Caution; Selection Of Refrigerant Piping; Refrigerant Piping System - LG Multi V Space II ARUN053GF2 Installation Manual

9. The Multi V will stop due to an abnormality like excessive or insuffi-
cient refrigerant. At such a time, always properly charge the unit.
When servicing, always check the notes concerning both the piping
length and the amount of additional refrigerant.
10. Never perform a pump down. This will not only damage the com-
pressor but also deteriorate the performance.
11. Never use refrigerant to perform an air purge. Always evacuate air
by using a vacuum pump.
12. Always insulate the piping properly. Insufficient insulation will re-
sult in a decline in heating/cooling performance, drip of condensate
and other such problems.
13. When connecting the refrigerant piping, make sure the service
valves of the Outdoor Unit is completely closed (the factory setting)
and do not operate it until the refrigerant piping for the Outdoor and
Indoor Units has been connected, a refrigerant leakage test has
been performed and the evacuation process has been completed.
14. Always use a non-oxidizing brazing material for brazing the parts
and do not use flux. If not, oxidized film can cause clogging or dam-
age to the compressor unit and flux can harm the copper piping or
refrigerant oil.
1
2
3
1 Refrigerant piping
2 Pipe to be brazed
3 Nitrogen
WARNING
!
When installing and moving the air conditioner to another site, be
sure to make recharge refrigerant after perfect evacuation.
- If a different refrigerant or air is mixed with the original refriger-
ant, the refrigerant cycle may malfunction and the unit may be
damaged.
- After selecting diameter of the refrigerant pipe to suit total ca-
pacity of the indoor unit connected after branching, use an appro-
priate branch pipe set according to the pipe diameter of the
indoor unit and the installation pipe drawing.
Do not use anti-oxidants when brazing the pipe joints. Residue can
clog pipes and break equipment.

Selection of Refrigerant Piping

Outdoor unit
Gas pipe
Liquid pipe
Branching
pipe
Main pipe
Branching
pipe
6
4 5
4 Taping
5 Valve
6 Pressure-reducing valve
Indoor unit
No. Piping parts Name
Outdoor unit
↓
①
Main pipe
1st branching
section
Branching
section
Branching
②
↓
pipe
Branching
section
Branching
Indoor unit
section
③
connecting
↓
pipe
Indoor unit

Refrigerant piping system

Y branch method
Example : 5 Indoor Units
connected
Ⓐ : Outdoor Unit
Ⓑ : 1st branch (Y branch)
Ⓒ : Indoor Units
Total pipe length = A+B+C+D+a+b+c+d+e ≤ 145 m (475.7 ft)
Longest pipe length
L
A+B+C+D+e ≤ 70 m (230 ft) * A+B+C+D+e ≤ 90 m (295.2 ft)
Longest pipe length after 1st branch
B+C+D+e ≤ 40 m (131 ft)
Difference in height(Outside Unit ÷ Indoor Unit)
H
H ≤ 30 m (98.4 ft)
Difference in height (Indoor Unit ÷ Indoor Unit)
h
h ≤ 15 m (49 ft)
* : Assume equivalent pipe length of Y branch to be 0.5 m (1.6 ft),
that of header to be 1 m (3.3 ft), calculation purpose

CAUTION

!
• Indoor Unit should be installed at lower position than the header
Selection of pipe size
Size of main pipe
Outdoor unit Liquid pipe Gas pipe
capacity type [mm(inch)] [mm(inch)]
6 HP Ø9.52(3/8) Ø19.05(3/4)
Pipe size of between branching sec-
tions
Indoor unit
Liquid pipe Gas pipe
capacity
[mm(inch)] [mm(inch)]
[kW(Btu/h)]
≤ 5.6(19,100)
Ø6.35(1/4) Ø12.7(1/2)
< 16.0(54,600) Ø9.52(3/8) Ø15.88(5/8)
< 22.4(76,400) Ø9.52(3/8) Ø19.05(3/4)
Connecting pipe size of indoor unit
Indoor unit
Liquid pipe Gas pipe
capacity
[mm(inch)] [mm(inch)]
[kW(Btu/h)]
≤ 5.6(19,100)
Ø6.35(1/4) Ø12.7(1/2)
< 16.0(54,600) Ø9.52(3/8) Ø15.88(5/8)
L70 m (230 ft)
l 40 m (131 ft)
h 15 m (49 ft)
Equivalent pipe length
9