LG multi V ARUB160BT3 Instruction Manual page 40

Refrigerant piping system
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(Low pressure gas pipe), Ø15.88(liquid pipe), Ø28.58(High Pressure
liquid pipe)
2) Pipe diameter B after first branch according to 120% indoor unit combination(84kW) : Ø34.9(Low pressure gas
pipe), Ø19.05(liquid pipe), Ø28.58(High Pressure liquid pipe)
Therefore, pipe diameter B connected after first branch would be Ø34.9(Low pressure gas pipe), Ø15.88(liquid
pipe), Ø28.58(High Pressure 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(Low pressure gas pipe), Ø15.88(Liquid pipe), Ø22.2(High pressure gas 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(Low pressure gas pipe), Ø15.88(Liquid pipe), Ø22.2(High pres-
sure gas pipe) is used as the main pipe and the connection pipe between 1st and 2nd branch.
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)
≤ 28.0(95,900)
40 Outdoor Unit
Liquid pipe [mm(inch)]
Ø6.35(1/4)
Ø9.52(3/8)
Ø9.52(3/8)
Ø9.52(3/8)
Gas pipe [mm(inch)]
Ø12.7(1/2)
Ø15.88(5/8)
Ø19.05(3/4)
Ø22.2(7/8)