ELECTRONIC LOCOMOTIVE CONTROL SYSTEM IIA Caterpillar

Service Procedures

Usage:

Replacement Procedures

8.1: Mounting Group

Introduction

"4.12: Installation Diagrams (diagram 2)" shows the layout of the mounting group. There are six mounting holes for this group. All external electrical connections are via two terminal strips (TB391 and TB392). There is a pressure port connection for the barometric pressure measured downstream of the air cleaners.

Replacement Procedure

1. Disconnect the locomotive system wiring from TB391 and TB392.

2. Disconnect the pressure port connection on the derate module.

3. Temporarily secure the mounting group. Remove the six mounting bolts and remove the mounting group.

4. Locate the new mounting group. Insert and secure the six mounting bolts.

5. Re-connect the locomotive system wiring to TB391 and TB392.

6. Re-connect the pressure port connection to the derate module.

7. Remove the personality module from the old mounting group and fit it to the new mounting group according to "8.3: Personality Module".

8.2: Main Governor Box

Introduction

"4.12: Installation Diagrams (diagram 2)" shows the layout of the mounting group that contains the main governor box. This box is mounted using eight mounting bolts. The electrical connections are via 2 connectors, J1 and J2.

Replacement Procedure

1. Disconnect the harnesses from the J1 and J2 connectors.

2. Temporarily secure the governor box. Remove the eight mounting bolts and remove the governor box.

3. Locate the new governor box. Insert and tighten the eight mounting bolts.

4. Re-connect the J1 and J2 harnesses to the new governor box.

5. Remove the personality module from the old mounting group and fit it to the new mounting group according to "8.3: Personality Module".

6. Attach the self adhesive decal to the top face. This must be aligned carefully to the LED "window" prior to application.

8.3: Personality Module

Introduction

"4.12: Installation Diagrams (diagram 2)" shows the layout of the mounting group that contains the main governor box which the personality module bolts to. This personality module is mounted with four mounting bolts at its corners.

Replacement Procedure

1. Disconnect all electrical power to the mounting group.

2. Remove the four bolts from the four corner holes. The gasket sealant on the underside of the module has adhesive qualities which may make removal of the module difficult. Insert two of the four bolts into the two end holes marked "A" in the module. Tighten the two bolts to remove the personality module. Remove the two bolts from the original personality module.

3. Carefully clean all remnants of gasket sealant material from the surface of the main governor box.

4. Remove and discard the shipping cover, gasket and 2 bolts from the underside of the replacement personality module. Ensure that the underside flange surface of the replacement personality module is clean and free of all shipping cover gasket material and other foreign material.

5. Apply 6V6640 Gasket Maker to the underside flange surface of the replacement personality module.

NOTE: When attaching the personality module to the main governor box it is important that the electrical connector on the personality module is properly aligned with the electrical connector on the main governor box.

6. Insert two bolts into opposite corners of the personality module and use these as alignment guides while attaching it to the main governor box.

7. Install the remaining two bolts and then tighten all four bolts.

8.4: Altitude Derate Module

Introduction

"4.12: Installation Diagrams (diagram 2)" shows the location of the derate module on the mounting group that contains the main governor box. This module is mounted with two mounting bolts. The electrical connections are via nine terminals. There is a pressure port plumbed to the engine air inlet system between the air cleaners and the turbo chargers.

Replacement Procedure

1. Disconnect the harness from the terminal strip.

2. Disconnect the tube from the pressure port.

3. Remove the two mounting bolts. Remove the derate module to the plate.

4. Locate the new derate module. Insert and tighten the two mounting bolts.

5. Re-connect the tube to the pressure port.

6. Re-connect the harness to the terminal strip.

8.5: Non-Altitude Derate Module

Introduction

Replacement Procedure

1. Disconnect the harness from the terminal strip.

2. Remove the two mounting bolts. Remove the derate module to the plate.

3. Locate the new derate module. Insert and tighten the two mounting bolts.

4. Re-connect the harness to the terminal strip.

8.6: Diode Block

Introduction

"4.12: Installation Diagrams (diagram 2)" shows the location of the diode block on the mounting group that contains the main governor box. This block is mounted with two mounting bolts. The electrical connections are via 16 terminals.

Replacement Procedure

1. Disconnect the harness from the terminals.

2. Remove the two mounting bolts. Remove the diode block.

3. Locate the new block. Insert and tighten the two mounting bolts.

4. Re-connect the harness to the terminals.

8.7: Temperature Sensor

Introduction

This sensor is used to measure the coolant temperature at the inlet to the aftercooler. The sensor is a thermistor. At the system level it is used to lower the output power of the engine in the upper notches in a tunnel when the locomotive's cooling system is inadequate for the engine to deliver full power.

This sensor has 2 leads, each 24 inches long and mounts in a straight-thread O-ring port. Some early engines were equipped with similar sensor packaged to fit in a pipe-thread port. These early sensors are equipped with shorter leads, each terminated with a connector.

Replacement Procedure

Right Side View (Typical Example)
(1) Temperature sensor.

1. Drain the coolant to a level substantially below the level of the sensor.

2. Remove the cover from the pull-thru box mounted on the right side of the engine front housing just to the rear of the rack actuator.

3. Disconnect the sensor leads from TB254-B1 and TB254-B2 located inside the pull-thru box.

4. Cut the terminals from the sensor leads.

5. Loosen and remove the stainless steel braided conduit fitting from the rear of the sensor.

6. Pull the sensor leads out thru the loosened conduit.

7. Remove the old sensor (1).

8. Install a new O-ring (3K0360) onto the new 3E0380 sensor (1) and install the new sensor on the engine.

9. Insert the sensor leads thru the braided conduit and pull the excess lead length into the pull-thru box mounted on the right side of the engine front housing just to the rear of the rack actuator.

10. Attach the conduit to the rear of the new sensor and tighten securely.

11. Cut excess length from the sensor leads and attach the crimp-on terminals.

12. Connect sensor leads to TB254-B1 and TB254-B2.

13. Install the cover on the pull thru box.

14. Refill the cooling system.

Procedure To Replace The Pipe Thread Sensor

1. Drain the coolant to a level substantially below the level of the sensor.

2. Remove the cover from the pull-thru box mounted on the right side of the engine front housing just to the rear of the rack actuator.

3. Disconnect the sensor leads from TB254-B1 and TB254-B2 located inside the pull-thru box.

4. Cut the terminals from the sensor leads.

5. Pull the sensor leads out thru the flexible metal conduit.

6. Remove the old sensor.

7. Install the new sensor on the engine.

8. Remove the connectors from the new sensor leads.

9. Splice 24 inches of 16 gauge exane insulation wire onto the ends of each of the new sensor leads.

10. Individually insulate the splices with shrink tubing and then insulate the two wires as a group with shrink tubing. Make sure the second outer tubing is long enough to reach beyond the end of the flexible metal conduit.

11. Insert the extended leads into the end of the flexible metal conduit and pull the excess lead length into the pull-thru box mounted on the right side of the engine front housing just to the rear of the rack actuator.

