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Cummins/Onan DF Series — Voltage Regulator Adjustment

For the Cummins/Onan DF Series.

Applies to: Cummins Onan Df Series

Before you start

  • High voltages in the control present an electrical shock hazard which can cause severe personal injury or death. Proceed with care!

Procedure

  1. Move the Run/Stop/Remote switch on the engine control panel to the Run position.
  2. Operate Phase Selector switch to read generator output current and voltage.
  3. Insert a screwdriver into the Voltage Adjust R21 potentiometer located on the front of the generator set control.
  4. Using a wrench, carefully loosen the locking nut.
  5. Turn screwdriver to set adjustment screw to the mid-position and retighten locking nut being careful not to change the adjustment.
  6. Open control panel doors, locate VRAS-2 (upper left), and refer to Figure 20 to locate R32 potentiometer.
  7. While observing the voltmeter, insert a screwdriver into R32 potentiometer and slowly turn to increase or decrease voltage until adjusted to the rated nameplate voltage.
  8. Close control panel doors and operate Phase Selector switch to the Off position.

Tools required

  • Screwdriver
  • Wrench

Source: manual:960-0602 Onan DFM DFP Installation Manual (10-1986).pdf. Figures and steps are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.