Multi F Four-Way Ceiling Cassette Service Manual

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Copyright ©2014 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
Part 5. Trouble Shooting
Display
code
Title Cause of error Check point & Normal condition
25 Input Voltage high/low
Input voltage is over limited
value of the product (140V
or less, 300V or more)
1. Input voltage abnormal (R-S-T)
2. Outdoor unit main PCB assembly damage
(input voltage sensing part)
Error Diagnosis and Countermeasure Flow Chart
Yes
Yes
Recheck power and installation condition
Yes
Are there any power wire
connections normal?
No
Yes
1. Check L/N/G wiring conditions
Rewire them if abnormality found.
Is input voltage normal?
No
Check
R~S/S~T/T~R phase voltage is 220V 10%
Check connection condition and wiring if power is
abnormal
Is main PCB assembly power
connection normal?
No
Check connection between main PCB assembly and bridge
diode(misconnection, disconnection)
wiring again if abnormality found
Monitoring PCB LED display error
No
Replace main PCB assembly.