12. Cut excess length from the sensor leads and attach the crimp-on terminals.

13. Connect sensor leads to TB254-B1 and TB254-B2.

14. Install the cover on the pull thru box.

15. Refill the cooling system.

8.8: Temperature Interface Module

Introduction

This module is used to convert the coolant temperature sensor resistance (thermistor) into a DC voltage used by the main electronic control box to lower the power of the engine in the upper notches.

Location

8.8.2.1: Normal Location

Junction Box
(1) Temperature interface module.

The normal location of the temperature interface module (1) is inside the lid of the engine mounted junction box located on the lower right hand side of the engine just ahead of the rear housing.

8.8.2.2: Alternate Location

Engine Junction Box
(1) Temperature interface module.

The temperature interface module (1) is located inside the junction box that contains the start/stop and safety shutdown logic. This box was remote mounted on some engines and engine mounted on others (located on the right hand side of the rear housing).

Replacement Procedure

1. Disconnect the harness from the terminals 1 thru 5.

2. Remove the two mounting bolts making note of the correct assembly sequence for the various washers on the bolts. Remove the module.

3. Locate the new module. Insert and tighten the 2 mounting bolts (with the washers correctly assembled on them).

4. Re-connect the harness to the terminals.

8.9: Rack Position Sensor

Introduction

This sensor is used to sense engine load in the upper notches by measuring the fuel system rack position.

It is a linear potentiometer used in a voltage divider to produce a voltage proportional to rack position. This voltage is converted to a digital pulse coded signal by an analog to digital converter module. The converter module is wired directly to the sensor without the use of a connector and is therefore an integral part of the sensor assembly.

Location

This assembly is located on the left hand side of the front engine housing.

Rack Sensor And Housing
(1) Rod. (2) Guide. (3) Bolt. (4) Housing. (5) Spring. (6) Box assembly. (7) Digital converter module. (8) Bolt. (9) Locknut. (10) Collar. (11) Bolt.

The body of the sensor is located inside housing (4) which is attached to the front housing by four bolts (3). The body of the sensor is retained in the housing by an adjustment collar (10) and locknut (9) which hold the body against spring (5).

Rod (1) connects the sensor plunger to the internal rack linkage of the engine. This rod is supported by bushing (2).

The adjustment collar and locknut are housed in box assembly (6) which is attached to the rear face of the housing by four bolts (8). This box also houses the analog to digital converter module (7) and the sure-seal connectors for connection to the engine harness.

The engine harness enters the box through flexible metal conduit.

Replacement Procedure

1. Remove the cover of box assembly (6).

NOTE: This cover has captive screws that are not intended to be fully removed. The analog to digital (A/D) converter module (7) is also bolted to it.

2. Remove the mounting bolts and nuts (11) that hold the A/D module (7) to the cover. Pay careful attention to the assembly sequence of the various washers on the bolts.

3. Unplug the sensor connector from the engine harness connector.

4. Remove locknut (9) and slide it up the sensor leads.

5. Remove collar (10) from housing (4).

6. Remove the sensor body and A/D module from housing (4).

7. The collar (10) has a slot in it to assist in its removal from the sensor assembly. Remove the collar. Also remove spring (5) and locknut (9) from the sensor assembly.

8. Attach spring (5), locknut (9) and collar (10) to the new sensor assembly.

9. Insert the sensor body into housing (4) and partially tighten adjustment collar (10) into housing (4).

10. Plug the sensor connector into the engine harness connector.

11. Mount the A/D module (7) onto the box cover with the mounting bolts and nuts (11). Ensure that the assembly sequence of the various washers on the bolts is correct.

12. The sensor is now ready for calibration. Refer to Rack Sensor Calibration for the proper calibration procedure.

13. After calibration securely attach the box cover to the box (6).

8.10: Step (Temperature) Derate Switch

Introduction

This switch is used as a back up to the primary temperature derate function which is linear as a function of coolant temperature at the inlet to the aftercooler.

This switch shorts the linear temperature output signal of the temperature interface module to 0 volts at temperatures above its trip point. This will cause the electronic governing system to switch to full temperature power derate.

The set point and linear schedule are such that when this step becomes active, the linear derate would normally be at full derate.

Replacement Procedure

Right Side View (Typical Example)
(1) Step (temperature) derate switch.

1. Drain the coolant to a level substantially below the level of the sensor.

2. Remove the cover from the pull-thru box mounted on the right side of the engine front housing just to the rear of the rack actuator.

3. Disconnect the switch leads from TB254-T3 and TB254-T4 located inside the pull-thru box.

4. Cut the terminals from the switch leads.

5. Remove the access plate from the elbow at the rear of the switch.

6. Pull the switch leads out thru the access hole in the elbow.

7. Loosen and remove the conduit from its fitting on the elbow.

8. Remove the nipple, elbow and conduit fitting assembly from the rear of the switch.

9. Remove the old switch (1).

10. Install the new switch (1) using 5P3413 Pipe Sealant.

11. Insert the new switch leads thru the nipple and out thru the access hole in the elbow.

12. Secure the nipple, elbow and conduit fitting assembly to the rear of the new switch.

13. Attach the conduit to its fitting on the elbow and tighten securely.

14. Insert the new switch leads back into the access hole in the elbow and into the conduit and run them down into the pull thru box.

15. Cut excess length from the new switch leads and attach the crimp-on terminals.

16. Connect new switch leads to TB254-T3 and TB254-T4.

17. Install the cover on the pull thru box.

18. Refill the cooling system.

8.11: Speed Sensor

Introduction

The speed sensor is an active Di-Mag type that requires DC power which it receives from an isolated DC to DC power supply built into the main electronic control box. This sensor has a 3 pin connector. It is located on the engine flywheel housing and is used to count the starter ring gear teeth.

Replacement Procedure

1. Unplug the engine harness connector from the rear body of the sensor.

2. Loosen the locknut and remove the sensor from the flywheel housing.

3. Check that the center of one of the ring gear teeth is aligned with the center of the sensor hole. If not bar the engine over to achieve alignment.

4. Install new sensor into flywheel housing.

5. Screw sensor fully clockwise by hand until the tip of the sensor bottoms out on the ring gear tooth (do not apply excessive torque, use manual pressure).

6. Slowly turn the sensor body counterclockwise between 1/2 and 3/4 turn and tighten the locknut to 70 ± 14 N·m (50 ± 10 lb ft).

7. Inspect to determine whether the engine harness connector is now aligned correctly with sensor the connector.

If the connectors are not correctly aligned loosen the 90 degree end-bell on the back of the engine harness connector and rotate the body of the connector to achieve proper alignment. Tighten the end-bell.

8. Plug engine harness connector into the back of the sensor.

8.12: Scaling Network

Introduction

The scaling network is normally located within the main high voltage electrical cabinet. Refer to the locomotive prints for the precise location. This module is mounted using four mounting bolts. The electrical connections are through TB399.

