Toshiba MMU-AP0091H Installation Manual page 15

5-4. Allowable length/height difference of refrigerant piping
A
Header
Height
unit
difference
between
Outdoor unit
outdoor
units
H3 5 m
La
T-shape branching
joint
Main connecting piping between outdoor units
Length corresponded to farthest piping
between outdoor units LO
Main
piping
L1
Height
difference 1st branching
between
section
outdoor
units
H1 50 m
L3
• System restrictions
Max. No. of combined outdoor units
Max. capacity of combined outdoor units 48 HP
Max. No. of connected indoor units
H <15
2
Max. capacity of combined
indoor units
H >15
2
• Allowable length and height difference of refrigerant piping
Total extension of pipe (Liquid pipe, real length)
Farthest piping length L
Piping
Equivalent length of farthest piping from 1st branching Li (∗1)
length
Equivalent length of farthest piping between outdoor units LO (∗1)
Max. equivalent length of main piping (∗3)
Max. equivalent length of outdoor unit connecting piping
Max. real length of indoor unit connecting piping
Height between indoor
and outdoor units H1
Height
difference
Height between indoor units H2
Height between outdoor units H3
∗1 (D) is outdoor unit farthest from 1st branching, and ( j ) is indoor unit farthest from 1st branching.
∗2 If the height difference (H2) between indoor units exceeds 3m, set below 30m.
∗3 If the maximum capacity of combination of the outdoor units is 46 HP or more, the maximum equivalent length is
restricted up to 70m.
B C
Follower Follower
unit 1 unit 2
Connecting
piping of
outdoor unit
Lb Lc
LA LB
25 m
Branching piping L2
Connecting piping of indoor unit
a
Equivalent length corresponded to farthest piping L
Equivalent length corresponded to farthest piping after 1st branching Li
L4
Y-joint
f g
Note 1) Combination of outdoor units : Header unit (1 unit) + Follower units (0 to 3 units).
4 units
Header unit is the outdoor unit nearest to the connected indoor units.
Note 2) Install the outdoor units in order of capacity.
(Header unit > Follower unit 1 > Follower unit 2 > Follower unit 3)
48 units
Note 3) Refer to outdoor unit combination table.
135%
Note 4) Piping to indoor units shall be perpendicular to piping to the head outdoor unit as <Ex.1>.
105%
Do not connect piping to indoor units in the same direction of Head outdoor unit as <Ex.2>.
Real length
Equivalent length
Upper outdoor unit
Lower outdoor unit
D
Follower
<Ex. 1>
unit 3
Header Follower
unit unit 1
Ld
GOOD
NOTE :
In case of connecting method <Ex. 2>, a large amount of
refrigerant and refrigerant oil may return to the head unit.
Therefore, set the T-shape joint so that oil does not enter directly.
Branching
header
L7
b c
Indoor unit
175 m
L6
L5
h
Indoor unit
Allowable value
300 m
150 m
175 m
65 m
25 m
85 m
10 m
30 m
50 m
40 m (∗2)
30 m
5 m
15
<Ex. 2>
Follower Header Follower
unit 2 unit unit 1
NOT GOOD
d e
65 m
i j
Piping section
LA + LB + La + Lb + Lc + Ld + L1 + L2 + L3 + L4+
L5 + L6 + L7 + a + b + c + d + e + f + g + h + i + j
LA + LB + Ld + L1 + L3 + L4 + L5 + L6 + j
L3 + L4 + L5 + L6 + j
LA + LB + Ld, (LA + Lb, LA + LB + Lc)
L1
Ld, (La, Lb, Lc)
a, b, c, d, e, f, g, h, i, j
——
——
——
——
Follower
unit 2
2
Height difference
between indoor
units
H2 30 m