4. Installing the refrigerant piping
4.2.2. Connection with Branch Box (Fig. 4-2)
• This unit has flared connections on each indoor unit and branch box and outdoor unit sides.
• Remove the valve cover of the outdoor unit, then connect the pipe.
• Refrigerant pipes are used to connect the branch box and outdoor unit.
c1
D
b1
B
H
a1
h1
a2
a3
C
C
h3
Fig. 4-2
Total piping length
Farthest piping length (L) *
Permissible
Piping length between outdoor unit and branch boxes
length
Farthest branch box from the first joint (b2)
(one-way)
Farthest piping length after branch box (R)
Total piping length between branch boxes and indoor units
In indoor/outdoor section (H) *
Permissible
In branch box/indoor unit section (h1)
height difference
(one-way)
In each branch unit (h2)
In each indoor unit (h3)
Number of bends
*1 The piping specification table does not provide a minimum line set length. However, indoor units with connected piping length less than 16 ft. (5 m) could produce intermit-
tent noise during normal system operation in very quiet environments. Please be aware of this important information when installing and locating the indoor unit within the
conditioned space.
*2 Branch box should be placed within the level between the outdoor unit and indoor units.
L
b2
B
h2
R
a5
a6
a7 a8
a4
C
C
C
C
C
1
2
A Outdoor unit
B Branch box
C Indoor unit
D The first joint
c1 + b1 + b2 + a1 + a2 + a3 + a4 + a5 + a6 + a7 + a8 ≤ 150 m (492 ft.)
c1 + b2 + a8 ≤ 80 m (262 ft.)
c1 + b1 + b2 ≤ 55 m (180 ft.)
b2 ≤ 30 m (98 ft.)
a8 ≤ 25 m (82 ft.)
a1 + a2 + a3 + a4 + a5 + a6 + a7 + a8 ≤ 95 m (311 ft.)
H ≤ 50 m (164 ft.) (In case of outdoor unit is set higher than indoor unit)
H ≤ 40 m (131 ft.) (In case of outdoor unit is set lower than indoor unit)
h1 + h2 ≤ 15 m (49 ft.)
h2 ≤ 15 m (49 ft.)
h3 ≤ 12 m (39 ft.)
| c1 + b1 + a1 |, | c1 + b1 + a2 |, | c1 + b1 + a3 |, | c1 + b1 + a4 |, | c1 + b1 + a5 |, | c1 + b2 +
a6 |, | c1 + b2 + a7 |, | c1 + b2 + a8 | ≤ 15
en
8