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Fig. C
20-7/8 (530)
(Hanging bolt position)
Service access
Min. 17-11/16 (450)
Fig. D
4 (102)
Ceiling
Control box
Drain pipe
(connect the attached drain hose)
Indoor unit
3/4 (19)
Leveling
• Using a level, or vinyl hose filled with water, fine adjust so that the body is level.
• Inclined installation so as the drain pipe side is higher may cause a malfunction of the
float switch, and may cause water leakage.
Vinyl hoses
Unit: in (mm)
Cassette grille
Standard
Grid type
type
27-9/16
A
(700)
22-13/16
B
to 26 (580 to
to 24 (580 to
660)
Unit: in (mm)
1-9/16 (40)
3-7/8 (99)
Gas pipe
Liquid pipe
Special nut A (accessories)
1-3/16 (30) or more
Hook
After installing the body,
tighten the nuts.
Special nut B (accessories)
Hanging bolt
(locally purchased)
Ceiling
Drain pipe
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 0.004 oz/100 ft (40 mg/10 m).
Do not use copper pipes that have a collapsed, deformed, or discolored portion (es-
pecially 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.
24-7/16
• Never use copper pipes thinner than those indicated in the table even if they are avail-
(620)
able on the market.
22-13/16
Thicknesses of
610)
Annealed Copper
Pipes (R410A)
4.2. Pipe requirement
Refer to the installation manual for the outdoor unit for description of allowable pipe
length and height difference.
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 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 specified, condensa-
tion 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)).
4.3. Flare connection (pipe connection)
Tighten the flare nuts with a torque wrench using the specified tightening method. Oth-
erwise, the flare nuts could break after a prolonged period, causing refrigerant to leak
and generate hazardous gas if the refrigerant comes into contact with a flame.
4.3.1. Flaring
Use special flare 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 flare nut (always use the flare nut attached to the indoor and outdoor units (or
RB unit) respectively) onto the pipe and perform the flare processing with a flare tool.
Use the special R410A flare tool. Leakage of refrigerant may result if other flare nuts are
used.
(4) Protect the pipes by pinching them or with tape to prevent dust, dirt, or water from
entering the pipes.
CAUTION
CAUTION
Pipe outside diameter [in (mm)]
1/4 (6.35)
3/8 (9.52)
1/2 (12.70)
5/8 (15.88)
3/4 (19.05)
CAUTION
CAUTION
WARNING
Thickness [in (mm)]
0.032 (0.80)
0.032 (0.80)
0.032 (0.80)
0.039 (1.00)
0.039 (1.20)
En-4
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