Generator starts and runs but the automatic transfer switch does not transfer the house load to generator power.
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.
Possible Causes
How to Fix / Troubleshooting
Safety first: Utility and generator circuits can be lethal. Only qualified persons should open the ATS. Ensure generator is OFF and ATS is in a safe position before work.
- Verify generator output: Confirm the Firman generator is producing correct voltage and frequency at its terminals.
- Check ATS control signals: Inspect the low-voltage control wiring between generator and ATS for continuity and correct landing.
- Inspect transfer mechanism: Inside the ATS, look for mechanical binding, corrosion, or burned contacts. Do not force the mechanism; clean and lubricate per manufacturer instructions.
- Test ATS coil/motor: With proper safety measures, a technician can verify that the transfer coil or motor receives the correct signal and operates. Replace if inoperative.
Improper ATS service can cause backfeeding and severe hazards; involve a licensed electrician for diagnosis and repair.
Repair Difficulty
Required Part
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