Test 46 - Check Wire 56 Voltage - Generac Power Systems 7 kW NG Repair Manual

Section 4.5
Diagnostic Tests
C. Test Battery State of Charge:
(Non-Maintenance Free Battery)
1. Use an automotive type battery hydrometer to test
battery state of charge.
2. Follow the hydrometer manufacturer's instructions
carefully. Read the specific gravity of the electrolyte fluid
in all battery cells.
3. If cells are low, distilled water can be added to refill cell
compartment.
4. If the hydrometer does not have a "percentage of charge"
scale, compare the reading obtained to the following:
a. An average reading of 1.260 indicates the battery is
100% charged.
b. An average reading of 1.230 means the battery is 75%
charged.
c. An average reading of 1.200 means the battery is 50%
charged.
d. An average reading of 1.170 indicates the battery is
25% charged.
USE A TEMPERATURE
CHECK EACH CELL
AFTER CHARGING
Figure 111. Using a Battery Hydrometer
5. Test Battery Condition:
a. If the difference between the highest and lowest reading
cells is greater than 0.050 (50 points), battery condition
has deteriorated and the battery should be replaced.
b. However, if the highest reading cell has a specific
gravity of less than 1.230, the test for condition
is questionable. Recharge the battery to a 100
percent state of charge, and then repeat the test for
condition.
Results
1. Remove the battery and recharge with an automotive
battery charger, if necessary.
2. If battery condition is bad, replace with a new battery.
3. If the VOM indicated less than 10.5 VDC during Step 7,
replace or recharge battery.
Page 118
COMPENSATED
HYDROMETER
PART 4
4. If battery condition is good, refer back to flow chart.
TEST 46 – CHECK WIRE 56 VOLTAGE
Discussion
During an automatic start or when starting manually, an internal
crank relay energizes. Each time the crank relay energizes,
the controller should deliver 12 VDC to a start contactor relay
(SCR), or starter contactor (SC) and the engine should crank.
This test will verify (a) that the crank relay on the controller is
energizing, and (b) that the controller is delivering 12 VDC to
the SCR relay or the SC.
Note: If the unit does not crank the Alarm Log will display,
"Stopped-Alarm RPM Sense Loss."
Procedure
1. Set the Volt-Ohm-Milliammeter (VOM) to measure DC
voltage.
2. Locate and disconnect Wire 56 from the SCR on V-Twin
units and the SC on single cylinder units.
3. Connect one meter test lead to Wire 56 and the other
meter test lead to a clean frame ground.
4. Set the AUTO-OFF-MANUAL switch to MANUAL. Observe
the meter, the VOM should indicate battery voltage. If
battery voltage was measured, stop testing and refer back
to the flow chart. If voltage was NOT measured, proceed
to Step 5.
5. 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 112.
6. Set the AUTO-OFF-MANUAL switch to the MANUAL
position and observe digital output Number 6. If the
controller is working correctly output Number 6 will
change from a "0" to a "1", observe and record the
change in state.
7. Set a VOM to measure resistance.
8. Remove 7.5 amp fuse.
9. Disconnect the J4 connector from the controller.
10. Remove Wire 56 from the starter contactor relay (V-twin
units) or from the starter contactor (single cylinder units).
11. Connect one meter test lead to disconnected Wire 56
and connect the other test lead to J4 Pin 17 (Wire 56),
measure and record the resistance.
ENGINE/DC CONTROL