Kohler — Testing MPAC 550 Controller and Initializing Automatic Transfer Mechanism

Testing & diagnosis · MPAC 550 controller / transfer mechanism

From a Kohler service manual — check it applies to your exact model before use.

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Procedure

1. For uninstalled load centers, provide a 240 V, 3-wire, single-phase, 60 Hz source capable of 5 A continuous.
2. Deenergize the test source and remove the front cover.
3. Connect the test source to the L1, N, and L2 power terminals of the load center.
4. Connect a grounding wire from the test source to the grounding bar.
5. Replace the front cover and energize the test source.
6. Inspect the transfer mechanism location indicator; it should be in the Generator position.
7. Ensure the generator circuit breaker is ON and open all branch circuit breakers.
8. Check the MPAC 550 controller response; the mechanism should transfer to utility power.
9. From the controller, command transfer to generator; the mechanism should transfer to generator.
10. Verify the QO-PLILC branch circuit breakers switch ON and OFF correctly.
11. Shut down the generator set.
12. Close all branch circuit breakers and restore the main circuit breaker state.

Source: Kohler 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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