System Installation - Hitachi RAS-2-HVNP Service Manual

3. Piping work and refrigerant charge
3.3.6 System installation
N O T E
• Pipe connection size on outdoor units, indoor units and the multikit or distributor vary according to the sys-
tem.
• The sizes of the indoor and outdoor units could be different. Adjust the flare adapter (accessory) to the indoor
pipe connection in these cases.
  
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 building 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.
  
Installing Distributor
1 Install the Distributor supplied by HITACHI on request.
A tee 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 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 between the pipe and a fixing metal.
70
Indoor unit
Indoor
Height Difference between two
unit
indoors smaller than H (m)
Smaller than 3 m
Premium
Standard
Vertical
Fixing the branch pipe to
the surface of pillar or wall
SMGB0079 rev.0 - 01/2013
Branch pipe
≤
O.U. (HP) H (m)
2-3 3
4-12 10
3-12 3
Horizontal
To Indoor unit
Fixing the branch pipe to
ceiling or beam
≤
Horizontal