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Home›Repair guides›Generac›Voltage Regulator Adjustment (12.5 and 15 kW Units)

Generac — Voltage Regulator Adjustment (12.5 and 15 kW Units)

Adjustments

From a Generac service manual covering: GPS 12500, GPS 15000, GPS 17500. Check it applies to your exact model before use.

Applies to: Generac GPS 12500, Generac GPS 15000

Procedure

  1. Connect AC voltage/frequency meter across Wires 11 and 44 at 50A main circuit breaker; verify 59-61 Hz.
  2. Set Voltage Adjust pot fully counterclockwise; set Gain to midpoint (12 o'clock).
  3. Set Stability and Under Frequency pots to midpoint (12 o'clock).
  4. Start generator; perform this adjustment under a no-load condition.
  5. Turn Voltage Adjust pot clockwise to obtain 238-242 VAC line-to-line.
  6. If red regulator LED is flashing, slowly turn stability pot until flashing stops.

Tools required

  • AC voltage/frequency meter Amazon

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

Specs & values

Source: Generac 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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