Figure 10-1. Annunciator Alarm System, Simplified Schematic Diagram
Pressing pushbutton S15 also connects battery positive to all annunciator panel A9 lights, while
disconnecting alarm relay K26. Disconnecting relay K26 prevents activation of the flasher, which is
described in step c, above. All annunciator panel A9 lights will remain constantly lit as long as pushbutton
Si5 is depressed.
Releasing pushbutton SI5 disconnects battery positive from the horn and the lights and reconnects alarm
relay K26. The horn goes dead, the lights go out, and the alarm system is prepared for normal operation.
Engine Shutdown and Load Circuit Breaker CB101 Trip Circuits. Several of the alarm system self-latching relays
have additional contact sets in the engine shutdown circuit or the load circuit breaker CB1 01 trip circuit. These
contact sets function as follows:
Tripping undervoltage, reverse power, or underfrequency alarm relays Al OK8, Al1 K1, or Al1 K5,
respectively, will energize circuit breaker trip relay K30. Relay K30 energizes the trip coil in bad circuit
breaker CB1 01, opening the breaker to disconnect generator G1 from the bus. The engine will continue to
run, but load circuit breaker CB101 will be uncloseable until the annunciator alarm system is reset via
ANNUNCIATOR RESET pushbutton S12.
Tripping overvoltage alarm relay Al 0K7 will energize engine shutdown relays K20A and K20B. Relay
K20A deenergizes self-latching engine run relay K1 5B. As a result, engine fuel solenoid L1 loses power,
doses, and cuts off fuel to the engine; the engine shuts down. Relay K20B energizes circuit breaker trip
relay K30. Relay K30 energizes the trip coil in load circuit breaker CB1 01, opening the breaker to
disconnect generator G1 from the bus. The generator set cannot be restarted until the annunciator alarm
system is reset via ANNUNCIATOR RESET pushbutton Si2 on the upper door of cabinet A.
High and Low Level Fuel Circuits. Two of the alarm system self latching relays have additional contact sets in
the high and low fuel level circuits. These contact sets function as follows: