ENGINE AR-PRIMARY 3351530 - Caterpillar

The EMCP 4.4 has an automatic synchronization feature. The synchronization feature verifies that the voltage, frequency, and phase of the bus match the voltage, frequency, and phase of the generator. If any one of these parameters does not match, the EMCP 4.4 will not allow the breaker to close.If the breaker is already closed and one of the parameters changes dramatically, then the EMCP 4.4 will issue a "Breaker Trip" command.Table 1 lists the conditions that will generate the "Breaker Trip" command. The codes may be generated if a breaker fails to close as expected.
Table 1
Breaker Trip Commands
"GEN TO BUS SYNCHRONIZATIONFAILURE SHUTDOWN"
"GEN TO BUS SYNCHRONIZATIONFAILURE "
"GEN NOT READY TO AUTO PARALLEL "
"GEN TO BUS PHASE DIFFERENCE ON BREAKER CLOSE "
"GEN BREAKER INCONSISTENT SENSING "
"UTILITY BREAKER INCONSISTENT SENSING"
"GENERATOR PHASE SEQUENCE INCORRECT " Test Step 1. CHECK BUS PHASE ROTATIONVerify bus sensing matches generator sensing.Expected Result:Bus phase rotation matches generator phase rotation.Results:
OK - Phase rotation matches. Proceed to Test Step 2.
NOT OK - The phase rotation does not match.Repair: Repair phase rotation. Try to synchronize again.STOPTest Step 2. CHECK BUS SENSING WIRINGVerify that bus sensing lines are connected to the proper EMCP 4.4 input pins.Expected Result:Bus sensing is wired to the correct EMCP 4 input pins.Results:
OK - Bus sensing wiring is correct. Proceed to Test Step 3.
NOT OK - The bus sensing wiring is not correct.Repair: Repair the bus sensing wiring. Try to synchronize again.STOPTest Step 3. CHECK GENERATOR VOLTAGE
Place the Sync Mode switch into the "Check" position.
Navigate to the "Sync Overview" screen.
Verify that generator voltage falls within the values for synchronization. Verify generator voltage stays within the required values. Expected Result:Generator voltage matches bus voltage.Results:
OK - The generator voltage is acceptable. Proceed to Test Step 4.
NOT OK - The voltage is not acceptable.Repair: Adjust the voltage gain settings. Try to synchronize again.STOPTest Step 4. CHECK GENERATOR FREQUENCY
Place the Sync Mode switch into the "Check" position.
Navigate to the "Sync Overview" screen.
Verify that generator frequency falls within the values for synchronization. Verify generator frequency stays within the required values. Expected Result:Generator frequency matches bus frequency.Results:
OK - Generator frequency matches bus frequency. Proceed to Test Step 5.
NOT OK - The generator frequency does not match the bus frequency.Repair: Adjust the frequency gain settings. Try to synchronize again.STOPTest Step 5. CHECK BREAKER WIRINGVerify that breaker control wiring is connected according to the proper wiring diagram.Expected Result:Breaker control wiring is connected according to the proper wiring diagram.Results:
OK - Breaker control wiring is correct.Repair: The EMCP 4 may have failed. Failure of the EMCP 4 is unlikely. Exit this procedure and perform this procedure again. If the failure is not found, replace the EMCP 4. Refer to the "Electronic Control Module (Generator Set) - Replace" information in the "Testing and Adjusting" section of this publication.STOP
NOT OK - The breaker control wiring is incorrect.Repair: Repair the breaker control wiring. Try to synchronize again.STOP