HYDRAMECHANICAL PROTECTIVE SYSTEM
TROUBLESHOOTING
PROTECTIVE SYSTEM WITH ENGINE SHUTDOWN FOR OVERSPEED ONLY, ALARMS FOR OTHER FUNCTIONS (LOP, HWT) 1. Oil line to air inlet shutoff actuator. 2. Return line from air inlet shutoff actuator. 3. Oil line to thermostatic pilot valve. 4. Return line from diverter valve. 5. Oil line to diverter valve. 6. From two-way valve at the diverter valve to drain. 7. From diverter valve to governor (fuel) shutoff actuator. 8. Oil pressure switch for alarms. AIR INLET SHUTOFF CHECK Operate the engine at low idle and pull the red, emergency knob. The air inlet shutoff valve must close and stop the engine. Low oil pressure and high coolant temperature alarms should also be activated, if so equipped. The fuel shutoff actuator must also move the governor and fuel control linkage to the "SHUTOFF" position. PROTECTIVE SYSTEM OIL LINES
NOTICE
3. Oil line to thermostatic pilot valve. 5. Oil line to diverter valve. 6. From two-way valve (at the diverter valve) to drain.
After this test has been performed, the air inlet shutoff valve must be opened. Also, the startup override valve must be operated to release hydraulic pressure from the governor shutoff actuator before the engine can be started again.
START-UP OVERRIDE VALVE CHECK On an engine with an air start system, start and operate the engine at low idle. Loosen the drain line from the two-way (palm) valve. There should be no oil present. If there is any oil flow, the valve has failed and replacement is necessary.
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