Generac Power Systems 941-2 - Manual (Page 127)

Section 7.2
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING
TEST 29 - 12 POSITION HARNESS
CONTINUITY TEST
1) Set VOM to measure Resistance.
2. Measure from pin location #1 on one end of the 12 position
harness to pin location #1 on the opposite end of the harness.
A reading of “Continuity” should be measured. Repeat proce-
dure for each pin position on the 12-wire harness. If an open
condition is detected, replace the defective harness as neces-
sary.
3. If needed, check for continuity on the A6060 circuit board wire
harness in the control panel. This connection is at location J1
on the circuit board. Follow the same procedure as steps 1 and
2 above.
TEST 30 - 12 POSITION HARNESS SIGNALS TEST
ASSUMPTION:
• Engine runs
• Inverter not connected
TEST PROCEDURE:
1. Disconnect the 12-wire cable from the inverter. Disconnect the
Red-Black-Blue-Green DC Link wires from the inverter.
Note: Cap the DC Link wires with a wire nut for
safety.
2. On units with A6060 circuit board revision “D” or higher soft-
ware, jump pin #10 to pin #11 on the 12 position cable previ-
ously removed from the inverter. The 12 position cable should
be connected to the 12 position socket on the generator control
panel. This will enable the generator to run with CB1 turned
ON.
3. Turn CB1 to ON position. Start generator. The engine should
run at approximately 3300rpm.
4. Set a DVOM to DC volts. Measure from the free end of the 12
position harness according to the chart below. Connect the
negative and positive test leads as indicated in the chart.
(Note: Fluke 87 true RMS meter used in test.)
5. Set a DVOM to AC volts. Measure the the free end of the 9-
Wire harness according to the chart below. Connect the nega-
tive and positive test leads as indicated in the chart.
Figure 10 Free End of 12 Position Harness
Page 7.2-17
Test With DVOM
Set At DC Volts
Connect negative lead to: Connect positive lead to: Reading should be:
Inverter Signals Ground Pin 9 (0 v) Pin 2 (En/Com) < 0.10 vdc
Inverter Signal Pin 2 (En/Com) Pin 1 (PWM1) 2.5 v ± 0.15 vdc
Inverter Signal Pin 2 (En/Com) Pin 3 (PWM2) 2.5 v ± 0.15 vdc
Temperature Voltage Pin 9 (0 v) Pin 10 (TEMP) 5.0 v ± 0.1 vdc
Inverter Fan Voltage Pin 9 (0 v) Pin 4 (Wire #14) 12 v ± 1.0 vdc
Shield Wire
Test for Ground
Pin 12 (SHIELD) Pin 4 (Wire #14) 12 v ± 1.0 vdc
Test With DVOM
Set At AC Volts
Connect negative lead to: Connect positive lead to: Reading should be:
Inverter Signal Pin 2 (En/Com) Pin 1 (PWM1) 2.5 v ± 2.0 vac*
Inverter Signal Pin 2 (En/Com) Pin 3 (PWM2) 2.5 v ± 2.0 vac*
* Tolerance is large because readings will vary,
depending on type of meter used.