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English
Necessary conditions
Example: Only the allowable length after branch for the indoor unit 9 exceeds 130 ft. (40 m) in the
figure in the lower right
1. Upsize the liquid pipe from the first
refrigerant branch kit to the final
refrigerant branch kit for the indoor
unit beyond 130 ft. (40 m).
• If upsizing is impossible, the condi-
tions are not satisfied.
• If the upsized line would become
larger than the main pipe, then the
main pipe should also be upsized.
Upsize the liquid pipes b, c, d, e, f and g in the
figure in the right.
The upsizing specifications should be as fol
-
lows:
φ
3/8 in. (9.5 mm)
→
φ
1/2 in. (12.7 mm)
φ
1/2 in. (12.7 mm)
→
φ
5/8 in. (15.9 mm)
φ
5/8 in. (15.9 mm)
→
φ
3/4 in. (19.1 mm)
φ
3/4 in. (19.1 mm)
→
φ
7/8 in. (22.2 mm)
C
REFNET joints
G
b
d
m
B
f
A
c
D
9
H
e
g
6
h
n
F
i
4
Outdoor unit
3
a
7
E
5
1
8
(A-G)
p
Indoor unit (1-9)
j
k
B1
B2
B3
B4
B5
B6
B7
2
s
r
q
Branch Selector units (B1-B7)
b+c+d+e+f+g+p>130 ft. (40 m)
From outdoor unit to the farthest indoor unit 9
From outdoor unit to the nearest indoor unit 1
2. The total piping length, calculated by
doubling the piping length as upsized
in 1 above, is ≤1640 ft. (500 m).
(The main pipe, and lines that are
not upsized, should not be doubled.)
a +
b×2+c×2+d×2+e×2+f×2+g×2
+h+i+j+k+l+m+n+p+q+r+s
≤1640 ft. (500 m)
3. The actual piping length from each
indoor units to the nearest refriger-
ant branch kit are all ≤130 ft. (40 m).
•
i, j ∙∙∙, p≤130 ft. (40 m)
•
h+q+r≤130 ft. (40 m)
•
h+q+s≤130 ft. (40 m)
4. The difference between the actual
piping length from the outdoor unit
to the farthest indoor unit, and the
actual piping length from the outdoor
unit to the nearest indoor unit, is
≤130 ft. (40 m).
Actual piping length of 9 Actual piping length of 1
(a+b+c+d+e+f+g+p) − (a+h+q+r)
≤130 ft. (40 m)
In the case of a multi Branch Selector unit, if a junction pipe kit (separately sold) is used for combining 2 lines, the actual piping length between the
multi Branch Selector unit and the indoor units should be ≤65 ft. (20 m).
This limitation can be extended beyond 65 ft. (20 m), if all of the three conditions below are satisfied.
1. Upsize the liquid line between the joined 2 branches and the indoor unit.
2. Actual pipe length between the multi branch selector box and the indoor unit needs to be ≤130 ft. (40 m).
3. Double the pipe length of upsized line between joined 2 branches and the indoor unit, when calculating the overall total piping length.
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01_EN_03_3P734038-2.indd 13
2023/05/29 11:59:33
2023/05/29 11:59:33