McQuay MDS Series User Manual

Service Manual SM-MDS_(ii) 67
27
Ambient temperature is
out of operation limit
range (slave unit)
 Ambient temperature is out of operation limit range
1. Cooling ambient temperature range: 0ºC – 43ºC
2. Heating ambient temperature range: -15ºC – 16ºC
 Outdoor slave unit circulating air short-circuit
1. Result in ambient temperature raising to exceed operation limit range when cooling
2. Result in ambient temperature falling down to exceed operation limit range when
heating
84
30
Digital compressor
overloaded (slave unit)
 Fixed compressor 4 operating current too high, overload protector OL4 on
77
31
Fixed compressor 1
overloaded (slave unit)
 Fixed compressor 1 operating current too high, overload protector OL1 on
32
Fixed compressor 2
overloaded (slave unit)
 Fixed compressor 2 operating current too high, overload protector OL2 on
33
Fixed compressor 3
overloaded (slave unit)
 Fixed compressor 3 operating current too high, overload protector OL3 on
34
High pressure too high
(slave unit)
 Slave unit motor broken
 Slave unit circulation air short-circuiting (cooling)
 Slave unit heat exchanger too dirty (cooling)
 Slave unit ball valve not open
 Indoor circulation air short-circuit (heating)
 Indoor heat exchanger too dirty (heating)
 Indoor unit filter blocked by dirt (heating)
 Indoor EXV not switched on properly (heating)
 Refrigerant over charged
 Slave unit PCB high pressure output port abnormal
 Slave unit pressure sensor broken
 Slave unit pressure switch broken
78
35
High pressure sensor
malfunction (slave unit)
 Slave unit high pressure sensor connecting wire broken
 Slave unit PCB HS port broken
74
36
Discharge temperature
too high (slave unit)
 Preserved
-
40
Super heat protecting
value too small (slave
unit)
 Indoor motor not work when cooling
 Indoor EXV opening degree abnormal when cooling
 Outdoor motor not work when heating
 Slave unit EXV opening degree abnormal when heating
 Slave unit low pressure sensor abnormal
 Refrigerant over charged
86
41
Low pressure too low
(slave unit)
 Slave unit ball valve not open
 Slave unit heat exchanger efficiency too low when heating
 Slave unit motor run abnormally when heating
 Refrigerant leaked or insufficient charged
 Slave unit PCB low pressure output port abnormal
 Slave unit low pressure sensor broken
78
42
Low pressure sensor
broken (slave unit)
 Slave unit low pressure sensor connecting wire broken
 Slave unit PCB LS port broken
74
6

McQuay MDS Series Specifications

General

Brand	McQuay
Model	MDS Series
Category	Compressor
Language	English