ELBOW-EXHAUST 7C6447 - Caterpillar

If the engine speed drops below the "Engine Underspeed Threshold" setpoint value, the underspeed timer will begin timing. When the timer expires, the "Engine Underspeed" event is made active (if the engine speed has been below the threshold level continuously while timing). If the engine speed rises above the engine underspeed threshold, the "Engine Underspeed" event will be made inactive and the timer will be reset. If an underspeed condition is detected, "ENGINE UNDERSPEED SHUTDOWN" or "ENGINE UNDERSPEED " will be displayed on the OCP. These messages are to inform the operator of an underspeed condition.Note: The severity of the underspeed condition will determine if a warning or shutdown event occurs.Conditions Which Generate This Code:The code for engine underspeed is generated when the OCP determines that an engine underspeed condition has occurred. Test Step 1. TALK TO THE OPERATOR
Determine the conditions that caused the underspeed condition. Expected Result:An underspeed was caused by an occurrence known to the operator. The operator would like to place the generator set back into service.Results:
OK - The operator can determine the cause for the underspeed condition. The condition has been repaired and the operator wants to place 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 underspeed condition was not caused by an occurrence known to the operator. Proceed to Test Step 2Test Step 2. CHECK THE SETPOINTS.
View the "Engine Speed Monitor" setpoints. Make a note of the setpoints. Refer to Testing and Adjusting, "Electronic Control Module (ECM) - Configure". Compare the setpoints against the default setpoints of the particular generator set. Expected Result:The setpoints are correct.Results:
OK - The setpoints are correct for your particular generator set. Proceed to Test Step 3 for EUI engines. Proceed to Test Step 4 for MUI engines
NOT OK - The setpoints are NOT correct.Repair: Reprogram the setpoints. Reset the generator set. Resume normal operation and verify that the problem has been corrected.STOPTest Step 3. VERIFY ENGINE SPEED CAN BE VIEWED AND ADJUSTED FROM THE OCP (EUI ENGINES WHERE ADEM IS SET TO CAN)Verify that the engine speed can be viewed and adjusted from the OCP display screen.Expected Result:The engine speed can be viewed and adjusted from the OCP display screen.Results:
OK - The engine speed can be viewed and adjusted from the OCP display screen.Repair: Adjust the engine speed to meet site requirements. Resume normal operation and verify that the problem has been corrected.STOP
NOT OK - The engine speed cannot be adjusted. Proceed to Test Step 7
NOT OK - The engine speed reads zero on the OCP display screen.Repair: The engine speed sensor may have failed or needs adjustment. See Testing and Adjusting, "Speed Sensor (Engine) - Adjust". If the problem remains, replace the engine speed sensor.STOPTest Step 4. CHECK THE SYSTEM BY USING THE SPEED POTENTIOMETER (MUI ENGINES ONLY)
With the engine running, adjust the speed of the engine by turning the speed potentiometer. Expected Result:The engine can be adjusted to the desired