LG ARUN Series, Service Manual

Page: 105 / 134

Troubleshooting Guide
- 105 -
Copyright ©2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
■
Error diagnosis and countermeasure flow chart
1. Bad connection of air temperature connector
2. Defect of air temperature connector(Open/Short)
3. Defect of outdoor PCB
1. Bad connection of air temperature connector
2. Defect of air temperature connector(Open/Short)
3. Defect of outdoor PCB
1. Bad connection of air temperature connector
2. Defect of air temperature connector(Open/Short)
3. Defect of outdoor PCB
Error No. Error Type Error Point Main Reasons
Abnormal value of
sensor (Open/Short)
Abnormal value of
sensor
(Open/Short)
Abnormal value of
sensor (Open/Short)
Sensor error of
outdoor air temper-
ature
Piping temperature
sensor error of heat
exchanger in
master & slave out-
door unit heat
exchanger (A,B)
Compressor suc-
tion temperature
sensor error
44*
Master 441
Slave 442
46*
Master 461
Slave 462
45*
Master 451
Slave 452
48*
Master 481
Slave 482
Is sensor connected
to PCB correctly??
Is sensor value correct?*
Connect sensor to PCB correctly
Replace sensor
Replace corresponding
outdoor unit PCB
Yes
No
No
Yes
* If value is 100k
Ω ↑
(open) or 100
Ω↓
(short), error occurs
NB: Resistance value of temperature sensor change according to
temperature
It is normal if value shown as below (
±
5% error)
Sensor of air temperature: 10
°
C(50
°
F) = 20.7k
Ω
, 25
°
C(76
°
F) = 100k
Ω
, 50
°
C(122
°
F) = 3.4k
Ω
Sensor of piping temperature: 10
°
C(50
°
F) = 10k
Ω
, 25
°
C(76
°
F) = 5
Ω
, 50
°
C(122
°
F)=1.8k
Ω
Refer to CH41
Refer to CH45
Error No. Error Type
Error Point
Main Reasons
Abnormal value of
sensor (Open/Short)
Abnormal value of
sensor (Open/Short)
Discharge piping
temperature sen-
sor error of con-
stant compressor
Piping temperature
sensor error of heat
Exchanger in master
& slave outdoor unit
heat exchanger (B)
47*
Master 471
Slave 472
48*
Master 481
Slave 482