Kohler COM7.5 Service Manual page 44

5.2.1 Low Oil Pressure (LOP) Shutdown
The low oil pressure (LOP) switch closes 5 seconds
after the oil pressure drops below 5 psi, shutting down
the generator set and lighting the fault LED on the
control board. The low oil pressure shutdown does not
function during the first 30 seconds after startup.
To test the operation of the LOP shutdown, connect a
jumper wire from pin J4-13 of the controller-to-engine
wiring harness to the generator set ground. Start the
generator set. After approximately 35 seconds the
generator set shuts down and the fault lamp lights. If the
generator set does not shut down, replace the control
board.
Note: Always check wiring before replacing the control
board.
5.2.2 High Oil Temperature (HOT)
Shutdown
The high oil temperature (HOT) switch closes 5 seconds
after the generator set temperature reaches 305°F,
shutting down the generator set and lighting the fault
LED on the control board. The high engine temperature
shutdown does not function during the first 30 seconds
after startup.
To test the HOT shutdown, connect a jumper from the
HOT switch (lead ) to the generator set ground. Start the
generator set. After approximately 35 seconds the
generator set shuts down and the fault LED lights. Five
seconds after the jumper is removed, the fault LED goes
out and the generator set restarts. If the generator set
does not shut down and restart as described, replace
the control board.
Note: Always check wiring before replacing the control
board.
5.2.3 Overcrank Shutdown
The generator set shuts down and the fault LED lights
after approximately 75 seconds of cyclic cranking (three
attempts to start). The manufacturer sets the circuit
board for three cranking attempts: crank 15 seconds,
rest 15 seconds, crank 15 seconds, rest 15 seconds,
crank 15 seconds, shutdown.
procedure to test the overcrank shutdown operation.
34 Section 5 Controller Operation and Test
Use the following
Overcrank Shutdown Test Procedure
1. Turn off the fuel supply to prevent flooding.
2. Move the generator set master switch to the RUN
position.
3. Verify that the generator set stops cranking and the
fault lamp lights after the third crank/rest cycle.
5.2.4 Overspeed Shutdown
The generator set shuts down and the fault LED on the
control board lights when the engine speed exceeds
3850 rpm.
Use the following procedure to test the operation of the
overspeed shutdown.
Overspeed Shutdown Test Procedure
Note: Do not increase the engine speed above
3950 rpm. Increasing the engine speed above
3950 rpm can raise the output voltage high
enough to damage the generator and connected
equipment.
1. Disconnect the load from the generator set.
2. Connect a tachometer to the engine spark plug
lead to measure the engine speed during the test.
Note: If a tachometer is not available, connect a
frequency meter across terminals 2 and 3 on
the AC side of the voltage rectifier. Increase
the engine speed as instructed in step 3.
The generator set should shut down when
the output frequency reaches 770 Hz. Do
not exceed 790 Hz.
3. With the generator set running, carefully move the
throttle linkage to increase the engine speed.
Watch the tachometer and note the speed when
the generator set shuts down.
4. Reset the controller by moving the master switch to
the OFF position and then back to AUTO.
If the generator set does not shut down when the engine
speed exceeds 3850 rpm, replace the control board.
TP-6120 5/02