Replacement Procedure

1. Disconnect the locomotive wiring from TB399.

2. Remove the four mounting bolts and remove the module.

3. Locate the new module. Insert and tighten the four mounting bolts.

4. Re-connect the locomotive wiring to TB399.

8.13: Wheelslip Module

Introduction

The wheelslip module is mounted on a mounting group which is normally located within the main high voltage electrical cabinet. Refer to the locomotive prints for the precise location. This module is mounted using four mounting bolts. The electrical connections are through TB393 and TB394.

Replacement Procedure

1. Disconnect the wiring from TB393 and TB394.

2. Remove the four mounting bolts and remove the module.

3. Locate the new module. Insert and tighten the four mounting bolts.

4. Re-connect the wiring to TB393 and TB394.

8.14: Electronic Speed (Overspeed) Switch

Introduction

This module provides the following functions for the START/STOP/SHUTDOWN logic:

* Crank/terminate speed switch.

* Oil step speed switch.

* Overspeed switch.

* Nine second time delay.

* Engine has stopped turning indication.

Location

The Electronic Speed (Overspeed) Switch is located in the remote mounted junction box that also contains the start/stop and shutdown logic. On a limited number of early engines this box was engine mounted (located on the right hand side of the rear housing).

Replacement Procedure

1. Disconnect the harness from the Electronic Speed (Overspeed) Switch terminals.

2. Remove the four mounting bolts making note of the correct assembly sequence for the various washers and soft-mount bushings on the bolts.

3. Locate the new module. Insert and tighten the four mounting bolts (with the washers and bushings correctly assembled on them).

4. Re-connect the harness to the Electronic Speed (Overspeed) Switch terminals.

5. Calibrate the Electronic Speed (Overspeed) Switch according to "8.16: Electronic Speed (Overspeed) Switch".

Calibration Procedures

8.15: Rack Sensor

Introduction

Each individual personality module has a unique set point or reference defined in its memory to calibrate this rack position sensor.

Each engine is set up so that the calibrate position is the maximum mechanical rack limit.

The sensor is calibrated by setting the electronic governing system into the calibrate mode and holding the rack linkage against the maximum mechanical rack screw. The governing system then compares the sensor signal with the calibration set point in the personality module memory and indicates, through an LED display, which way to turn the adjustment collar to achieve correct calibration.

Calibration Procedure

1. Shut the engine down.

2. Manually move the rack linkage and hold it against the maximum stop screw with a rubber bungee cord.

3. Remove the plug on the personality module labelled "CAL" and turn the now exposed calibration switch clockwise with a small screwdriver.

Note the status of the four lower LED's on the front face of the main governor box. The status displayed should be one of the three indicated(Turn Cal In, Cal Correct, Turn Cal Out).

It is possible, if the sensor is severely out of adjustment, that diagnostic code 1 is being displayed. This is normal.

Rack Sensor And Housing
(1) Rod. (2) Guide. (3) Bolt. (4) Housing. (5) Spring. (6) Box assembly. (7) Digital converter module. (8) Bolt. (9) Locknut. (10) Collar. (11) Bolt.

4. Remove the cover of the sensor box assembly (6).

NOTE: This cover has captive screws that are not intended to be fully removed. The A/D converter module (7) is also bolted to it. This cover must therefore be securely taped to the box body to avoid damaging the sensor leads by letting the cover hang on them.

5. Loosen locknut (9).

6. Adjust collar (10) according to the status of the LED display to obtain a "CAL CORRECT" display on the LED's.

NOTE: If diagnostic code 1 is being displayed it will be necessary to first experiment by slowly turning the collar from fully counterclockwise (threads barely engaged) to fully clockwise until the code 1 goes away.

7. Tighten locknut (9).

8. Loosen the bungee cord and move the rack linkage several times from shutoff to maximum and then resecure it against the maximum screw with the bungee cord.

Make sure that the LED display still displays a "CAL CORRECT" status.

If not, loosen the locknut and recalibrate. Repeat until the LED continually displays "Cal Correct".

After calibration remove the bungee cord, securely attach the box cover to the box (6). Turn the calibrate switch in the personality module counter clockwise and install the plug.

8.16: Electronic Speed (Overspeed) Switch

Introduction

This procedure covers the calibration of the following functions:

* Crank/terminate speed switch setting.

* Oil step speed switch setting.

* Overspeed switch setting.

For the full checkout procedure refer to "8.21: Electronic Speed (Overspeed) Switch".

Calibration Procedure

This procedure requires an 8T5200 Signal Generator/Counter Group and a 4C6534 Harness. Special Instructions, SEHS8579 and SEHS8657 give complete details for use of these tools.

8.16.2.1: Initial Hook-up

1. Disconnect the speed input harness connections to switch terminals 3 and 4.

2. Hook up the 8T5200 Signal Generator/Counter Group to switch terminals 3 and 4 using the 4C6534 adapter harness. Refer to Special Instruction, SEHS8657, for hook-up procedure.

3. Refer to Special Instruction, SEHS8579, for procedures on adjusting the signal from the 8T5200 service tool and reading its frequency.

8.16.2.2: Crank Terminate Calibration

1. Set the frequency to 0 Hz.

2. Measure the voltage on ESS terminals 10, 11 and 12 with respect to TB395-R1.

Terminal 10 should be at 0 volts.

Terminal 11 should be at battery positive (+).

Terminal 12 should be at battery positive (+).

If terminal 10 is not at 0 volts, there is a problem with the junction box wiring or the switch.

Disconnect all wires from switch terminal 10 and recheck the voltage. If it is now at 0 volts there is a problem with the junction box wiring. Refer to "4.13: Wiring Diagrams" to investigate. If terminal 10 voltage is still not 0 volts there is a problem with the switch. Replace it according to "8.14: Electronic Speed (Overspeed) Switch".

If terminal 11 is not at battery positive (+), there is a problem with the junction box wiring. Refer to "4.13: Wiring Diagrams" to investigate.

If terminal 12 is not at battery positive (+), there is a problem with the switch. Replace it according to "8.14: Electronic Speed (Overspeed) Switch".

3. Slowly increase the input frequency until;

* Terminal 10 is at battery positive (+).

* Terminal 11 is at battery positive (+).

* Terminal 12 is at 0 volts.

Note this frequency.

4. Remove the plug covering "Crank Terminate" potentiometer.

5. Step 3 frequency should be 900 ± 10 Hz (295 ± 3 rpm).

If it is not adjust the crank terminate potentiometer and repeat steps 1 thru 3.

6. Repeat step 5 until step 3 frequency is 900 ± 10 Hz (295 ± 3 rpm).

8.16.2.3: Oil Step Calibration

1. Set the frequency to 0 Hz.

2. Remove the plug covering the "OIL STEP" potentiometer. Note that there is an LED visible through the exposed hole.

3. Slowly increase the input frequency until the LED comes on. Note this frequency.

4. Step 3 frequency should be 3507 ± 10 Hz (1150 ± 3 rpm).

If it is not adjust the oil step potentiometer and repeat steps 1 thru 3.

