LG MULTI V M ARNU07GTU 4 Series Svc Manual page 63

Error
Error Type
No.
251
Input Voltage high/low
n Error Diagnosis and Countermeasure Flow Chart
Are there any power wire
connections normal?
Yes
Is input voltage normal?
Yes
Is Inv. PCB
bridge diode joining condition normal?
Yes
Is DC_Link Wire connection
condition normal?
Yes
Inv. PCB LED display error
Yes
Recheck power and installation condition
Error Point
Input voltage is over limited
value of the product (173V
or less, 289V or more)
No
1. Check R/S/T/N wiring conditions
→ Rewire them if abnormality found.
Check
R~S/S~T/T~R phase voltage is 380V 10%
No
R~N/S~N/T~N phase voltage is 220V 10%
→ Check connection condition and wiring if power is
abnormal
Check joining condition of Inv. PCB and bridge diode
No
→ joining again if abnormality found
1.Check Inv. PCB P,N connector
No
connection condition
2.Check Inv. PCB P,N connector
connection condition
3. Check wire disconnection and wiring
→ Reassemble if abnormality found
No
Replace Inv. PCB
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Troubleshooting Guide
Main Reasons
1. Input voltage abnormal (R-N)
2. Compressor Module Inv. PCB damage
(input voltage sensing part)
3. N phase line disconnection
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