Alarm Z1 Phase monitoring — Missing electrical phase

What does 5273 mean?

This alarm indicates that a phase is missing from the power supply. For 3-phase models, the Heat Pump shuts down if L3 is missing, and the indoor unit shuts down if L1 is missing.

• Tripped fuse in the indoor unit (tower).
• Phase/phases missing on terminals for supply voltage in the Heat Pump.
• Phase/phases missing on terminals for supply voltage on the EMI filter in the inverter.

Click steps to track your progress.

1. 1

   Reset any tripped fuses located in the indoor unit.

2. 2

   Visually inspect the main power connections to the Heat Pump and ensure all phases are properly connected.

3. 3

   If the alarm persists, contact a qualified technician to check that each phase carries the correct voltage to the EMI filter.