torque at the wheel.
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GT46MAC Locomotive Servive Manual
0 Because the pinion gear and axle gear are meshed at the tooth contact area, the forces at this point must be equal and opposite when the locomotive is powered - the gear ratio changes the ratio of torques - a greater number of teeth on the axle gear causes this force to be distributed over a longer radius thereby increasing the torque on the wheel. In this way, motor torque is transmitted to the wheel. The wheel torque is then applied to the rail in the form of tractive effort which is the force of the wheel on the track. Refer to Figure 9C-19.
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Figure 9C-19 Tractive Effort At Wheel Overall control of the locomotive is maintained by the primary (EM2000) computer that is located in the #1 electrical cabinet. This computer is instructed through “programs” to provide the maximum value of motor torque for each throttle position and operating condition. The amount of torque produced by each traction motor is transferred to the wheel and proportioned by the overall locomotive gear ratio to produce tractive effort at the wheel. Tractive effort provided by each wheelset combine to produce the overall locomotive performance characteristics shown. The maximum value of traction motor torque for continuous operation is 13190.5 NM foot-pounds per motor. This amount of torque is translated by the locomotive gear ratio (90:17) and applied to the locomotive wheel. The amount of tractive effort that can be developed is independent of locomotive weight. The tractive effort that can be utilized on a particular locomotive is dependent on locomotive weight. The primary consideration in determining tractive effort is the ratio of tractive effort to weight on the driven axle. Refer to Figure 9C-19. If tractive effort (in pounds) exceeds 25% of the weight (in pounds) on a particular locomotive axle, then the chance of a slipping wheel is high. Of course, the actual tractive effort is determined by the rail conditions at that instant. AC MOTOR - THEORY OF OPERATION 9C-23
AC MOTOR POWER/DYNAMIC BRAKE THEORY •
NOTE AC MOTOR WITH NO LOAD - Inverter frequency = Motor electrical frequency
•
AC MOTOR IN POWER - Inverter frequency above motor electrical frequency
•
AC MOTOR IN BRAKE - Inverter frequency below motor electrical frequency In dynamic brake, traction motor torque must be developed in the opposite direction to power operation. This requires that the motor be re-oriented to act as a generating device instead of a power device. During power operation, the inductance of the motor causes motor voltage to lead motor current - a leading edge voltage (lagging power factor) waveform. In dynamic brake, power must flow out from the inverter to the DC link. The DC link is not allowed to drop below 600 VDC in dynamic brake. This lowered potential is seen by the traction motor as a current sink and the capacitance of the inverter input filter changes the power waveform into leading edge current (leading power factor) which re-orients the motor into a generating device. The inverter input filter capacitor facilitates power flow INTO the DC link because of its lower potential and creates a leading edge current to force the motors to act as generators. The power generated by the motor is supplied to the DC link where it is dissipated on the brake grids. Dynamic brake operation is possible with AC motors because the output frequency of the inverter is made lower than the motor operating frequency which produces negative SLIP. Negative slip causes negative torque in the motor which causes it to slow down.
NOTE In dynamic brake, the GTOs are out of the circuit and all of the motor generated current goes through the GTO circuit diodes.
9C-24
GT46MAC Locomotive Servive Manual
SECTION 9D. INVERTER OPERATIONS NOTE! Schematics are provided ONLY as an example. Be sure to refer to the proper schematics when working on a GT46MAC locomotive.
This section deals with many of the concepts concerning the operation and protection of the inverters used for AC traction systems on the GT46MAC. Descriptions of individual components used to execute the functions described here come in the following sections.
GTO SWITCHING An inverter with voltage source DC Link suits the requirements for a three phase generation system quite well. The use of GTO thyristors in such an application allows for a wide range of output voltage frequencies. This design exhibits a high efficiency by virtue of the use of GTOs. Figure 9D-1 shows the fundamental configuration of a VSI three phase system. The system consists of a voltage source supply (DC Link), a large capacitance connected in parallel with the source (marked Cd) to stabilize the voltage source, and three phase modules to perform the switching of DC Link for inversion to AC. Each phase module can be distinguished by the dotted lines drawn in rectangular fashion. The GTOs of three phase modules combine to create a three phase AC input to the wye connected fields of the traction motors. By varying the switching patterns of the GTOs, the inverter controls the amplitude (voltage) and the frequency (rotating speed) of the AC wave form. For the sake of simplicity, we will consider only one of the three wave forms produced by the inverter.
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Figure 9D-1 Simplified Inverter Schematic A thyristor is a special kind of diode. As we all know, a diode will conduct electricity only when forward biased by the voltage placed across it. A thyristor is nothing more than a diode that can be given a “signal” telling it when to conduct. INVERTER OPERATIONS 9D-1
When the signal is given, the thyristor will conduct, provided of course that it is “forward biased.” Many of us are already familiar with this type of thyristor, the Silicon Controlled Rectifiers or SCRs used in the excitation circuit of the locomotive’s Main Generator (Traction Alternator). In this case, the SCR receives a “turn-on” signal and remains conductive until it becomes reverse biased. In other words, there is no way to “tell” the SCR to stop conducting. However, a GTO is a type of thyristor which can be “told” to turn off, hence the name Gate Turn-Off thyristor. So, a GTO can really be thought of as a switch. What makes a GTO “turn-on?” A thyristor, as mentioned in the previous paragraph, is selectively conductive. The element will begin conducting when it receives an “injection of electrons” on its gate lead from some external source. With an SCR, the element continues to conduct until such time that the forward voltage across it has gone to zero or below. A GTO, however, can stop conducting if that “injection of electrons” is drawn back. If for some reason the "injection" cannot be withdrawn, the GTO cannot shut off. Such a condition would be recognized by the inverter computer, and operation would cease. In this particular case, the fault logged would likely read "GTO STORAGE TIME EXCEEDED." In other words, the injection of electrons has been stored in the GTO for too long, and since it has not been withdrawn by this point in time, the inverter shuts down. Why shut down the inverter in such a case? The GTO's in a phase module alternate on and off. Both GTOs in a module can never be on at the same time otherwise the DC Link will see a direct short circuit. So since one of the GTOs cannot be turned off, we must stop operation before the other GTO of the same phase module turns on in order to prevent an overcurrent condition. Figure 9D-2 shows the fundamental system design with the GTO's drawn as switches.
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Figure 9D-2 GTOs shown as switches With these “switches” in place, it becomes easy to connect and disconnect each output leg with either positive or negative DC Link. Now, by specifying GTO switching durations and their sequence in time, output voltages can be created which closely follow a sine curve. Again, both the wave frequency and amplitude can be adjusted by changing GTO switching patterns. Let’s take a look now at an example of how a variable AC waveform can be passed on to the motors.
