Test 6 - Test Excitation Windingcircuit 2 And 6; Test 7 - Test The Stator With A Vom - Generac Power Systems 7 kW NG Repair Manual

Section 2.4
Diagnostic Tests
9. Connect one-meter test lead to C1 Pin 1 (Wire 44) and
the other meter test lead to the NEUTRAL connection,
measure and record the resistance.
Results
1. If the meter indicated a resistance value of less than
0.2 ohms in Steps 5 through 9, refer back to flow chart
(Good).
CI CONNECTOR
Figure 52. C1 Connector
2. If the meter indicated a resistance value of OPEN in Step 5
and a value less than 0.2 ohms in Step 8, repair or replace
Wire 11 between the controller and the C1 connector.
3. If the meter indicated a resistance value of OPEN in Step 6
and a value less than 0.2 ohms in Step 9, repair or replace
Wire 44 between the controller and the C1 connector.
4. If the meter indicated OPEN in either Step 8 or Step 9,
proceed to Test 7 "Test Stator."
TEST 6 – TEST EXCITATION WINDING
CIRCUIT 2 AND 6
Discussion
The voltage regulator (internal to the controller) requires an
unregulated voltage in order to regulate DC excitation current to
the rotor. The alternator may be producing a voltage, but if the
voltage regulator cannot "sense" the voltage, it will fault out for
under-voltage. This test will verify the integrity of the Excitation
winding inside the stator.
Required Tools
• Meter test leads that are capable of measuring voltage inside
a connector without damaging the socket. A set of black
and red test leads for this application are available from the
manufacturer. Contact your nearest servicing dealer for more
information. See Figure 47.
Note: It is not recommended to use any testing device other
than the manufactures approved test lead adapters.
Page 52
PART 2
Procedure
1. Remove the 7.5 amp fuse from the control panel.
2. Remove the controller and the cover to expose the lower
harness connections.
3. Disconnect the J5 connector from the controller.
4. Set the Volt-Ohm-Milliammeter (VOM) to measure
resistance.
5. Connect one-meter test lead to J5 Pin 5 (Wire 2) and the
other meter test lead to J5 Pin 14 (Wire 6). Measure and
record the resistance.
a. If the meter indicated a resistance value of less than
0.2 ohms in Step 5, stop testing and refer back to the
flow chart (Good).
b. If the meter indicated OPEN in Step 5, proceed to Step 6.
6. Disconnect the lower bulkhead C1 connector.
7. Connect one-meter test lead to C1 Pin 4 (Wire 2) and the
other meter test lead to C1 Pin 3 (Wire 6). Measure and
record the resistance.
Results
1. If the meter indicated a resistance value of less than 0.2
ohms in Steps 5 through 9, refer back to the flow chart
(Good).
2. If the meter indicated a resistance value of OPEN in Step
5 and a value less than 0.2 ohms in Step 7, repair or
replace Wire 2 and 6 between the controller and the C1
connector.
3. If the meter indicated a resistance value of OPEN in Step
7, verify connection, then replace the stator.
TEST 7 – TEST THE STATOR WITH A VOM
Discussion
This test will use a Volt-Ohm-Milliammeter (VOM) to test the
stator windings for the following faults:
• An OPEN circuit condition
• A "short-to-ground" condition
• A short circuit between windings
Table 14 (next page) has been provided to record the results of
the following procedure. These results may be required when
requesting factory support.
Additional copies of Table 14 can be found in Appendix A
"Supplemental Worksheets" at the back of this manual.
Note: It is the recommendation of the factory to preform
this test procedure using piercing probes on the wire side
of the connector. Testing inside the connector itself can
cause unneeded damage to the unit resulting in poor or
loose connections.
AC GENERATORS