Digital Voltage Regulator Caterpillar

1. Turn the engine off.

2. Check the PM wiring.

   Expected Result: The wiring is correct.

   Results:

   • OK: Go to Step 2.

   • NOT OK: The CT polarity or PT polarity is incorrect. Reverse the polarity. See the proper wiring diagram for details. Refer to Testing And Adjusting, "Wiring Diagrams". STOP.

1. Disconnect all accessory wiring from terminals 3, 5, 6, 7, 40, 41, 42, 43, 44, 45, and 50. Remove the serial data link, if installed.

2. Start the generator set and operate at "No Load".

   Expected Result: The generator set operates properly.

   Results:

   • OK: The generator set operates properly. There is a problem with an accessory which has been disconnected. Reconnect one accessory and operate the generator set again at "No Load". Continue this process of reconnecting one accessory at a time until the faulty accessory is found. STOP.

   • NOT OK: The generator set does not operate properly. Temporarily disconnect and then reconnect the battery voltage to the regulator. If proper AC voltage is present at terminals 26 and 30, and the fault is still present, the regulator is faulty. Replace the regulator.

Note: Shielded cable should be provided for all remote adjustment potentiometers. Connect the shield drain wire to regulator terminal 45. Insulate the wiring shield from touching all other objects, including Earth ground. This will eliminate the possibility of induced voltages (EMI spikes) causing an intermittent shutdown.

Note: It is also possible to get the loss of frequency shutdown fault (fault code 803), if a fault is reset on a self excited generator connection with the generator still spinning. Always stop the generator before resetting faults when using a self excited connection.