Generac — Testing All Stator Windings to Ground
Testing & diagnosis
From a Generac service manual covering: GPS 12500, GPS 15000, GPS 17500. Check it applies to your exact model before use.
Applies to: Generac GPS 12500, Generac GPS 15000
Before you start
- Disconnect electronic components, relays, Voltage Regulators before high voltage insulation testing
Procedure
- Disconnect stator output leads Wire 11 and Wire 44 from 50A circuit breaker.
- Remove stator output lead Wire 22 from neutral terminal on back of 50A outlet.
- Disconnect C1 connector from bottom of control panel (right side facing panel).
- Connect terminal ends of Wires 11, 22, and 44 together.
- Connect Hi-Pot red probe to joined leads; black lead to clean frame ground.
- Set tester to 1500 volts; apply voltage no longer than 1 second.
- If breakdown lamp lights, clean and dry stator then repeat test.
- If stator fails second test, replace stator assembly.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 1500 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.