Applicable Systems
Carrier ComfortLink Thermostat/Controller
Symptoms
Phase reversed. The phase sequence of the three-phase supply is incorrect.
Possible Causes
- Phase wiring reversed during installation
- Utility power phase rotation changed
Troubleshooting Steps
- Step 1: Check the phase sequence with a rotation tester
Phase sequence is reversed - Step 2: Swap two phase wires to correct the sequence
Phase sequence is correct
How to Reset
To reset: Correct the phase sequence, then reset the controller.
Source: Carrier HVAC Troubleshooting Guide, Carrier Corporation
Category: HVAC Residential