Check The Amount Of Refrigerant - LG MULTI V 5 Manual Book

3.2 Not reach target high pressure
Checking Item Symptom
Not reach the target low
Bypass by defective
pressure under full /
outdoor valve
partial / single operation
Comp. max
Not reach the target
Hz operation
high pressure under
Lack of outdoors
full operation, but reach
capacity
the target low pressure
under partial operation
Compressor protection
control operation
Not max Hz
operation
Excessive low pressure Heating low pressure
drop control operation
Low outdoor tem-
perature
Compressor operation Defective installation of
Fan. max RPM
limit by excessive low outdoor unit
operation
pressure drop
Excessive foreign sub-
stance of outdoor heat
exchanger
Difective of fan motor,
motor shaft, fan fixing
screw, fan balance and
fan breakage
Not reach max. RPM
Not max. RPM
under max. RPM display
operation Fan heatsink tempera-
on the LGMV
ture limit
Fan lock
※ Compressor operation : The compressor controls the Hz to reach the target high pressure during the
heating operation.
- If the compressor does not reach the target high pressure while the compressor is operating at Max.
Hz, the outdoor capacity is insufficient compared to the indoor load or excessive low outdoor temp.
the flow is bypassed.
- If the compressor is not in Max Hz operation, it is in emergency control to limit compressor operation.
※ Fan operation : During heating operation, the fan controls the RPM to match the target low pressure.
- If the present low pressure is lower than the target low pressure, the RPM is raised.
- If the present low pressure is lower than the target low pressure, the RPM is decreased.
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_TROUBLE SHOOTING GUIDE BOOK
Judgment Countermeasure
Check the outdoor valve
Check the outdoor installation environ-
ment
Remove the foreign substance
Check the amount of thermal grease
between the fan PCB and the heat
sink.
Remove foreign substance around the
fan operation.

4. Check The Amount of Refrigerant

4.1 Cooling
Item Refrigerant shortage
• EEV open
Indoor unit EEV
(approx. 400 pls or more)
• Refrigerant noise
The degree of superheat
(@ indoor unit)
above 5 ℃
(Pipeout Temp. - Pipein
Temp.)
Low pressure below target low pressure
High pressure below target high pressure
• below 5 ℃
The degree of subcooling (@ single operation )
• below 10 ℃
(@ outdoor unit)
(@ full operation)
Inverter discharge
high
temperature
The degree of suction
above target degree
superheat
※ The table above is not an absolute measure of the amount of refrigerant.
Please judge comprehensively with other factors.
Refrigerant overcharging
EEV close
(approx. 150 pls or less)
below 0 ℃
above target low pressure
High pressure limit
* Even if the compressor Hz is low,
easily increase high pressure)
• below 25 ℃
(@ single operation )
• below 20 ℃
(@ full operation)
low
below target degree
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