HEINZMAN GOVERNOR (3600 MARINE APPLICATION) Caterpillar

Introduction

This troubleshooting guide can be an aid for service personnel to find the cause of existing problems. Several common problems are covered in the guide, but these problems are not arranged in any particular sequence.

Identify your particular problem from the Troubleshooting Problem List, then go directly to that problem in the guide. When you begin the procedure for your problem, begin at Step 1 and follow through the step by step procedure. The steps for a particular problem provide a definite sequence to be followed for a logical, one by one elimination of many variables. These steps are arranged in order from the more probable/easiest to check, to the less probable/more complex to check.

Whenever the cause of the problem is found and corrected, stop the test. Do NOT continue through the complete procedure.

1. The Governor Does NOT Open On Starting 22

2. The Governor Moves To Maximum Fuel Injection When The Power Supply Is ON 23

3. The Engine Overspeeds Upon Starting 23

4. The Governor Is Unstable 23

5. Speed Is Reduced Under Engine Load 24

6. The Governor Linkage Is Hunting 24

Troubleshooting Problems

Problem 1. The Governor Does NOT Open On Starting

Probable Cause:

1. No signal from the magnetic pickup. Verify with the AC voltmeter or oscilloscope.

There is excessive pickup clearance.

Adjust the clearance to [0.5 to 0.8 mm (.02 to .03 in)] if necessary.

Check the resistance at the cable socket of the KG30 Governor Control Unit [A2/B2, (approximately 200 ohms)].

Replace the cable or the speed pickup if needed.

Check the starting speed voltage at the cable socket of the KG30 Governor Control Unit [A2/B2 (approximately .5 VAC)].

Replace or clean the speed pickup if needed. The KG30 Governor Control Unit must have its own speed pickup. The KG30 Governor Control Unit cannot share a pickup with another device.

Wiring fault, the magnetic pickup is defective.

Repair or replace as needed.

The control lamp must be lit when the power supply is ON and must go out from the starting frequency upwards.

NOTE: If the KG30 Governor Control Unit works with the Heinzmann Tester but NOT on the engine, the fault is in the speed pickup or the speed pickup cable.

2. The shutdown switch is ON.

Disconnect the shutdown switch at pins H3 and I3 for troubleshooting.

3. The Remote Speed Setpoint potentiometer connections are wrong or incomplete.

Disconnect the 14 pin connector from the KG30 Governor Control Unit and use an ohmmeter to verify the resistance at the cable socket of the wiring harness.

When the Remote Speed Setpoint potentiometer is at Minimum Speed:

A-B = 5k ohms

B-C = 0k ohms

A-C = 5k ohms

When the Remote Speed Setpoint potentiometer is at maximum speed:

A-B = 0k ohms

B-C = 5k ohms

A-C = 5k ohms

4. The Setpoint potentiometer or Maximum Speed/Low Speed potentiometer settings are too low.

Verify the speeds are correct with the Heinzmann Tester.

5. There is a wiring fault in the cable harness.

6. The supply voltage is inadequate or the polarity is reversed.

Verify with a DC voltmeter.

7. There is no DC voltage at the KG30 Governor Control Unit.

Verify with a DC voltmeter.

8. The actuator is impeded or the linkage is adjusted wrong.

Manually move the linkage to verify.

9. The Start Fuel Limit is incorrectly adjusted (if used).

Put the Start Fuel Limit switch in position 2 or 3. Try to START the engine. If the engine starts, shut down the engine and put the Start Fuel Limit slide switch in position 4. Readjust the Start Fuel Limit according to the Start Fuel Limit adjustment procedure in the Initial Checks and Adjustments section.

10. The speed pickup cable or speed setpoint cable is open or shorted.

Verify with the ohmmeter.

11. The actuator is defective.

Check the resistance at terminals [B-C on the actuator (approximately. 2 ohms)].

Replace the actuator.