9D-2
GT46MAC LOCMOTIVE SERVICE MANUAL
0 Let’s start with a simple condition that must be met. In order to have a defined voltage across a phase winding in the motor, two GTOs must be switched on to complete a circuit through the motor. In other words, we cannot just connect one side to positive DC Link and let the other side float. From analyzing the inverter block sketch, we see that the two GTOs of the same module cannot be switched on simultaneously for two reasons. First, from circuit analysis we can see that this will not give us a complete circuit through any phase. Secondly then, two GTOs from different phase modules must be used to create a phase. The creation of so called “phase-to-phase” voltages (voltage between two output terminals) are considered here. The possible phase-to-phase voltages are:
Uv1 = Urs = Ur - Us
Uv2 = Ust = Us - Ut
Uv3 = Utr = Ut - Ur To create Uv1, GTOs 1, 2, 3, & 6 must all work together. An example of this can be seen in Figure 9D-3. Notice in this demonstration that DC Link negative is actually called zero. This is for simplified mathematics in demonstration. The diagram shows a randomly selected switching sequence from the many that are possible. Let’s examine the sequence over the time span indicated, and learn how the GTOs all collaborate to create the fundamental phase-to-phase wave. Assume that Ud = 100, and that a new switching state occurs every second.
INVERTER OPERATIONS 9D-3
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Figure 9D-3 Output Wave Formation by GTO switching At t=1, 3+6 are switched. Since phase R connects directly to the zero side of the input, the level of Ur equals zero on the graph of Figure 9D-4; likewise, Us equals +100 because phase S connects directly to the positive side of the input in this switching state. If we recall the formula from before that stated Uv1 = Ur Us, we can substitute these values and find what the voltage should be.
Uv1 = Urs = Ur - Us
Uv1 = Urs = 0 - 100 = -100 According to our computations, the resultant voltage should equal -100 at this point. The graph in Figure 9D-3 shows this to be true for the time t=1. Let’s take a look at the next step. At t=2, 6+2 are switched. Both phase R and phase S are connected to the zero side of the input. Remembering the formula again, it is easy to see that the resultant voltage between phases R and S should be zero. 9D-4
GT46MAC LOCMOTIVE SERVICE MANUAL
0 Common sense also tells us this since voltage is nothing more than a measurement of the difference in electrical potential between two points. The section of the graph at t=2 shows the resultant voltage at zero as expected. Notice also that the sine wave is beginning to take shape as voltage rises. At t=3 and t=4, 1+2 are switched. This condition connects phase R directly to the positive input and phase S to the negative. Again, using the formula or just plain common sense, it can be seen that the voltage between phases R and S will be +100. The graph illustrates this. Notice that the polarity of the phases has now reversed as must be the case to have an alternating or AC current flow. As the resultant voltage reaches its peak here, the sine wave is now more recognizable. When t=5, 1+3 are switched. This creates zero voltage between phases R and S since both phases are connected to the positive side of the input. As usual, the graph does verify the existence of zero as the resultant potential. The resultant sine wave has begun its decent toward zero on its negative going cycle. Finally at t=6, the switches return to their initial state of 3+6 turned on. Just as with the sample examined from t=1, the voltage resultant here equals -100. We have now completed one full cycle of a particular GTO switching sequence. This particular sequence is known as full block. Not by coincidence, it happens to be the simplest of all switching patterns. It is typically used at very high motor RPM. Now let’s take a look at how all of the switching comes together to create a 3 phase simulated AC output. Figure 9D-4 shows when each phase module is connected to the positive or zero side of the input. Furthermore, this figure shows which GTOs are switched simultaneously and how the modules work together to create a 3 phase output. Notice that a module by itself cannot create a phase; it must work with the other modules. Now take a look at the same figure when a GTO has failed open. For the case demonstrated in Figure 9D-5, GTO #3 has failed. Notice the disruption in the phase symmetry.
INVERTER OPERATIONS 9D-5
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Figure 9D-4 Creation of a Three-Phase Output
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Figure 9D-5 Inverter Output with GTO #3 Failed Open 9D-6
GT46MAC LOCMOTIVE SERVICE MANUAL
PHASE VOLTAGES INSIDE THE MOTOR Up until this point, we have seen how the inverter creates its 3 phase output to the load (motor). However, we have not seen what the voltage steps or “chops” look like inside the motor. Figure 9D-6 shows a graph measuring voltage on each of the 3 Phases inside the motor. Previous examples have shown phase to phase measurements. This illustration though, shows a measurement from the input lead to the center point of the Y-connected motor field. These are the voltages that are directly responsible for the formation of the rotating magnetic field.
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Figure 9D-6 Motor Field Voltages as a Result of GTO Switching. Each time a new GTO switching state occurs, the motor field phase leads are connected across the DC Link in a different configuration. As a result of the variable connections, the varying voltage levels develop. To help understand how each GTO switching state creates the voltage shown on the graph, Figure 9D-8 diagrams the actual field winding connections during those particular switching states. The switching states of the graph have been numbered to match with the corresponding motor field configurations. Assume the DC Link input voltage to be 300 VDC and the impedance of each field winding to be 10W. In state #1, GTOs 3, 5, & 6 are switched on. Examining the simplified schematic shown in Figure 9D-7 it can be seen that this causes phases S & T to be connected to DC Link positive, while phase R connects with DC Link negative. Using simple circuit analysis and Ohm’s Law, it can be deduced that phases S & T measure +100 Volts with respect to the Y-center point, while phase R measures -200 Volts. The graph of Figure 9D-6 follows this assessment.
INVERTER OPERATIONS 9D-7
.
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Figure 9D-7 Simplified Inverter Schematic
Figure 9D-8 Motor Field Configurations Still assume that DC Link input voltage is 300 VDC. In state #2, GTOs 2, 5, & 6 are switched on. The simplified schematic shows that this situation causes phase T to connect with DC Link positive, while phases S & R connect with DC Link negative. Again using simple circuit analysis and Ohm’s Law, we see that phase T has a potential of +200 Volts with respect to the center point, while phases R & S measure -100 Volts.
9D-8
GT46MAC LOCMOTIVE SERVICE MANUAL
0 Continuing on this repetitious path, we can prove all of the claims made by the graph for each of the 6 motor field configurations using the same principles as above.
PULSE WIDTH MODULATION The maximum possible phase-to-phase voltage output from the inverter depends on the DC-Link voltage input. The maximum possible output can be calculated from the formula. MAX Uv
= .78Ud
In other words, phase to phase output can equal only as much as 78% of the input voltage. Such a case can exist when the full block switching pattern as demonstrated previously is used. For lower output voltage settings, the GTOs are switched so that partial areas of the widths defined in the previous example can be removed. The sine wave output is a result of the average value of DC Link switched on over a time period. In the first demonstration, a “full block” of DC Link was passed through to the output of the inverter without interruption, hence the name “full block.” Keeping the Link switched on without interruption means a high average value. If portions of the “full block” are cut out or chopped, though, the average value goes down as more is cut out. This concept is demonstrated in Figure 9D-9. In this example, the resultant wave is controlled by cutting out six areas.
