Alpha Technologies AlphaGen 3.5_5.0kW Kohler COM5 - Manual (Page 59)

TP-6482 8/06 59 Section 6 Controller Operation and Test
6.5 Control Board Tests
Use the troubleshooting procedures in Section 4 to
diagnose generator set and engine problems. If the
troubleshooting procedures indicate a problem with the
controller circuit board, use the tests in this section to
check the board.
Refer to the wiring diagrams in Section 8 when
troubleshooting the generator set control circuit board.
Circuit board components cannot be repaired or
replaced; if the troubleshooting process reveals a faulty
component on the circuit board, replace the board.
Note: Use an ohmmeter or continuity tester to check for
shorts or open leads in the wiring harnesses
before replacing the controller circuit board or
other system components.
Disconnect the generator system from the remote
control system at plug P6 and use the generator set
master switch to operate the generator set.
If the
generator set operates normally when P6 is
disconnected, then the problem is with the remote
control system. Refer to the manufacturer’s instructions
for the remote control system to troubleshoot the
problem.
If the problem persists after P6 is
disconnected, use the troubleshooting procedures in
this manual to diagnose the problem.
Hazardous voltage.
Will cause severe injury or death.
Only authorized personnel should
open the enclosure.
DANGER
Hazardous voltage.
Can cause severe injury or death.
Operate the generator set only when
all guards and electrical enclosures
are in place.
Moving rotor.
WARNING
Servicing the generator set when it is operating. Exposed
moving parts can cause severe injury or death. Keep
hands, feet, hair, clothing, and test leads away from the belts
and pulleys when the generator set is running.
Replace
guards, screens, and covers before operating the generator
set.
Short circuits. Hazardous voltage/current can cause
severe injury or death. Short circuits can cause bodily injury
and/or equipment damage.
Do not contact electrical
connections with tools or jewelry while making adjustments or
repairs. Remove all jewelry before servicing the equipment.
6.5.1 Fuel Control Circuit
Move the generator set master switch to the START
position and check for 12 VDC on pin P5-1 (lead 70) of
the fuel valve connector. If the valve receives voltage
but does not open, replace the valve.
If there is no voltage to the valve, check the battery
voltage, battery connections, and ignition system (see
Section 5.5). If the battery and ignition system function
correctly but the fuel valve does not receive voltage,
replace the controller circuit board.
6.5.2 Speed Sensing and Governor
(Throttle Control) Circuits
The controller monitors the AC voltage produced by the
stator to sense and control the engine speed. If the
engine speed varies erratically, test the governor
operation as described in Section 5.4. If the tests show
that the erratic operation is not caused by a faulty
governor, replace the controller circuit board.
6.5.3 Start Circuits
Move the generator set master switch to the START or
RUN position. If the engine does not crank, check the
following components.
1. Check the battery voltage. Recharge or replace a
weak or dead battery.
2. Check for 12 VDC to the starter motor. Also verify
that the starter motor is grounded. See Section 8,
Wiring Diagrams. If the starter motor is receiving
voltage but not functioning, replace it. If there is no
voltage to the starter motor, check the harness and
connections and then proceed to step 3 to check
the starter (crank) relay.
3. Check for 12 VDC to the crank relay. See
Section 8, Wiring Diagrams. If the crank relay is
receiving voltage but not functioning, replace it. If
there is no voltage to the crank relay, check the
harness and connections.
4. Check for 12 VDC from the control board at P2-1. If
there is no voltage, replace the controller circuit
board.