Refrigerant Piping Selection; Connecting Flare Adapter - Hitachi RAS-3HVRNS3 Installation And Operation Manual

14 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
Outdoor Unit HP
Gas
2 / 2.5 Ø12.70
3 Ø15.88
2 indoor units system
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.
30m
IU2
10m (IVX-P)
3m (IVX-C)
0.5m (ES)
IU1
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.
16
(mm)
Pipe Size (L)
Liquid
Ø6.35
Ø9.52
(mm)
Multi-kit
ES
IVX Series
series
TE-03N1 -
TE-03N1
(mm)
Pipe Size (B, C)
Gas Liquid
Ø6.35
Ø6.35
OU1
3m (ES
20m
3m (ES
OU1
PMML0318A - P5415337
2 Installing the distributor
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
Vertical
unit
To outdoor unit
Fixing the branch pipe to
the surface of pillar or wall
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:
Greater
Main pipe
than 0.5 m
Refrigerant
direction
• This is wrong position:
Refrigerant direction
Main pipe
Branch pipe
Branch pipe

14.3.5 Connecting flare adapter

Flare nut (accessories)
Pipe (accessories)
Liquid line
Pipe
(field
supplield)
Gas line
Flare adapter (accessories)
The piping sizes for indoor unit and outdoor unit are different.
Attach the flare adapter (accessories) at the indoor piping union
part.
Use the adequate flare adapter as follows:
Indoor unit
2.0 HP
( 15.88→
∅
2.5 HP
( 15.88→
∅
To indoor unit Horizontal
Fixing the branch pipe to
ceiling or beam
Up
Branch pipe
Refrigerant
direction
Main pipe
Down
Main pipe
Refrigerant
direction
Branch pipe
Indoor unit
Flare adapter
Gas pipe Liquid pipe
Big size
-
12.70)
∅
Big size Small size
12.70) ( 9.52→
∅ ∅
Horizontal
6.35)
∅