14 Piping installation
Installation and operation manual
29
BS4~12A14AJV1B
VRV 5 branch selector unit
4P670163-1 – 2022.02
g
a
f
e
b
c
g
g
d
g
g
g
gg
g
a, b
See table below
c
Maximum limit of 16 downstream ports of BS units in
refrigerant flow-through. Unused ports must also be
counted. E.g. 16 ports=BS12A+BS4A or BS8A+BS4A
+BS4A
d
At least one indoor unit must be connected to a BS unit
e
Combine two ports when indoor unit capacity is over 140
f
Cooling only indoor units cannot be installed. All indoor
units must be connected to the branch pipes of a BS unit
g
BS unit
Description
Model
BS4A BS6A BS8A BS10A BS12A
Maximum number of
connectable indoor units per
BS unit (
a
)
20
30
40
50
60
Maximum number of
connectable indoor units per
BS unit branch (
b
)
5
Maximum capacity index of
connectable indoor units per
BS unit (
a
)
400
600
750
Maximum capacity index of
connectable indoor units per
branch (
b
)
140
Maximum capacity index of
connectable indoor units per
branch if 2 branches are
combined (
e
)
250
Maximum capacity index of
indoor units connected to BS
units in refrigerant flow-
through (
c
)
750
Maximum number of ports of
BS units in refrigerant flow-
through (
c
)
16
Maximum number of indoor
units connected to BS units in
refrigerant flow-through (
c
)
64
14.2
Preparing refrigerant piping
14.2.1
Refrigerant piping requirements
NOTICE
The piping and other pressure-containing parts shall be
suitable for refrigerant. Use phosphoric acid deoxidised
seamless copper for refrigerant.
▪ Foreign materials inside pipes (including oils for fabrication) must
be ≤30 mg/10 m.
14.2.2
Refrigerant piping material
▪
Piping material:
Phosphoric acid deoxidised seamless copper.
▪
Piping temper grade and thickness:
Outer diameter
(Ø)
Temper grade
Thickness (t)
(a)
6.4 mm (1/4")
9.5 mm (3/8")
12.7 mm (1/2")
Annealed (O)
≥0.80 mm
t
Ø
15.9 mm (5/8")
Annealed (O)
≥0.99 mm
19.1 mm (3/4")
22.2 mm (7/8")
Half hard (1/2H)
≥0.80 mm
28.6 mm (1 1/8")
Half hard (1/2H)
≥0.99 mm
(a)
Depending on the applicable legislation and the maximum
working pressure of the unit (as indicated on the unit nameplate),
larger piping thickness might be required.
14.2.3
Refrigerant piping insulation
▪ Use polyethylene foam as insulation material:
▪ with a heat transfer rate between 0.041 and 0.052 W/mK (0.035
and 0.045 kcal/mh°C)
▪ with a heat resistance of at least 120°C
▪ Insulation thickness
Ambient
temperature
Humidity
Minimum thickness
≤30°C
75% to 80% RH
15 mm
>30°C
≥80% RH
20 mm
14.3
Connecting the refrigerant piping
DANGER: RISK OF BURNING/SCALDING
14.3.1
To connect the refrigerant piping
e
e
b
a
d
c
g
h
e
f f
f f
f f
f
