En-4
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4.1. Selecting the pipe material
CAUTION
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 0.04 oz. /100 ft. (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 [in. (mm)] Thickness [in. (mm)]
1/4 (6.35) 0.032 (0.80)
3/8 (9.52) 0.032 (0.80)
1/2 (12.70) 0.032 (0.80)
5/8 (15.88) 0.039 (1.00)
3/4 (19.05) 0.047 (1.20)
1
4.2. Pipe requirement
CAUTION
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.•
CAUTION
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 248°F (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 9/16 in. (15 mm)
or thicker and if the expected humidity exceeds 80 %, use heat insulation that is
13/16 in. (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 68°F
(20°C)).
1
4.3. Flare connection (pipe connection)
WARNING
Tighten the fl are nuts with a torque wrench using the specifi ed tightening method.
Otherwise, the fl are nuts could break after a prolonged period, causing refrigerant to
leak and generate a hazardous gas if the refrigerant comes into contact with a fl ame.
4.3.1. Flaring
Use special fl are tool exclusive for R410A.
(1) Cut the connection pipe to the necessary length with a pipe cutter.
(2) Hold the pipe downward so that cuttings will not enter the pipe and remove any burrs.
(3) Insert the fl are nut (always use the fl are nut attached to the indoor and respectively)
onto the pipe and perform the fl are processing with a fl are tool. Use the outdoor units
(or RB unit) special R410A fl are tool, Leakage of refrigerant may result if other fl are
nuts are used.
(4) Protect the pipes by pinching them or with tape to prevent dust, dirt, or water from
entering the pipes.
L
Check if [L] is fl ared uniformly and
is not cracked or scratched.
Die
Pipe
A
B
3.3.2. Leveling
Use the procedure in the following fi gure to adjust the levelness.
AB
(Front)
Level meter
BA
Level meter
(Side)
The side A of the unit with the drain port should be slightly lower than the opposite side B of the
unit. The height difference between sides A and B should be from 0 to 13/16 in. (0 to 20 mm).
3.3.3. Mounting the duct
Follow the procedure in the following fi gure to install the ducts.
33-15/16 (862)
Intake port fl ange
33-1/2 (851)
9/16 (14)
12-3/4
(324)
9/16 (14)
Spacing between fl ange and drain pan.
Outlet port fl ange
1 (26)
11-5/8
(295)
1-1/16 (27)
Unit: in. (mm)
CAUTION
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.
The static pressure outside the unit is as follows.
ARUH 36 Model: 0.4 to .0.8 in. WG (100 to 200 Pa)
ARUH 48/60 Models: 0.4 to 1.0 in. WG (100 to 250 Pa)
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 can not be
detected.
Unit
Duct
(Field supply)
Outlet Grille
(Field supply)
Inlet Grille
(Field supply)
(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.
4. PIPE INSTALLATION
]
CAUTION
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.
9373870135-03_IM.indb Sec1:49373870135-03_IM.indb Sec1:4 10/24/2013 2:57:11 PM10/24/2013 2:57:11 PM
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