AL14
Kohler-SDMO Generator Overvoltage Protection Trip

Controller displays AL14 / Alternator Overvoltage while running under light load.

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Faulty AVR (Automatic Voltage Regulator), Incorrect AVR sensing wiring, Loose or broken voltage sensing leads, Incorrect voltage setpoint on the AVR.

How to Fix / Troubleshooting

Safety first: Open the generator output breaker and isolate the generator from the load. Turn the controller to OFF and disconnect the battery negative terminal before opening the alternator terminal box.

  • Measure output voltage: With the generator running in MANUAL mode and no load, measure line-to-line voltage. Compare to the nameplate (e.g., 400 V). If significantly high, suspect the AVR or sensing.
  • Inspect AVR connections: Locate the AVR in the alternator terminal box (e.g., Leroy-Somer alternator on Kohler-SDMO units). Check sensing wires (usually marked 0–220/400 V) for tightness and damage.
  • Check AVR settings: Some AVRs have a voltage adjustment pot. If misadjusted, carefully reduce the voltage to nominal while monitoring with a meter. Do not exceed manufacturer limits.
  • Replace AVR: If the voltage is unstable or uncontrollable, replace the AVR with the correct Kohler-SDMO specified model.
  • Reset alarm: After corrections, clear AL14 and test under gradual load.

Incorrect AVR wiring or settings can damage connected equipment; if unsure, involve a qualified electrician.

Advertisements

Repair Difficulty

Hard 4/5

Required Part

Automatic Voltage Regulator (AVR)
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements