Kohler — Contactor Replacement Procedure (Three-Phase Models)
Repair & overhaul
From a Kohler service manual — check it applies to your exact model before use.
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Before you start
- Hazardous voltage. Disconnect all power sources before opening the enclosure.
Procedure
- Disable all connected generator sets.
- Disconnect normal and emergency power to the transfer switch and open the enclosure.
- Check for zero volts on the normal and emergency power lugs.
- Remove the tie wraps securing the harness and disconnect the contactor harness from the interface board harness.
- Disconnect the engine start leads from the ATS engine start terminals.
- Disconnect the emergency, normal, and load power supply cables, marking each cable as removed (e.g. E1, E2, E3).
- Remove the four nuts securing the power panel and remove the contactor.
- Install the new contactor onto the studs in the back of the enclosure and fasten with flat washers, lock washers, and nuts.
- Torque the nuts to 7.3 Nm (65 in. lb.).
- Connect the contactor harness to the controller harness at the inline connector.
- Connect and tighten the load, normal, and emergency cables to 16.3 Nm (12 ft. lb.) each.
- Install tie wraps, connect the generator set engine start leads, and close the enclosure.
- Connect power to the ATS, enable the generator set, press AUTO, and test operation.
Tools required
- Basic electrician's hand tools
- Multimeter digital or analog Amazon
- Wiring harness Amazon
- Tie wraps Amazon
- Rubber insulating gloves class 0 Amazon
- Safety glasses Amazon
- Electrical hazard safety shoes Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Power panel nuts torque 7.3 Nm (65 in. lb.)
- Terminal connecting bolts torque 16.3 Nm (12 ft. lb.)
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.