LG UU85W U74 - Page 49

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Part 4 Trouble Shooting
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6.6 Troubleshooting Outdoor Error
CH 21 (DC Peak / Comp IGBTM Fault)
1
2
Is how long power on during
operation?
Does failure appears again
when starting operation?
Method to measure insulation
resistance
Method to measure coil
resistance
1) Power on for 12 hours or more
2) Power on for 12 hours or less
1) The compressor stops and same
error appears again.
2) If output voltage of the inverter is
stably output. Note 1)
3) If output voltage of the inverter is
unstable or it is 0V.
(When incapable of using a digi-
tal tester)
* Go to No.2.
* Go to No.2 after applying
power for designated time (12
hours).
* Check IGBTM may fail.
*
Check coil resistor and insulation
resistor. If normal, restart the
unit. If same symptom occurs,
replace the compressor.
* Insulation resistor : 50MΩ or more
* Coil resistor (below table)
* Check the IGBTM.
If the IGBTM is normal, replace
the inverter board.
* Check coil resistor and insula-
tion resistor.
No. Checking Item Symptom Countermeasure
Comp.
Tester
pipe
Figure 1.
Comp.
Tester
V
U
W
Figure 2.
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
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