12. The KG30 Governor Control Unit is defective.

Replace the KG30 Governor Control Unit.

Problem 2. The KG30 Governor Control Unit Moves To Maximum Fuel Injection When The Power Supply Is On

Probable Cause:

1. There is a wiring fault in the harness.

2. There are faults in the magnetic pickup cable.

Check the shield.

3. The KG30 Governor Control Unit is defective.

Replace the KG30 Governor Control Unit and retest.

Problem 3. The Engine Overspeeds On Starting

Probable Cause:

1. The Maximum Speed potentiometer setting is too high.

Verify the maximum speed with the Heinzmann Tester.

2. There is excessive magnetic pickup clearance (only a portion of the gear teeth are recorded).

Make sure the gap is correct.

3. There is poor contact in the magnetic pickup line.

Check all of the connections.

4. The linkage cannot move freely.

Move the linkage manually.

5. The feedback voltage is incorrectly adjusted.

Verify the adjustment of the feedback voltage with the Heinzmann Tester or a DC voltmeter.

6. The actuator or KG30 Governor Control Unit is defective.

Replace the KG30 Governor Control Unit and retest.

NOTE: If the actuator applies torque in one direction only, the problem is with the KG30 Governor Control Unit.

Problem 4. The Governor Is Unstable

Probable Cause:

1. Noise in the magnetic pickup cable.

Check the shield.

2. There is noise in the Remote Speed Setpoint potentiometer cable.

Check the shield.

3. There is load fluctuations.

Run the engine at a constant load for troubleshooting.

4. There are faults in the Speed Setpoint signal (Defective Speed potentiometer or external speed setting device).

Verify the signal is steady using the multimeter.

5. The supply voltage is too low.

Verify the voltage is 20 to 35 VDC.

6. There is poor electrical contact.

Check with an ohmmeter.

7. There is play or excessive friction in the linkage.

Replace the rod ends if worn.

8. The feedback voltage is NOT properly adjusted.

Verify the voltage is 1.5 to 5 VDC.

9. The KG30 Governor Control Unit is incorrectly adjusted.

Verify the setup procedure was performed correctly.

10. Oil or metal shavings are in the tip of the speed pickup.

Clean or replace the speed pickup.

Problem 5. The Engine Has Reduced Speed Under Load

Probable Cause:

1. The Droop Isochronous Selector switch is in the DROOP position.

Switch to the ISOCHRONOUS position if desired.

2. The actuator is on 100 percent Fuel Injection Stop.

The engine is overloaded.

3. There is a fault in the KG30 Governor Control Unit.

Replace the KG30 Governor Control Unit and retest.

Problem 6. The Governor Linkage Is Hunting

Probable Cause:

1. There is excessive voltage fluctuation of the supply voltage.

Verify the DC supply is constant.

2. There are faults at the shields.

Check the shield.

3. There is a poor setpoint signal.

Verify the steady signal with the multimeter. If the Remote Speed Setpoint potentiometer is used, connect the Heinzmann Tester. Follow the procedure for the Rated speed and shake the Remote Speed Setpoint potentiometer while watching the Heinzmann Tester readout. If the readout changes while shaking, the Remote Speed Setpoint potentiometer is defective.

NOTE: If the actuator moves violently back and forth between the SHUTOFF and FULL FUEL, the power supply voltage is unsteady or not of sufficient amperage (8A min) at the KG30 Governor Control Unit. Use a voltmeter to verify the steady DC voltage at the KG30 Governor Control Unit. The maximum tolerable voltage fluctuation is 10 percent and should be less. The DC voltage at the KG30 Governor Control Unit should NOT drop more than 1V between a stopped engine and an engine at RATED LOAD. A large voltage drop could indicate small diameter power cables, bad connections, or a power supply with inadequate amperage. Verify the wire diameters are correct by referring to the wiring schematic. Verify the power supply meets requirements of Power Supply Check procedure in the Initial Checks and Adjustments section.