Mains Power Phase Reversal / Open Phase Detection

What does E32 mean?

The anti-phase device has detected that two phases of the mains power need to be swapped, indicating a phase reversal. Alternatively, the L2 phase of the mains power (primary side of contactor) has been detected as open, leading to unbalanced power.

• Power supply phase sequence is reversed (e.g., L1-L2-L3 instead of L1-L3-L2).
• One phase of the main AC power supply is missing (open phase).
• Internal power module protection against phase reversal.
• Incorrect wiring at the main power input terminals.
• Power source unstable with fluctuating phase presence.

Click steps to track your progress.

1. 1

   Verify the phase sequence of the mains power supply using a phase rotation meter. If reversed, correct the L1, L2, L3 phase connections at the outdoor unit.

2. 2

   Measure the voltage across all phases (L1-L2, L2-L3, L3-L1) at the primary side of the contactor to check for an open L2 phase.

3. 3

   Inspect the contactor for proper operation, looking for signs of pitting or loose connections at the terminals.