LG Therma V fault CH22

What it means

The current/power input to the Inverter PCB (Outdoor) has exceeded the maximum allowable limit, triggering a protective shutdown to prevent damage to the inverter components.

Likely causes

1. Bent refrigerant pipes or abnormalities
2. Abnormal refrigerant pressure
3. Compressor wiring reverse phase loss
4. Faulty wiring between PCB and U, V, W terminals
5. Inv PCB(Outdoor) connection fault (loose/false wiring)
6. Inv PCB(Outdoor) IPM failure
7. PCB current sensing component fault
8. Inverter PCB assembly or connector connection fault
9. Communication line shorted or disconnected
10. Main PCB(Indoor) CN-REMO voltage not present (fault on Main PCB)
11. Noise near wired remote control or communication line

Where to start

1. Check if product installation is in good condition: check whether the fan is bound, remove shields around heat exchangers, secure distance between outdoor unit and wall, check for bent pipes and abnormalities, SVC valve lock check, EEV connection/operation status check, check refrigerant pressure. If No, correct installation issues.
2. If installation OK, check resistance value between each terminal and the compressor insulation resistance value: compressor restraint check, check compressor wiring for reverse phase, check resistance between each terminal of compressor (0.529 ~ 0.631 Ω ± 7%), check insulation resistance between compressor terminal and pipe (more than 50 MΩ). If abnormal, address compressor restraint/wiring/insulation issue.
3. If compressor resistance OK, check compressor wiring condition: check connection status between PCB and U, V, W terminals, check wiring status (false or unconnected), check wiring status between each terminal of compressor. If abnormal, correct wiring.