Grandstream Networks 005261-0 User Manual

Page of 64
ENGINE PROTECTIVE DEVICES
The Stationary Emergency Generator may be required 
to operate for long periods of time without an opera-
tor 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 run-
ning too fast.
NOTE:
Engine protective switches and sensors are men-
tioned here for the reader’s convenience. Also 
refer to the applicable control panel manual for 
additional automatic engine shutdown informa-
tion.
HIGH COOLANT TEMPERATURE SWITCH
 
‹
The switch will close if the temperature should 
exceed approximately 140° C (284° F), initiating an 
engine shutdown. The generator 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 coolant 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 pressure 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 func-
tion 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 har-
ness adjacent to the DC alternator. It is used to pre-
vent 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 replace-
ment part number.)
4-1
Stationary Emergency Generator
Engine Protective Devices
EngProt001  Rev.
 B  09/08