Service manual

62 Service Manual SM-MDS_(i)
Cool/Heat Sleep/Fan Time/Dry
BLINKING OFF BLINKING
High/low pressure switch trip
Error Code #6
Description
Possible causes
• High pressure trip
- outdoor unit motor broken
- outdoor circulating air short (cooling)
- outdoor heat exchanger too dirty (cooling)
- outdoor ball valve not open
- indoor circulating air short (heating)
- indoor heat exchanger too dirty (heating)
- indoor unit filter web blocked (heating)
- indoor unit EXV not turn on properly (heating)
- too much refrigerant
- outdoor unit PCB high pressure output port malfunction
- pressure sensor broken
- pressure switch broken
• Low pressure trip
- Outdoor ball valve not open
- Outdoor heat exchanger efficiency too low when heating
- Outdoor motor run abnormally when heating
- Refrigerant leakage or insufficient
- Outdoor PCB low pressure output port abnormal
- Low pressure sensor broken
78
Cool/Heat Sleep/Fan Time/Dry
BLINKING BLINKING OFF
Compressor overload
Error Code #7
Description
Possible causes
• Digital compressor’s operating current too high, overload protector on
• Fixed compressor’s operating current too high, overload protector on
77
Cool/Heat Sleep/Fan Time/Dry
BLINKING BLINKING BLINKING
System failure
Error Code #8
Description
Possible causes
• High pressure malfunction occur 3 times within 1 hour
• Low pressure malfunction occur 3 times within 1 hour
• Too high discharge temperature occur once
• Compressor overload protector shut and occur 3 times
80
Cool/Heat Sleep/Fan Time/Dry
BLINKING ON ON
Others
Error Code #9
Description
Possible causes
• Examine outdoor unit for error code.
• Connect wired controller to the unit to retrieve exact error code.
6