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Figure 9D-9 “Full block” (not chopped) modulation creates sine wave
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Figure 9D-10 “Chopped” DC Link creates a sine wave. Operation at 7-pulse modulation The number of areas to be cut out of a wave will always be even, while the number of pulses left over will always be odd. In Figure 9D-10, 5 pulses are left over, so the inverter is said to be operating at 5-pulse modulation. The number of pulses in a pulse train can be any odd number from 1 to 21.
INVERTER OPERATIONS 9D-9
Notice that the duration of each pulse becomes longer as the center of the pulse train approaches, and then the pulse pattern on the trailing part of the train is merely a mirror image of those on the leading end. Also observe that a longer pulse duration creates a higher resultant wave. By varying the duration or width of each pulse, the resultant or fundamental wave voltage can be modulated. This method of control is referred to as pulse width modulation. Achieving different fundamental wave voltages by varying pulse width is illustrated in Figure 9D10. All of the 3 examples use 3-pulse modulation with various pulse widths to obtain the desired voltage output.The frequency of the output voltage wave is controlled by the length of the pulse train. A shorter pulse train means a higher frequency.
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Figure 9D-11 Pulse duration varies voltage. Examples show operation at 3 pulse modulation
9D-10
GT46MAC LOCMOTIVE SERVICE MANUAL
MODULATION MODES Before diving into this subject, let’s clearly define two terms that are key to understanding the following discussion. Inverter output frequency is the frequency of the voltage wave being sent from the inverter to the traction motors. GTO switching frequency is how quickly the GTO thyristors on turning off and on in order to create the inverter output voltage wave. It is entirely possible to have switching frequency be equal to output frequency, while it is also possible to have switching frequency exceed output frequency by nearly 25 times. With this said, let’s take a look at how these two frequencies are related. During operation, demands on the inverter with regards to range of frequency output vary continually. The inverter best controls the motors when the pulse number is the highest allowable. The demands for frequency range can be met by changing the length of a pulse train. Herein lies a limitation. The maximum switching frequency remains possible to only a certain rotor RPM, after that the inverter cannot switch the GTOs fast enough (field frequency must exceed rotor frequency to maintain power operation).
At very low speeds, the inverter operates at the maximum GTO switching frequency. This is known as “free modulation.” The inverter adjusts output voltage and frequency through pulse width modulation as explained earlier. The inverter maintains outstanding control over the motors; since such a great number of switching pulses per train is possible, it can regulate output voltage very closely. As the rotor spins faster, though, the GTOs must also switch faster to provide the required output frequency.
Eventually as rotor speed continues to increase, the inverter cannot switch the GTOs any faster, so an even number of pulses must be eliminated from the pulse train. The inverter now operates in n-pulse modulation, where n = the number of pulses in a pulse train. As stated earlier, n can be any odd number from 1 to 21; 1 would be “full block,” and 21 would be very near to “free modulation.” Again, as the rotor of the motor spins faster, the switching must become more rapid until eventually the inverter cannot switch the GTOs any faster. Once again, the inverter eliminates a few pulses from the train. By removing pulses from the train, the inverter sacrifices a certain amount of control over the motors. However, as speed increases precise motor control becomes less critical. So since motor speed has increased in this case, nothing is really lost by eliminating just a few pulses from the train as speed increases.
As the motor approaches the upper speed range, the inverter can no longer switch fast enough to produce multiple pulses in a pulse train. At this point, the inverter will supply only one pulse per half wave of AC; in other words, the inverter will operate in a full block mode. Full block in the high speed range has the special name of fundamental frequency modulation. This just means that the GTO switching will be at the exact same frequency as the inverter voltage wave output frequency. Since this is a full block mode, pieces cannot be cut out to reduce the voltage of the resultant wave. Rather, the input source must change when running at high speeds in fundamental frequency modulation. Figure 9D12 shows each of the 3 inverter modulation modes over a speed range and how the number of pulses in a pulse train becomes less as output frequency rises. INVERTER OPERATIONS 9D-11
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Figure 9D-12 Modulation Modes. Let’s interpret this graph by following the solid jagged line across. Examine point 1 where the inverter output frequency is very low. This means that motor speed will be very low, hence maximum GTO switching frequency is possible and looking at the graph we can see that in fact free modulation is active. Remember that maximum switching frequency is desirable since it affords the greatest amount of motor control. The line makes a sharp drop soon after. This drop is at point 2 on the graph. The inverter had been operating at maximum GTO switching frequency as demonstrated by the flat top portion following point 1. As motor speed increased, switching frequency came near to violating the minimum GTO "ON" time, so in order to maintain power operation (field frequency must exceed rotor frequency) a few pulses must be eliminated.
9D-12
GT46MAC LOCMOTIVE SERVICE MANUAL
0 Continuing from point 2 of the graph, the slope of the jagged line indicates that as field frequency increases GTO switching frequency must also increase in order to maintain a field that runs faster than rotor speed (field frequency must exceed rotor frequency for power operation). At point 3 on the graph we see that again the inverter has reached the maximum GTO switching frequency. So, in order to maintain a field that runs faster than the rotor, the inverter must reduce the number of pulses in a train just as before. This process is repeated over and over throughout the operating range of the inverter. As speed climbs into the upper reaches of the inverter’s operating range, the number of pulses in a pulse train goes to one (at about 40 MPH). This is the case at point 4 on the graph. Once the drop on the graph is made to 1 pulse per half wave or train, the inverter is now said to be in fundamental frequency modulation or full block mode.
DYNAMIC BRAKE/REGENERATIVE OPERATION BRAKE MODE CONCEPT The basic concept of dynamic braking has not changed a bit in the switch from DC to AC technology. The motors harness the mechanical energy created by the rolling train and convert it to electrical energy. This electrical energy is sent through low resistance, high power grids. The electrical load of these grids make the motor (which is now actually operating as a generator / alternator) very hard to turn. This reluctance to rotation acts to slow the train down. Exactly how the motors are controlled, and how energy passes from the motors up to the grids has changed somewhat. On a DC locomotive, the generator connects to the fields of the traction motor. The generator provides a variable power source used for excitation in the motor field windings. For more braking effort, the generator supplies more excitation. The energy created by the rotating machine far exceeds the energy supplied to it by the generator. Excitation of the AC machine is fairly similar. As we already know, the generator does not vary its output in order to control the power input to the traction motors; rather, the inverters control how much of the power available from the generator is passed on to the motors. The same variable excitation concept holds true, though. The more excitation supplied by the inverter, the greater the braking effort of the motor. Let’s take a closer look at how the entire AC system works together.
