Cummins/Onan — Governor Gain Adjustment

Adjustments · EFC electric governor

From a Cummins/Onan owner's manual covering: 450 DFW, 450 DM, 500 DM, 600 DFY, 750 DFZ. Check it applies to your exact model before use.

Applies to: Cummins/Onan 450 DFW, Cummins/Onan 450 DM, Cummins/Onan 500 DM, Cummins/Onan 600 DFY, Cummins/Onan 750 DFZ, Cummins/Onan VTA-28-GI engine, Cummins/Onan VT-28-G engine, Cummins/Onan VTA28-G2 engine, Cummins/Onan KTA-38-GI engine

Procedure

1. Close main line circuit breaker and apply approximately 1/4 of rated load.
2. Make sure engine speed is constant.
3. Turn GAIN potentiometer clockwise slowly until engine speed is not constant.
4. Turn potentiometer counterclockwise until a constant speed is achieved.
5. Turn counterclockwise an additional 1/2 division.
6. Use SPEED ADJUST potentiometer for fine speed adjustments of less than ±100 RPM.

Source: Cummins/Onan owner'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.

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