Hitachi RAS-3HVNC1 - Refrigerant Piping Selection and Installation; Piping Selection and Distributor Installation

16
PMML0318A - P5415337
Refrigerant piping & refrigerant charge14
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
(mm)
Outdoor Unit HP
Pipe Size (L)
Gas Liquid
2 / 2.5 Ø12.70 Ø6.35
3 Ø15.88 Ø9.52
2 indoor units system
(mm)
Outdoor
Unit HP
Pipe Size (A) Multi-kit
Gas Liquid IVX Series
ES
series
2 / 2.5 Ø12.70 Ø6.35 TE-03N1 -
3 Ø15.88 Ø9.52 TE-03N1
Pipe connection size after branch pipe
(mm)
Indoor Unit capacity
Pipe Size (B, C)
Gas Liquid
≤ 1.5 HP Ø12.70 Ø6.35
1.8 / 2.0 HP Ø15.88 Ø6.35
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.
ื
10m (IVX-P)
3m
0.5m
(IVX-C)
(ES)
ืืืื
20m
ื
30m
IU1
IU2
OU1
OU1
ื
3m (ES ืP
ื
3m (ES ืP

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
Fix the branch pipe horizontally to the pillar, wall or ceiling. Piping
must not be xed rigidly to the wall as thermal expansion and
contraction can cause pipe fracture.
Horizontal
To indoor
unit
To outdoor unit
Vertical
To indoor unit
Fixing the branch pipe to
the surface of pillar or wall
Horizontal
Horizontal
Fixing the branch pipe to
ceiling or beam
NOTE
Fix the piping from outside of insulation or inserting absorber bet-
ween the pipe and a xing metal.
3 Correct position of twin distributor
• This is the correct position of twin branch pipe:
Greater
than 0.5 m
Main pipe
Refrigerant
direction
Up
Branch pipe
Main pipe
Refrigerant
direction
Down
• This is wrong position:
Main pipe
Refrigerant direction
Branch pipe
Branch pipe
Refrigerant
direction
Main pipe
Branch pipe
14.3.5 Connecting are adapter
Flare nut (accessories)
Pipe (accessories)
Indoor unit
Flare adapter (accessories)
Gas line
Pipe
(eld
supplield)
Liquid line
The piping sizes for indoor unit and outdoor unit are different.
Attach the are adapter (accessories) at the indoor piping union
part.
Use the adequate are adapter as follows:
Indoor unit
Flare adapter
Gas pipe Liquid pipe
2.0 HP
Big size
(∅15.88→∅12.70)
-
2.5 HP
Big size
(∅15.88→∅12.70)
Small size
(∅9.52→∅6.35)