Cummins/Onan — Electric Governor Adjustments (Beginning Spec F)

Adjustments · Electric governor controller

From a Cummins/Onan service manual — check it applies to your exact model before use.

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Procedure

1. Initially set switches: SW1 ADJ1 down; 50HZ/60HZ up for 50 Hz or down for 60 Hz; 4CYL/6CYL up for 4 cylinder or down for 6 cylinder.
2. Set SW2 (rotary switch) GAIN to position 4.
3. Set SW3 all positions down.
4. Ensure governor control terminals 5 and 6 are jumpered.
5. Attach tachometer to engine or frequency meter to generator output leads.
6. Start the set and hold throttle linkage so engine will not overspeed.
7. If engine overspeeds, shut down, turn GAIN switch to next higher position, and restart.
8. Warm up set under at least 1/4 load to normal operating temperature, then disconnect load.
9. If consistent hunt at 1 to 2 Hz, adjust GAIN rotary switch until stable and responsive.
10. Manually actuate governor linkage several times to ensure correct gain adjustment.
11. For audibly fast hunt, set SW3 position 3 up; return down if no change.
12. For inconsistent slow barely audible hunt, set SW3 position 2 up; return down if no change.
13. For very slow hunt at 0.5 Hz, set SW1 position 1 up to add friction compensation.
14. Check for stability under no-load to full-load range.
15. For undershoot on load acceptance, turn GAIN rotary switch clockwise and repeat Steps 6 and 11.

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.

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