INVERTER OPERATIONS 9D-13
The Main Generator produces 600 VDC at all times. However, power from the generator is used in only two unique situations: 1. When first entering regenerative operation. 2. When braking effort is extremely low and speed is low. When neither of these cases is true, the excitation system is self-supplying. Each TC receives data from the EM2000 with instructions for how much braking effort to provide. Each TC Computer then decides on its own exactly how to provide the excitation in the motors required to achieve the braking effort requested by the EM2000. As in power, the inverters have the ability to correct for wheel slips independently of each other. Variable amounts of excitation are achieved via the same method as in power; the GTOs fire in sequence. Different firing patterns are used to attain various excitation levels. For brake mode, excitation is provided such that field frequency (or rotational speed) is less than rotor rotational speed. The motion of the rotor moving faster than this rotating field creates average power flow back into the inverter. The power that flows back into the inverter is rectified to DC by the free-wheeling diodes in each phase module before being passed on to the DC Link capacitors. The capacitors make operation of the entire system more energy efficient, however they add complexity in construction and function. They serve two purposes here: 1. Supply a constant energy source for motor field excitation. 2. Smooth out ripple in DC Link from both the generator and the rectified output from the inverters. As stated in point #1, the capacitors act as the constant energy source for the inverters in brake mode. This is why the AC system is much more energy efficient in brake mode than the DC system. We don’t need the generator at all times during dynamic braking. The motor excitation is self-supplying except at low braking effort/low motor speed. Figure 9D-13 and Figure 9D-14 provide an analogy for how this occurs. Inverters take their supply from DC Link. Initially, the capacitors are uncharged, in other words the pool is empty. So the generator, putting out 600 VDC, begins to pump “water” into the pool thereby charging the capacitors. As the motors begin to see excitation, they begin to produce output. This output is pumped into the DC Link. Because the motors are producing much more power than they are consuming from the pool, the pool quickly “fills up.” When the voltage on the DC Link exceeds that across the Main Generator, the rectifying banks connected to the generator become reverse biased. This shuts off the output of the generator, symbolized by the float valve. The grids act as a drain for the pool. Any energy not used for excitation is drained off through the grid resistors.
9D-14
GT46MAC LOCMOTIVE SERVICE MANUAL
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Figure 9D-13 “Full pool” of DC Link” Assume now that the locomotive operates at low speed, and a low amount of braking effort is requested. A low braking effort means that very small amounts of energy will be drained from the pool for excitation purposes. Likewise, due to the low excitation level and low rotor speed, the power pumped back into the pool as regenerative power will be of a small amount. Notice however, that the “big drain” still exists since the grid resistors are still in place. Without the generator available, the grids would drain the pool very quickly. With the pool drained, there would be no energy left for excitation of the motors and brake operation would not be possible. This is demonstrated by Figure 9D-14.
INVERTER OPERATIONS 9D-15
.
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Figure 9D-14 Main Gen. sustains DC Link "pool" level when "draining." AC POWER FLOW IN BRAKE MODE Regenerative operation of an AC induction machine is not easy to explain. To examine the entire braking process, consider first a DC machine in a generating mode. In this case, a stationary magnetic field is established in the stator of the motor. The momentum of the train causes the motors to turn. As the motor turns, the armature “cuts through” the stationary magnetic field in the stator. This “cutting” generates a current flow in the armature which is spent through resistor grids. On this DC machine, four power cables run to the motor. Two cables connect to the fields, and two to the armature. The cabling that runs to the grids makes connection with the armature by use of brushes and a commutator. For power operation, all leads connect to the generator, while only the field leads do so in brake mode; the armature leads connect to the resistive grids. This brings up an interesting question when considering an AC machine. Only 3 power cables connect with the motor. These cables supply the 3 phase AC source needed by the motors in both power and brake mode. For more braking effort, the inverter supplies more power to the fields. So, if power must always flow into the motor in order to excite the fields (regardless of the operating mode), how can power also flow out of the motor on the same 3 power leads? The key to the answer is remembering that we now deal with AC current and voltage waves rather than steady DC supplies.
9D-16
GT46MAC LOCMOTIVE SERVICE MANUAL
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Figure 9D-15 DC in brake mode (left) Figure 9D-16 AC traction system in brake mode(right) The power that flows on these 3 leads is in alternating directions at all times. In power mode, power flows into the motor most of the time, but out of the motor for very brief intervals. In brake mode, power flows out of the motor most of the time, but into the motor for very brief intervals (this is necessary for excitation purposes). Power is defined by two components, voltage & current. The direction of power flow depends on the relationship between voltage and current with respect to time or "phase relationship." The "phase relationship" depends on speed of the rotating field with respect to the rotating speed of the rotor. If rotor speed lags field speed, voltage and current are nearly "in-phase" and power flows into the motor most of the time; if rotor speed exceeds field speed, voltage and current are "out of phase" by nearly 180° and power flows out of the motor most of the time. This is illustrated by Figure 9D-17 & Figure 9D-18 which show voltage and current relationships with respect to time ("phase relationships") for both power and brake mode. Power flow into the motor is denoted by light grey areas while flow out of the motor shows as dark grey.
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Figure 9D-17 Power Flow in Power Mode.
INVERTER OPERATIONS 9D-17
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Figure 9D-18 Power Flow in Brake Mode. Another way to understand mathematically how power flows in the AC motor is by mathematical calculation. To do this, we must consider the formula for calculating power in the machine as seen here
P=3VIcosø where 3 represents the 3 phases of the motor, P=power, V=AC voltage, I=AC current, and ø=phase angle between voltage & current. For our demonstration purposes, we can make things a bit simplified by dropping the 3 from the equation. V & I magnitudes as well as their angle of separation determine the magnitude of power flow. But, direction of power flow is defined by the cosø term, therefore we must understand the meaning of the cosø term in the equation.
THE MEANING OF COSØ The way to tackle the cosø term is to show how ø is measured, then examine how cosø affects the equation. ø is defined as the degree or angle of separation between voltage and current. Figure 9D-19 & Figure 9D-20 illustrate how the degree of separation is measured.
