Generac 4700 / QuietPact 40 — Stator Short-to-Ground Insulation Test
Testing & diagnosis
For the Generac 4700 / QuietPact 40, from the Generac service manual.
Applies to: Generac 4700, Generac QuietPact 40, Generac GH-220 engine
Before you start
- Insulation resistance testers such as hi-pot testers and megohmmeters are a source of high and dangerous electrical voltage.
- Do not connect tester leads to any leads routed into the generator control panel.
Procedure
- Disconnect and isolate all Stator leads (11S, 22S, 11P, 22P, 33, 44, 2, 6, 55, 66, 77).
- Connect the terminal ends of all Stator leads together.
- Connect tester leads across all Stator leads and to frame ground on the Stator can.
- Apply a voltage of 1500 volts. Do NOT apply voltage longer than one (1) second.
- If insulation breakdown is indicated, clean and dry the Stator and re-test; replace Stator if it fails the second test.
Tools required
- Hi-pot tester or megohmmeter Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 1500 volts applied
- Do not exceed 1 second
Full service-parts list: Generac 4700 →, Generac QuietPact 40 →
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.