Mitsubishi Electric PUHY-HP72 Service Handbook page 54

[2-10 Restrictions on Refrigerant Pipes ]
(2) HP144 - HP240 models
Outdoor unit Outdoor unit
A B
C
Second gas refrigerant distributor
Second liquid refrigerant distributor
First liquid refrigerant distributor
First gas refrigerant distributor
First branch
Length Between outdoor units
Total pipe length
Total pipe length (L) from the outdoor unit to the
farthest indoor unit
Total pipe length from the first branch to the far-
thest indoor unit ( )
Height Between indoor and outdoor units
difference
Between indoor units
Between outdoor units
*1. If the piping length exceeds 40 meters (but does not exceed 90 meters), use one-size larger pipes for all the liquid
pipes beyond 40 meters. In the figure above, the pipes whose size should be increased by one size are indicated
by "I," "c," and "d" when the piping length exceeds 40 meters at point I.
*2. If the vertical difference between indoor units exceeds 15 meters (but does not exceed 30 meters), use one-size
larger liquid pipes for piping between the first branch and the relevant indoor units. In the figure above, the pipes
whose size should be increased by one size are indicated by "J," "K," "M," "e," "f," "g,"and "i" when the "h1" ex-
ceeds 15 meters.
See the next page for the detailed description of the sample application above.
HWE18240_GB
Note1 Install the pipe that connects the branch pipe and the outdoor units in
the way that it has a downward inclination toward the branch pipe.
Downward inclination
Upward inclination
L
(Note)
E F G I
a c
b
Indoor Indoor Indoor
1 2 3
J K M
e g
f
Indoor Indoor Indoor
5 6 7
Operation
Provide a trap on the pipe (gas pipe only) within 2 m from the
joint pipe if the total length of the pipe that connects the joint
pipe and the outdoor unit exceeds 2 m.
To indoor unit
2m [6ft]
Trap
(gas pipe
only)
To indoor unit
2m [6ft] Max.
d
E
Indoor
4 Note : "Total sum of downstream unit model numbers"
in the table is the sum of the model numbers
of the units after point E in the figure.
i
Indoor
8
Pipe sections
A+B+C
A+B+C+E+F+G+I+J+K
+M+a+b+c+d+e+f+g+i
A(B)+C+E+J+K+M+i
G+I+J+i
H
h1
h2
To indoor unit
Joint pipe
To indoor unit
Joint pipe
To downstream units
Unit: m [ft]
Allowable length of
pipes
10 [32] or less
1000 [3280] or less
165 [541] or less
(Equivalent length 190
[623] or less)
*1
40 [131] or less
50 [164] or less
(40 [131] or below if
outdoor unit is below in-
door unit)
*2
15 [49] or less
0.1[0.3] or less
27
chapter 2 -