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4.3. Flare connection (pipe connection)
4.3.1. Flaring
Use special pipe cutter and flare tool exclusive for R410A.
•
Cut the connection pipe to the necessary length with a
(1)
pipe cutter.
Hold the pipe downward so that cuttings will not enter the
(2)
pipe and remove any burrs.
Insert the flare nut (always use the flare nut attached to
(3)
the indoor and outdoor units respectively) onto the pipe
and perform the flare processing with a flare tool. Use the
special R410A flare tool, or the conventional flare tool.
Leakage of refrigerant may result if other flare nuts are
used.
Protect the pipes by pinching them or with tape to prevent
(4)
dust, dirt, or water from entering the pipes.
B
Die
A
Pipe
Check if [L] is flared uniformly
and is not cracked or scratched.
L
Pipe outside
diameter
[mm (in.)]
Dimension A [mm]
Dimension B
-
0
0.4
[mm]
Flare tool for R410A,
clutch type
6.35 (1/4)
0 to 0.5
9.1
9.52 (3/8)
13.2
12.70 (1/2)
16.6
15.88 (5/8)
19.7
19.05 (3/4)
24.0
When using conventional flare tools to flare R410A pipes,
the dimension A should be approximately 0.5 mm more than
indicated in the table (for flaring with R410A flare tools) to
achieve the specified flaring. Use a thickness gauge to meas
-
ure the dimension A.
Pipe outside
diameter [mm (in.)]
Width across flats
of Flare nut [mm]
6.35 (1/4)
17
9.52 (3/8)
22
12.70 (1/2)
26
15.88 (5/8)
29
19.05 (3/4)
36
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 120 °C.
(Reverse cycle model only)
In addition, if the humidity level at the installation loca-
tion of the refrigerant piping is expected to exceed 70 %,
install heat insulation around the refrigerant piping.
If the expected humidity level is 70-80 %, 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
specified, 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. 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.
4.1. Selecting the pipe material
CAUTION
Do not use existing pipes.
•
Use pipes that have clean external and internal sides
•
without any contamination which may cause trouble dur-
ing 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, de-
•
formed, 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 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.)]
Thickness [mm]
6.35 (1/4)
0.80
9.52 (3/8)
0.80
12.70 (1/2)
0.80
15.88 (5/8)
1.00
19.05 (3/4)
1.20
4.2. Pipe requirement
CAUTION
Refer to the Installation Manual of the outdoor unit for
•
description of the length of connecting pipe or for differ-
ence of its elevation.
Diameter [mm (in.)]
Liquid
9.52 (3/8)
Gas
15.88 (5/8)
Width across
1125-9379122009.indd 6
2008/11/26 7:57:05
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