Cummins/Onan RGA-IN1 — Testing Exciter Stator
Testing & diagnosis
For the Cummins/Onan RGA-IN1, from the Cummins/Onan service manual.
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Procedure
- Disconnect F1+ and F2- exciter field leads from terminal block in generator end bell.
- For open/shorted windings: resistance between field leads should be 12.1 ohms ± 10% at 77°F (25°C).
- For grounds: connect megger or insulation resistance meter applying 500 VDC or more between either field lead and exciter stator lamination.
- Reading should be 100,000 ohms or greater.
- If not, exciter stator may require oven drying and retest. A shorted stator must be replaced.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 12.1 ohms ± 10% at 77°F (25°C)
- 100,000 ohms or greater
Source: Cummins/Onan 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.