Cummins/Onan — Generator Frequency Adjustment
Adjustments · Generator Set
From a Cummins/Onan service manual — check it applies to your exact model before use.
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Before you start
- AC power within the cabinet presents a shock hazard.
Procedure
- Operate Run/Stop/Remote switch to RUN; GenSet starts but the transfer switch will not transfer.
- Observe the frequency meter; if not as specified on the nameplate, adjust.
- Locate FREQ ADJUST on GenSet control panel; use a screwdriver to hold and loosen the locking nut.
- Slowly turn clockwise to increase or counterclockwise to decrease frequency to the nameplate value.
- Retighten the locking nut without changing the adjustment.
- Operate the Phase Selector switch to confirm zero output current, then to OFF.
- Place the Run/Stop/Remote switch to STOP to stop the GenSet.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Frequency as specified on the nameplate
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.