LG ARNU Series, Service Manual

Page: 171 / 226

Service Manual 171
Troubleshooting Guide
Communication
error (indoor ›
Main PCB )
Error
Code
Error Contents Meaning Main Causes
Error display
position
53
The indoor cannot receive
signal from the Main PCB
Concerned
Remote
Controller
Outdoor unit
1. The communication cable is not
connected
2. Communication cable is cut or short
3. Defective outdoor Main / indoor
PCB
■
Defect inspection method
1) Check the indoor unit's control box's power supply and communication connecting condition (terminal block )
2) Check if the communication cable is short or open and remove the cause if any
(Open confirmation :
After the power OFF short the two cables with each other and measure the resistance with a tester ’ If above 5
Ω
then it is Open)
(Short confirmation :After power OFF separate the cables and measure the resistance with a tester › If below
5
Ω
then it is short )
3) In case there is no error in above given cases 1~2 the separate all the communication cables and recheck after
connecting the indoor units individually
(The error code is displayed when the defective PCB is connected to the indoor unit) › Replace the concerned
indoor unit's PCB .
4) In case one indoor or a few indoor has 'CH53' error display :
Re operate the Auto-Addressing and check whether the all indoor units have Auto-Addressing setting .
(After the power ON, make sure to operate the Auto-Addressing after one minute )
› In case the any PCB has not got the Auto-Addressing then recheck the communication cable and replace the
indoor PCB if required .
5) Make sure to separate the power line (AC220/380V) and the communication line by at least 30 cm
CAUTION
• In case you replace the communication cable with the power cable by mistake then al indoor units PCB can be
damaged
Outdoor 3 phase
power supply
wrong wiring
(Phase omission )
Error
Code
Error Contents Meaning Main Causes
Error display
position
54
Wrong wiring at the out-
door 3 phase
(Phase omission )
Concerned
Remote
Controller
Outdoor unit
1. Defective inverter PCB
2. R, S, T power not connected
3. Main Fuse damaged
■
Defect inspection method
1) Check the outdoor Main fuse .
2) If the error code exists even after replacing the outdoor PCB then request the building's electric in charge to
recheck the power supplied.