Applicable Systems
RTAC 200
Symptoms
Phase loss or phase sequence fault. The three-phase power supply has a missing or reversed phase.
Possible Causes
- One phase wire disconnected or breaker tripped
- Phase wiring reversed during installation
Troubleshooting Steps
- Step 1: Check all three phase voltages at the unit
One phase is missing or voltage is unbalanced - Step 2: Verify the phase sequence with a phase rotation tester
Phase sequence is incorrect
How to Reset
To reset: Restore all phases and correct the sequence, then reset the controller.
Source: Trane HVAC Service Manual, Trane Inc.
Category: HVAC Residential