LG ACHH Series Manual page 61

Error
Error Type
No.
Inverter PCB Assy. IGBT
21*
Fault occur
n Error diagnosis and countermeasure flow chart
Are there any power wire
connections normal?
Yes
Are the resistance
Between each phase and
insulation resistance of Inverter
compressor normal?
Yes
Is compressor
Wire connection
condition normal?
Yes
Is DC_Link Wire connection
condition normal?
Yes
Is Comp IPM heat sink's
joining condition normal?
Yes
Is Inverter PCB assembly
normal?
Yes
Recheck power and installation condition
Error Point
IPM self protection circuit
activation
(Overcurrent/IPM overheat-
ing/Vcc low voltage)
No
1. Check R/S/T/N Wiring Condition
→ Rewire them if abnormality found
1. Check resistance between each terminal of compressor
Compressor
Temp.
No
U-V
V-W
W-U
2. Check insulation resistance between compressor
terminal and pipe (over 50M )
→ 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 Inverter PCB assembly P,N connector
No
connection condition
2.Check wire disconnection and wiring
→ Reassemble if abnormality found
1.Check Inverter PCB assembly Comp IPM heat sink
No
joining condition
→ Reassemble if abnormality found
Check Inverter PCB assembly IPM normality.
No
→ Replace Inverter PCB assembly
if abnormality found.
- 61 -
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 disassembled)
4.Inverter compressor terminal disconnected
or loose
5.Inverter PCB assembly damaged
6.ODU input current low
JQC068MA* JQC048MA*
25℃ 75℃ 25℃
0.216 ± 7% Ω 0.258 ± 7% Ω 0.302 ± 7% Ω
0.216 ± 7% Ω 0.258 ± 7% Ω 0.302 ± 7% Ω
0.216 ± 7% Ω 0.258 ± 7% Ω 0.302 ± 7% Ω
Error code check
75℃
0.360 ± 7% Ω
0.360 ± 7% Ω
0.360 ± 7% Ω