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Figure 9D-19 Phase shift in power mode
9D-18
GT46MAC LOCMOTIVE SERVICE MANUAL
F43640
Figure 9D-20 Phase shift in brake mode Now that we have a better understanding of the cosø term, let’s consider it’s mathematical effect on the finished product of the equation for power. The cosø term always results in some value between +1 and -1. For our concerns, the magnitude requires little attention, but the sign of the value determines if power flow is positive (into the motor) or negative (out of the motor). The table here shows the value (positive or negative) of cosø for various ranges of ø. mode power brake brake power
ø 0°-90° 90°-180° 180°-270° 270°-360°
cosø positive negative negative positive
power flows into motor out of motor out of motor into motor
EFFECT OF IPS ON DYNAMIC BRAKE DC traction locomotives commonly implement a form of "extended range" dynamic braking which maintains near maximum brake effort from 24 MPH down to approximately 10 MPH. To accomplish this, DC units would short out segments of the brake grid thereby reducing the effective resistance of the load on the motors. The AC traction units have the ability to provide maximum braking effort down to almost 5 MPH without the use of such contactors. This is because the TCCs maintain very precise control over the frequency of power supplied to the motors. During this extended range operation, wheel slides are very possible, especially when air brakes are applied to the locomotive. Therefore, DC traction units deenergize the contactors that provide the extended range capability as a means of lowering brake effort and minimizing the likelihood of a wheel slide anytime that the Independent Pressure Switch (IPS) picks up. AC units don't have these contactors, therefore the method of brake effort reduction is a bit different. Anytime IPS picks up on AC traction units, brake effort automatically ramps down from the "flat-top" portion of the B.E. versus speed curve to a reduced level which would be equivalent to a DC locomotive operating at the samespeed without extended range capability.
INVERTER OPERATIONS 9D-19
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Figure 9D-21 Reduced BE with IPS picked up.
TCC PROTECTION SCHEME In order to protect the TCC in the event of potentially damaging situations, a system called IPS (Inverter Protection System) has been installed for each inverter. The system consists of several monitoring devices and power dissipation components. Essentially, two crowbar type circuits make up the system. The two crowbar circuits are of different types, one a soft crowbar and the other a hard crowbar. Before getting too involved in the protection scheme, let’s first define what a crowbar is. When most people hear the word “crowbar,” they think of a large steel tool in the shape of a cane used for prying. How can this tool be associated with an electrical circuit? To explain an “electrical” crowbar, follow this example which employs the “steel” crowbar.
Figure 9D-22 Simple source/load circuit Consider the circuit shown in Figure 9D-22. A source provides an output via bus bars. Between the bus bars and the source is a circuit breaker. The bus has wires coming off of it that supply a load. The purpose of an electrical crowbar device is to protect both the load and supply from potentially damaging overvoltage and overcurrent conditions. To do this, obviously current and voltage must be monitored.
9D-20
GT46MAC LOCMOTIVE SERVICE MANUAL
0 If those monitored values exceed values set by software or hardware, then protection is activated which intentionally short circuits the source. How does this function make the device similar to the “steel” crowbar? Consider the circuit as shown in Figure 9D-23.
Figure 9D-23 Crowbar analogy When protection is activated, the “steel” crowbar is dropped across the bus bars creating a dead short circuit of the source. Obviously, this would trip the circuit breaker rather hastily. As mentioned before, two methods of protection (either a “hard” or a “soft” crowbar) can be initiated. The hard crowbar creates an authentic short circuit of the source with virtually zero resistance. The soft crowbar performs the same action, but with a resistance in series of approximately 3 Ohms. This resistance is the IPR (Inverter Protection Resistor) discussed in Section 9E of this manual. In both cases, the EM2000 is instantly notified of the crowbar firing, and Main Generator excitation is shut down. The signal that the crowbar fired can either come via serial link or be detected directly by EM2000 DC Link current feedback signals. The serial link signal, DC Link Current feedbacks, and EM2000 collectively make up the "circuit breaker" in this high power circuit. In any case, since generator excitation ceases, the output will rapidly decay through the crowbar and protect the traction system from further damage potential. Tripping of either crowbar comes at the command of Siemens equipment only! All locomotive components outside the TCC, including the EM2000, do not have the capability of triggering a crowbar. Conditions for which an SC (soft crowbar) may be fired are listed here. •Number of peak current Total Blocking incidents is too high for a given time span. •Motor current is too high more than twice in 1 second or three times in 10 seconds and Total Blocking attempts to control the condition are not effective. This may be an indication of a faulty transducer! •No load TCC output current exceeds ±100 A and Total Blocking attempts to rectify condition are ineffective. •DC Link Overvoltage. Total Blocking not effective. •User requests crowbar test through EM 2000.
INVERTER OPERATIONS 9D-21
•Serial link informs ASG that the other TCC has attempted to trip its soft crowbar.
The hard crowbar can be fired by either the ASG or by hardware built into the Inverter Protection System. All trips are initiated by the ASG unless otherwise noted. Events that can cause the triggering of the hard crowbar are listed here. •BOD initiated due to DC Link overvoltage. All ASG attempts to suppress the condition have failed. •TCB initiated due to GTO storage time exceeded. •Serial link informs ASG that other TCC attempted to fire its hard crowbar. •User requests crowbar test through EM2000. •ASG power supply breaks down. •Gate Unit power supply out of range. •DC Link overvoltage before BOD trip level. •Approximately 1.5 seconds after soft crowbar fires. Done to remove burden from the IPR (Inverter Protection Resistor). The table below describes the actions taken by the IPS in response to various DC Link overvoltage conditions. Level 3000 VDC 3200 VDC 3400 VDC 3600 VDC 1700-2100 AAC* 2300 AAC 2400 AAC
Action Block GTO firing until 2600 VDC ASG triggers soft crowbar ASG triggers hard crowbar BOD triggers hard crowbar Block faulty phase Block all phases ASG fires hard crowbar
*Depending on throttle position, speed, etc.
As shown by the progression of the table, the inverter reacts more aggressively as DC Link levels climb higher. If possible, the TCC brings the faulty condition back under control by simply interrupting GTO firing pulses (Total Blocking). Occasionally, this may not be enough and the ASG fires the soft crowbar. If the soft crowbar fails to control the situation fast enough (or simply fails to fire) DC Link may continue to rise. Also, DC Link may rise so fast that the soft crowbar may not catch the “run away” condition. For these reasons, the ASG would fire the hard crowbar. Finally, as a last resort the BOD element may signal for the trigger. The BOD (which is entirely independent of the ASG) is intended only as a backup device in the case that software cannot act for protection. For example, if the ASG fails and DC Link goes out of control, then the BOD comes to the rescue.