5. Repeat step 4 until step 3 frequency is 3507 ± 10 Hz (1150 ± 3 rpm).

8.16.2.4: Overspeed Calibration

NOTE: The overspeed function may not calibrate properly if the crank terminate function is not calibrated. Ensure that the procedures in Crank Terminate Calibration are performed before attempting to perform the overspeed calibration procedure.

1. Momentarily depress the reset button on the front face of the switch and set the frequency to 0 Hz.

2. Note the status of the overspeed LED on the front face of the switch is "OFF".

If not, there is a problem with the switch. Replace it according to "8.14: Electronic Speed (Overspeed) Switch".

3. Slowly increase the input frequency until the LED goes on. This frequency should be 6252 ± 10 Hz (2050 ± 3 rpm).

If the frequency is not 6252 ± 10 Hz (2050 ± 3 rpm) go to step 4.

4. Remove the cap on the front face of the switch that covers the overspeed potentiometer. Adjust the overspeed potentiometer and repeat steps 1 thru 3.

5. Repeat steps 1 thru 4 step 3 frequency is 6252 ± 10 Hz (2050 ± 3 rpm).

Checkout Procedures

8.17: Temperature Interface Module

Checkout Procedure

This procedure requires a decade resistance box that can carry at least 20 milliamps and can be set to the following values:

* A 915.3 ± 1 Ohm

* B 678.3 ± 1 Ohm

* C 510.3 ± 1 Ohm

Alternatively these resistance values can be provided by suitably sized fixed resistors.

8.17.1.1: Hook-up

1. Disconnect the engine harness connections from terminals 1, 2 and 3 on the temperature interface module.

2. Connect the decade resistance box across terminals 1 and 2.

3. Hook-up a digital multimeter (at least 50 volts DC full scale) to monitor the voltage on terminal 3 with respect to terminal 5.

8.17.1.2: Test Procedure

1. Turn on the local control battery power breaker.

2. Select resistance value A. Note voltage on the meter. It should be 38.39 ± 2.50 volts.

3. Select resistance value B. Note voltage on the meter. It should be 24.68 ± 2.50 volts.

4. Select resistance value C. Note voltage on the meter. It should be 10.97 ± 2.50 volts.

5. If the results of any of the steps 2, 3 or 4 are out of specification, replace the temperature interface module according to "8.8: Temperature Interface Module".

8.18: Generator Voltage Sense Scale Factor

Introduction

The generator voltage sense signal scale factor is defined in 3500 Locomotive Engines Personality Module Settings, SENR5187. This publication has a section for each personality module. On locomotives equipped with dynamic brakes there are two scale factors; one for motoring mode and one for dynamic brake mode. It is important that reference be made to the section of SENR5187 that is pertinent to the particular personality module fitted to the locomotive.

To determine which personality module is fitted to the locomotive governor, inspect the personality module that is bolted to the top face of the main locomotive governor box. The part number should be stamped on an aluminum plate attached to the personality module casting.

The voltage sense signal is measured on TB391-L11 with reference to TB391-L9. This signal is generated by one (or two) three phase potential transformers mounted in the traction generator. Refer to "4.12 Installation Diagrams (diagrams 9, 10 and 23)". The output signals of these transformers are rectified by three phase full wave rectifier circuits located in the scaling network. On locomotives not equipped with dynamic brakes there is only one potential transformer. On locomotives equipped with dynamic brakes there are two potential transformers.

Measuring The Scale Factor

The scale factor can be determined by comparing the generator sense voltage with the actual generator output voltage while the engine is carrying a load.

This cannot be done with the locomotive stalled because the generator voltage under this extreme condition will be too low.

The locomotive must be put in a load test mode; either with a self test feature, or with an external load bank. Refer to "8.27: Load Testing The Engine" for the general procedure to do this.

8.18.2.1: Test 1-Check For A Voltage Sense Fault Indication

Run the engine loaded in each notch and observe the LED display on the main electronic governor box to determine whether any diagnostic codes are displayed.

If the governor displays a diagnostic code, refer to "Section 7: Diagnostic Code Troubleshooting" to rectify the problem before proceeding.

If the governor displays only a voltage sense diagnostic indication (see "Section 7: Diagnostic Code Troubleshooting") while attempting to load test the engine proceed to "8.18.2.2: Test 2".

If the governor displays no diagnostic indication (see "Section 7: Diagnostic Code Troubleshooting") while attempting to load test the engine proceed to "8.18.2.3: Test 3".

8.18.2.2: Test 2-If Voltage Sense Fault Indication

If the governor displays a voltage sense diagnostic indication (see "Section 7: Diagnostic Code Troubleshooting") while attempting to load test the engine it will not load correctly.

The correct load can be run, and the voltage sense scale factor can be measured in the upper notches (with "engine power control mode") by initially executing the following procedure:

1. Disconnect the locomotive system wire to TB391-L11

2. Obtain an external DC voltage source and adjust it to a value equal to 2 volts DC.

3. Connect this voltage source to TB391-L11 (reference to TB391-L9).

4. Run the load test in the upper notches (with "engine power control mode").

NOTE: Do not run the engine loaded in the lower notches with "Traction Power Control Mode".

There are several methods of achieving this. Turn the "Gen Field" switch on the operator's control console to "off" in the lower notches.

If the voltage sense diagnostic indication persists, there is a problem with the governor mounting panel. Refer to "6.21.2.5: Troubleshooting Governor Mounting Panel" before proceeding with the rest of the checkout.

Run the engine loaded in each of these upper notches and note the generator voltage (A) and generator voltage sense signal for each notch.

The generator voltage should be measured at the locomotive's test points. If the locomotive is not equipped with these test points it should be measured at the load bank test points.

If the locomotive is not equipped with dynamic brakes, the voltage sense signal (B) should be measured at TB399-R12 with respect to TB391-L9.

If the locomotive is equipped with dynamic brakes, the voltage sense signal (B) should be measured at TB399-R11 with respect to TB391-L9 and the DB voltage sense signal (C) on TB399-R12 with respect to TB391-L9 for each notch.

For each notch compute the following ratios for signals A thru C:

Locomotive Without Dynamic Brakes

Motoring Voltage Scale Factor = A/B

Locomotive With Dynamic Brakes

Motoring Voltage Scale Factor = A/B

DB Voltage Scale Factor = A/C

Compare the above computed ratios with the two ratios defined in 3500 Locomotive Engines Personality Module Settings, SENR5187.

In notches 5 thru 8 they should be within ± 3 percent.

In notches 1 thru 4 they should be within ± 6 percent.

8.18.2.3: Test 3-If No Voltage Sense Fault Indication

Run the engine loaded in each notch and note the generator voltage (A) and generator voltage sense signal for each notch.

The generator voltage should be measured at the locomotive's test points. If the locomotive is not equipped with these test points it should be measured at the load bank test points.

The voltage sense signal (B) should be measured at TB391-L11 with respect to TB391-L9.

If the locomotive is equipped with dynamic brakes, also measure the DB voltage sense signal (C) on TB399-R12 with respect to TB391-L9 for each notch.

