1. When engine mounted water temperature, oil pressure and/or overspeed contactors close, current flows through solenoid of shutdown relay which energizes shutoff circuit and alarm lamp is lit. Current flows through contacts of shutdown relay to rack solenoid which closes engine fuel rack. A parallel circuit through the fuel pressure switch flows through the run relay contacts to the rack solenoid. Shutdown relay remains energized until SW-2 is manually moved to OFF position.
CONTROL PANEL CALLING FOR ENGINE SHUTDOWN (ENGINE MOUNTED TROUBLE SENDING UNITS DIRECTED)
2. Initiating contacts open, interrupting current flow to initiating relay and run relay which opens normally open IR contacts and closes normally closed RR contact. Current flows through contacts of run relay to rack solenoid which closes engine fuel rack.
CONTROL PANEL CALLING FOR ENGINE SHUTDOWN (EMERGENCY POWER NOT REQUIRED: INITIATING CONTACTORS DIRECTED)