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Cummins/Onan DF Series — Generator Voltage Adjustment (Detector AC Option)

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. While observing the voltmeter, slowly turn the screwdriver clockwise to increase voltage or counterclockwise to decrease voltage, and adjust to the rated nameplate voltage.
  6. If correct voltage cannot be attained through this adjustment, proceed to Voltage Regulator Adjustment procedure.
  7. After setting correct voltage, retighten locking nut being careful not to change the adjustment.
  8. Operate Phase Selector switch to the Off position.

Tools required

  • Screwdriver
  • Wrench

Specs & torque values

  • Voltage adjustment range: within 5% of rated nameplate voltage

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.