Generac Power Systems 8 kW LP - Manual (Page 128)

Page 126
teSt 62 – check Wire 56 VoltaGe
DISCUSSION:
During an automatic start or when starting manually,
a crank relay on the circuit board should energize.
Each time the crank relay energizes, the circuit board
should deliver 12 VDC to a starter contactor relay
(SCR), or starter contactor (SC), and the engine
should crank. This test will verify (a) that the crank
relay on the circuit board is energizing, and (b) that
circuit board action is delivering 12 VDC to the starter
contactor relay or starter contactor.
PROCEDURE:
1. Set a VOM to measure DC voltage.
2. Connect the positive (+) test probe of a DC voltmeter
(or VOM) to the Wire 56 connector of the starter
contactor relay (SCR, on models with V-twin engines)
or the starter contactor (SC, on models with single
cylinder engines). Connect the common (-) test probe
to frame ground.
3. Observe the meter. Then, set the AUTO-OFF-MANUAL
switch to the MANUAL position. The meter should
indicate battery voltage. If battery voltage is measured,
stop testing and refer back to flow chart.
4. Navigate to the Digital output display screen.
a. Press “ESC” until the main menu is reached.
b. Press the right arrow key until “Debug” is flashing.
c. Press “Enter”.
d. Press the right arrow key until “Outputs” is flashing.
e. Press “Enter”.
f. Digital Output 6 is Wire 56 output from the
board. Refer to Figure 6.
5. Actuate the AUTO-OFF-MANUAL switch to the MANUAL
position and observe digital output Number 6. If the
printed circuit board is working correctly output Number
6 will change from a “0” to a “1”. If output did not change
replace printed circuit board.
6. Set a VOM to measure resistance.
note: remove 7.5 amp fuse before disconnecting
j1 connector.
7. Remove Wire 56 from the starter contactor relay (V-twin
units) or from the starter contactor (single cylinder
units). Connect one meter test lead to disconnected
Wire 56. Remove the J2 Connector from the printed
circuit board. Connect the other test lead to Wire 56 at
J2. CONTINUITY should be measured. If CONTINUITY
is not measured, repair or replace Wire 56.
RESULTS:
1. If battery voltage is indicated in Step 3 refer back to
flow chart.
DEBUG
OUTPUTS
OUTPUT 6
OUTPUTS 1 - 8:
1 0 1 1 0 0 0 1
Figure 6. The Home Page, Debug and Output Screens
teSt 63 – teSt Starter contactor
relay (V-tWin only)
DISCUSSION:
The starter contactor relay (SCR) located in the con-
trol panel must be energized for cranking to occur.
Once the SCR is energized, it’s normally open con-
tacts will close and battery voltage will be available
to Wire 16 and to the starter contactor (SC).
COM NO
16 13
56 0
13
16
0
56
Figure 7. The Starter Contactor Relay
Part 4 DC CONTROL
sEctioN 4.4
DiaGNostic tEsts