For each notch compute the following ratios for signals A thru C.

Locomotive Without Dynamic Brakes

Motoring Voltage Scale Factor = A/B

Locomotive With Dynamic Brakes

Motoring Voltage Scale Factor = A/B

DB Voltage Scale Factor = A/C

Compare the above computed ratios with the two ratios defined in 3500 Locomotive Personality Module Settings, SENR5187.

In notches 5 thru 8 they should be within ± 3 percent.

In notches 1 thru 4 they should be within ± 6 percent.

8.19: Generator Current Sense Scale Factor

Introduction

The generator current sense signal scale factor is defined in 3500 Locomotive Personality Module Settings, SENR5187. This publication has a section for each personality module. On locomotives equipped with dynamic brakes there are two scale factors; one for motoring mode and one for dynamic brake mode. It is important that reference be made to the section of SENR5187 that is pertinent to the particular personality module fitted to the locomotive.

The current sense signal is measured on TB391-L10 with reference to TB391-L9. This signal is generated by three current transformers mounted in the traction generator. Refer to installation diagrams 9, 10 and 23 in the Installation section. The output signals of these transformers are rectified by three phase full wave rectifier circuits located in the scaling network. The DC feedback signal for the governing system is generated through a burden resistor in the scaling network. There are two burden resistors located in the scaling network. On locomotives not equipped with dynamic brakes there is one scale factor and the two burden resistors are permanently connected in parallel with a jumper. On locomotives equipped with dynamic brakes there are two scale factors. In DB mode only one burden resistor is connected. In motoring/load test mode the second one is connected in parallel with the first by the dynamic brake selection logic to provide the second scale factor.

Measuring The Scale Factor

The scale factor can be determined by comparing the generator current sense signal with the actual generator output current while the engine is carrying a load.

It is preferred that this be done in load test mode; either with a self test feature, or with an external load bank. Refer to "8.27: Load Testing The Engine" for the general procedures to do this.

8.19.2.1: Test 1-Check For A Current Sense Fault Indication

Run the engine loaded in each notch and observe the LED display on the main electronic governor box to determine whether any diagnostic codes are displayed.

If the governor displays a diagnostic code, refer to "Section 7: Diagnostic Code Troubleshooting" to rectify the problem before proceeding.

If the governor displays only a current sense diagnostic indication (see "Section 7: Diagnostic Code Troubleshooting") while attempting to load test the engine proceed to "8.19.2.2: Test 2".

If the governor displays no diagnostic indication (see "Section 7: Diagnostic Code Troubleshooting") while attempting to load test the engine proceed to "8.19.2.3: Test 3".

8.19.2.2: Test 2-If Current Sense Fault Indication

If the governor displays a current sense diagnostic indication (see "Section 7: Diagnostic Code Troubleshooting") while attempting to load test the engine it will not load correctly.

The correct load can be run, and the current sense scale factor can be measured in the upper notches (with "engine power control mode") by initially executing the following procedure:

1. Disconnect the locomotive system wire to TB391-L10.

2. Obtain an external DC voltage source and adjust it to a value equal to 2 volts DC.

3. Connect this voltage source to TB391-L10 (reference to TB391-L9).

4. Run the load test in the upper notches (with "engine power control mode").

NOTE: Do not run the engine loaded in the lower notches with "Traction Power Control Mode".

There are several methods of achieving this. Turn the "Gen Field" switch on the operator's control console to "off" in the lower notches.

If the current sense diagnostic indication persists, there is a problem with the governor mounting panel. Refer to "6.22.2.5: Troubleshooting Governor Mounting Panel" proceeding with the rest of the checkout.

Run the engine loaded in each of the upper notch and note the generator current (A) and generator current sense signal for each notch.

The generator current should be measured at the locomotive's test points. If the locomotive is not equipped with these test points it should be measured at the load bank test points.

On locomotives without dynamic brakes the current sense signal (B) should be measured at TB399-R10 with respect to TB391-L9.

On locomotives with dynamic brakes the current sense signal (B) should be measured at TB399-R10 with respect to TB391-L9. The current sense signal (C) should be measured at TB399-R10 with respect to TB391-L9 with the connection to TB399-R4 disconnected.

For each notch compute the following ratios for signals A, B and C.

Motoring Scale Factor = A/B

DB Scale Factor = A/C

Compare the above computed ratios with the ratio defined in 3500 Locomotive Engines Personality Module Settings, SENR5187.

In notches 5 thru 8 it should be within ± 3 percent.

In notches 1 thru 4 it should be within ± 6 percent.

8.19.2.3: Test 3-If No Current Sense Fault Indication

Run the engine loaded in each notch and note the generator current (A) and generator current sense signal for each notch.

The generator current should be measured at the locomotive's test points. If the locomotive is not equipped with these test points it should be measured at the load bank test points.

On locomotives without dynamic brakes the current sense signal (B) should be measured at TB391-L10 with respect to TB391-L9.

On locomotives with dynamic brakes the current sense signal (B) should be measured at TB391-L10 with respect to TB391-L9. The current sense signal (C) should be measured at TB391-L10 with respect to TB391-L9 with the connection to TB399-R4 disconnected.

For each notch compute the following ratios for signals A, B and C.

Motoring Scale Factor = A/B

DB Scale Factor = A/C

Compare the above computed ratios with the ratio defined in 3500 Locomotive Engines Personality Module Settings, SENR5187.

In notches 5 thru 8 it should be within ± 3 percent.

In notches 1 thru 4 it should be within ± 6 percent.

8.20: Motor Current Sense

Introduction

Reference should be made to "4.12 Installation Diagrams (diagrams 11 thru 15)" to understand motor current sensing.

The motor currents are monitored by transductors with a 1000:1 ratio. The transductors are excited between two phases of the 220 volt 3 phase AC power that drives the cooling fans and air compressor.

The current output of each transductor goes to an input module on the wheelslip mounting group that converts the signal to a DC voltage. The DC output signals from the input modules are connected to analog input channels on the wheelslip module.

"4.12: Installation Diagrams (diagram 23)" is the functional block diagram of the wheelslip module. The wheelslip module has six analog inputs for up to six traction motor currents. It also has a seventh analog input for the dynamic brake grid cooling fan motor current. Each traction motor current (analog) input has an associated motor cutout (digital) input.

Total System Check

The following procedures are intended to be performed with a stationary locomotive. This eliminates a check of the system at, or near, the maximum traction motor current limit.

If it is felt necessary by the individual troubleshooter, and at his/her discretion, the following procedures could be performed with a loaded (and therefore possibly moving) locomotive at higher levels of current.

Add shunts (or some other DC current measuring device) to monitor each traction motor current.

Monitor the DC voltage signals (> 50 volts full scale) on TB392-R4 (signal A) and TB392-R5 (signal B) with respect to TB391-L9 with a digital multi-meter.

Ensure the locomotive brakes are adequately set to hold the locomotive and select notch 1 with the reverser in forward or reverse.

