Hitachi FSG Series, Technical Catalogue

Page: 280 / 424

13
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REFRIGERANT PIPING AND REFRIGERANT CHARGE
13.1.2. REFRIGERANT PIPING LENGTH
The refrigerant piping between the indoor unit and the
outdoor unit should be designed using the following chart. Keep the design point within the dark area of the chart,
which is showing the applicable height difference according
to piping length.
?
NOTE:
1. Piping: The piping sizes are as shown below
(* Conditions).
2. DSW: Dip Switch on Outdoor Unit PCB
(DSW3 must be set when the outdoor unit is installed
lower than indoor unit with height difference indicated
and when longer piping is required).
3. Division line is included in the below area
&
CAUTION:
– In case that the total piping length is long and the
outdoor unit is installed lower than the indoor units by
more than Height indication; perform the DSW setting
correctly according to figures.
– If outdoor unit is installed lower than the indoor units
by more than Height indication and it is outside of
part shown in figures, change the pipe side of
the main liquid pipe and perform the DSW setting
correctly according to figures.
RAS-(5/10/16)FSG
Figure 1
* Conditions:
Outdoor Unit Liquid Piping Ø
RAS-5FSG 9.53
RAS-10FSG 12.7
RAS-16FSG 15.88
RAS-20FSG
Figure 2
* Conditions:
Outdoor Unit Liquid Piping Ø
RAS-20FSG 15.88
Height
difference
(m)
Piping
Length
(m)
When the
outdoor unit
is installed
higher than
indoor unit.
Total length between outdoor
unit and each indoor unit
DSW3 is required
When the
outdoor unit
is installed
lower than
indoor unit.
DSW3 : Not Set (Factory-Supplied)
(1=OFF, 2= OFF)
DSW3 : Set
(1=ON, 2 = OFF)
Refer to fig. 3
Height
difference
(m)
Piping
Length
(m)
When the
outdoor unit
is installed
higher than
indoor unit.
Total length between
outdoor unit and each
indoor unit
DSW3 is required
When the
outdoor unit
is installed
lower than
indoor unit.
DSW3 : Not Set (Factory-Supplied)
(1=OFF, 2= OFF)
DSW3 : Set
(1=ON, 2 = OFF)
Refer to fig. 3