Test 75 - Test 120 Volt Input (T1); Test 76 - Verify Dc Voltage Output Of The Controller; Of The Controller; Test 77 - Check Wire 13 And Wire 0 - Generac Power Systems 7 kW NG Repair Manual

Section 4.5
Diagnostic Tests
TEST 75 – TEST 120 VOLT INPUT (T1)
Discussion
The controller requires 120 VAC supplied from the LOAD side
of the CONTACTOR in the transfer switch to function properly.
When the circuit is supplied to the controller it will allow the
controller to remain ON, but in a disabled mode where it will not
crank or function properly.
Procedure
Note: "Inspect Battery" alarm may appear while performing
this test procedure. Ignore this alarm, it is a symptom of
the test procedure.
1. Locate the 7.5 amp fuse on the controller.
2. Remove the fuse and observe the LCD screen.
Results
1. If the controller remained illuminated or continued to show
its status after the fuse was removed, the 120 VAC input
is good.
2. If the controller powered down when the fuse was
removed, the controller is not getting the 120 VAC input.
Return to the flow chart (Test 79).
TEST 76 – VERIFY DC VOLTAGE OUTPUT OF
THE CONTROLLER
Discussion
The battery voltage of the unit can be viewed within the "Status"
menu of the controller. This test procedure will verify battery
voltage connections to the controller.
Procedure
1. Navigate to the "Battery Voltage" menu in the controller.
a. Press "ESC" until the main menu screen is present
b. Press the right arrow key until "Status" is flashing.
Press Enter.
c. Press the right arrow key until "Display" is flashing.
Press Enter.
d. Press the right arrow key until "Battery Voltage"
displays. Press Enter.
2. Record the displayed voltage.
Results
1. If the battery voltage indicated on the display is greater
than 12 VDC, the connections to the controller from the
battery are good. Refer back to flow chart.
2. If the battery voltage indicated on the display is 0 VDC, the
connections to the controller are bad. Refer back to flow
chart.
3. If the battery voltage indicated on the display is between 1
VDC to 11VDC, charge or replace the battery.
Page 140
PART 4
TEST 77 – CHECK WIRE 13 AND WIRE 0
Discussion
The previous test indicated that battery voltage was not
available to the controller and it was operating only off of the
120 VAC input from T1.
Procedure
1. Set Volt-Ohm-Milliammeter (VOM) to measure DC voltage.
2. Remove the 7.5 Amp fuse from the controller.
3. Connect one meter lead to the left side of the fuse holder
where the fuse was previously connected. Connect the
other meter test lead to a clean frame ground. Measure
and record the voltage.
4. Disconnect the J4 connector from the controller.
5. Connect one meter test lead to J4 Pin 3 (Wire 13) and the
other meter test lead to J4 Pin 2 (Wire 0). Measure and
record the voltage.
Results
1. If the VOM indicated battery voltage in Steps 3 and 5,
replace the controller.
2. If the VOM indicated battery voltage in Step 3, but did NOT
indicate battery voltage in Step 5, replace or replace Wire
0 between the J4 connector and the ground stud.
TEST 78 – TEST DC CHARGE CURRENT TO
THE BATTERY
Discussion
Previous testing has verified the 120 VAC input connection and
the battery connection. This test procedure will determine if
there is a negative draw on the battery or a positive one, which
will indicate successful operation of the charger.
Procedure
Note: An "Inspect Battery" alert may be generated during
this test procedure. It will not effect the results of the test
and can be acknowledged when testing is complete.
1. Set the AUTO-OFF-MANUAL switch to the MANUAL
position and crank the engine for 2 -3 seconds.
2. Disconnect the negative cable battery.
3. Set the Volt-Ohm-Milliammeter (VOM) to measure DC
amperage.
Note: Consult the meters owner's manual to ensure proper
setup of meter and that the internal fuse is good before
proceeding.
3. Connect the positive (red) meter test lead to the negative
battery post and connect the negative (black) meter test
lead to disconnected negative battery cable. Measure and
record the amperage.
ENGINE/DC CONTROL