AMMETER The am meter should register in the charging
In cold weather the temperature gauge may fluctuate in or
range when the engine is running above low idle. If the
near the cold range. This indicates the engine is being
gauge still registers a discharge as the engine speed is
overcooled. In these instances the use of radiator louvers
increased, determine the cause.
If the engine fails to start, the cranking timer will time out
An automatic start-stop system ensures that power is
and lock the start circuit open, preventing the batteries
supplied to a load when the normal power source is
from being discharged.
Interrupted. The cranking panel is the heart of the system
During the cranking cycle, the safety shutoffs are
and consists of the failure warning system and relays to
inoperative to prevent a low oil pressure shut down.
start and stop the engine. When a power failure occurs
When oil pressure reaches a safe level the safety circuit
the system senses the failure, starts the engine and
is armed by the arming relay. High water temperature or
transfers the load to standby. When power is restored, it
low oil pressure will now stop the engine and prevent
senses power restoration, transfers the load from standby
and stops the engine. The major use of automatic start-
If an unsafe engine condition exists, a sending unit
stop systems is standby electric sets. This discussion is
completes the circuit to the safety relay and locking relay.
limited to that application.
The safety relay de-energizes the fuel solenoid and stops
The remote contacts close when a power failure
the engine. The locking relay insures that the circuit to
occurs and completes the circuit to the cranking timer and
the safety relay is complete even if the remote contacts
the start slave relay. The start slave relay completes the
circuit to the starter motor and the engine begins
The safety circuit must be reset by moving the start
selector switch to the OFF position. Before restarting any
As the engine starts and increases In speed, the
unit which has been shut down by the safety circuit, the
cause must be determined and corrected.
starts the slave relay. This disconnects the starter motor
circuit and protects the starter from overspeed damage.
DETERMINING THE CAUSE OF SHUTDOWN
Anytime an engine is shut down by its safety circuit,
the cause must be determined. In some cases the cause
DO NOT remove the pressure cap of an
will be obvious but often an investigation will have to be
overheated unit. The coolant is under
made. Do not put the engine back into service without
pressure and relieving this pressure will
determining and correcting the cause of the shutdown.
cause the coolant to flash into steam.
Serious burns and engine damage can
HIGH WATER TEMPERATURE
result from the escaping coolant.
Pressure in a radiator or surge tank may
Look for the obvious first.
be reduced by pouring warm water on
the top tank to condense the steam.
Check for water on the floor from spilled or
Check the water temperature gauge for
NEVER add cold water to an overheated
Check air flow through the radiator.