9D-22
GT46MAC LOCMOTIVE SERVICE MANUAL
0 As a rule, it is desirable for the soft crowbar to attempt to provide protection before firing HC. Some situations, however, call for the more drastic measures provided by the HC. For example, if a GU power supply (device PS-GTO) is out of range or “STORAGE TIME EXCEEDED” fault is signalled by the Thyristor Control Board (TCB), the HC fires immediately. Storage Time Exceeded indicates that a GTO could not be switched off. Likewise, improper GU power supply may prevent a GTO from being switched off. Such faults create an impending DC Link short circuit condition through the GTO thyristors. GTOs are not designed to handle such high current levels. They would easily be destroyed and possibly create further inverter damage. For this reason, drastic corrective action must be taken immediately, thus the firing of the hard crowbar before the soft. In response or reaction to any crowbar action, the locomotive drops its load, and both ASGs as well as the EM2000 record a fault to document the event. To recover from such an event, the EM2000 will automatically cycle the DC Link switchgear to the shorted position once DC Link has sufficiently decayed to ensure that the crowbar thyristors disengage. (Remember that crowbar thyristors are just like SCRs in the Main Generator excitation circuit; they will continue to conduct until forward voltage goes to zero.) Provided that another crowbar event has not occurred within the past 10 minutes, the switchgear will automatically motor back to the power position. Also, both inverters run automatic self tests to verify that operation is still possible. Once this is done, the EM2000 and Traction computers bring the locomotive back on line without the operator touching a single button. The time for this entire sequence may take as long as 20 seconds. The table of the previous page mentioned "blocking" as a protective action. A module in the ASG called "Control Systems Monitoring" monitors critical variables such as current, voltage, temperature, and CPU processing time. Should any of these variables exceed a pre-set limit, this module initiates an action called "Total Blocking" which interrupts GTO firing pulses momentarily until the faulty condition has been suppressed. Figure 9D-24 demonstrates Total Blocking in the case of an output current fault. If Total Blocking takes place too many times within a certain time span, TCC operation ceases and a fault is logged.
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Figure 9D-24 Total Blocking.
INVERTER OPERATIONS 9D-23
SECONDARY WHEEL SLIP PROTECTION
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Figure 9D-25 K-band radar location on the GT46MAC Microprocessor controlled locomotives built by Electro-Motive in the past have all used a “wheel creep control” system to enhance rail adhesion. Studies show that allowing the wheels of the locomotive to turn slightly faster than ground speed increases the adhesion ratio for that locomotive. In so doing, however, the locomotive can no longer rely upon the feedback signals generated by traction motor speed pick-ups, axle generators, or any other sort of wheel speed sensing device for an estimation of ground speed. Since an accurate assessment of ground speed is essential in calculating the amount of “wheel creep” allowed at any given moment, some alternative method of measuring ground speed must be implemented. The method employed on the GT46MAC is K-Band RADAR.
Figure 9D-25 shows the K-RADAR module and its mounting location under the cab of the locomotive near the end plate. This particular type of RADAR system mounts at an angle of 37.5° with respect to the rail. It is particularly susceptible to signal error as a result of inaccurate mounting. More information on RADAR, including how to troubleshoot suspected defects, can be found in Section 9J of this manual.
When the RADAR system fails to operate or provide an accurate signal, then “wheel creep control” as executed by the EM2000 is no longer possible. The same was true for older model DC locomotives. In the past, the EMD control system would fall into its “back-up” wheel slip detection / correction system called IDAC (Instantaneous Detection and Correction). With the AC traction systems built by Siemens, a similar situation occurs.
9D-24
GT46MAC LOCMOTIVE SERVICE MANUAL
0 The IDAC back-up wheel slip system is no longer a part of the EMD control system logic. Whenever the RADAR signal is determined to be invalid (in the instance of a RADAR failure), the Siemens back-up wheel slip system takes over. The back-up system is a sort of hybrid of the old IDAC system that so many are familiar with, and the Super Series wheel creep control that evolved with the EMD 50 Series and later locomotives. To understand the system, let’s take a look at a simulated “strip” chart to examine system reaction to various events. Figure 9D-26 shows the strip chart simulation for a single inverter to be examined. Only speed and torque will be examined here. The lower portion of the graph shows torque. The upper shows wheel speed. Delta N or dN is the amount of creep the wheels are allowed. Adding this number to the actual ground speed, N, yields the value for wheel rotational speed limit at that particular time. For example, if ground speed, N, is 5 MPH, and dN is 0.7 MPH, then the wheels will be allowed to rotate at a maximum of 5.7 MPH. If the wheels exceed 5.7 MPH, then torque from the inverter will be reduced.
F43646
Figure 9D-26 Torque vs. Speed strip chart Following the chart from the left we encounter point 1. Speed is at 5 MPH and the wheels have begun to exceed ground speed, but they have not yet reached the restricting N+dN limit. For this reason, torque remains steady. As time goes by we come to point 2; wheel speed has exceeded the N+dN limit. In order to control the wheels, torque must be reduced as the chart demonstrates. Once wheel speed falls back below its N+dN limit, then torque can be steadily increased again. This is represented at point 3. At point 4, the wheels hover just below the N+dN limit, but never exceed it. For this reason, torque is not reduced. At point 5, we notice that a RADAR failure has occurred recently. When a failure occurs, the Siemens system takes over. It sets an N+dN limit of approximately 10% of the last valid ground speed measurement. This is what makes it different from the IDAC system of the past. At this point, we see that the torque reduction in the event of N+dN being exceeded is much more aggressive than the primary creep control system. Furthermore, the recovery back to full torque takes longer as well.
INVERTER OPERATIONS 9D-25
The main difference in the back-up wheel creep system and the primary wheel creep systems are as follows. •Back-up has only one N+dN limit. It cannot adjust the limit based on speed, throttle, etc. •Back-up system reaction to wheel slip is much more aggressive. •Back-up system is much slower to recover.
9D-26
GT46MAC LOCMOTIVE SERVICE MANUAL
SECTION 9E. TCC COMPONENTS NOTE:
For maximum safety wear high voltage gloves (>4000 V DC) during the measuring and grounding process. Discussions in previous Sections have covered some of the major AC traction system components in light detail. In this Section, we will cover each of the components housed by the Traction Converter Cabinet (TCC) as well as any components closely related with (and sometimes assumed to be a part of) the inverter. Traction computers (also known as Traction computers or a TC) receive more attention in this section where each printed circuit board and component in the TC room is discussed. Much of the information contained in this module was provided by Siemens Transportation Systems.
SAFETY PRECAUTIONS Before discussion of any traction inverter system components takes place, some safety precautions pertaining to work with high voltage systems must be covered. Unlike the high voltage circuits implemented on conventional DC traction locomotives, the AC inversion system design requires storage elements (capacitors). In order to ensure safe working conditions, proper discharge and grounding procedures must be followed. This procedure can be found on WARNING tags on the High Voltage Cabinet upper doors in the cab. Be certain to adopt these practices when working near high voltage circuitry on this locomotive. As the inverter on this locomotive is of the Voltage Source type, capacitors connect in parallel with the load to provide a constant voltage supply. Eight “cannon type” capacitors per TCC form a storage bank for energy. This bank has the capability of storing a fault condition DC Link overvoltage charge of 3600 VDC, though the nominal charge does not exceed 2700 VDC. Several automatic discharge systems operate on this unit. Recommended procedures, according to the publication, "Safety Precautions for GT46MAC Locomotives", ought to be pursued.
