LG ARNU Series, Service Manual

Page: 145 / 226

Service Manual 145
Troubleshooting Guide
Maximum over
current
(MAX CT)
Error
Code
Error Contents Meaning Main Causes
Error display
position
22
The current flowing at the
CT sensing circuit should
be more than the maxi-
mum value of the current
tolerance for the product .
Concerned
Remote con-
troller
Panel Display
Outdoor unit
1. Comp. damage
2. Current sensing sensor damage
(CT)
3. Low input voltage
4. Comp. terminal is disconnected or
loose .
5. Abnormality at the Outdoor /Indoor
Unit fan
7. Cover or chocking (Outdoor Unit
covering during cooling mode /
Filter chocked at the Indoor during
heating mode )
6. Defective inverter PCB/IPM PCB .
■
Defect inspection method : Refer error code 21
1) Check whether the current measured at the R phase during operation is above 18~20A ?
In case the current measurement is normal (During compressor operation :3~16A), Replace the inverter PCB.
2) In case the current is above 18~20A, check the comp. insulation and the motor coil resistance
(Refer error code 21)
→
In case the resistance is abnormal, then replace the comp.
3) Check whether the Main input power is 360Vac~410Vac.
Check whether a deviation exists between the main power voltage of each phase (Below 5~10V)?
In case there is a deviation in the required power supply in each phase or the abnormality of the input voltage,
then please request the building electricity in charge to change the power supply accordingly.
4) Please remove any obstacle in path of the outdoor heat exchange and also clean the Indoor filter.
5) Check whether the IPM Pin connecting PCB soldering is normal ?
(Check the PCB soldering at the back side of PCB after dismantling the PCB)
In case of any abnormality, then please replace the IPM PCB .
6) Measure the current between each phase of the inverter comp (U,V,W) during the trial run after the inspection .
In case of current deviation between each phase is above 1.5A, then replace the inverter PCB.
Measure current of Phase 'R'