RETAINER 9Y7455 - Caterpillar

System Operation Description:If the current rises above the generator reverse power percentage threshold set point value, then the reverse power timer will begin timing. When the timer expires, the generator reverse power event is made active if the current has been above the threshold level continuously while timing. If the current drops below the generator reverse power percentage threshold, then the generator reverse power event will be made inactive. The timer will be reset.If a reverse power condition is detected, "GEN REVERSE POWER SHUTDOWN" or "GEN REVERSE POWER " will be displayed on the EMCP 3. The message is used to inform the operator of a reverse power condition.Note: The severity of the reverse power condition will determine if a warning or shutdown event occurs.The code for generator reverse power is generated when the EMCP 3 determines that a generator reverse power condition has occurred.Test Step 1. TALK TO THE OPERATOR.
Determine the conditions that caused the reverse power condition.Expected Result:A reverse power was caused by an occurrence known to the operator and the operator would like to put the generator set back into service.Results:
OK - The operator can determine the cause for the reverse power condition. The condition has been repaired, and the operator wants to put the generator set back into service.Repair: Reset the generator set. Resume normal operation and verify that the problem has been corrected.STOP
NOT OK - The reverse power condition was not caused by an occurrence known to the operator. Proceed to Test Step 2.Test Step 2. CHECK THE SET POINTS.
View the generator reverse power set points. Make a note of the set points. Refer to Testing and Adjusting, RENR7902, "Electronic Control Module (Generator Set) - Configure". Compare the set points against the default set points of the particular generator set.Expected Result:The set points are correct.Results:
OK - The set points are correct for your particular generator set. Proceed to Test Step 3.
NOT OK - The set points are NOT correct.Repair: Reprogram the set points. Reset the generator set. Resume normal operation and verify that the problem has been corrected.STOPTest Step 3. CHECK THE POLARITY OF THE CURRENT TRANSFORMERS.
Illustration 1 g00607036
(A) Current transformer polarity dot
Press the "STOP" key in order to shut down the engine.
Check the polarity of the current transformers. The polarity dots on all of the transformers should be towards the generator set. Refer to Illustration 1.Expected Result:The polarity of the current transformers should be correct.Results:
OK - The polarity of the current transformers is correct.Repair: A failed EMCP 3 is unlikely. Exit the procedure and perform the entire procedure again. If the problem remains, replace the EMCP 3. Refer to Testing and Adjusting, RENR7902, " Electronic Control Module (Generator Set) - Replace".STOP
NOT OK - The polarity of the current transformers is NOT correct.Repair: Install the current transformers as shown on the wiring diagram for your particular generator set. Reset the generator set. Resume normal operation and verify that the problem has been corrected.STOP