LG multi V ARUN Series Installation Manual page 38

Pipe connections between indoor and outdoor unit
u Outdoor unit Connection
WARNING
• In case of pipe diameter B connected after first branch is bigger than the main pipe diameter A, B should be of
the same size with A.
Ex) In case indoor unit combination ratio 120% is connected to 70kW outdoor unit.
1) Outdoor unit main pipe diameter A : Ø34.9(gas pipe), Ø15.88(liquid pipe)
2) Pipe diameter B after first branch according to 120% indoor unit combination(84kW) :Ø34.9(gas pipe),
Ø19.05(liquid pipe)
Therefore, pipe diameter B connected after first branch would be Ø34.9(gas pipe)/Ø15.88(liquid pipe)
which is same with main pipe diameter.
[Example]
Do not choose the main pipe diameter by downward indoor unit total capacity but its outdoor unit model name.
Do not let the connection pipe from branch to branch exceed the main pipe diameter chosen by outdoor unit model
name.
EX) Where connecting the indoor units to the 22 HP (61.5 kW) outdoor unit to 120% of its system capacity (73.8 kW)
and branching 7k (2.1kW) indoor unit at the 1st branch
Main pipe diameter(22 HP outdoor unit): Ø28.58(Gas pipe) Ø15.88(Liquid pipe)
Pipe diameter between 1st and 2nd branch (71.7kW indoor units):
Ø34.9(Gas pipe) Ø19.05(Liquid pipe) in conformity with downward indoor units.
Since the main pipe diameter of 22HP outdoor unit is Ø28.58(Gas pipe) and Ø15.88(Liquid pipe), Ø28.58 (Gas pipe) and
Ø15.88 (Liquid pipe) is used as the main pipe and the connection pipe between 1st and 2nd branch.
* High/Low Pressure Common Pipe: Ø19.05(22HP or more)
u Indoor Unit Connection
Ú Indoor Unit connecting pipe from branch (a,b,c,d,e,f)
Indoor Unit capacity [kW(Btu/h)]
≤ 5.6(19,100)
< 16.0(54,600)
< 22.4(76,400)
38 Outdoor Unit
Liquid pipe
[mm(inch)] [mm(inch)]
Ø6.35(1/4)
Ø9.52(3/8) Ø15.88(5/8)
Ø9.52(3/8) Ø19.05(3/4)
Gas pipe
Ø12.7(1/2)