NOTE: Do not leave the locomotive in this condition for more than a few seconds.

Wait for the traction motor currents to stabilize then note all four (or six) motor currents and the two DC signals.

Repeat this procedure in notch 2. It may not be possible to repeat this procedure in higher notches. It depends on the effectiveness of the locomotive's brakes and the stall motor current limits programmed into the personality module. Performing this test in higher notches can only be done at the discretion of the individual troubleshooter.

Review the results and identify the value of the highest motor current and the lowest motor current for each notch.

Compute the two scale factors for each notch as follows and compare them with the scale factor "Motor Current Sense (1)" published in 3500 Locomotive Engines Personality Module Settings, SENR5187. They should both be within ± 4 percent.

High current scale factor = (highest current)/(signal A)

Low current scale factor = (lowest current)/(signal B)

Transductor Check

NOTE: Do not perform this procedure if "Total System Check" results are within specification.

This requires adding shunts (or some other DC current measuring device) to monitor each traction motor current.

Add current monitoring resistors in series with each transductor output between the transductor and the input module. Refer to "4.12 Installation Diagrams (diagrams 11 thru 15)". Use known resistor values of less than 1 ohm. Monitor the AC current signal out of each transductor with an oscilloscope. The current waveform should be a square wave with a peak-peak value as follows:

Peak-Peak Amps = 2×(Traction Motor Current)÷(Transductor Ratio)

Ensure the locomotive brakes are adequately set to hold the locomotive and select notch 1 with the reverser in forward or reverse.

NOTE: Do not leave the locomotive in this condition for more than a few seconds (15 to 20).

Wait for the signals to stabilize. Note each of the traction motor currents and their corresponding transductor outputs currents.

Compute the transductor turns ratio for each notch and compare it with the value published in 3500 Locomotive Engines Personality Module Settings, SENR5187. This should be within ± 1 percent.

Input Module Test

NOTE: Do not perform this procedure if "Total System Check" results are within specification.

Monitor the following DC voltage signals:

Signal A-TB393-L1 with respect to TB393-L11-(15 Volts full scale)

Signal B-TB393-R1 with respect to TB393-L11-(15 Volts full scale)

Signal C-TB393-L5 with respect to TB393-L11-(15 Volts full scale)

Signal D-TB393-R5 with respect to TB393-L11-(15 Volts full scale)

Signal E-TB393-L7 with respect to TB393-L11-(15 Volts full scale)

Signal F-TB393-R7 with respect to TB393-L11-(15 Volts full scale)

Ensure the locomotive brakes are adequately set to hold the locomotive and select notch 1 with the reverser in forward or reverse.

NOTE: Do not leave the locomotive in this condition for more than a few seconds.

Wait for the signals to stabilize. Note each of the signals (A thru F) plus the peak-peak current signals out of the transductors.

NOTE: On 4 axle locomotives signals E and F will be zero and should be ignored.

Signals A thru F are feedback signals representing traction motor currents (1 thru 6 respectively) at the scale factor, "Motor Current Sense (2)" identified in 3500 Locomotive Engines Personality Module Settings, SENR5187.

Compute the scale factor for each motor and verify that it is within ± 3 percent.

Wheelslip Module Current Scaling Check

NOTE: Do not perform this procedure if "Total System Check" results are within specification.

Monitor the following DC voltage signals

Signal A-TB393-L1 with respect to TB393-L11-(15 Volts full scale)

Signal B-TB393-R1 with respect to TB393-L11-(15 Volts full scale)

Signal C-TB393-L5 with respect to TB393-L11-(15 Volts full scale)

Signal D-TB393-R5 with respect to TB393-L11-(15 Volts full scale)

Signal E-TB393-L7 with respect to TB393-L11-(15 Volts full scale)

Signal F-TB393-R7 with respect to TB393-L11-(15 Volts full scale)

Signal G-TB392-R4 with respect to TB391-L9-(50 Volts full scale)

Signal H-TB392-R5 with respect to TB391-L9-(50 Volts full scale)

Ensure the locomotive brakes are adequately set to hold the locomotive and select notch 1 with the reverser in forward or reverse.

NOTE: Do not leave the locomotive in this condition for more than a few seconds.

Wait for the signals to stabilize. Note all 8 signals.

Review the results and, for each notch, identify the values of the highest and the lowest of signals A thru F.

NOTE: On 4 axle locomotives, signals E and F will be zero and should be ignored.

Compute the two scale factors "High Motor Current Sense Factor" and "Low Motor Current Sense Factor" for each notch as follows and compare them with the scale factor "Motor Current Sense (1)" published in 3500 Locomotive Engines Personality Module Settings, SENR5187.

High Factor = Highest Signal×Motor Current Sense (2) ÷ Signal G

Low Factor = Lowest Signal×Motor Current Sense (2) ÷ Signal H

They should be within ± 1 percent.

8.21: Electronic Speed (Overspeed) Switch

Checkout Procedure

This procedure requires a 8T5200 Signal Generator/Counter Group and a 4C6534 Harness. Special Instructions, SEHS8579 and SEHS8657 give complete details for use of these tools.

8.21.1.1: Initial Hook-up

1. Disconnect the speed input harness connections to switch terminals 3 and 4.

2. Hook up the 8T5200 Signal Generator/Counter Group to switch terminals 3 and 4 using the 4C6534 adapter harness. Refer to Special Instruction, SEHS8657, for hook-up procedure.

3. Refer to Special Instruction, SEHS8579, for procedures on adjusting the signal from the 8T5200 service tool and reading its frequency.

8.21.1.2: Crank Terminate Checkout

1. Set the frequency to 0 Hz.

2. Measure the voltage on switch terminals 10, 11 and 12 with respect to TB395-R1.

Terminal 10 should be at 0 volts.

Terminal 11 should be at battery positive (+).

Terminal 12 should be at battery positive (+).

If terminal 10 is not at 0 volts, there is a problem with the junction box wiring or the switch.

If terminal 11 is not at battery positive (+), there is a problem with the junction box wiring. Refer to "4.13: Wiring Diagrams" to investigate.

If terminal 12 is not at battery positive (+), there is a problem with the switch. Replace it according to "8.14: Electronic Speed (Overspeed) Switch".

3. Slowly increase the input frequency until;

* Terminal 10 is at battery positive (+).

* Terminal 11 is at battery positive (+).

* Terminal 12 is at 0 volts.

Note this frequency.

4. Slowly reduce the input frequency until;

* Terminal 10 is at 0 volts.

* Terminal 11 is at battery positive (+).

* Terminal 12 is at battery positive (+).

Note this frequency.

5. Step 4 frequency should be less than 20 Hz.

If it is not, there is a defect in the switch replace it according to "8.14: Electronic Speed (Overspeed) Switch".

6. Step 3 frequency should be 900 ± 110 Hz (295 ± 36 rpm)

If it is not refer to "8.16: Electronic Speed (Overspeed) Switch" to recalibrate.

