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To prevent people from touching the parts inside the unit, be sure to install grilles on
the inlet and outlet ports. The grilles must be designed in such a way that cannot be
removed without tools.
If an intake duct is installed, take care not to damage the temperature sensor (the
temperature sensor is attached to the intake port fl ange).
Install the air inlet grille for air circulation. The correct temperature cannot be detected.
Outlet grille
(locally purchased)
(Room)
Be sure to install the air fi lter in the air inlet. If the air fi lter is not installed, the heat
exchanger may be clogged and its performance may decrease.
3.3.5. Fresh air intake
(Processing before use)
(1) When taking in fresh air, cut a slit shaped cabinet in the left side of the outer case
with nippers.
Cut
Cut
Cabinet (Iron plate)
When removing the cabinet (iron plate), be careful not to damage the indoor unit
internal parts and surrounding area (outer case).
When processing the cabinet (iron plate), be careful not to injure yourself with burrs,
etc.
(2) Install the round fl ange (optional parts) to the fresh air intake.
(3) Connect the duct to the round fl ange.
(4) Seal with a band and vinyl tape, etc. so that air does not leak from the connection.
Duct
En-5
CAUTION
Unit
Duct
(locally purchased)
Inlet grille
(locally purchased)
Round hole
CAUTION
Round duct
4. PIPE INSTALLATION
Be more careful that foreign matter (oil, water, etc.) does not enter the piping than with
refrigerant R410A models. Also, when storing the piping, securely seal the openings
by pinching, taping, etc.
While welding the pipes, be sure to blow dry nitrogen gas through them.
4.1. Selecting the pipe material
Do not use existing pipes from another refrigeration system or refrigerant.
Use pipes that have clean external and internal sides without any contamination which
may cause trouble during use, such as sulfur, oxide, dust, cutting waste, oil, or water.
It is necessary to use seamless copper pipes.
Material : Phosphor deoxidized seamless copper pipes
It is desirable that the amount of residual oil is less than 40 mg/10 m.
Do not use copper pipes that have a collapsed, deformed, or discolored portion
(especially on the interior surface). Otherwise, the expansion valve or capillary tube
may become blocked with contaminants.
Improper pipe selection will degrade performance. As an air conditioner using R410A
incurs pressure higher than when using conventional (R22) refrigerant, it is necessary
to choose adequate materials.
•
Thicknesses of copper pipes used with R410A are as shown in the table.
•
Never use copper pipes thinner than those indicated in the table even if they are
available on the market.
Thicknesses of Annealed Copper Pipes (R410A)
Pipe outside diameter [mm (in)]
6.35 (1/4)
9.52 (3/8)
12.70 (1/2)
15.88 (5/8)
19.05 (3/4)
4.2. Pipe requirement
Refer to the Installation Manual of the outdoor unit for description of the length of
connecting pipe or for difference of its elevation.
• Use pipe with water-resistant heat insulation.
Install heat insulation around both the gas and liquid pipes. Failure to do so may
cause water leaks.
Use heat insulation with heat resistance above 120 °C. (Reverse cycle model only)
In addition, if the humidity level at the installation location of the refrigerant piping is
expected to exceed 70 %, install heat insulation around the refrigerant piping. If the
expected humidity level is 70 to 80 %, use heat insulation that is 15 mm or thicker and
if the expected humidity exceeds 80 %, use heat insulation that is 20 mm or thicker.
If heat insulation is used that is not as thick as specifi ed, condensation may form on
the surface of the insulation. In addition, use heat insulation with heat conductivity of
0.045 W/(m·K) or less (at 20 °C).
4.3. Flare connection (pipe connection)
Tighten the flare nuts with a torque wrench using the specified tightening method.
Otherwise, the fl are nuts could break after a prolonged period, causing refrigerant to
leak and generate hazardous gas if the refrigerant comes into contact with a fl ame.
CAUTION
CAUTION
Thickness [mm]
0.80
0.80
0.80
1.00
1.20
CAUTION
CAUTION
WARNING
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