LG AMNW07GDBL1 Service Manual page 88

Display
Title
code
AC Input Instant over
27
Current Error
WARNING
Before checking PCB 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.
■ Error Diagnosis and Countermeasure Flow Chart
Is installation
condition normal?
Is input voltage normal?
Is AC input Wire connection
condition normal?
Is compressor
Wire connection
condition normal?
Is inverter PCB assembly
normal?
Recheck power and
installation condition
❈ PFCM Moudle checking method
① Set the multi tester to diode mode.
② Check short between input signal pin which are
placed below PFC Module
③ Replace PCB assembly if it is short between pins
except No.4,5 pins.
CAUTION
PFCM module No.4,5 pins are internal short state.
Copyright ©2014 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Cause of error
Inverter PCB input
current is over100A(peak)
for 2us
1.Check Pipe clogging/distortion
2.Check Covering (Indoor/Outdoor Unit)
No
3.Check EEV connector assemble condition/normal operation
4.Check refrigerant pressure
→ Reassemble or manage if abnormality found
Yes
Check
No
L~N phase voltage is 230V ± 15%
→ Check connection condition and wiring if power is abnormal
Yes
1.Check L,N connection condition
No
2.Check wire disconnection and wiring
→ Reassemble if abnormality found
Yes
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
Yes
No
Check inverter PCB assembly PFCM normality
→ Replace inverter PCB assembly
Yes
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 (L,N)
4. Power line assemble condition abnormal
5. Inverter PCB assembly Damage (input current
sensing part)
<Short Check Point>
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Part 5. Trouble Shooting
LGE Internal Use Only