LG Therma V fault CH23

What it means

The Inverter PCB (Outdoor) DC Link voltage is not charging correctly, or the DC Link voltage exceeds the defined limit, indicating a problem in the DC bus voltage supply chain of the inverter.

Likely causes

1. Incorrect wiring of DC Link terminal / poor terminal contact (loose)
2. Condenser (capacitor) burnout
3. Inv PCB(Outdoor) burnout (DC Link voltage detection part)
4. Input voltage abnormality (R, S, T, N)
5. Bad power connection (N phase missing)
6. Fan locked
7. Obstruction/shield around the heat exchanger
8. Insufficient distance between product and wall
9. Piping condition issues such as pipe bending
10. EEV operation/connection status fault
11. Abnormal refrigerant pressure
12. Compressor restraint
13. Compressor wiring reverse phase loss
14. Short circuit or opening of internal connection line in compressor
15. Compressor winding resistance out of spec
16. Compressor insulation resistance failure
17. Inverter PCB assembly or connector connection fault
18. IGBTM failure

Where to start

1. Check if S-phase fuse is normal. If No, replace S phase fuse.
2. If fuse OK, check if input voltage is normal: R~N / S~N / T~N voltage should be 220 V ± 15%. If abnormal, check the connection status and power supply, and check the power of the switchboard.
3. If input voltage OK, check wiring between the input power supply and noise filter: check wire and connector connection between power input and noise filter. If abnormal, reconnect/assemble.