Applicable Systems
Carrier ComfortLink Thermostat/Controller
Symptoms
Frequency abnormal fault. The supply frequency is outside the normal operating range.
Possible Causes
- Generator frequency instability
- Utility power frequency deviation
Troubleshooting Steps
- Step 1: Check the supply frequency at the unit
Frequency is outside the rated range - Step 2: Wait for the frequency to stabilize or switch sources
Frequency returns to within range
How to Reset
To reset: Restore the frequency to within range, then reset the controller.
Source: Carrier HVAC Troubleshooting Guide, Carrier Corporation
Category: HVAC Residential