En-5
CAUTION
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.)]
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
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 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 speci
fi
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).
1
4.3. Flare connection (pipe connection)
WARNING
Tighten the
fl
are nuts with a torque wrench using the speci
fi
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 outdoor units (or
RB unit) respectively) onto the pipe and perform the
fl
are processing with a
fl
are tool.
Use the 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
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 (R22)
fl
are tools to
fl
are R410A pipes, the dimension A should
be approximately 0.5 mm more than indicated in the table (for
fl
aring with R410A
fl
are
tools) to achieve the speci
fi
ed
fl
aring. Use a thickness gauge to measure the dimension A.
It is recommended that a R410A
fl
aring tool is used.
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
4.3.2. Bending pipes
The pipes are shaped by your hands or pipe bender. Be careful not to collapse them.
•
Do not bend the pipes in an angle more than 90°.
•
When pipes are repeatedly bend or stretched, the material will harden, making it dif
fi
cult
•
to bend or stretch them any more. Do not bend or stretch the pipes more than 3 times.
CAUTION
To prevent breaking of the pipe, avoid sharp bends.
If the pipe is bent repeatedly at the same place, it will break.
4.3.3. Pipe connection
(1) Remove the
fi
lter guide.
Indoor unit
Filter guide
(2) Attach the connection pipe.
Indoor unit
Large pipe
Small pipe
• For
2
Top piping and
3
Right piping connections, use the Auxiliary pipe (Gas pipe)
provided.
2
Top piping
Connection pipe (Gas)
Indoor unit (Rear)
Connection pipe (Gas)
3
Right piping
Auxiliary pipe (Gas pipe)
(Accessories)
Width across
fl
ats
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