CONTROL PANEL (TYPE 3)
SYSTEMS OPERATION
Manual Shutdown
When engine control switch (ACS) is turned to the STOP or OFF
position, contacts (9 or 10) close and contacts (2 and 3) are both open,
no shutdown indicators can operate. (9 to 10) closed completes a circuit
to shut-off solenoid (SS). The shut-off solenoid moves the rack to the
fuel OFF position. (2 and 3) open deenergizes run relay (RR).
When run relay (RR) is de-energized, contacts (RR2) close and
contacts (RR1) open. (RR2) closed completes a parallel circuit to shut-
off solenoid (SS). This circuit is necessary to stop the engine when the
engine control switch is in the AUTO or MAN position. After the engine
stops, (PSW) will open to deenergize the shut-off solenoid. (RR1) open
de-energizes arming relay (AR) and dual speed switch (DSS).
Diode (D1) helps prevent electrical sparks (arcing), at the contacts in
the shut-off solenoid circuit when the shut-off solenoid is de-energized.
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