High Pressure Rise - LG multi V PLUS Service Manual

Fault diagnosis and Trouble shooting guide
Error
Error Item
Display No.
34: High pressure rise of
main outdoor unit
34

143: High pressure rise

143
of Sub1 outdoor unit
145
145: High pressure rise
of Sub2 outdoor unit
Trouble shooting Flow
Check open status of the service valve.
Is discharge pressure actually high?
Is the fan of the indoor/outdoor
unit normal?
Is heat exchange normally done?
Is LEV or check valve of outdoor/indoor
unit normal?
The quantity of additional filling of
refrigerant is correct?
Is there shielding?
• Remove shielding of the outdoor unit
• Check the indoor unit filter
Meaning
Compressor stops by
excessive rise of high
pressure
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
Self-diagnosis function
Major Error Occurrence Cause
• Failure of high pressure sensor or high
pressure sensor detection circuit part
• Failure of indoor/outdoor unit fan
• Poor heat exchange by installation
conditions, damage of heat exchanger
• Clogging of discharge pipe
• Excessive filling of refrigerant
Is the pressure
sensor normal?
Yes
Check or replace the PCB.
Check or replace the fan.
Check installation conditions so that
heat exchange is done.
Check LEV and check valve of
the outdoor/indoor unit
Recalculate and refill filling
quantity of refrigerant.
Check pipe clogging or refrigerant
No
Replace the
pressure sensor.
Service Manual 273