Mitsubishi Electric CITY MULTI Data Book page 353

1. Piping Design
Piping length and height between IU and BC controller
250
200
150
100
50
0
0 5 10 15 20
Height difference between Main BC controller
and farthest indoor unit (ft)
Fig. 2
Main
BC
SUB
Fig. 3 BC
Fig. 2
IU IU
Piping "A"size selection rule
Heat source Model
P72TLMU, YLMU
P96-120TLMU, YLMU
P144-192TLMU, YLMU
P216TLMU, YLMU
P240TLMU, YLMU
*11. When the piping length is 65 m or longer, use the ø28.58 [1-1/8]
pipe for the part that exceeds 65 m.
Piping "B", "C", "D", "E" size seleciton rule
Total down-stream Indoor capacity
P54 or less
P55-P72
P73-P96
Piping "a", "b", "c", "d", "e", "f", "g", "i", "j", "k", "m", "n" size selection rule
Indoor Unit size
P04-P18
P24-P54
P72
P96
Piping "F", "G", "J", "K" size selection rule
Total down-stream Indoor capacity
P72 or less
P73 to P108
P109 to P126
P127 to P144
P145 to P180
P181 to P234
P235 to P288
P289 to P360
P361 or above
HP: High pressure, LP: Low pressure
MEES19K187
25 30 35 40 45
Fig. 3
*9. When the piping length or the vertical separation exceeds the limit specified in Fig. 2, connect
SUB
BC
Fig. 2 Fig. 2
IU
Pipe(High pressure) Pipe(Low pressure)
ø15.88 [5/8"] ø19.05 [3/4"]
ø19.05 [3/4"] ø22.20 [7/8"]
ø22.20 [7/8"] ø28.58 [1-1/8"]
ø22.20 [7/8"] *11 ø28.58 [1-1/8"]
ø22.20 [7/8"] *11 ø34.93 [1-3/8"]
Pipe(Liquid)
ø9.52 [3/8"]
ø9.52 [3/8"]
ø9.52 [3/8"]
Pipe(Liquid)
ø6.35 [1/4"]
ø9.52 [3/8"]
ø9.52 [3/8"]
ø9.52 [3/8"]
Pipe(Liquid) Pipe(HP Gas)
ø9.52 [3/8"] ø15.88 [5/8"]
ø9.52 [3/8"] ø19.05 [3/4"]
ø12.70 [1/2"] ø19.05 [3/4"]
ø12.70 [1/2"] ø22.20 [7/8"]
ø15.88 [5/8"] ø22.20 [7/8"]
ø15.88 [5/8"] ø28.58 [1-1/8"] ø28.58 [1-1/8"]
ø19.05 [3/4"] ø28.58 [1-1/8"] ø34.93 [1-3/8"]
ø19.05 [3/4"] ø28.58 [1-1/8"] ø41.28 [1-5/8"]
ø19.05 [3/4"] ø34.93 [1-3/8"] ø41.28 [1-5/8"]
300
250
*9
200
150
100
50
0
0 5 10 15 20
Height difference between Main BC controller
and farthest indoor unit (ft)
Fig. 3
a sub BC to the system.
The restriction for a system with a sub BC connection is shown in Fig. 3.
When a given system configuration falls within the shaded area in Fig. 3, increase the size of
the high-pressure pipe and the liquid pipe between the main BC and sub BC by one size.
The maximum liquid branch pipe diameter is ø19.05. If a given system already has a ø19.05-pipe
between the main BC and sub BC, there is no need to increase the pipe size.
When using P12, P15, P18, P36, or P48 model of indoor units, increase the size of the liquid
branch pipe between the sub BC and indoor unit by one size.
When using indoor models P54 or larger, the restrictions shown in Fig. 2 cannot be exceeded.
Selection criteria for joints_A
(mm [in.])
Total down-stream Indoor capacity
-P72
P73-P96
Selection criteria for joints_B
Total down-stream Indoor capacity
-P120
P121-P216
(mm [in.])
Pipe(Gas)
ø15.88 [5/8"]
ø19.05 [3/4"]
ø22.20 [7/8"]
(mm [in.])
Pipe(Gas)
ø12.70 [1/2"]
ø15.88 [5/8"]
ø19.05 [3/4"]
ø22.20 [7/8"]
(mm [in.])
Pipe(LP Gas)
ø19.05 [3/4"]
ø22.20 [7/8"]
ø28.58 [1-1/8"]
ø28.58 [1-1/8"]
ø28.58 [1-1/8"]
25 30 35 40 45
Joint
CMY-Y102SS-G2
CMY-Y102LS-G2
Joint
CMY-R201S-G
CMY-R202S-G
342