Download Section 12 – Troubleshooting

Section 12 – Troubleshooting
CFP33 Series
Page 12-83
Engine Overspeed Trip
NOTE: An engine overspeed trip occurs when the engine’s speed exceeds the value specified on the Factory
setting Tag described in Section 2. The trip isolates the fuel supply to the engine and it stops immediately. The
trip is indicated on the local control panel and inside the local control panel on the speed switch. Additionally, a
trip output is supplied to the fire protection system for remote display.
Cause
Correction
Engine actually operated at too great a speed due to
catastrophic load failure such as pipe break, pump
mechanical failure, or loss of suction.
Correct the cause of the load failure.
Engine actually operated at too great a speed due to
configuration error.
Check rated speed setting as specified on the Factory
Setting Tag described in Section 2. Refer to Rated
Speed Setpoint Adjustment and Testing in Section 3.
Overspeed switch is set at too low a setpoint.
Check overspeed speed setting as specified on the
Factory Setting Tag described in Section 2. Refer to
Overspeed Setpoint Adjustment and Testing in Section
3.
Speed switch wiring failure has occurred.
Check continuity and insulation from ground for the
signal power wiring and ground wiring to the speed
switch. Refer to Drawing 10423 Sheet 1 in Section 13.
Replace defective components and repair electrical
faults.
Speed switch failure has occurred.
If the speed switch fails to operate as per Overspeed
Setpoint Adjustment and Testing in Section 3, replace
the speed switch. Refer to Overspeed Switch
Removal/Installation in Section 7.
Contact an Authorized Cummins Repair Facility.
Drawing No. 9774, Section 12, Rev. 02-07