14 Piping installation
Installation and operation manual
25
RXYSA4~6A7V/Y1B
VRV 5-S system air conditioner
4P600329-1E – 2023.02
A
Piping between outdoor unit and (first) refrigerant branch
kit
B-1 B-2
Piping between refrigerant branch kits
C-1~C-4
Piping between refrigerant branch kit and indoor unit
In case the required pipe sizes (inch sizes) are not available, it is
also allowed to use other diameters (mm sizes), taken the following
into account:
▪ Select the pipe size nearest to the required size.
▪ Use the suitable adapters for the change-over from inch to mm
pipes (field supply).
▪ The additional refrigerant calculation has to be adjusted as
mentioned in
"15.2 To determine the additional refrigerant
A: Piping between outdoor unit and (first)
refrigerant branch kit
When the equivalent pipe length between outdoor unit and the
furthest indoor unit is 90 m or more (b+d), the size of the main gas
pipe (b) must be increased (size-up). If the recommended gas pipe
(size-up) is not available, you must use the standard size (which
might result in a small capacity decrease).
e
d
b
c
a
a
Outdoor unit
b
Main gas pipe (increase piping size if length b+d ≥ 90 m)
c
First refrigerant branch kit
d
Piping between indoor unit and first refrigerant branch kit
e
Furthest indoor unit
Outdoor unit
capacity type
(HP)
Piping outer diameter size (mm)
Gas pipe
Liquid pipe
Standard
Size-up (only
'b')
4+5+6
15.9
19.1
9.5
B: Piping between refrigerant branch kits
Choose from the following table in accordance with the indoor unit
total capacity type, connected downstream. Do not let the
connection piping exceed the refrigerant piping size chosen by the
general system model name.
Indoor unit capacity
index
Piping outer diameter size (mm)
Gas pipe
Liquid pipe
0≤x≤182
15.9
9.5
Example:
Downstream capacity for B-1 = capacity index of unit 3-1
+ capacity index of unit 3-2
C: Piping between refrigerant branch kit and
indoor unit
Use the same diameters as the connections (liquid, gas) on the
indoor units. The diameters of the indoor units are as follows:
Indoor unit capacity
index
Piping outer diameter size (mm)
Gas pipe
Liquid pipe
10~32
9.5
6.4
40~80
12.7
6.4
100~140
15.9
9.5
14.1.4
To select refrigerant branch kits
For piping example, refer to
"14.1.3 To select the piping size"
Refnet joint at first branch (counting from outdoor unit)
When using refnet joints at the first branch counted from the outdoor
unit side, choose from the following table in accordance with the
capacity of the outdoor unit.
Example:
Refnet joint A→B‑1.
Outdoor unit capacity type
(HP)
Refrigerant branch kit
4~6
KHRQ22M20TA
Refnet joints at other branches
For refnet joints other than the first branch, select the proper branch
kit model based on the total capacity index of all indoor units
connected after the refrigerant branch.
Example:
Refnet joint
B‑1→C‑1.
Indoor unit capacity index
Refrigerant branch kit
<182
KHRQ22M20TA
Refnet headers
Concerning refnet headers, choose from the following table in
accordance with the total capacity of all the indoor units connected
below the refnet header.
Indoor unit capacity index
Refrigerant branch kit
<182
KHRQ22M29H
INFORMATION
Maximum 8 branches can be connected to a header.
14.2
Connecting the refrigerant piping
DANGER: RISK OF BURNING/SCALDING
14.2.1
To remove the spun pipes
WARNING
Any gas or oil remaining inside the stop valve may blow off
the spun piping.
If these instructions are NOT followed correctly it may
result in property damage or personal injury, which may be
serious depending on the circumstances.
Use the following procedure to remove the spun piping:
1
Make sure that the stop valves are fully closed.
2
Connect the vacuuming/recovery unit through a manifold to the
service port of all stop valves.
a
a
b
b
a
Service port
b
Stop valve
3
Recover gas and oil from the spun piping by using a recovery
unit.
CAUTION
Do NOT vent gases into the atmosphere.
4
When all gas and oil is recovered from the spun piping,
disconnect the charge hose and close the service ports.
