AUTOMATIC START-STOP - TM-5-3895-349-14-P0357

OIL PRESSURE

WATER TEMPERATURE

AMMETER

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.

is suggested.

AUTOMATIC START-STOP

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

major damage.

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

open.

circuit to the starter motor and the engine begins

The safety circuit must be reset by moving the start

cranking.

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

frequency sensing relay turns off the cranking timer and

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,

WARNING

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

leaking coolant.

CAUTION

Check the water temperature gauge for

NEVER add cold water to an overheated

accuracy.

engine.

Check air flow through the radiator.