RING-BACKUP 1211603 - Caterpillar

System Operation Description:If the voltage drops below the generator under voltage percentage threshold or the automatic voltage regulator (AVR) request set point value, the under voltage timer will begin timing. When the timer expires, the generator under voltage event is made active (if the frequency has been below the threshold level continuously while timing). If the voltage rises above the generator under voltage percentage threshold, the generator under voltage event will be made inactive. The timer will be reset. If an under voltage condition is detected, "GEN UNDERVOLTAGE SHUTDOWN" or "GEN UNDERVOLTAGE " will be displayed on the EMCP 3. The message is used to inform the operator of an under voltage condition.Note: The severity of the under voltage condition will determine if a warning or shutdown event occurs.The code for generator under voltage is generated when the EMCP 3 determines that a generator under voltage condition has occurred.Test Step 1. TALK TO THE OPERATOR.
Determine the conditions that caused the under voltage condition.Expected Result:An under voltage was caused by an occurrence known to the operator. The operator would like to put the generator set back into service.Results:
OK - The operator can determine the cause for the under voltage 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 under voltage 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 following set points:
Generator under voltage
Automatic voltage regulator (AVR) desired voltage request
Generator AC monitorMake 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. VERIFY VOLTAGE CAN BE ADJUSTED.Verify that the generator output voltage can be adjusted from the EMCP 3 display.Expected Result:The generator output voltage can be adjusted from the EMCP 3 display.Results:
OK - The generator output voltage can be changed from the EMCP 3 display.Repair: Adjust the generator output voltage to meet site requirements. Resume normal operation and verify that the problem has been corrected.STOP
NOT OK - The generator output voltage cannot be adjusted. Proceed to Test Step 4.Test Step 4. CHECK CAT DATA LINK BETWEEN THE EMCP 3 AND THE VOLTAGE REGULATOR.Refer to the generator set electrical system schematic in the service manual. Check the data link wiring between the EMCP 3 and the voltage regulator. For more information on troubleshooting the data link, refer to Troubleshooting , RENR7902, "Data Link Circuit Fault ".Results:
OK - The data link wiring is correct. Proceed to Test