Generac Power Systems 8 kW LP - Manual (Page 133)

sEctioN 4.4
DiaGNostic tEsts
Page 131
PORT 3
PORT 1
PORT 2
Figure 20 (12-20 kW) Gas Pressure Test point
note: Where a primary regulator is used to estab-
lish fuel inlet pressure, adjustment of that regula-
tor is usually the responsibility of the fuel supplier
or the fuel supply system installer.
12-20 kW UNITS ONLY:
note: the test port (port 3) below the fuel solenoid
maybe used to take a fuel pressure reading before
the fuel solenoid. consistent pressure should be
measured at this port while the generator is run-
ning and when the generator is off.
RESULTS:
1. If fuel supply and pressure are adequate, but engine will
not start refer back to flow chart.
2. If generator starts but runs rough or lacks power, repeat
the above procedure with the generator running and
under load. The fuel system must be able to maintain
10-12 inches water column at all load requirements for
propane, and 5-7 inches water column for natural gas.
If proper fuel supply and pressure is maintained, refer to
Problem 18 Flow Chart.
teSt 67 – check circuit Board Wire 14
output
DISCUSSION:
During any cranking action, the circuit board’s crank
relay and run relay both energize simultaneously.
When the run relay energizes, it’s contacts close and
12 VDC is delivered to Wire 14 and to a fuel solenoid.
The solenoid energizes open to allow fuel flow to the
engine. This test will determine if the circuit board is
working properly.
PROCEDURE: 12-20 kW UNITS
1. Set the AUTO-OFF-MANUAL switch to OFF.
2. Set a VOM to measure DC voltage.
3. Disconnect Wire 14 from the fuel solenoid (FS).
4. Connect the positive test lead to the disconnected Wire
14 from Step 3. Connect the negative test lead to a
clean frame ground.
5. Set AUTO-OFF-MANUAL switch to the MANUAL position.
The meter should indicate battery voltage.
a. If battery voltage is indicated, refer back to
flow chart.
b. If battery voltage is not measured, navigate to
the Digital Output display.
c. Press “ESC” until the display screen is present.
d. Press the right arrow key until “Debug” is flashing.
Press “Enter”.
e. Press the right arrow key until “Outputs” is
flashing. Press “Enter”.
DEBUG
OUTPUTS
OUTPUT 5
OUTPUTS 1 - 8:
1 0 1 1 0 0 0 1
Figure 21. The Home Page, Debug and Output
Screens
f. Output 5 is Wire 14 out from the printed circuit
board. If the printed circuit board is functioning
properly, Output 5 will change from a “0” to a “1”
while the unit is cranking.
g. If voltage was not measured in Step 5 and
output did not change in Step 5f, replace the
printed circuit board.
note: disconnect the 7.5 amp Fuse before dis-
connecting the j2 connector.
h. If voltage was not measured in Step 5 and out-
put changed in Step 5f, remove the J1 connec-
tor from the printed circuit board. See Figures
on Pages 92-95.
DC CONTROL Part 4