Indoor Error Code For Wired Controller Mc301 - McQuay MDS Series Service Manual

6.3 Indoor Error Code for Wired Controller MC301

Error
Description
Code
E0 System malfunction
E1 TH1 open/short circuit
(discharge T.)
E2 TH2 open/short circuit
(1# inlet coil)
E3 TH3 open/short circuit
(1# midlet coil)
E4 TH4 open/short circuit
(2# inlet coil)
E5 TH5 open/short circuit
(2# midlet coil)
E8 TH8 open/short circuit
(ambient T.)
E9 TH9 open/short circuit
(outlet T.)
EA TH10 open/short circuit
(sub-cool outlet)
EB TH11 open/short circuit
(sub-cool suction)
Service Manual SM-MDS_(ii)

High pressure malfunction occur 3 times within 1 hour
- outdoor unit motor broken (cooling)
- 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 malfunction occur 3 times within 1 hour
- outdoor ball valve not open
- refrigerant leakage or shortage
- outdoor unit PCB low pressure output port malfunction
- low pressure sensor broken

Too high discharge temperature occur once
- outdoor unit motor broken (cooling)
- outdoor circulating air short (cooling)
- outdoor heat exchanger too dirty (cooling)
- outdoor unit EXV not turn on properly (heating)
- indoor unit EXV not turn on properly
- refrigerant leakage or shortage
- outdoor ball valve not turns on

Compressor overload protector shut and occurs 3 times
- too much current flow in the compressor
- compressor overload protector protecting value wrongly set

Outdoor discharge temperature sensor TH1 broken or loose

Outdoor 1# condenser inlet coil temperature sensor TH2 broken or loose

Outdoor 1# condenser midlet coil temperature sensor TH3 broken or loose

Outdoor 2# condenser inlet coil temperature sensor TH4 broken or loose

Outdoor 2# condenser midlet coil temperature sensor TH5 broken or loose

Outdoor ambient temperature sensor TH8 broken or loose

Outdoor outlet coil temperature sensor TH9 broken or loose

Outdoor sub-cool outlet temperature sensor TH10 broken or loose

Outdoor sub-cool suction temperature sensor TH11 broken or loose
Possible Causes Page
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