CONTROL PANEL (TYPE 5)
SYSTEMS OPERATION
Shutdown Caused By Overspeed
When the engine is shutdown due to an overspeed condition, the
overspeed relay (OSR) is energized and locked in by the overspeed
switch (OSS) contact of the dual speed switch (DSS).
The normally closed contact (OSR2) opens to de-energize the run
relay (RR). The normally open contact (OSR1) closes to complete a
circuit through the closed (TDX1) contact.. This energizes the optional
air shutoff solenoid (ASO).
Closed contacts (RR2) and (TDX2) will energize the shutdown
solenoid (SS). As soon as the oil pressure switch (OPS) starts to close,
(TDR) starts a time delay for 70 seconds. After 70 seconds, the (TDR)
contact opens and de-energizes relay (TDX). Then all (TDX) contacts
open.
To reset the overspeed fault relay, rotate the (ACS) to OFF/RESET.
This will de-energize the dual speed switch and permit the OSS contact
to open.
Before restarting, check for possible causes of the overspeed.
NOTE: The shutdown solenoid and air shut-off solenoid are
each protected with thermal type circuit breakers. If either
solenoid does not energize to shutdown, check breaker
condition by pressing button to reset.
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