Generac Power Systems 9344-1 - Manual (Page 9)

ADDITIONAL INFORMATION
AUTOMATIC LOW OIL PRESSURE
SHUTDOWN
The engine is equipped with a normally-closed (N.C.)
oil pressure switch (Figure 6). Engine oil pressure holds
the switch open during cranking and operation. Should
oil pressure drop below about 15 psi, the switch contacts
close and the engine automatically shuts down.
HIGH COOLANT TEMPERATURE
SHUTDOWN
This switch (Figure 7) is a normally open (N.O.) thermo­
static device which is immersed in engine coolant.
Should engine coolant temperature exceed about
230°F (110°C), the switch contacts close and the en­
gine shuts down.
Figure 7
—
High Coolant Temperature Switch
OVERSPEED SHUTDOWN
The generator control panel houses an Engine Control­
ler circuit board (Figure 8). That circuit board receives
a-c frequency signals from generator stator leads 11
and 22. Should a-c frequency exceed about 72 Hz
(2160 rpm), circuit board action initiates an automatic
shutdown after a few seconds.
Figure 8
—
Engine Controller Circuit Board
NOTE: After an overspeed shutdown, the engine may
be cranked and re-started. However, if the engine
overspeeds again, the engine shuts down again.
ENGINE GOVERNED SPEED
The generator is equipped with a 4-pole revolving field
(rotor) which must be driven at 1500 rpm to produce the
unit’s rated a-c frequency of 50 Hz. The diesel engine
governor was factory set to about 52 Hz. (1560) at
no-load. After installing it, the installation technician
should check and adjust the governed speed. Setting
the no-load frequency slightly high helps prevent exces­
sive frequency, rpm and voltage droop under heavy
electrical loading.
DANGER; DO NOT TAMPER WITH THE ENGINE
GOVERNOR SETTINGS. EXCESSIVELY HIGH
ENGINE SPEEDS ARE DANGEROUS AND IN­
CREASE THE RISK OF PERSONAL INJURY AND
DAMAGE TO EQUIPMENT AND/OR PROPERTY.
EXCESSIVELY LOW SPEEDS IMPOSE A HEAVY
LOAD ON THE ENGINE WHEN ADEQUATE EN­
GINE POWER IS NOT AVAILABLE AND MAY
SHORTEN ENGINE LIFE. THE GENERATOR SUP­
PLIES CORRECT RATED FREQUENCY AND
VOLTAGE ONLY AT THE PROPER SPEED.
SOME ELECTRICAL DEVICES MAY BE DAM­
AGED BY INCORRECT FREQUENCY AND/OR
VOLTAGE. IF ENGINE SPEED APPEARS TO BE
INCORRECT, CONTACT YOUR NEAREST AU­
THORIZED SERVICE FACILITY.
25-HOUR BREAK-IN PERIOD
The first 25 hours of operation is the break-in period for
the generator. Properly breaking in the generator is
essential to reducing oil consumption and enhancing
engine performance. During the break-in period, ob­
serve the following rules:
• For the first 25 hours, run the generator at varying
electrical loads, to help set the enaine piston rings
properly.
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