AUKS AL-H18/4DR1(U), Service Manual

Page: 117 / 161

AUKS DC Inverter 1 Drive1 50HZ R410A Trouble shooting
117
C6
Suction pipe
temperature of
compressor "Ts"
failure
Yes
Temperature sensor failure or test temperature exceed
limit.
Sensor connection is incorrect.
Outdoor unit PCB failure.
C8
Coil Center
temperature sensor
“Tcm” failure
Yes
Temperature sensor failure or test temperature exceed
limit.
Sensor connection is incorrect.
Outdoor unit PCB failure.
H1
DC inverter
compressor high
pressure switch
"HPS" failure
No
System pressure exceed high pressure switch limit
High pressure switch failure
Instantaneous power-off
Stop valve closed
Outdoor unit fan stop
Outdoor unit air outlet block
In heating mode indoor unit fan stop
In heating mode indoor unit EXV block
H4
Low pressure switch
"LPS" failure
Yes
System pressure lower than low pressure switch limit.
Low pressure switch failure
Instantaneous power-off
Stop valve closed
In cooling mode indoor unit EXV close or block
In heating mode outdoor unit EXV close or block
In heating mode outdoor unit fan stop
In heating mode outdoor unit air outlet block
E1
4 way valve
protection
Yes
4 way valve block
Outdoor unit PCB failure
E3
DC inverter
discharge
temperature "Td" too
high shutdown
protection
No
System less refrigerant
DC inverter Compressor failure
Compressor air return filter block
EXV open degree is small
EXV block
Gas pipe stop valve closed
Liquid pipe stop valve closed
System exhaust sensor failure
Outdoor unit PCB failure
E8
Coil Center
temperature
sensor “Tcm”too
high shutdown
protection
Yes
System over refrigerant
EXV open degree is small
EXV block
System exhaust sensor failure
Outdoor unit PCB failure
J2
The communication
between outdoor unit
and indoor unit
failure
Yes
The communication wire between indoor unit and outdoor
unit disconnect, short circuit or connect incorrect.
Indoor unit main power failed
Indoor unit PCB failure
J3
The communication
between PCB and
INV module failure
Yes
The connection between driving module and main PCB
failure
The communication part of outdoor unit control PCB failure
Frequency driving board failure
Compressor failure