Midea MLCAC-UTSM-2010-10

MLCAC-UTSM-2010-10 Troubleshooting
Outdoor Units 91
11. P4 malfunction
When compressor discharge temperature is higher than 115°C, the unit will stop, and unit runs again when
compressor discharge temperature is lower than 90°C.
P4 display
Discharge temperature protection of compressor
Check whether the compressor discharge temp. is more than 115°C ?
No
Check whether the wiring connection is right
between compressor discharge temp. sensor and
PCB according to wiring diagrams
Yes
Method: Check whether the resistance of compressor discharge
temp. sensor is right refer to the Annex 2
No
Correct the wiring connection
Yes
Replace outdoor main board
Judge: The discharge temp. sensor is broken
No
Replace the compressor
discharge temp. sensor
Check whether the refrigerant is leak
Stop leaking and add refrigerant
Yes
Yes