Generator produces voltage but automatic transfer switch does not transfer load to generator during outage.

Safety first: Work on the ATS only with both utility and generator sources isolated and locked out. This work should generally be done by a licensed electrician.

• Verify generator output: Confirm correct voltage and frequency at the ATS generator terminals when the generator is running.
• Check ATS control signals: Inspect the control wiring between the Siemens controller and ATS (e.g., generator available, transfer command). Tighten loose terminals and repair damaged wires.
• Test ATS mechanism: With all power off, manually operate the ATS transfer mechanism (if design allows). Ensure it moves freely and is not obstructed.
• Check ATS coil: During a simulated outage, measure voltage at the ATS transfer coil terminals. If the coil is energized but the switch does not move, replace the ATS mechanism or coil.
• Controller configuration: Verify that the controller is configured to send transfer commands and that any interlocks are correctly set.