LG ARUN Series Service Manual page 86

Troubleshooting Guide
Error
Error Type
No.
21*
Master
Inverter PCB Assy IPM
211
Fault occur
Slave
212
I Error diagnosis and countermeasure flow chart
Are the resistance
Between each phase and
insulation resistance of Inverter
compressor normal?
Yes
Is compressor
Wire connection
condition normal?
Yes
Is inverter heat sink
cooling fan normal?
Yes
Is inverter PCB assembly
normal?
Yes
Recheck power and installation condition
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Only for training and service purposes
Error Point
IPM self protection circuit
activation
(Overcurrent/IPM overheat-
ing/Vcc low voltage)
1. Check resistance between each terminal of compressor
(refer to page 63)
No
2. Check insulation resistance between compressor
terminal and pipe (over 50MΩ )
¡ Replace compressor if abnormality found
1.Check inverter PCB assembly U,V,W connector
connection condition
No
2. Check wire disconnection and wiring
3. Check compressor terminal connection condition
(bad contact)
¡ Reassemble if abnormality found
1. Check heat sink cooling fan connector connection
condition
2. Check heat sink cooling fan wire disconnection and
wiring
¡ Reassemble and change wire if abnormality found
3. Check heat sink cooling fan output voltage during
No
compressor operation
(Check main PCB assembly CN15 fan connector output
voltage : AC 220V)
¡ Replace main PCB if output voltage isn't AC 220V
4. Check heat sink cooling fan motor wire disconnection
(measure resistance between each ends of motor
connector)
(measured value should be within 1.7kΩ ±10%)
¡ Replace fan motor if motor wire is disconnected.
Check inverter PCB assembly IPM normality.
No
¡ Replace inverter PCB assembly if abnormality found.
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Main Reasons
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
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