Hitachi SET FREE Serie Manual De Instrucciones página 25

PIPING WORK AND REFRIGERANT CHARGE
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Pipe size selection
Select the pipe size in line with the following instructions:
1 Between the outdoor unit and the branch pipe (multikit):
select the same pipe connection size as for the outdoor unit.
2 Between the branch pipe (multikit) and the indoor unit: select
the same pipe connection size as for the indoor unit.
!
C A U T I O N
• Do not use refrigerant pipe sizes other than those indicated in the
technical information. The diameter of the refrigerant pipes depends
directly on the power of the outdoor unit.
• If larger diameter refrigerant pipes are used, the circuit lubrication oil
tends to separate from the gas carrying it. The compressor will be
seriously damaged due to a lack of lubrication.
• If smaller diameter refrigerant pipes are used, the gas or liquid
refrigerant will have serious difficulties in circulating. System
performance will be affected. The compressor will run under more
severe conditions than foreseen and will be damaged in a short
space of time.
!
C A U T I O N
• The copper pipe used in the refrigeration installations is different to
the copper pipe used in installations carrying domestic or heating
water.
• The copper pipe for refrigeration installations is especially treated for
outdoors and indoors. The interior surface finish makes it easier for
the refrigerant to circulate and withstands the action of the lubricant
oil applied to outdoor equipment.
Always use clean copper pipes with no signs of knocks or
cracks. Make sure there is no dust or dampness on the inside.
Before you install the pipes, clean the inside with oxygen-
free nitrogen gas to eliminate any remains of dust or other
substances.
!
C A U T I O N
• Do not use hand saws, circular saws, abrasive grinders or other tools
that generate shavings.
• Strictly follow national or local regulations regarding occupational
health and safety.
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Connection position of outdoor unit pipes
Refrigerant piping outlet
(Low pressure gas)
82
(Knockout square hole)
2 control cable outlets
(∅33 knockout hole)
(High/low pressure gas, liquid)
15 PMML0392B rev.1 - 07/2016
Power source cable outlet
(∅65 knockout hole)
65 190
A
110
E
130 108
F
250
G
Refrigerant piping outlet
H
(knockout square hole)
• Wear appropriate means of protection during cutting or brazing
operations and installation (gloves, eye protection, etc).
On completing the installation of the refrigerant pipes, insulate
them appropriately using suitable insulating material and seal
the open space between the holes made and the pipe.
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Pipe connection
Cover the end of the pipe appropriately when it is to be inserted
through holes in walls and roofs, etc.
Keep the ends of the pipes covered while other installation work
is being carried out to avoid the entry of dampness or dirt.
Do not place the pipes directly on the ground without
appropriate protection or adhesive vinyl tape to cover the ends.
Where the pipe installation is not completed for a certain amount
of time, braze the ends of the pipe to seal. Then fill it with
oxygen-free nitrogen gas through a Schrader valve to avoid the
accumulation of humidity and/or contamination through dirt.
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N O T E
• Where polyethylene foam insulation is used, a 10 mm thick layer
should be used for the liquid pipe and between 15 and 20 mm for
the gas pipe.
• Install the insulation after the pipe surface temperature has dropped
to the same temperature as that of the room, otherwise the insulation
may melt.
Do not use insulating material that contains NH
as it could damage the copper in the pipe and subsequently
cause leaks.
Where the fitter has supplied his own branches, these should
be appropriately insulated to avoid decreases in capacity in line
with to environmental conditions and dew on the surface of the
piping due to low pressure.
Fit and secure refrigerant pipes correctly to prevent
vibrations and strain on the stop valves.
The pipes may be fitted in three directions (front,
rear or inferior) from the base of the unit.
B
Remove the cover of the gas and liquid pipes -H-
and connect using the accessories factory-supplied
with the unit.
C
D
Fit the cover on the pipes and completely seal
around them and the cover to prevent the entrance
of water, rodents and dirt.
I
(ammonium),
3