Kohler — Voltage, Frequency, and Phase Rotation Check Procedure
Testing & diagnosis · Sources and transfer switch
From a Kohler service manual — check it applies to your exact model before use.
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Before you start
- Hazardous voltage. Backfeed to the utility system can cause severe injury, death, or property damage. Before energizing the transfer switch, verify that both the normal and emergency contacts are not left in the closed position.
- Only authorized personnel should open the enclosure.
- Testing live electrical circuits. Use adequately rated test equipment with electrically insulated probes.
Procedure
- Ensure that all downstream loads are switched off.
- If the source being measured is a generator set, start it by moving the master switch to RUN.
- Use a voltmeter to check source phase-to-phase and phase-to-neutral terminal voltages and frequency.
- If Source N is utility and measured input does not match the nameplate, STOP and do not proceed.
- If generator output voltage and frequency do not match nominal, adjust the generator set per manufacturer's instructions.
- Use a phase rotation meter to check phase rotation at the source terminals.
- Rewire the transfer switch source terminals to obtain correct phase sequence if necessary.
- If the source is a generator set, stop it by moving the master switch to OFF/RESET.
- Repeat steps 2 through 5 for Source E.
- Close and lock the transfer switch enclosure door.
- Perform the Lamp Test and then proceed to the Automatic Operation Test.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
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.