L3 Open Phase Detection

What does F2 mean?

The outdoor unit has detected an open circuit in the L3 phase of the main power supply. This indicates a loss of one of the three input phases, potentially leading to unbalanced operation or motor damage.

1. 1

   Measure voltage between L1-L2, L2-L3, and L3-L1 at the outdoor unit main power terminals — expect balanced 3-phase voltage.

2. 2

   Inspect all wiring connections for the L3 phase at the outdoor unit's main power terminals for looseness or corrosion.

3. 3

   Check the integrity of the circuit breaker or fuse protecting the L3 phase in the electrical panel.