60
Troubleshooting
Diagnostic procedure for check code
Check code Operation cause
[AE] 1. Ps pressure switch error.
Low pressure fault (Ps) 2. Ps switch connection error.
Detected by low pressure switch <0.02 MPa 3. Compressor compressing error.
4. 4-way valve error.
5. Refrigeration undercharge.
6. Gas leak.
Is Ps switch connector
correctly connected?
Is Ps switch normally closed (NC)?
Is low pressure below
0.95 MPa during
operation of compressor?
Check interface PC board.
Modify connector connection.
PJ9 (MCC-1223)
Ps switch error.
Replace switch.
Check compressor.
Confirm refrigeration charge correct.
(No leaks from system.)
Does refrigerant bypass
from outlet to inlet on 4-way
valve?
Check 4-way valve.
j
j
j
j
h
h
h
h
No
Ye s
Ye s
Ye s
No
No
No
Ye s
Check code Operation cause
[AF] Abnormal power phase order or missing phase of
Outdoor unit power source phase power supply to the outdoor unit.
order miswiring
There is an abnormal power phase order or missing phase of power supply to the outdoor unit. Check
power supply wiring.