LG Multi V PRHR042A Installation Manual page 23

WARNING
!
• It is recommended that difference of piping length for pipes
connected to the Indoor Unit is minimized. Performance
difference between Indoor Units may occur.
• When the any one (or both ) of below conditions are satisfied,
the diameter of main pipe (A) must be increased according to
below table.
- The equivalent length between outdoor unit and the farthest
indoor unit is 90 m or more. (Liquid and Gas pipes are
increased.)
Refrigerant pipe diameter from outdoor unit to first branch. (A)
System(Ton) Liquid pipe [mm(inch)]
3, 4 Ø 9.52(3/8)
Refrigerant pipe diameter from branch to branch (B,C)
Downward Indoor
Unit total capacity Liquid pipe [mm(inch)]
[kW(Btu/h)]
≤ 5.6(19 100)
Ø 6.35(1/4)
< 16.0(54 600) Ø 9.52(3/8)
≤ 22.4(76 400)
Ø 9.52(3/8)
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
24 HP(67.2 kW) outdoor unit.
1) Outdoor unit main pipe diameter A : Ø 34.9(Gas pipe),
Ø 15.88(liquid pipe)
2) Pipe diameter B after first branch according to 120 %
indoor unit ombination(80.6kW) : Ø 34.9(gas pipe),
Ø 19.05(liquid pipe)
Therefore, pipe diameter B connected after first branch
would be Ø 34.9(gas pipe) / Ø 15.88(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 (61.6 kW)
outdoor unit to 130 % of its system capacity (80.1 kW) and
branching 7k (2.2 kW) indoor unit at the 1st branch.
1) Main pipe diameter(22 HP outdoor unit): Ø 28.58(gas pipe),
Ø 15.88(Liquid pipe)
2) Pipe diameter between 1st and 2nd branch (77.9 kW indoor
units) :
Ø 34.9(Gas pipe), Ø 19.05(Liquid pipe) in conformity with
downward indoor units.
Since the main pipe diameter of 22 HP outdoor unit is
Ø 28.58(gas pipe), Ø 15.88(Liquid pipe) is used as the main
pipe and the connection pipe between 1st and 2nd branch.
Indoor Unit Connection
Indoor Unit connecting pipe from branch (a,b,c,d,e,f)
Indoor Unit capacity Liquid pipe
[kW(Btu/h)] [mm(inch)]
≤ 5.6(19,100)
Ø6.35(1/4)
< 16.0(54,600) Ø9.52(3/8)
< 22.4(76,400) Ø9.52(3/8)
< 28.0(95,900) Ø9.52(3/8)
!
• Bending radius should be
at least twice the diameter
of the pipe.
• Bend pipe after 500mm
(19-5/8inch) or more from
branch(or header).
Do not bend U type.
It may cause Performance
unsatisfactory or noise.
The amount of Refrigerant
The calculation of the additional charge should take into account the
Gas pipe [mm(inch)]
length of pipe and CF(correction Factor) value of indoor unit.
Ø 15.88(5/8)
Additional charge(kg)
Gas pipe [mm(inch)]
Ø 12.7(1/2)
Ø 15.88(5/8)
Ø 19.05(3/4)
Amount refrigerant of Indoor units
Example) 4Way Ceiling Cassette 14.5kW -1ea, Ceiling concealed
Attach the additional refrigerant table of IDU.
!
• Regulation for refrigerant leakage
: the amount of refrigerant leakage should satisfy the following
Volume of the room at which Indoor Unit of
If the above equation can not be satisfied, then follow the
following steps.
• Selection of air conditioning system: select one of the next
- Installation of effective opening part
- Reconfirmation of Outdoor Unit capacity and piping length
- Reduction of the amount of refrigerant
- Installation of 2 or more security device (alarm for gas leakage)
• Change Indoor Unit type
: installation position should be over 2m(6.6ft) from the floor (Wall
Gas pipe [mm(inch)]
• Adoption of ventilation system
: choose ordinary ventilation system or building ventilation
Ø12.7(1/2)
Ø15.88(5/8)
• Limitation in piping work
Ø19.05(3/4)
: Prepare for earthquake and thermal stress
Ø22.2(7/8)
CAUTION
500mm
(19-5/8inch)
or more
= Total liquid pipe : Ø25.4 mm (1.0 inch)
+ Total liquid pipe : Ø22.2 mm (7/8 inch)
+ Total liquid pipe : Ø19.05 mm (3/4 inch)
+ Total liquid pipe : Ø15.88 mm (5/8 inch)
+ Total liquid pipe : Ø12.7 mm (1/2inch)
+ Total liquid pipe : Ø9.52 mm (3/8inch)
+ Total liquid pipe : Ø6.35 mm (1/4 inch)
+ Number of installed HR unit
+ CF value of indoor unit
Duct 7.3kW-2ea, Wall Mounted 2.3kW-4ea
CF = 0.64 × 1 + 0.26 × 2 + 0.24 × 4 = 2.12kg(4.67lbs)
WARNING
equation for human safety.
Total amount of refrigerant in the system
the least capacity is installed
mounted type → Cassette type)
system
23
500mm
(19-5/8inch)
or more
x 0.480 kg/m (0.323 lbs/ft)
x 0.354 kg/m (0.238 lbs/ft)
x 0.266 kg/m (0.179 lbs/ft)
x 0.173 kg/m (0.116 lbs/ft)
x 0.118 kg/m (0.079 lbs/ft)
x 0.061 kg/m (0.041 lbs/ft)
x 0.022 kg/m (0.015 lbs/ft)
x 0.5 kg (1.1 lbs)
※ 6 & 8 Branches
Model : 1.0kg/EA
(2.2 lbs/EA)
≤0.44kg/m
3
3
(0.028lbs/ft )