Generac 91401256S / Bsc 556 — Testing Stator Insulation to Ground
Testing & diagnosis · stator windings
For the Generac 91401256S / Bsc 556, from the Generac service manual.
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Before you start
- Connect tester probes only to stator leads. Do not connect to control console leads.
Procedure
- Disconnect and isolate all stator output leads in AC connection panel.
- Connect terminal ends of all stator output leads together.
- Ensure none of the lead terminal ends contact the generator frame.
- Connect red hi-pot test probe to joined stator lead terminal ends.
- Connect black tester probe to clean frame ground on stator can.
- Turn hi-pot tester switch off, set voltage selector to 500 volts.
- Turn tester on and check pilot lamp.
- Observe breakdown lamp, wait one second, then turn tester off.
- If breakdown lamp illuminates, clean and dry stator and repeat test.
- If breakdown occurs again after cleaning and drying, replace 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
- one second maximum
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.