DANGER! High Voltage within Cabinets Be sure to follow the discharge procedures as outlined in the publication “Safety Precautions for GT46MAC Locomotives” in appendix C when working on High Voltage Components
TCC COMPONENTS 9E-1
ORIENTATION AND LAYOUT The traction system of the GT46MAC utilizes one TCC or inverter per truck. Figure 9E-1 shows the location of each of these cabinets. Cabinet orientations, with respect to the locomotive, do not match identically. The phase module side of each cabinet is noted in the diagram.
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SIDE VIEW
Figure 9E-1 Cabinet locations.
1. 2. 3. 4. 5. 6.
KNORR electronic air brake equipment (engineer's side). High Voltage Cabinet. #1 inverter cabinet. AC cabinet (engineer's side). #2 inverter cabinet. Battery box.
Let’s examine the Figure 9E-3, and assume for the sake of example that we are talking about TCC #1. For clarity, walls and doors that might otherwise obstruct the view are not shown in the diagram. View 1 shows the TCC as seen from the operator’s side walkway. In the shorthood side of the cabinet are the Phase Modules, A1, A2, & A3. Mounted directly to the longhood side of each Phase module is a Gate Unit, A1-11, A211, & A3-11. In the upper left portion of the view (longhood end) resides C11..15, the capacitive grounding set of capacitors, as well as temperature probe F2, a PT 100 type which measures air temperature above the R2 snubber resistor. Taking up a large portion of the view here is the capacitor bank C1..C8. These are the DC Link Capacitors. Access to the terminals is gained only from View 1. The elements are mounted in a recessed location to provide working space. Just below the DC Link capacitor bank are the components used in the Inverter Protection System or IPS. Components of the IPS are discussed later in the section. Below the IPS, very near to the walkway, sits a row of connectors Xa..Xg. 9E-2
GT46MAC LOCOMOTIVE SERVICE MANUAL
0 These connectors are the TCCs link with the entire outside world including EM2000 interface, feedbacks from probes, and outputs to drive devices. Mounted below the IPS, near the center of the cabinet but toward the longhood, is C21..24. This bank composes a snubber capacitor used in conjunction with the R2-snubber resistor seen in Views 2 & 3. View 2 shows the opposite side of the cabinet. Again assuming we look at TCC #1, this view can be seen from the conductor’s side walkway. The DC Link Capacitor bank, C1..8, comes nearly flush with this side of the cabinet. In other words it is not recessed as it was from the other side. The upper left or shorthood side contains the TC which is called out as TCC A5 in the drawing. Just below the TC room mounts the snubber resistor, R2. This ribbon grid type resistor requires a cooling air flow which is generated by the M1 blower mounted directly behind it. Below R2 are the DC Link input terminals P & N, as well as the 3-phase output terminals R, S, & T which connect to the traction motors.
F43651
Figure 9E-2 View of the TCC Terminals Box As in View 1, the IPS mounts directly below C1..8. Finally, in the lower right portion of View 2 is L1..3. This reactor limits DC Link current surges when the GTO thyristors fire. View 3 of the cabinet can be seen from the Dynamic Brake Grid Blower Motor room just behind the High Voltage Cabinet. The TC room occupies the upper right or conductor’s side of the TCC. In the center appear components X1, X2, Z1, Z2, etc. These are contained within the Traction Computer room. Most are power supply components. Along the left or operator’s side of the TCC, are the phase modules. In the lower center area is C21..24, which was also identified in View 1. The snubber capacitor group actually resides at the rear of this view or in the longhood side of the cabinet. In the center of the entire cabinet is the blower, M1. Recall that air is drawn in across the phase modules and forced out through the snubber resistor. Lastly, several feedback devices mount in the lower right of this view. U1 is the DC Link Voltage transducer, while U3..5 are the output current transducers (one per phase). Also, T1 & T2, which are output voltage transformers, mount here and monitor two of the three phase voltages (which is sufficient for calculating motor field flux). TCC COMPONENTS 9E-3
Figure 9E-3 Traction Converter Cabinet views
The cabinets mount 180° opposite each other. Air is taken from the central air compartment and used for cooling and pressurizing in some (but not all) parts of the inverter cabinet. This air supply keeps dirt from contaminating areas containing DC Link Capacitors, Gate Units, and Traction computers. Because the source is the central air compartment, the air has already been inertially filtered. In addition to this filtering, a paper filter for each cabinet located under the cabinet just below the phase modules serves to clean the supply an extra step. This air supply is not the same as that used for phase module cooling. Air for phase module and cabinet cooling comes directly from the ambient supply. A blower in each cabinet driven by its own 3-phase AC, motor draws the air in across the modules and expels it across the R2-snubber resistor. Since the cabinets mount opposite each other, air draws in on the engineer’s side of the locomotive for TCC #1, and in on the conductor’s side for TCC #2. Figure 9E-1 shows the proper direction for air flow through each cabinet. 9E-4
GT46MAC LOCOMOTIVE SERVICE MANUAL
INVERTER COMPONENTS The contents of the inverter cabinet can, for the most part, be sorted into four categories. These groups are: 1.Power parts 2.Protection parts 3.Feedbacks 4.Traction Computer parts. We begin here by examining the power parts which involves components needed for creating a smooth supply of three-phase AC power to the traction motors from the DC Link input voltage. Be aware that many components within the inverter may carry DC Link voltage regardless of physical appearance or size!
POWER PARTS TCC BLOWER The blower motor is, as mentioned before, a dual speed three-phase AC induction motor. It can operate as a parallel-Y wound machine for high speed, and as a series-Y wound machine for lower speed. (Only the low speed configuration is used on GT46MAC locomotives) Power for the motors is taken from the Companion Alternator through the main contacts of TCC1SS and TCC2SS. From the contactors, power is routed to the Xg connector in the TCC. Connectors Xa..Xg can be seen in Figure 9E-4. The Xg connector is the interface for power connections to the motor between EMD & Siemens wiring.
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Figure 9E-4 TCC connectors Xa..Xg.
TCC COMPONENTS 9E-5
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Figure 9E-5 TCC Blower motor The EM2000 exercises control of the blower contactors at the request of the Traction computer via RS-485 serial link. The blower is one of the Siemens components that does appear in the EMD schematic as well as the Siemens print. Notice that wire identification from the Xg connector to the blower does not appear in the EMD print, but does (as color-coded) in the Siemens drawing.
