Installation and operation manual
14
10T8Y1B
VRV-W IV System Air Conditioner
4P399208-1 – 2015.01
Maximum allowable length after branch
The pipe length from the first refrigerant branch kit to the indoor unit
≤
40 m.
Example 1.1: unit 8: b+c+d+e+s
≤
40 m
Example 1.2: unit 5: b+k
≤
40 m, unit 8: m+n+p
≤
40 m
Example 1.3: unit 8: o
≤
40 m
However, extension is possible if all below conditions are met. In this
case limitation can be extended up to 90 m.
1
Outdoor units
2
Refnet joints (A~G)
3
Indoor unit (1~8)
a.
The piping length between all indoor to the nearest branch kit is
≤
40 m.
Example: h, i, j … p
≤
40 m
b.
It is necessary to increase the pipe size of the suction gas and
liquid piping if the pipe length between the first and the final
branch kit is over 40 m.
If the increased pipe size is larger than the pipe size of the main
pipe, increase is not allowed, extension till 90 m can not be
done.
Increase the pipe size as follows:
9.5
→
12.7; 12.7
→
15.9; 15.9
→
19.1; 19.1
→
22.2; 22.2
→
25.4
(1)
; 28.6
→
31.8
→
Example: unit 8: b+c+d+e+f+g+p
≤
90 m and b+c+d+e+f+g
>40 m; increase the pipe size of b, c, d, e, f, g.
c.
When the piping size is increased (step b), the piping length has
to be counted as double (except for the main pipe and the pipes
that are not increased in pipe size).
The total piping length has to be within limitations (see table
above).
Example:
a+b*2+c*2+d*2+e*2+f*2+g*2+h+i+j+k+l+m+n+p
≤
300 m.
d.
The piping length difference between the nearest indoor from
first branch to the outdoor unit and farthest indoor to the outdoor
unit is
≤
40 m.
Example: The farthest indoor unit 8. The nearest indoor unit 1
→
(a+b+c+d+e+f+g+p)–(a+h)
≤
40 m.
9.7.
Multi outdoor unit system piping installation
9.7.1
Precautions when connecting piping between outdoor
units
To connect the piping between outdoor units, an optional multi
outdoor unit connection piping kit BHFQ23P907/1357 or
BHFQ22P1007/1517 is always required. When installing the
piping, follow the instructions in the installation manual that
comes with the kit.
Only proceed with piping work after considering the limitations
on installing listed here and in chapter
refrigerant piping" on page 15
, always referring to the installation
manual delivered with the kit.
9.7.2
Possible installation patterns and configurations
The piping between the outdoor units must be routed level or
slightly upward to avoid the risk of oil retention into the piping.
1
Piping between outdoor units
2
To indoor unit
Prohibited patterns:
change to pattern 1 or 2.
1
Piping between outdoor units
2
To indoor unit
3
Oil remains in piping
For the gas piping (both discharge and suction gas pipings in
case of the heat recovery system) after the branch, install a trap
of 200 mm or larger using the piping included in the piping kit for
connecting the outdoor unit. Otherwise, the refrigerant may stay
in the piping, causing damage to the outdoor unit.
1
≥
200 mm
If the piping length between the outdoor unit connecting pipe kit
or between the outdoor units exceeds 2 m, create a rise of
200 mm or more in the gas line within a length of 2 m from the
kit.
If
≤
2 m
1
To indoor unit
2
≤
2 m
3
Piping between outdoor units
If
≥
2 m
1
To indoor unit
2
≤
2 m
3
Rising height:
≥
200 mm
4
≥
2 m
(1)
If available on the site. Otherwise it cannot be increased.
a
A
h
i
j
k
l
m
n
B
C
D
E
F
G
p
b
c
d
e
f
1
2
3
4
5
6
7
8
g
H1
H2
1
2
3
Pattern 1
Pattern 2
1
2
2
1
1
2
3
1
1
2
3
1
1
3
2
1
2
4
3
