LG UU70W U34 - Page 51

- 51 -
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Part 4 Trouble Shooting
Purpose
Judgment of the IGBTM part fault
of PCB assembly.
Main Reasons
1. Over current detection at Inverter
compressor(U,V,W)
2. Compressor damaged (insulation
damaged/Motor damaged)
3. IGBTM overheating
(Heat sink disassembled)
4. Inverter compressor terminal
disconnected or loose
5. Inverter PCB assembly damaged
6. ODU input current low
IGBTM Check
6.6 Troubleshooting Outdoor Error
CH 21 (DC Peak / Comp IGBTM Fault)
■ 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.(Refer to the right side tables.)
2. Check insulation resistance between
compressor terminal and pipe (over 50m)
→ Replace compressor if abnormality found
Are there any power wire
connections normal?
No
Yes
1. Check R/S/T/N Wiring Condition
→ Rewire them if abnormality found
Is Inv. PCB
normal?
No
Check Inv. PCB IGBTM normality.
(Refer to P.53)
→ Replace Comp PCB assembly if
abnormality found.
Is compressor
Wire connection
condition normal?
No
1. Check Inv. PCB U,V,W connector
connection condition
2. Check wire disconnection and wiring
3. Check compressor terminal connection
condition(bad contact)
→ Reassemble if abnormality found
1.Check Inv. PCB P,N connector
connection condition
2. Check wire disconnection and wiring
→ Reassemble if abnormality found
Yes
Yes
Is DC_Link Wire connection
condition normal?
No
1.Check Inv. PCB IGBTM heat sink
joining condition
→ Reassemble if abnormality found
Yes
Is Comp IGBTM heat sink’s
joining condition normal?
No
Temp 25°C 75°C
U-V 0.163 ± 7% Ω 0.195 ± 7% Ω
V-W 0.163 ± 7% Ω 0.195 ± 7% Ω
W-U 0.163 ± 7% Ω 0.195 ± 7% Ω
JBA068MAF