Controller displays E17, generator runs but transfer switch does not transfer load
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: Work inside the transfer switch involves lethal voltages. Only qualified personnel should open the ATS enclosure. Turn the generator OFF and open the main utility breaker before servicing.
- Listen for transfer action: When the generator starts, listen at the ATS for a distinct clunk indicating the contactor is moving. No sound suggests coil or control issues.
- Check ATS control fuse: With power off, open the ATS and locate the low-voltage control fuse. Replace if blown with the same rating.
- Inspect control wiring: Verify that the control wires from the generator to the ATS are secure and landed on the correct terminals.
- Manually exercise mechanism: Some ATS units allow manual operation with a handle. With all power off, operate the mechanism to ensure it moves freely.
- Test coil (technician): A technician can measure coil resistance and verify that the generator is sending the correct voltage to the coil during start.
If the coil is open or the mechanism is seized, the ATS contactor assembly will need replacement.
Repair Difficulty
Required Part
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