LG THERMA V AHNW16606B0, Service Manual, Page: 57 / 81

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Inverter compressor over
current
(AHUW**6A2)
Inverter Compressor
input current is 30A.
(AHUW**8A2)
Inverter Compressor
input current is 24A.
1. Overload operation
(Pipe clogging/Covering/EEV defect/Ref. over-
charge)
2. Compressor damage(Insulation damage/Motor
damage)
3. Input voltage low
4. ODU PCB assembly 1 damage
Display
code
Title Cause of error Check point & Normal condition
n
Error Diagnosis and Countermeasure Flow Chart
Is installation
condition normal?
No
Yes
Yes
Yes
Recheck power and installation condition
1. Check Pipe clogging/distortion
2. Check Covering (Unit)
3. Check EEV connector assemble condition/normal
operation
4. Check refrigerant pressure
→
Reassemble or manage if abnormality found
Yes
Is input voltage normal?
No Check
U-V,V-W,W-U phase is 220~240 V ±10%
→
Check connection condition and wiring if power is
abnormal
Yes
Is PCB assembly 1
normal?
No
Check PCB assembly 1 IPM normality
→
Replace inverter PCB assembly
Are the resistance
between each phase and
insulation resistance of Inverter
compressor normal?
No
1. Check resistance between each terminal of compressor
(0.188 ±7%)
2. Check insulation resistance between compressor
terminal and pipe (over 50 MΩ)
→
Replace compressor if abnormality found
Is compressor
wire connection
condition normal?
No
1. Check PCB assembly 1 U,V,W connector
connection condition
2. Check wire disconnection and wiring
3. Check compressor terminal connection condition
(bad contact)
→
Reassemble if abnormality found
Check Flow Chart
WARNING
Before checking PCB(Inverter) or each outdoor electric parts, wait for 3 minutes after the power is off. When measuring at standby
state of power supply, after checking the measurement mode of the meter, be careful of the short-circuits with other parts.