Hitachi UTOPIA RAS-4HVRP2E Installations- Und Betriebshandbuch Seite 40

Refrigerant piping & refrigerant charge
8 REFRIGERANT PIPING & REFRIGERANT CHARGE
8.1 PIPING MATERIALS
1 Prepare locally-supplied copper pipes.
2 Select the piping size with the correct thickness and correct
material which can have sufficient pressure strength.
3 Select clean copper pipes. Make sure there is no dust and
moisture inside. Blow the inside of the pipes with oxygen
free nitrogen to remove any dust and foreign materials
before connecting pipes.
?
N O T E
• A system with no moisture or oil contamination will give maximum
performance and lifecycle compared to that of a poorly prepared
system. Take particular care to ensure all copper piping is clean and
dry internally.
• There is no refrigerant in the cycle of the indoor unit.
!
C A U T I O N
• All external piping shall be selected in size and dimension avoiding
any mechanical strength due to contraction or expansion, vibration or
refrigerant pulsation.
• All the piping shall be protected against any environmental effect like
water freezing, corrosion, etc. When flexible pipe is used, precautions
shall be taken against mechanical damages, excessive stresses by
torsion or any other.
• Flare nut connections shall be accessible for maintenance purposes.
8.2 PIPING CONNECTION FOR OUTDOOR UNIT
1 The pipes can be connected from 4 directions. Make holes
in the piping cover or cabinet for taking out pipes. Take the
piping cover away from the unit, and make holes by cutting
along the guideline at the rear of the cover or punching
with a driver. Remove the burr with a cutter, and place a
insulation (field supplied) to protect cables and pipes.
Nº
Rear side piping work

Pipe Cover

Right side piping work

Bottom side piping work (Knock out hole)

Front side piping work

Piping work

Stop Valve

Removing Direction for Service Cover

(picture as example)
9 PMML0545 rev.2 - 04/2021
Description
• Ensure that refrigerant piping is earthed prior to units interconnection
and in case of additional refrigerant charging is required.
• Cap the end of the pipe when pipe is to be inserted through a hole.
• Do not put pipes on the ground directly without a cap or vinyl tape at
the end of the pipe.
• If piping installation is not completed until next day or over a longer
period of time, braze off the ends of the piping and charge with
oxygen free nitrogen through a Schrader valve type access fitting to
prevent moisture and particle contamination.
• Do not use insulation material that contains NH
damage cooper pipe material and can be a source of future leakage.
• Completely insulate both refrigerant gas piping and liquid piping
between the indoor unit(s) and the outdoor unit.
• If not insulated, dew will occur on the piping surface.
After connecting the refrigerant piping, seal the refrigerant
pipes by using the field-supplied insulation material. Insulate
the unions and flare-nuts at the piping connections completely.
Insulate the liquid piping and gas piping completely to avoid
decreasing of performance and dewing on the surface of the
pipe.
!
C A U T I O N
Notes to open/close the service cover:
• Remove the screws following the instructions to the above figure.
• Slowly press down the cover.
?
N O T E
Hold the cover with a hand to remove screws as the cover may fall down.
(picture as example)
a. For the front and side piping
To use racking or conduit tubes, check the size and
remove part following the slit.
because it can
3
Service cover
Clasp (3 places)
Front piping hole
Side piping hole