ENGLISH
a.
The total piping length should be reduced as follows:
(m)
Outdoor unit
Quantity of combined indoor units
≤ 6
7
8
9
10
11
12
RAS-4FS(V)N(Y)3E
125
113
101
-
-
-
-
RAS-5FS(V)N(Y)3E
135
135
135
123
111
-
-
RAS-6FS(V)N(Y)3E
135
135
135
135
123
111
99
b.
In these cases HITACHI recommends using header branch as distribution system than line branch.
c.
For
Line branch
reduce the maximum length between multikit and indoor unit (L3) to 5m or less.
d.
The following considerations must be taken into account:
-
Divide the installation into many branches as possible and equilibrate the length and the ratio of total indoor unit connected
capacity of each part.
-
Reduce as much as possible the following lengths:
- Height difference between outdoor and indoor unit (Hi-O)
- Height difference between each indoor unit (H1)
-
The installation position of big capacity indoor unit should be as far away as possible from the first branch.
?
N O T E
In case of installations not following the above considerations, please contact with your Hitachi dealer for advice.
!
C A U T I O N
In case of exceeding the quantity of indoor units shown before, and in some extreme conditions in terms of piping length and temperature, when all
indoor units are in simultaneous operation, performance can decrease and discharge temperature of some indoor units can be lower than comfort
temperature.
11.5 REFRIGERANT PIPING SIZE
Table
: Outdoor unit to first multi-kit
Outdoor unit
Pipe size (Ø mm)
Multi-kit
Gas
Liquid
RAS-(4-6)FS(V)N(Y)3E
15.88
9.52
E-102SN3
Table
: First mukti-kit to last branch
Total indoor units capacity
Pipe size (Ø mm)
Multi-kit
Gas
Liquid
<2.3HP
12.7
6.35
E-102SN3
2.3<HP<7.0
15.88
9.52
E-102SN3
Table
: Mukti-kit to indoor unit
Indoor unit capacity
(HP)
Pipe size (Ø mm)
Gas
Liquid
0.8 to 1.5
12.70
6.35 (*)
2.0
15.88
6.35 (*)
2.5 to 6.0
15.88
9.52
?
N O T E
•
(*): The pipe size must be the same size of the piping connection
hole of the I.U.
•
The pipe shown in the above table is applicable for both: the line
branch and the header branch.
Table
: Header branch
Applicable model
Pipe size (Ø mm)
Multi-kit model
Gas
Liquid
2~4
Branches
2~8
Branches
RAS-(4-6)FS(V)N(Y)3E
15.88
9.52
MH-84AN
MH-
108AN
REFRIGERANT PIPING & REFRIGERANT CHARGE
PMML0354A rev.1 - 03/2015
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