6
Refrigerant Piping
• Set the outdoor unit first connected to the bridging pipe to the indoor units as the header unit.
• Install the outdoor units in order of their capacity codes: A (header unit) B C
• When connecting gas pipes to indoor units, use Y-shaped branching joints to keep pipes level.
• When piping to outdoor units using Outdoor unit connection piping kits, intersect the pipes to the outdoor unit and
those to indoor units at a right angle as shown in figure 1 on “Installation of the outdoor unit”. Do not connect
them as in figure 2 on “Installation of the outdoor unit”.
(*1) : (C) is outdoor unit furthest from the 1st branch and (j) is the indoor unit furthest from the 1st branch.
(*2) : If the height difference (H1) between indoor and outdoor unit exceeds 3m, set 65m or less.
(*3) : If the max. combined outdoor unit capacity is 46HP or more, then max. equivalent length is 70m or less
(real length is 50m or less).
(*4) : If the height difference (H2) between indoor units exceeds 3m, set 50m or less.
(*5) : If the height difference (H2) between indoor units exceeds 3m, set 30m or less.
(*6) : Total charging refrigerant is 140kg or less.
(*7) : Extension up till 90m is possible with conditions below.
Item
Allowable
value
Piping section
Piping length
Total extension of pipe (Liquid
pipe, real length)
Below 34HP
300m
LA + LB + La + Lb + Lc+ L1 + L2 + L3 +
L4+ L5 +L6 + L7 + a + b + c + d + e + f +
g + h + i + j
34HP or more 1000m (*6)
Farthest piping Length L (*1)
Equivalent
length
235m
LA+ L1 + L3 + L4 + L5 + L6 + j
Real length
190m
Equivalent length of farthest piping from 1st
branching Li (*1)
90m (*2)
L3 + L4 + L5 + L6 + j
Equivalent length of farthest piping between
outdoor units LO
25m
LA + Lc(LA + Lb)
Max. equivalent length of main
piping
Equivalent
length
120m (*3)
L1
Real length
100m (*3)
Max. equivalent length of outdoor unit connecting
piping
10m
Lc(La, Lb)
Max. real length of indoor unit connecting piping
30m
a, b, c, d, e, f, g, h, i, j
Max. equivalent length between branches
50m
L2, L3, L4, L5, L6, L7
Difference in
height
Height between indoor and
outdoor units H1
Upper outdoor
unit
–
70m
(*4, *7)
Lower outdoor
unit
–
)
5
*
(
m
0
4
–
m
0
4
2
H
s
ti
n
u
r
o
o
d
n
i
n
e
e
w
t
e
b
t
h
g
i
e
H
–
m
5
3
H
s
ti
n
u
r
o
o
d
t
u
o
n
e
e
w
t
e
b
t
h
g
i
e
H
Liquid piping
▼
Figure 1
Main pipe
Header unit
A
Follower unit
B
Follower unit
C
To the indoor unit
Correct
▼
Figure 2
Main pipe
Header unit
A
Follower unit
B
Follower unit
C
To the indoor unit
Incorrect
NO GOOD
- Outdoor Temperature Cooling : 10°C to 46°C (Dry-bulb temp.)
Heating : -5°C to 15.5°C (Wet-bulb temp.)
- Equivalent length of farthest piping from 1st branching Li<50m
- Real length of main piping L1<100m
- Height difference between indoor units H2<3m
- Total capacity of combined indoor units : 90%-105%
- Single CDU, and up to 20HP
- Minimum capacity of connectable indoor unit : 4HP or Larger
<Cooling,Heat pump type>
Cautions for installation
Allowable length and allowable height difference of refrigerant piping
Summary of Contents for SMMS-e
Page 96: ...Quick Reference ...