Generac Power Systems QT05030AVAN, Owner'S Manual

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ENGINE PROTECTIVE DEVICES
The Stationary Emergency Generator may be required to operate
for long periods of time without an operator on hand to monitor
such engine conditions as coolant temperature, oil pressure or
rpm. For that reason, the engine has several devices designed to
protect it against potentially damaging conditions by automatically
shutting down the unit when the oil pressure is too low, the coolant
temperature is too high, the coolant level is too low, or the engine
is running too fast.
NOTE:
Engine protective switches and sensors are mentioned here for
the reader’s convenience. Also refer to the applicable control
panel manual for additional automatic engine shutdown infor-
mation.
HIGH COOLANT TEMPERATURE SWITCH
The switch will close if the temperature should exceed approxi-
mately 140° C (284° F), initiating an engine shutdown. The gen-
erator will automatically restart and the LED will reset once the
temperature has returned to a safe operating level.
LOW COOLANT LEVEL SENSOR
To prevent overheating, the engine has a low coolant level sensor.
If the level of engine coolant drops below the level of the low cool-
ant level sensor, the engine automatically shuts down.
LOW OIL PRESSURE SWITCH
This switch has normally closed contacts that are held open by
engine oil pressure during cranking and operating. Should oil pres-
sure drop below the 8 psi range, switch contacts close, and the
engine shuts down. The unit should not be restarted until oil is
added, and the AUTO/OFF/MANUAL switch must be turned to OFF
and then back to AUTO.
OVERCRANK SHUTDOWN
After a prespecified duration of cranking, this function ends the
cranking if the engine has failed to start. The overcrank LED will
turn ON. Turn OFF the AUTO/OFF/MANUAL switch, then turn switch
back to AUTO to reset the generator control board.
NOTE:
If the fault is not corrected, the overcrank feature will continue
to activate.
Approximate Crank Cycle Times
• 15 seconds ON
• 7 seconds OFF
• 7 seconds ON
• 7 seconds OFF
• Repeat for 45 seconds
Approximately 90 seconds total.
OVERSPEED SHUTDOWN
A speed circuit controls engine cranking, start-up, operation and
shutdown. Engine speed signals are delivered to the circuit board
whenever the unit is running. Should the engine overspeed above
a safe, preset value, the circuit board initiates an automatic engine
shutdown. Contact the nearest Authorized Dealer if this failure
occurs.
RPM SENSOR LOSS SHUTDOWN
If the speed signal to the control panel is lost, engine shutdown
will occur.
DC FUSES
Fuse F1 (15 amp) is located inside of the control panel. It protects
the panel wiring and components from damaging overload. Always
remove this fuse before commencing work on the generator. The
unit will not start or crank if the fuse is blown.
Fuse F2 (25 amp) is located in the engine wire harness adjacent
to the DC alternator. It is used to prevent circuit failure due to DC
alternator falure. If this fuse is blown, battery charging will not
occur while the engine is running. Replace these fuses with the
same size, type, and rating. (See the exploded views and parts
lists at the end of this manual for replacement part number.)
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EngProt001 R ev. C 06/10
Engine Protective Devices