8-time blink 2.5 seconds OFF — PAM protection / Zero cross detecting circuit issue

What does 8-time blink 2.5 seconds OFF mean?

The outdoor unit LED blinks 8 times with a 2.5-second pause. For MUZ-AP25/35/42/50/60 models, this indicates PAM protection due to overcurrent in PFC or high bus-bar voltage (394V+). For MUZ-AP71, it indicates the zero cross signal cannot be detected. Both can be caused by instantaneous power voltage drops or distortion of primary voltage.

• Instantaneous power voltage drop (short time power failure)
• High power supply voltage (MUZ-AP25/35/42/50/60 models)
• Distortion of primary voltage (MUZ-AP71 models)
• Overcurrent in PFC (Power factor correction) circuit

Click steps to track your progress.

1. 1

   Check if there have been any recent power fluctuations or outages in your area.

2. 2

   Power cycle the air conditioner by turning off the main circuit breaker for 30 seconds, then turning it back on.

3. 3

   If the issue persists, a qualified technician should check the power supply and inverter P.C. board.