Cummins/Onan — Adjust voltage regulator
Adjustments
From a Cummins/Onan service manual covering: 4A2.3, 6A3.4-GS, 6AT3.4-GS, DL4, DL6, QSA3, QSA4, QSA6. Check it applies to your exact model before use.
Applies to: Cummins/Onan DGAB, Cummins/Onan DGAC, Cummins/Onan DGAD, Cummins/Onan DGAE, Cummins/Onan DL4, Cummins/Onan DL6
Before you start
- Use insulating mat or dry wood platform when control doors are open.
Procedure
- Open control panel doors and set S1, S2, and S3 per table.
- Connect accurate voltmeter to TB1-2 and TB1-3 if no AC meter.
- Start genset and bring temperature to normal.
- Turn R32 to set no-load voltage.
- Stop genset and close control panel doors.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Example: for 120/240 volt connection set no-load voltage approximately 246 volts.
- Do not adjust R34.
Full service-parts list: Cummins/Onan DGAB →, Cummins/Onan DGAC →, Cummins/Onan DGAD →, Cummins/Onan DGAE →, Cummins/Onan DL6 →
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.