LG Multi V

Troubleshooting Guide
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Only for training and service purposes
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Inverter PCB Assy IPM
Fault occur
Error
No.
Error Type Error Point Main Reasons
IPM self protection circuit
activation
(Overcurrent/IPM overheat-
ing/Vcc low voltage)
1.Over current detection at Inverter compres-
sor(U,V,W)
2.Compressor damaged (insulation dam-
aged/Motor damaged)
3.IPM overheating
(Heat sink fan damaged/Heat sink fan con-
nector disconnected/Heat sink disassem-
bled)
4.Inverter compressor terminal disconnected
or loose
5.Inverter PCB assembly damaged
6.ODU input current low
■ Error diagnosis and countermeasure flow chart
Are the resistance
Between each phase and
insulation resistance of Inverter
compressor normal?
No
Yes
Recheck power and installation condition
Yes
1. Check resistance between each terminal of compressor
(0.188 ±7%)
2. Check insulation resistance between compressor
terminal and pipe (over 50MΩ )
→ Replace compressor if abnormality found
Is inverter PCB assembly
normal?
No
Check inverter PCB assembly IPM normality.
→ Replace inverter PCB assembly if abnormality found.
Is compressor
Wire connection
condition normal?
No
1.Check inverter PCB assembly U,V,W connector
connection condition
2. Check wire disconnection and wiring
3. Check compressor terminal connection condition
(bad contact)
→ Reassemble if abnormality found
Yes
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