Cummins/Onan — Voltage Adjustment [G]
Adjustments · Voltage regulator board
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan HDKA, Cummins/Onan HDKAQ, Cummins/Onan HDKAR
Before you start
- Disconnect both battery cables, negative (-) cable first, when repairs are made.
- Contact with high voltage can cause severe personal injury or death.
Procedure
- Attach a voltmeter securely to the L1 and L2 leads.
- Start the generator set and place a typical load on its output.
- Use a flat-blade screwdriver to set the voltage adjust potentiometer for correct voltage.
- For most 60 Hz applications, the ideal setting is 120 VAC at 60-61 hz.
- Retighten the locking nut when complete.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
Full service-parts list: Cummins/Onan HDKA →, Cummins/Onan HDKAQ →, Cummins/Onan HDKAR →
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.