LG Multi V 5 - Lgmv; Lack of Cooling

064 065
_TROUBLE SHOOTING GUIDE BOOK _
2.1 Not reach target low pressure
2. Lack of Cooling
Checking Item Symptom Judgment Countermeasure
Inlet temp. of
indoor unit
≥ 14 ℃ Refrigerant shortage
Check the indoor EEV opening pulse. When the
opening pulse is small or closed, please lower the
degree of superheat of the corresponding indoor unit
Check the indoor unit EEV
Check the liquid pipe blocking or the foreign sub
-
stances in the strainer.
Check indoor unit with bypass flow
(Confirm total flow while changing full / partial /
single operation)
The degree of
superheat of
indoor unit
≥ 5 ℃
Cooling overload
Recheck the load design, Check the ambient air
flow, (if duct type) inlet / outlet chamber installation
Refrigerant shortage Check the amount of refrigerant
Defective temp.
sensor of indoor
unit
Check the temperature sensor of indoor unit
Defective EEV of
indoor unit
Check the indoor unit EEV
Discharge
temp. is
normal under
full operation
but discharge
temp. is
abnormal
under partial
operation
Bypass on indoor
flow
If the liquid pipe and the gas pipe are connected to
a place without an indoor unit, separate the con-
nected pipe.
※ the inlet temperature of the indoor unit : When the present low pressure reaches the target low pres
-
sure, the inlet temperature of the indoor unit should be not more than evaporation temperature + 10 ℃
※ The degree of superheat of indoor unit (It may be different depending on the outdoor unit control)
> 2 ℃ : EEV Open
< 2 ℃ : EEV Close
1. LGMV
- The value of LGMV in steady-state condition after driving more than 80% of the indoor unit - The above value is not the absolute value, it can be changed according to the installation environment and operating condition. - The above causes are the most common causes, there can be other possible causes.
Mode No. Item Unit
R410a
Cause & Check Point
Normal condition Abnormal condition
Cooling
1 High Pressure kPa 2000~3600
Above 3800 Overcharging, Outdoor Fan lock
Below 1800 Ref. Leakage or Ref. Shortage
2
Low Pressure
(Cooling)
kPa 500~1000
Above 1300 Overcharging
Below 400 Ref. Leakage or Ref. Shortage, Comm Line Wrong connection
3 Indoor EEV Pulse 200~600
Above 1000 Ref. Leakage or Ref. Shortage
Below 100 Overcharging, Indoor Pipe Temp. Sensor Defect
4 Outdoor EEV Pulse
32/2000(Normal) -
Normal Mode : Upper EEV → full close Lower EEV → full open
2000/32
(Cooling low temp.)
Low Temp Mode : Upper EEV → full open Lower EEV → full close
5
Indoor pipe △T
△T = Outlet - Inlet
℃ 0~10 Below -1
Below 0℃ : EEV leakage, Malfunction Above 10℃ : EEV clogging, Malfunction, Pipe Clogging, Wrong Piping
6 Indoor pipe Inlet, Outlet ℃ 6~15 above 17
Ref. Leakage or Ref. Shortage Indoor Path Clogging EEV Fault, Indoor Pipe Temp, Sensor Defect
Heating
7
High Pressure
(Cooling)
kPa 2300~3300
Above 3400
Overcharging, Comm Line Wrong connection Indoor Fan Lock
below 2200 Ref. Leakage or Ref. Shortage
8 Low Pressure kPa 200~1200
Above 1300 Overcharging
below 120 Ref. Leakage or Ref. Shortage, Outdoor EEV Fault
9 Indoor EEV Pulse 150~1350 -
10 Outdoor EEV Pulse 200~800
Above 1500 Ref. Leakage or Ref. Shortage
Below 150 Overcharging
Common
11 Comp, Discharge T ℃ 60~100 Above 105 Ref. Leakage or Ref. Shortage
12
Suction Superheat
(Tsuc-Tdew)
℃ Above 0.5 below 0
SC EEV Fault, Overcharging EEV Fault
13
Discharge Superheat
(Tdis-Tbub)
℃ Above 15 Below 5 SC EEV Fault, Overcharging
Basic Part
Multi V 5
Intorduction
Trouble Shooting
Function Control
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