LG THERMA V AHNW16606B0 Service Manual page 74

Display
Title
code
AC input instant over cur-
rent error
73
(Matter of software)
n Error Diagnosis and Countermeasure Flow Chart
Is installation
condition normal?
Yes
Is input voltage normal?
Yes
Is AC input Wire connection
condition normal?
Yes
Is compressor
Wire connection
condition normal?
Yes
PCB assembly 1
normal?
Yes
Recheck power and
installation condition
Cause of error
(AHUW**6A2)
PCB(Inverter) input
power current is over
48A(Peak) for 2ms.
(AHUW**8A2)
PCB(Inverter) input
power current is over
27A(Peak) for 2ms.
1.Check Pipe clogging/distortion
2.Check Covering (Unit)
No
3.Check EEV connector assemble condition/normal operation
4.Check refrigerant pressure
→ Reassemble or manage if abnormality found
Check
No
R-S, S-T, T-R phase voltage is 220~240 V ± 10%
→ Check connection condition and wiring if power is abnormal
1.Check R,S,T connection condition
No
2.Check wire disconnection and wiring
→ Reassemble if abnormality found
1.Check PCB assembly 1 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
No
Check PCB assembly 1 IPM normality
→ Replace PCB assembly 1
Check point & Normal condition
1. Overload operation (Pipe clogging/Covering/EEV
defect/Ref.overcharge)
2. Compressor damage
(Insulation damage/Motor damage)
3. Input voltage abnormal
4. Power line assemble condition abnormal
5. PCB assembly 1 damage
(input current sensing part)
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