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Transformer / Power Supply Troubleshooting

Applies to: CT24ACE (24VAC Earthed Transformer) · CT24ACM (Mini Transformer)

No 24VAC supply — system not operating​

The system has no power or zones are unresponsive across the board.

Check the following:

  • Verify the transformer is plugged into an earthed GPO and the GPO is switched on
  • Confirm output voltage from the transformer is ~24VAC using a multimeter
  • Ensure the transformer is not wired directly to the AC unit's power supply — this is not supported
  • Check wiring polarity and that all connectors are fully seated

Transformer overheating or tripping​

The transformer is warm to touch and cutting out intermittently.

Steps to resolve:

  1. Count the number of zone motors connected — the CT24ACE supports up to 12 zone motors; the CT24ACM supports fewer
  2. Remove some zone motors temporarily to check if the transformer stabilises
  3. If using a CEXT, verify the zone count does not exceed the transformer rating
  4. Ensure the transformer is mounted in a location with adequate ventilation — do not enclose it

CT24ACM not providing enough power for the system​

The system behaves intermittently or some zones fail to respond.

Steps to resolve:

  1. The CT24ACM is a mini transformer suitable for smaller systems only — count all connected loads
  2. If the system has more than 6 zone motors, a CEXT, and a CSL, upgrade to the CT24ACE
  3. Check that no additional devices are drawing power from the same transformer circuit without approval