NUT 8T4132 - Caterpillar

System Operation Description:If the frequency rises above the "Generator Over-frequency Percentage Threshold" set point value, then the over-frequency timer will begin timing. When the timer expires, the generator over-frequency event is made active (if the frequency has been above the threshold level continuously while timing). If the frequency rises above the generator over-frequency percentage threshold, then the generator over-frequency event will be made inactive and the timer will be reset. If an over-frequency condition is detected, then "GEN OVERFREQUENCY SHUTDOWN" or "GEN OVERFREQUENCY " will be displayed on the EMCP 4 in order to inform the operator of an overfrequency condition.Note: The severity of the over-frequency condition will determine if a warning or shutdown event occurs.Conditions Which Generate This Code:The code for generator over-frequency is generated when the EMCP 4 determines that a generator over-frequency condition has occurred. Test Step 1. TALK TO THE OPERATOR
Determine the conditions that caused the over-frequency condition. Expected Result:An over-frequency condition was caused by an occurrence that is known to the operator and the operator would like to put the genset back into service.Results:
OK - The operator can determine the cause for the over-frequency condition, the condition has been repaired, and the operator wants to put the genset back into service.Repair: Reset the generator set. Resume normal operation and verify that the problem has been corrected.The generator set operates normally.
NOT OK - The overfrequency condition was not caused by an occurrence known to the operator. Proceed to Test Step 2Test Step 2. CHECK THE SET POINTS.
View the generator over-frequency and generator desired engine speed request set points. Make a note of the set points. See Testing and Adjusting, "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 genset. Proceed to Test Step 3 for EUI engines. Proceed to Test Step 4 for MUI engines
NOT OK - The set points are NOT correct.Repair: Reprogram the set points. Reset the genset. Resume normal operation and verify that the problem has been corrected.STOPTest Step 3. VERIFY FREQUENCY CAN BE VIEWED AND ADJUSTED FROM THE EMCP 4 (EUI ENGINES WHERE ADEM IS SET TO CAN)Verify that the generator output frequency can be viewed and adjusted from the EMCP 4 display screen.Expected Result:The generator output frequency can be viewed and adjusted from the EMCP 4 display screen.Results:
OK - The generator output frequency can be viewed and adjusted from the EMCP 4 Display Screen.Repair: Adjust the generator output frequency to meet site requirements. Resume normal operation and verify that the problem has been corrected.STOP
NOT OK - The generator output frequency cannot be adjusted. Proceed to Test Step 7
NOT OK - The generator frequency reads zero on the EMCP 4 Display Screen. Proceed to Test Step 8Test Step 4. CHECK THE SYSTEM BY USING THE SPEED POTENTIOMETER. (MUI ENGINES ONLY)
With the engine running, adjust the generator output frequency by turning the speed