Service manual

72 Service Manual SM-MDS_(i)
ER63 Slave outdoor unit
communication failure
• Master and slave communication wire broken
• Master and slave communication wire loose
• Master and slave communication wire A B reversed
• Slave unit power not on
• Master and slave jump wire not correct, still on update status
• Last outdoor unit terminal resistance of communication wire not short-circuit
• Master and slave PCB program not compatible.
• Master and slave PCB abnormal
79
ER64 TH1 temperature
sensor failure
• Outdoor discharge temperature sensor TH1 broken or loose
ER65 TH2 temperature
sensor failure
• Outdoor 1# condenser inlet coil temperature sensor TH2 broken or loose
ER66 TH3 temperature
sensor failure
• Outdoor 1# condenser midlet coil temperature sensor TH3 broken or loose
ER67 TH4 temperature
sensor failure
• Outdoor 2# condenser inlet coil temperature sensor TH4 broken or loose
ER68 TH5 temperature
sensor failure
• Outdoor 2# condenser midlet coil temperature sensor TH5 broken or loose
ER71 TH8 temperature
sensor failure
• Outdoor ambient temperature sensor TH8 broken or loose
ER72 TH9 temperature
sensor failure
• Outdoor outlet coil temperature sensor TH9 broken or loose
ER73 TH10 temperature
sensor failure
• Outdoor sub-cool outlet temperature sensor TH10 broken or loose
ER74 TH11 temperature
sensor failure
• Outdoor sub-cool suction temperature sensor TH11 broken or loose
ER75 TH12 temperature
sensor failure
• Outdoor suction temperature sensor TH12 broken or loose
73
ER76 High pressure sensor
failure
• High pressure sensor communication wire broken
• Outdoor PCB HS port broken
ER77 Low pressure sensor
failure
• Low pressure sensor connecting wire broken
• Outdoor PCB LS port broken
74
EC78 All indoor units
communication failure
• Indoor and outdoor communication wire broken
• Indoor and outdoor communication wire loose
• Indoor and outdoor communication wire A and B reversed
• Communication wire too long, should less than 1000m
• Outdoor PCB not power on
• Indoor and outdoor jump wire not correct, still on update status
• Last indoor unit terminal resistance of communication wire not short-circuit
• Indoor and outdoor PCB program not compatible
• Indoor and outdoor PCB abnormal
76
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