LG ACHH Series Manual page 78

Error code check
Error
Error Type
No.
Communication error
52 between
(Inverter PCB ' CYCLE
(521)
Main PCB)
n Error diagnosis and countermeasure flow chart
Is communication
LED (Yellow) of inverter
compressor
PCB on?
Yes
Is communication cable
connected correctly?
Yes
Is CYCLE Main PCB
normal?
Yes
Replace inverter compressor PCB
* The method of checking CYCLE Main PCB and inverter compressor PCB (If normal, communication LED blinks)
Fan board
Error Point
Main controller of Master
unit can't receive signal
from inverter controller
No
Is noise filter or fuse
normal?
Yes
Replace inverter compressor PCB
No
Re-connect communication cable
No
Replace CYCLE Main PCB
Inverter PCB 1
1. Power cable or communication cable is not
connected
2. Defect of outdoor Main fuse/Noise Filter
3. Defect of outdoor Main / inverter PCB
No
Replace noise filter or fuse
Inverter PCB 2
- 78 -
Main Reasons
Main PCB