F43654
Figure 9E-6 TCC Blower in EMD print 9E-6
GT46MAC LOCOMOTIVE SERVICE MANUAL
F43655
Figure 9E-7 TCC Blower in Siemens Print
PHASE MODULES Phase modules are used to “chop” the DC Link into a simulated three-phase AC system which is used as Traction motor input. An evaporation bath dissipates thermal losses of the GTO thyristors and other elements contained within the module. This bath fills up approximately 2/3 of the container. As seen in Figure 9E-8, each module contains 2 GTO thyristors (V1, V2), 2 free wheeling or anti-parallel diodes (V3, V4), snubber elements, heating elements, and a temperature probe. All components within the module, with the exception of the temperature probe and heating elements, are permanently fixed in a clamping compound. Semiconductors V1..6 are assembled in columns with heat sinks between them. Mounted externally on the module (but not permanently) is a Gate Unit, shown in Figure 9E-8 as two boxes labeled A11. The Gate Unit consists of two Gate Drivers and a two channel controller. The Gate Unit serves as an interface between the Traction Computer and the GTO. This assembly is discussed more in detail later in this module. TCC COMPONENTS 9E-7
The snubber circuit within the phase module consists of 6 capacitors (C1..C6), 3 resistors (R1..R3), and two more diodes (V5, V6). This snubber circuit acts to limit voltage spikes on the AC side of the inverter created by GTO switching (snubber capacitors C21..C24 serve this function on the DC side). An external ribbon grid type snubber resistor consumes overloads of the snubber circuit within the phase module. Notice that only major power components and a few snubber elements within the module are shown.
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Figure 9E-8 Phase Module circuitry There are 12 terminals on each phase module. The connections are as follows.
Terminal #
9E-8
Purpose
1
Connects to R2 snubber resistor
2
Positive DC link input
3
AC load output (to Traction motor)
4
Negative DC Link input
5
Heater power supply from CA6A
6
Heater power supply from CA6A
7
Not used
8
Not used
9
GTO (V2) gate supply
10
GTO (V2) gate return
11
GTO (V1) gate supply
12
GTO (V1) gate return
GT46MAC LOCOMOTIVE SERVICE MANUAL
0 There are a few ways in which the TC can detect a suspected phase module failure. First, if DC Link Voltage breaks down without one of the crowbars being fired, a short circuit of the DC Link via GTO thyristors may be possible. Second, the Gate Unit may signal that one of the GTOs could not be switched off, meaning possible GTO failure. Third, an overcurrent at the output of the module may indicate a failure. HEATING ELEMENTS The heating elements are resistors R4.7 which are permanently fixed within the module. Module heating is needed for proper operation of the semiconductors at extremely low temperatures (The heating elements are not connected on the GT46MAC locomotives).
F43663
Figure 9E-9 Gate Unit Assembly.
GATE UNIT ASSEMBLY A Gate Unit Assembly performs essentially the same duties as the FCD module does in the EM2000 control system. The GTO is a “controllable” semiconductor just as the SCRs in the Main Generator excitation circuit are. In order to control when these semiconductors do conduct, a control signal must be applied. Unfortunately, the required signal is much stronger than a computer’s 5 VDC circuitry can provide. Therefore, an intermediate device (signal transformer or booster) must be implemented. This device, in the case of the TCC, is the Gate Unit Assembly or GU. A GU mounts on the front of each phase module with screws. The assembly consists of three separately shielded sections. Two of the sections are identical. The two identical sections are the “gate drivers.” Each gate driver controls a single GTO. At the bottom of each gate driver are three LEDs: one red, one yellow, one green. The location of these indicators is illustrated by Figure 9E-10. TCC COMPONENTS 9E-9
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Figure 9E-10 Bottom view of Gate Unit showing LED location These LEDs indicate the following LED color RED
Meaning Firing pulse received from TC
GREEN
No firing pulse received from TC
YELLOW
Fault condition. Firing pulse not received by GTO. Signal lost on GU wiring or bus bar from GU to phase module
WARNING Be aware that the black shielding covers on the Gate Unit Assembly, as well as many other inverter parts, are under high voltage when loading! If the Assembly functions properly, both the red and green LEDs should appear to be “on” simultaneously whenever the locomotive is loading to that inverter. In actuality, they are pulsing on and off at a very rapid frequency, so high that the human eye cannot detect it. In fact, the two LEDs are (again in actuality) never “on” at the same time; they alternate (but again the human eye cannot detect this). Should the yellow LED appear “on” at any time, this may be an indication of a failed Gate Unit. The yellow LED actually indicates that the GTO never received its firing pulse. This firing pulse may have been lost due to a wiring/connection failure resident to the GU or on bus bar connections between the GU and phase module. The third section of the Gate Unit Assembly is a two channel controller. This controller acts as the interface between the 5 VDC system of the Traction Computer and the high voltage output on the “Gate Drivers”, which drive the GTO thyristor. On the cover shield of this portion is a 10 terminal AMP-plug. This plug “locks” into position via plastic clamps on either side when applied, to ensure continuity of connections. During normal operation, the plug tends to "sag" in the receptacle ever so slightly. This movement causes momentary loss of continuity in the connections. Many times, the connection is tie-wrapped to prevent this trouble. The pin configuration of the plug follows. 9E-10
GT46MAC LOCOMOTIVE SERVICE MANUAL
Pin #
Signal
1
24 VDC power supply
2
24 VDC power return
3
GTO (V1) ON
4
GTO (V1) OFF
5
GTO (V2) ON
6
GTO (V2) OFF
7
GTO (V2) storage time exceeded fbk. to TC
8
GTO (V2) storage time exceeded fbk. to TCB (A11)
9
GTO (V1) storage time exceeded fbk. to TCB (A11)
10
GTO (V1) storage time exceeded fbk. to TC
Weak Gate signals from TC
Pins 1 & 2 are the 24 VDC GTO power supply that originates from PS-GTO (power supply). This power enters the TCC via connectors 1XE and 2XE pins 2 & 4. Pins 3-6 of the controller connector carry the "weak" gate signals from the TC. These are current signals of 70mA. Pins 7 & 10 provide feedback to the TC via 12 VDC signal to indicate a storage time exceeded fault. These signals, as well as the "weak" gate signals can be measured with respect to common on the 15 volt power supply (board C121). Be sure and measure the signal with respect to the C121 Module for the inverter being worked on. Pins 8 & 9 provide same signals to the Thyristor Control Board (TCB). In the case of the TCB feedbacks, though, a 70 VDC signal means everything is OK, while
Pick Up Contactor
