Cummins/Onan 2100 Series — Testing the PMG
Testing & diagnosis · Permanent Magnet Generator
For the Cummins/Onan 2100 Series, from the Cummins/Onan service manual.
Applies to: Cummins/Onan DFAB, Cummins/Onan DFAC, Cummins/Onan DFBF, Cummins/Onan DFCB, Cummins/Onan DFCC, Cummins/Onan DFCE, Cummins/Onan DFGB, Cummins/Onan DFGE, Cummins/Onan DFLB, Cummins/Onan DFLC, Cummins/Onan DFLE
Before you start
- Hazardous voltage inside control housing and output box.
Procedure
- Disconnect PMG leads PMG 2, PMG 3 and PMG 4 from AC harness.
- Start engine and let speed stabilize.
- Measure voltage across PMG 2&3, PMG 3&4 and PMG 4&2.
- Voltage should be at least 150 VAC for 50 Hz sets.
- At least 180 VAC for 60 Hz sets; readings approximately equal.
- Stop set and measure resistance across lead pairs.
- Refer to Table 7-2 for resistance values.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- At least 150 VAC (50 Hz) / 180 VAC (60 Hz)
Full service-parts list: Cummins/Onan DFBF →, Cummins/Onan DFCC →, Cummins/Onan DFCE →, Cummins/Onan DFGB →, Cummins/Onan DFGE →, Cummins/Onan DFLB →, Cummins/Onan DFLC →, Cummins/Onan DFLE →
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.