Generac — Test Stator Insulation - Air Cooled Units
Testing & diagnosis
From a Generac service manual — check it applies to your exact model before use.
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Procedure
- Disconnect stator AC output leads 11 and 44 from the main line circuit breaker.
- Remove the wire nut joining leads 22 and 33 and separate the leads.
- Disconnect stator excitation winding leads 2 and 6 and battery charge winding leads 55, 66, and 77.
- Connect the terminal ends of all stator leads together, isolated from ground.
- Connect the red Hi-Pot test probe to the joined leads and black probe to clean frame ground.
- Set tester to 500 volts and turn on for one second only, observing breakdown lamp.
- If breakdown lamp comes on, clean and dry the stator and repeat the test.
- If the stator fails the second test, replace the stator assembly.
Tools required
- Hi-Pot tester Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 500 volts
- Do not apply voltage longer than 1 second.
Source: Generac service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.