Hitachi YUTAKI Serie Manual De Instrucciones página 20

REFRIGERANT PIPING & REFRIGERANT CHARGE
8 REFRIgERANT PIPINg & REFRIgERANT ChARgE
!
C A U T I O N
Make sure that refrigerant piping installation complies with the legislation EN378 and local legislation.
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.
• Ensure that refrigerant piping is earthed prior to units interconnection
and in case of additional refrigerant charging is required.
8.2 PIPINg CONNECTION FOR OUTDOOR UNIT
1 Take the piping cover away from the unit. Then fetch the pipes through the rear side and route piping according to the installation
place as shown in the figure. 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.
2 Attach the pipe cover in order to prevent rainwater from entering inside the cabinet.
3 Use a pipe bender for pipe bending work when connecting pipes.
4 Check to ensure that the stop valves are completely closed before connecting pipes.
5 Connect the field supplied refrigerant pipes to the indoor unit and outdoor unit. Apply the oil thinly at the seat flare nut and pipe
before tightening.
6 Operation of stop valve should be performed according to the following section.
8 PMML0509 rev.0 - 02/2019
• 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 NH3 because it can
damage cooper pipe material and can be a source of future leakage.
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
• Do not use insulation material that contains NH3 because it can
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.
Pipe cover
Rear side
piping
Stop valve
Direction to remove pipe cover
Connecting
piping