8.21.1.3: Time Delay Checkout

1. Set the frequency between 1050 and 1250 Hz.

2. Switch off the 8T5200 service tool.

3. Measure the continuity between switch terminals 17 and 18 and between 17 and 16. It should be as follows:

* Continuity between terminals 17 and 18.

* No continuity between terminals 17 and 16.

If it is not, there is a problem in the junction box wiring or switch.

Disconnect all wires from switch terminals 16, 17 and 18 and recheck the continuity. If it is now OK there is a problem with the junction box wiring. Refer to "4.13: Wiring Diagrams" to investigate. If the continuity is still not OK there is a problem with the switch. Replace it according to "8.14: Electronic Speed (Overspeed) Switch".

4. Start a stop watch and switch on the 8T5200 service tool so that the input frequency switches from 0 Hz to 1050 to 1250 Hz.

Monitor the continuity between switch terminals 17 and 18 and between 17 and 16. Note the time it takes to change to the following state:

* No continuity between terminals 17 and 18.

* Continuity between terminals 17 and 16.

5. Step 4 results should be 9 ± 2 seconds.

If it is not, there is a defect in the switch. Replace it according to "8.14: Electronic Speed (Overspeed) Switch".

8.21.1.4: Oil Step Checkout

1. Set the frequency to 0 Hz.

2. Measure the continuity between switch terminals 14 and 13 and between 14 and 15. It should be as follows:

* Continuity between terminals 14 and 15.

* No continuity between terminals 14 and 13.

If it is not, there is a problem in the junction box wiring or switch.

Disconnect all wires from switch terminals 13, 14 and 15 and recheck the continuity. If it is now OK there is a problem with the junction box wiring. Refer to "4.13: Wiring Diagrams" to investigate.

If the continuity is still not OK there could be a problem with the junction box wiring to the OIL STEP LATCH input (terminal 2).

Measure the voltage on switch terminal 2 with respect to TB395-R1. It should be at 0 volts.

If not OK, there is a problem with the junction box wiring. Refer to "4.13: Wiring Diagrams" to investigate.

If OK, there is a problem with the switch. Replace it according to "8.14: Electronic Speed (Overspeed) Switch".

3. Remove the plug covering the "OIL STEP" potentiometer and note that there is a LED visible through the exposed hole.

Slowly increase the input frequency until the LED comes on. Start a stop watch when this happens.

Note this frequency.

4. Monitor the continuity between switch terminals 14 and 15 and between 14 and 13. Note the time it takes to change to the following state:

* No continuity between terminals 14 and 15.

* Continuity between terminals 14 and 13.

5. Step 3 results should be 3507 ± 110 Hz (1150 ± 36 rpm).

If it is not refer "8.16: Electronic Speed (Overspeed) Switch" to recalibrate.

6. Step 4 results should be 9 ± 2 seconds.

If it is not, there is a defect in the switch. Replace it according to "8.14: Electronic Speed (Overspeed) Switch".

8.21.1.5: Overspeed Checkout

NOTE: This section may not checkout properly if the crank terminate function is defective. Ensure the procedures in "8.21.1.2: Crank Terminate Checkout" are performed before attempting to perform the procedures in this section.

1. Set the frequency to 0 Hz.

2. Set the frequency between 1050 and 1250 Hz.

Measure the voltage on switch terminals 7, 8 and 9 with respect to TB395-R1.

* Terminal 7 should be at 0 volts.

* Terminal 8 should be at battery positive (+).

* Terminal 9 should be at battery positive (+).

If terminal 7 is not at 0 volts, there is a problem with the junction box wiring or the switch.

If terminal 8 is not at battery positive (+), there is a problem with the junction box wiring. Refer to "4.13: Wiring Diagrams" to investigate.

If terminal 9 is not at battery positive (+), there is a problem with the switch. Replace it according to "8.14: Electronic Speed (Overspeed) Switch".

3. Slowly increase the input frequency until;

* Terminal 7 is at battery positive (+).

* Terminal 8 is at battery positive (+).

* Terminal 9 is at 0 volts.

Note this frequency.

4. Note the overspeed LED on the front face of the switch also comes on at the same time.

If it does not, there is a defect in the switch. Replace it according to "8.14: Electronic Speed (Overspeed) Switch".

5. Step 3 frequency should be 6252 ± 110 Hz (2050 ± 36 rpm).

If it is not refer to "8.16: Electronic Speed (Overspeed) Switch" to recalibrate.

6. Set the frequency to 0 Hz.

Note that the overspeed LED is still on and that:

* Terminal 7 is at battery positive (+).

* Terminal 8 is at battery positive (+).

* Terminal 9 is at 0 volts.

If not, there is a defect in the switch. Replace it according to "8.14: Electronic Speed (Overspeed) Switch".

7. Momentarily depress the reset button.

Note that the overspeed LED is now off and that:

* Terminal 7 is at 0 volts.

* Terminal 8 is at battery positive (+).

* Terminal 9 is at battery positive (+).

If not, there is a defect in the switch. Replace it according to "8.14: Electronic Speed (Overspeed) Switch".

8. Repeat steps 1 thru 4 with the "75% verify button" on the front face of the switch depressed.

9. Step 3 frequency should be 4689 ± 220 Hz (1537 ± 72 rpm).

If not, there is a defect in the switch. Replace it according to "8.14: Electronic Speed (Overspeed) Switch".

8.22: 24T Signal Scaling

Introduction

In all modes (dynamic braking, motoring and load test) the 24T trainline signal is scaled by an attenuating resistive network located within the scaling network. Refer to "4.12 Installation Diagrams (diagram 11 thru 15)".

In dynamic braking mode the input signal to the scaling network is connected directly to the 24T trainline signal.

In normal motoring and load test mode the input signal to the scaling network is connected to battery positive (+).

Scaling Check

1. Measure two DC voltages on TB399-L12 (Signal A) and TB392-R6 (Signal B), both with respect to TB391-L9.

2. Compute the ratio of (B/A).

This ratio should be 0.723 ± 10 percent with the truck slide relay de-energized. This ratio should be 0.105 ± 10 percent with the truck slide relay energized.

NOTE: Not all locomotives are equipped with a truck slide relay.

Miscellaneous Procedures

8.27: Load Testing The Engine

Introduction To Load Control And Power Measurement

The electronic governor system controls the engine at a specific load and speed for a specific notch code. It has two power control modes.

In the lower notches it controls the net traction power (to the traction motors) to a specific level for each notch.

In the higher notches it controls the gross engine power to a specific level by controlling the rack to a specific position for each notch. In these notches the net traction power will change as parasitic loads (cooling fans, air compressor) come on and off line.

Refer to Personality Module Settings, SENR5187 to determine which notches have which power control mode.

An incorrect scale factor of one or more of the four generator or traction motor feedback signals would cause incorrect power levels (high or low) in the low notch, traction power control mode.

An incorrect scale factor of one or more of the four generator or traction motor feedback signals could cause incorrect power levels (low only) under certain conditions in the high notch, gross engine power control mode. This happens because one of the following traction parameters would be limited to low incorrect value:

Generator voltage.

