Facts About Generators
GeneratorsDirectoryCompareRepairEnginesControllersPartsManufacturersGuides
Search models or part #
Home›Repair guides›Cummins/Onan›Testing Generator Set Stator

Cummins/Onan — Testing Generator Set Stator

Testing & diagnosis · Stator windings

From a Cummins/Onan service manual — check it applies to your exact model before use.

Applies to: Cummins/Onan HDKA

Before you start

  • Use a megger which applies not more than 500 VDC to the test leads.

Procedure

  1. Isolate the stator windings by disconnecting all six stator leads.
  2. Test for open circuits between T1-T2, T3-T4 and Q1-Q2.
  3. Test for grounded circuits between T1, T3 and B1 and the stator laminations or other unpainted grounding point.
  4. Test for continuity between coil leads; all pairs should have equal resistance.
  5. Replace the stator assembly if a winding is shorted, open or grounded.

Tools required

  • Megger or insulation resistance meter Amazon
  • Wheatstone bridge or digital ohmmeter Amazon

Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.

Specs & values

  • Stator resistances measured at 25°C (e.g. T1-T2 Amazon eBay/T3-T4 0.221 ohms single-phase)

Full service-parts list: Cummins/Onan HDKA →

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.

More Cummins/Onan repair guides →