LG ARNU Series, Service Manual

Page: 146 / 226

Troubleshooting Guide
146 Outdoor Unit
Inverter comp. dri-
ving voltage
charging defect
Error
Code
Error Contents Meaning Main Causes
Error display
position
23
Problem in DC charging
voltage after operating
relay On
Concerned
Remote con-
troller
Panel Display
Outdoor unit
1. Looseness of DC link terminal .
2. Damage operating relay
3. Capacitor damage
4. Three phase current diode damage
5. Abnormal power voltage
6. IPM damage
7. Defective sensing circuit of the
invert PCB
■
Defect inspection method : Refer error code 21
1) Check whether the starting relay / magnetic contactor at the control box are normal ?
(After about 30 seconds of operation the voltage at the IPM P/N terminal should be above 450Vdc)
2) In case the voltage is below 450Vdc,
- Make sure that the outdoor main input voltage is (360Vac~410Vac),
- Make sure that the magnetic contactor coil resistance (400~700
Ω
) when the power is Off and also check the
connecting conditions,
- Check whether the comp capacitor connection and the outer shape is normal.
(In case of any abnormality there is a shape change or expansion of the capacitor outer body )
3) Compressor insulation and the coil resistance and 3 phase rectification diode should also be checked.
(Refer error code 21).
4) In case the error code is still displayed after solving the issue from clause 1)~3), then replace the inverter PCB.