39
PH3300i SM, Rev. 2017-01-20
4.10 Measuring Stator Main Output Voltage While Running
Before conducting this test turn the ignition key ON and OFF. This will pre-set the
■
throttle in the proper position for starting the generator. This will prevent engine
overspeeding due to the throttle being left wide open during shutdown.
1. Remove the 6 control panel screws, carefully allowing it to hang out of the way.
2. Remove the maintenance door and disconnect the carburetor step motor connector. On some
models it is necessary to follow steps 1-7 in (section 5.1.1) because the step motor connector is
routed all the way to the inverter and cannot be accessed from the maintenance door.
3. Find and unplug the connector from the inverter and start the engine (Fig. 27). It will be
necessary to manually adjust the throttle to make the engine run in the upper RPM range
(3000-4000 RPM) before checking the stator main output voltage. Once set, do not alter the
throttle during the rest of the test.
4. Check voltage between pins 1 & 4, between pins 2 & 4 and between pins 1 & 2 (Fig. 28). There
should be approximately 180-300VAC at each test. The three readings should be approximately
equal within ±25VAC.
5. If one or more of the three tests fail, the problem is either a damaged wire harness or a defective
stator/rotor. Check the wire harness for damage, and repair and retest if necessary.
6. If it has been verified that there are no wiring issues, then the stator/rotor is faulty and will need to
be replaced. If all these tests are OK but there is still no or low voltage, the inverter will need to
be replaced (section 5.10.2).
Inverter unit
To 6-Pin Stator
Connector
To 120VAC
Output
Fig. 27
6-Pin Stator
Connector
Black Phase Wires
1, 2 & 4
White Sub
Windings
3 & 6
6
1
2
4
3
Fig. 28
