Cummins/Onan 12.5 RDJC / 15.0 RDJC — Generator Voltage Check and Adjustment
Adjustments · Voltage adjust potentiometer
For the Cummins/Onan 12.5 RDJC / 15.0 RDJC, from the Cummins/Onan operator's manual.
Applies to: Cummins/Onan 12.5 RDJC, Cummins/Onan 15.0 RDJC, Cummins/Onan RDJC
Before you start
- High voltages can cause injury or death; use extreme caution when working on electrical components
Procedure
- Move the Run/Stop/Remote switch on the engine control panel to the Run position.
- Move the Phase Selector switch to read generator output current and voltage.
- Insert a screwdriver into the Voltage Adjust potentiometer and carefully loosen the locking nut with a wrench.
- While observing the voltmeter, slowly turn the screwdriver clockwise to increase voltage or counterclockwise to decrease voltage.
- Adjust to the rated nameplate voltage.
- Tighten the locking nut, being careful not to change the adjustment.
- Move the Phase Selector switch to the Off position.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Output voltage can be adjusted plus or minus five percent of nominal voltage
Full service-parts list: Cummins/Onan RDJC →
Source: Cummins/Onan operator's 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.