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Home›Repair guides›Kohler›Voltage Regulator Board Calibration (New Style Boards Without Pot. 4 - Load Shed)

Kohler — Voltage Regulator Board Calibration (New Style Boards Without Pot. 4 - Load Shed)

Adjustments

From a Kohler service manual covering: 10/15RMOY, 15/17.5ROY, 15RMY, 22.5-47.5ROZ, 22.5/32.5RZ. Check it applies to your exact model before use.

Applies to: Kohler 15RMY

Before you start

  • DANGER OF ELECTROCUTION! High voltage is present at regulator board P1 connector and terminal strip when set is running.

Procedure

  1. Disconnect generator from load. Place generator main switch in OFF position. Lift enclosure cover to expose voltage regulator board and terminal strip.
  2. Check the wire jumpers on the regulator board and arrange as noted in the jumper condition table (J1, J2, J3).
  3. For single-phase connection, lift lead V9 from terminal strip and insulate lead end with electrical tape.
  4. Adjust the external voltage adjustment potentiometer to the approximate midpoint of its adjustment range.
  5. Connect AC voltmeter and frequency counter between leads V7 and V8.
  6. Break adjustment seals on Pots. 1, 2 and 3.
  7. Turn Pot. 1 to full clockwise (CW) position; turn Pot. 2 to full counterclockwise (CCW) position.
  8. Start the generator set with no load applied.
  9. Adjust Pot. 2 (Volt Adj.) while observing the AC voltmeter; adjust for a meter reading as specified for this set.
  10. Observe LED; if flickering, alternately adjust Pot. 3 (Volt Stb.) then Pot. 1 (FR Damp) until a steady glow is attained.
  11. Perform Overvoltage Shutdown Check (Pot. 6).
  12. Perform Overspeed Shutdown Check (Pot. 5).
  13. Regulator calibration complete. Turn main switch to OFF and wait until set shuts down. Seal Pots. 1, 2 and 3 with insulating varnish.

Tools required

  • AC voltmeter 0-300 V AC, +0.5% accuracy Amazon
  • Frequency counter 45-75 Hz, +1% accuracy Amazon
  • Potentiometer adjustment tool or small blade screwdriver Amazon
  • Load bank Amazon

Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.

Specs & values

  • Do not exceed 285 Volts when adjusting Pot. 2

Full service-parts list: Kohler 15RMY →

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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