Midea M-Thermal Series Service Manual page 67

M‐Thermal Split
4.17 P4 Troubleshooting
Digital display output
Description
 Discharge temperature protection.
 When the compressor the discharge temperature rises above 115°C, the system displays P4 protection and
M‐Thermal Split stops running. When the discharge temperature falls below 90°C, P4 is removed and normal
operation resumes.
 Error code is displayed on refrigerant system main PCB and user interface.
Possible causes
 Temperature sensor error
 High pressure side blockage.
 Poor condenser heat exchange.
 Outdoor unit main PCB damaged.
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