Generator current.

Traction motor current.

This would probably be perceived and reported by the locomotive operator as "low power".

In order to check the power output of the engine, the traction generator must be disconnected from the traction motors and connected to a DC load bank. The net traction power to the load bank can then be measured in each notch. The gross engine horsepower in the upper notches has to be inferred from the measured traction power, generator efficiency, and the known parasitic loads that are specific to the particular locomotive, or class of locomotive.

Many locomotives are equipped with a self load feature in which the dynamic brake resistive grids can automatically be switched in as a load bank.

NOTE: If an external load bank must be used, it is important to select a suitable value of resistance that will enable rated power to be dissipated with a current less than 1800 Amps and a voltage of less than (generator rated volts-100 volts). Refer to Personality Module Settings, SENR5187 for the generator rated voltage.

Also when an external load bank is used the locomotive system wire to TB391-L12 should be pulled from TB391-L12 and safely secured (it is connected to battery positive) for the duration of the test. This will set the control into the load test mode.

This wire must be RE-CONNECTED to TB391-L12 before putting the locomotive back into service. FAILURE to do so WILL RESULT in a very poorly performing locomotive with NO WHEELSLIP PROTECTION and a generator CURRENT LIMIT of only 2000 AMPS.

Locomotives equipped with a self load feature automatically open the signal to TB391-L12 when switched into self load mode.

Procedure For Load Testing The Engine

8.27.2.1: Locomotive Equipped with Self Load Feature

1. Switch it to self load. Perform all the normal Railroad safety procedures.

2. Confirm that the electronic governor is in self load mode by noting the status of the lower four LED's on the front face of the main electronic governing box. The lower three should be off and the 4th should be on continuously.

3. Run the engine in each notch loaded and note the following parameters and enter them in a copy of Table 1:

Generator output current

Generator output voltage

Engine speed

Generator current sense (TB391-L10 to TB391-L9)

Generator voltage sense (TB391-L11 to TB391-L9)

Excitor current (use 0.1 ohm, 25 watt resistor as a shunt)

Rack position (Use Caterpillar Service Tool 8T1000, refer to Special Instruction, SEHS8623)

NOTE: An accessory kit (Probe Contactor Point Group 6V6042) is available that contains a selection of different length extensions for the 8T1000 sensor. The correct extension is the same for all 3500 engines. The correct extension should be chosen so that the 8T1000 rack sensor will properly display shut-off rack position as sell as the maximum mechanical position. All 3500 engines require the sensor to be set up to display increasing rack with a retracting sensor. Calibrate the 8T1000 sensor with the linkage manually held against the mechanical rack stop prior to performing the load test procedure.

4. Compute the gross engine power in the upper notches from the known parasitics for the particular locomotive.

5. Compare the measured notch powers with those listed in Personality Module Settings, SENR5187.

8.27.2.2: Locomotive Not Equipped With Self Load Feature

1. Disconnect the traction generator from the traction motors and connect the traction generator to a suitably sized load bank. Perform all the normal Railroad safety procedures.

2. Disconnect the locomotive system wire to TB391-L12 and secure this wire safely (tied to battery positive).

3. Confirm that the electronic governor is in self load mode by noting the status of the lower four LED's on the front face of the main electronic governing box. The lower three should be off and the fourth should be on continuously.

4. Run the engine in each notch loaded and note the following parameters and enter them in a copy of Table 1:

Generator output current

Generator output voltage

Engine speed

Generator current sense (TB391-L10 to TB391-L9)

Generator voltage sense (TB391-L11 to TB391-L9)

Excitor current (use 0.1 ohm, 25 watt resistor as a shunt)

Rack position (Use Caterpillar Service Tool 8T1000, refer to Special Instruction, SEHS8623)

5. Compute the gross engine power in the upper notches from the known parasitics for the particular locomotive.

6. Compare the measured notch powers with those listed in Personality Module Settings, SENR5187.

7. Reconnect the locomotive system wire to TB391-L12.

8.28: Checking Automatic Sanders

Checkout Procedure

1. Insert a jumper with a series switch in series with the locomotive system wire connecting to TB392-R5.

2. Ensure the locomotive brakes are adequately set to hold the locomotive. Select notch 2 with the reverser in forward or reverse.

NOTE: Do not leave the locomotive in this condition for more than a few seconds.

3. Wait for the traction motor current to exceed 400 Amps, then turn the switch to the open position. Note the status of the Wheelslip LED on the electronic governor box and the status of the automatic sanders. They should both come on while the switch is open.

This may trigger a "high differential motor current" diagnostic condition. This diagnostic condition will then cause the generator exciter current to reduce to zero Amps.

This may also trigger a "low motor current" diagnostic condition. This diagnostic condition will then cause the motor current to reduce to 100 Amps.

8.29: Actuator Check

Installation

When actuator is mounted on engine, be sure that correct alignment is made with the engine fuel linkage.

A gasket should be placed between the actuator and the base mounting pad. For vertically mounted actuators, be careful to not block the drain hole(s) next to the centering pilot of the base. The oil that drains through drive shaft bore must flow freely to the sump. The splined drive shaft must fit into the drive with a free, slip fit; no tightness permitted. The vertically mounted actuator must drop onto the mounting pad of its own weight without applying force.

The actuator gets its oil supply from a sump in the mounting base. The engine overflows the sump (from the engine lube circuit) through an orifice that meters flow. The sump can be checked for fill level with the actuator removed. Cranking the engine will not make any oil flow at the actuator oil supply port. The actuator base gasket must not permit air leakage into the supply port.

The engine fuel linkage must be free of binding and without backlash. If there is a collapsible member (permits compression) on the linkage, be sure the spring does not yield each time the actuator moves the linkage rapidly.

8.30: Generator Coupling

Generator Coupling
(1) Bolt. (2) Fan. (3) Reference mark. (4) Fan reference mark. (5) Reference mark. (6) Distance between reference marks.

If erratic engine speed is encountered, excessive wear or loss of silicone fluid in the coupling due to a defective o-ring seal may cause excessive windup and unloading of the coupling drive group. This could result in backtalk and erratic engine control.

Checkout Procedure

1. Make sure the locomotive knife switch is in the open position and the proper "Do Not Start" flags are in place.

2. Remove the rear fan guard from the generator.

3. Scribe a reference line (4) on the fan and on the fan housing with a grease pencil or paint stick.

4. Using a torque wrench with an eight inch extension, apply 270 N·m (200 lb ft) torque counterclockwise (CCW) to one of the large bolts (1) connecting to the rotor shaft.

5. Mark the point of alignment (3) with the fan reference mark when the force is applied.

6. Now apply 360 ± 50 N·m (265 ± 35 lb ft) torque clockwise (CW) to one of the large bolts (1) connecting to the rotor shaft.

7. Mark the point of alignment (5) with the fan reference mark when the force is applied.

8. Measure the distance (6) between the two reference marks (3 and 5). Call the appropriate Caterpillar Customer Services group for further help on the generator coupling.