Generator Set Control Panel for Switchgear Conversion Caterpillar

Note: This procedure requires the Remote Start Switch to be opened and/or closed many times. In order to ease the troubleshooting process, a switch that is locally acquired can be connected to the terminals of the Remote Start Signal in the customer connection box. The terminals for the Remote Start Signal are Terminal 57 and Terminal 30.

1. Check The Obvious Causes.

   1. Check for a low oil pressure.

   2. Check the oil level.

   3. Check for oil leaks.

   4. Check for other obvious causes of low oil pressure.

      Expected Result: No obvious cause exists.

      Results:

      • OK: Proceed to the next Step.

      • Not OK: An obvious cause exists. Correct the fault. Refer to the Engine Service Manual. STOP.

2. Check The Low Oil Pressure Function (Check 1).

   1. Open the Remote Start Switch and then close the Remote Start Switch.

   2. Allow the oil pressure to stabilize.

   3. Check and note the actual oil pressure that is showing on the Oil Pressure Gauge (OPG).

      Expected Result: The actual pressure that is showing on the OPG should be greater than the trip point of the oil pressure switch (OPS). The control board should not shut down the engine because of low oil pressure.

      Results:

      • OK: The actual oil pressure is greater than the trip point of the OPS and the low oil pressure indicator is OFF. The problem is not present now. The problem may be intermittent. Check the harness and all electrical connections of the oil pressure circuit. See Testing And Adjusting, "Electrical Connector Inspection". STOP.

      • OK: The actual oil pressure is greater than the trip point of the OPS and the low oil pressure indicator is ON. Proceed to the next Step.

      • Not OK: The actual pressure that is showing is less than the trip point of the OPS. The pressure is correct for a low oil pressure shutdown. Therefore, the engine should shut down and the low oil pressure indicator should be ON. The OPS and the control board are operating properly. To find the cause of the low oil pressure, refer to the Engine Service Manual. STOP.

      Note: The operator may check the accuracy of the Oil Pressure Sending Unit (OPSU) and the Oil Pressure Switch (OPS). Install an accurate engine oil pressure gauge. Place the sensing element in an area as close as possible to the OPS and the OPSU.

3. Check The Low Oil Pressure Function (Check 2).

   1. Open the Remote Starting Switch and then close the Remote Starting Switch.

   2. Allow the oil pressure to stabilize. Note the oil pressure reading.

   3. Disconnect the engine harness from the OPS.

   4. Measure the resistance from contact "A" to contact "C" of the OPS.

      Expected Result: The resistance should measure 5 ohms or less.

      Results:

      • OK: The resistance is 5 ohms or less. The oil pressure is less than the pressure for the trip point. The OPS is faulty. Replace the OPS. STOP.

      • Not OK: Resistance is greater than 5 ohms. Proceed to the next Step.

4. Check The Low Oil Pressure Function (Check 3).

   1. Open the Remote Starting Switch and then close the Remote Starting Switch.

   2. Disconnect the engine harness from the OPS.

   3. Measure the resistance from Contact 7 of the control board to "B-" (battery negative terminal).

      Expected Result: The resistance should measure 5 ohms or less.

      Results:

      • OK: The resistance is 5 ohms or less. The wire harness is shorted to "B-" between the oil pressure signal and contact "C" of the harness connector for the OPS. The oil pressure signal is found at contact 7 of the control board. See Schematics And Wiring Diagrams. Remove one component or wire at a time that is in series with the oil pressure signal (Contact 7 of the control board) until the faulty component or the faulty wire is isolated. Repair the faulty component or replace the faulty component. Repair the faulty wiring or replace the faulty wiring. STOP.

      • Not OK: Resistance is greater than 5 ohms. Therefore, the control board is faulty. Replace the control board. STOP.