Cummins/Onan — Ground Fault Relay Test
Testing & diagnosis · ground fault relay (GFR)
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan DFHA, Cummins/Onan DFHB, Cummins/Onan DFHC, Cummins/Onan DFHD, Cummins/Onan QST30 engine
Procedure
- Verify that the N-G Fault Indicator on the GFR is not lit (lit indicates the bonding jumper circuit is open).
- Move the control switch to the Run position.
- Press the TEST switch on the ground fault relay.
- Verify that the control panel warning message is displayed and the Fault Indicator (>I) on the GFR is lit.
- Reset the control panel fault (this will also reset the ground fault relay).
Specs & values
- Relay time delay setting: zero to one second
- Relay current setting: 5 to 1200 amperes
Full service-parts list: Cummins/Onan DFHA →, Cummins/Onan DFHB →, Cummins/Onan DFHC →, Cummins/Onan DFHD →
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.