Midea R32 M thermal Arctic Mono fault H7

What it means

Error code 46. Abnormal main circuit voltage detected by user interface and refrigerant system main PCB.

Likely causes

1. AC power supply phase voltage at or above 265V for more than 30 seconds
2. Unstable or abnormal mains supply
3. Abnormally high AC supply voltage
4. Abnormally low AC supply voltage
5. Power supply voltage not within ±10% of rated voltage or a phase is missing
6. Outdoor unit powered on immediately after being powered off
7. Loosened wiring within electric control box
8. High voltage circuit error
9. Main PCB damaged
10. Main circuit voltage fault
11. Power supply fault
12. Main board fuse damaged/blown
13. Hydronic box main PCB fault
14. Damaged cables between hydronic box main PCB and outdoor unit main PCB
15. Outdoor unit main PCB fault
16. Incorrect or abnormal input power supply (N or L)
17. Insufficient refrigerant caused by refrigerant leakage
18. Low pressure side blocked by crushed or bent pipe, blocked EXV, or dirty filter
19. Poor air side heat exchanger heat exchange in heating or DHW mode
20. Insufficient water flow rate in cooling mode
21. Outdoor main PCB fault (last resort)

Where to start

1. Inspect for high voltage circuit errors including compressor malfunction, fan motor short-circuit, or inverter module short-circuit.
2. Inspect compressor for malfunction. Check fan motor for short-circuit. Check inverter module for short-circuit.
3. Check power supply voltage is within ±10% of rated voltage or a phase is missing on 3-phase models.