TIP-ABRASION 9N4452 - Caterpillar

Check the linkage.Note: This step applies to 3600 series engines. For other engines please go to 3.
While the engine is shut down, manually move the actuator lever and the actuator linkage to the full FUEL ON position against the stop screw. Expected Result: The linkage moves through full travel smoothly until the linkage is against a stop screw. The linkage moves without binding or excessive force.Results:
OK: Check backlash. Refer to the governor Service Manual, Service Procedures, "Linkage Calibration". If backlash is acceptable, go to 2. If backlash is not acceptable (more than specified wear limits), repair the worn components. STOP.
NOT OK: The linkage does not move through full travel to a stop screw. The linkage is stuck, or has binding and takes excessive force to reach a stop screw. Refer to the governor Service Manual, Service Procedures, "Linkage Calibration". STOP.
Check for the fuel linkage travel against the stop screw.
Run only one engine.
Load the engine until speed slows to 50 rpm less than rated speed.
Check fuel linkage to determine if linkage goes completely to maximum fuel position. If not enough load is available to move fuel linkage to maximum fuel position, look at fuel linkage during acceleration from low idle to rated speed to obtain maximum FUEL ON position against the stop screw.Note: 3600 ADEM engines use an electronic stop. The physical stop is set higher. The rack should come close to the stop, but not touch it. Maximum linkage position is 0.25 mm (0.010 inch) less than the physical rack stop.Expected Result: Linkage moves to maximum fuel position.Results:
OK: Go to 3.
NOT OK: Linkage does NOT move to maximum fuel position. Refer to the governor Service Manual, Troubleshooting, "Engine Will Not Carry Load (Low Power)". STOP.
Check for the engine speed control and response (at Part Load).
Run only one engine in Isochronous Mode at part load to full load.
Disconnect any external speed control components (such as synchronizer) from the load sharing module.
Adjust the potentiometers for stable operation. Refer to the governor Service Manual, Service Procedures, "Adjust for Stable Operation".
Set the "LOAD GAIN" voltage the same as all other units are set for at full load. Usually, the voltage is about 4 to 6 volts. Now check the engine speed control governor and its response to load changes.Expected Result: Engine speed is constant at constant load, and response to a load change is acceptable.Results:
OK: Go to 4.
NOT OK: Engine speed change is NOT constant after a load change (is not isochronous). Check output voltage of generator as the load is changed. Refer to the governor Service Manual, Service Procedures, "Speed Setting". STOP.Note: Volts/Hz regulators output voltage will be proportional to the Engine Speed/Hz characteristic.
Check the CT phasing.Note: Refer to Testing And Adjusting, "Phasing - Check" for current transformer phasing check instructions.Note: The load sharing module contains internal current transformers. Due to their low impedance, shorting their inputs (T4 to T5, T6 to T7, T8 to T9) is NOT effective.
Perform the phasing check.Expected Result: Load signal voltage drops by 1/3 for each