LG Multi V 5 - Check the Amount of Refrigerant

068 069
_TROUBLE SHOOTING GUIDE BOOK _
4.1 Cooling
4. Check The Amount of Refrigerant
Item Refrigerant shortage Refrigerant overcharging
Indoor unit EEV
• EEV open
(approx. 400 pls or more)
• Refrigerant noise
EEV close
(approx. 150 pls or less)
The degree of superheat
(@ indoor unit)
(Pipeout Temp. - Pipein
Temp.)
above 5 ℃ below 0 ℃
Low pressure below target low pressure above target low pressure
High pressure below target high pressure
High pressure limit
* Even if the compressor Hz is low,
easily increase high pressure)
The degree of subcooling
(@ outdoor unit)
•
below 5 ℃
(@ single operation )
•
below 10 ℃
(@ full operation)
•
below 25 ℃
(@ single operation )
•
below 20 ℃
(@ full operation)
Inverter discharge
temperature
high low
The degree of suction
superheat
above target degree below target degree
※ The table above is not an absolute measure of the amount of refrigerant.
Please judge comprehensively with other factors.
3.2 Not reach target high pressure
Checking Item Symptom Judgment Countermeasure
Comp. max
Hz operation
Not reach the target low
pressure under full /
partial / single operation
Bypass by defective
outdoor valve
Check the outdoor valve
Not reach the target
high pressure under
full operation, but reach
the target low pressure
under partial operation
Lack of outdoors
capacity
Not max Hz
operation
Compressor protection
control operation
Excessive low pressure
drop
Heating low pressure
control operation
Fan. max RPM
operation
Compressor operation
limit by excessive low
pressure drop
Low outdoor tem
-
perature
Defective installation of
outdoor unit
Check the outdoor installation environ
-
ment
Excessive foreign sub
-
stance of outdoor heat
exchanger
Remove the foreign substance
Not max. RPM
operation
Not reach max. RPM
under max. RPM display
on the LGMV
Difective of fan motor,
motor shaft, fan fixing
screw, fan balance and
fan breakage
Fan heatsink tempera
-
ture limit
Check the amount of thermal grease
between the fan PCB and the heat
sink.
Fan lock
Remove foreign substance around the
fan operation.
※ 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.
Basic Part
Multi V 5
Intorduction
Trouble Shooting
Function Control
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