Hitachi RAS-2HVNP Installations- Und Betriebshandbuch Seite 26

14
1 Refrigerant piping & refrigerant charge
14.3.3 Refrigerant piping selection
Select the piping connection sizes according to the following pro-
cedures
• Between outdoor unit and branch pipe: Select the same pipe
connection size as the pipe size of the outdoor unit.
• Between branch pipe and indoor unit: Select the same pipe
connection size as the pipe size of the indoor unit.
1 indoor unit system
Pipe Size (L)
Outdoor Unit HP
Gas
2 / 2.5 Ø12.70
3 Ø15.88
2 indoor units system
(mm)
Pipe Size (A)
Outdoor
Unit HP
Gas Liquid
2 / 2.5 Ø12.70 Ø6.35
3 Ø15.88 Ø9.52
Pipe connection size after branch pipe
Indoor Unit capacity
≤ 1.5 HP Ø12.70
1.8 / 2.0 HP Ø15.88
14.3.4 2 indoor units system installation

Height difference between indoor units and distributor
It is recommended to install all indoor units at the same height.
When the height difference between the indoor units due to buil-
ding construction is necessary, this should be less than the value
indicated in the table. Install the branch pipe at the same height of
indoor units or lower, but never higher.
Indoor unit
Height Difference between two
Indoor unit
indoors.
height difference: branch pipe/Indoor unit

Installing Distributor
1 Selecting the distributor
Install the distributor supplied by HITACHI on request the T-joint
can not be installed instead of a branch pipe.
2 Installing the distributor
26
(mm)
Liquid
Ø6.35
Ø9.52
Multi-kit
IVX Premium IVX Standard
Series Series
TW-22AN TE-03N1
TW-52AN TE-03N1
(mm)
Pipe Size (B, C)
Gas Liquid
Ø6.35
Ø6.35
Branch pipe
PMML0248A
Fix the branch pipe horizontally to the pillar, wall or ceiling. Piping
must not be fixed rigidly to the wall as thermal expansion and
contraction can cause pipe fracture.
Horizontal
To indoor
unit
To outdoor unit
N O T E
Fix the piping from outside of insulation or inserting absorber bet-
ween the pipe and a fixing metal.
3 Correct position of twin distributor
• This is the correct position of twin branch pipe:
ES
Greater
series
than 0.5 m
-
• This is wrong position:
Refrigerant direction
Branch pipe
14.3.5 Connecting flare adapter
Flare nut (accessories)
Liquid line
Pipe
(field
supplield)
Gas line
The piping sizes for indoor unit and outdoor unit are different. Atta-
ch the flare adapter (accessories) at the indoor piping union part.
Use the adequate flare adapter as follows:
Indoor unit
2.0 HP
2.5 HP
To indoor unit
Vertical
Fixing the branch pipe to
Fixing the branch pipe to
ceiling or beam
the surface of pillar or wall
Up
Branch pipe
Refrigerant
direction
Main pipe
Refrigerant
Down
direction
Main pipe
Main pipe
Refrigerant
direction
Branch pipe Branch pipe
Pipe (accessories)
Flare adapter (accessories)
Flare adapter
Gas pipe
Big size
( 15.88→ 12.70)
∅ ∅
Big size
( 15.88→ 12.70)
∅ ∅
Horizontal
Horizontal
Main pipe
Indoor unit
Liquid pipe
-
Small size
( 9.52→ 6.35)
∅ ∅