En-5
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)
0.039 (1.20)
4.2. Pipe
requirement
CAUTION
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.
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 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)
WARNING
Tighten the flare nuts with a torque wrench using the specified tightening method. Other-
wise, 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
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 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.
B
A
L
Check if [L] is flared uniformly and
is not cracked or scratched.
Pipe
Die
Pipe outside diameter
[in (mm)]
Dimension A [in (mm)]
Dimension B
0 (0)
-0.015 (-0.4)
[in (mm)]
Flare tool for R410A,
clutch type
1/4 (6.35)
0 to 0.020
(0 to 0.5)
3/8 (9.1)
3/8 (9.52)
1/2 (13.2)
1/2 (12.70)
5/8 (16.6)
5/8 (15.88)
3/4 (19.7)
3/4 (19.05)
15/16 (24.0)
When using conventional (R22) flare tools to flare R410A pipes, the dimension A should
be approximately 0.020 in (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 measure the
dimension A. It is recommended that a R410A flaring tool is used.
Width across
flats
Pipe outside diameter
[in (mm)]
Width across flats of Flare
nut [in (mm)]
1/4 (6.35)
11/16 (17)
3/8 (9.52)
7/8 (22)
1/2 (12.70)
1 (26)
5/8 (15.88)
1-1/8 (29)
3/4 (19.05)
1-7/16 (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 bent or stretched, the material will harden, making it difficult
to bend or stretch them anymore. 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
CAUTION
Be sure to install the pipe against the port on the indoor unit and the outdoor unit cor-
rectly. If the centering is improper, the flare nut cannot tightened smoothly. If the flare
nut is forced to turn, the threads will be damaged.
Do not remove the flare nut from the indoor unit pipe until immediately before connect-
ing the connection pipe.
Do not use mineral oil on flared part. Prevent mineral oil from getting into the system as
this would reduce the lifetime of the units.
Hold the torque wrench at its grip, keeping it at a right angle with the pipe, in order to
tighten the flare nut correctly.
When the flare nut is tight-
ened properly by your hand,
hold the body side coupling
with a separate spanner, then
tighten with a torque wrench.
(See the table below for the
flare nut tightening torques.)
Tighten with 2
wrenches.
Holding wrench
Flare nut
Connection pipe
Indoor unit pipe (Body side)
Torque wrench
Flare nut [in (mm)]
Tightening torque [lbf·ft (N·m)]
1/4 (6.35) dia.
11.8 to 13.3 (16 to 18)
3/8 (9.52) dia.
23.6 to 31.0 (32 to 42)
1/2 (12.70) dia.
36.1 to 45.0 (49 to 61)
5/8 (15.88) dia.
46.5 to 55.3 (63 to 75)
3/4 (19.05) dia.
66.4 to 81.1 (90 to 110)
5. FORMING THE DRAIN HOSE AND PIPE
CAUTION
Do not remove the flare nut from the indoor unit pipe until immediately before
connecting the connection pipe.
To prevent breaking of the pipe, avoid sharp bends.
If the pipe is bent repeatedly at the same place, it will break.
[For
1
Rear piping,
2
Right piping and
3
Bottom piping]
• Install the indoor unit piping in the direction of the wall hole and bind the drain hose and
pipe together with vinyl tape.
• Install the piping so that the drain hose is at the bottom.
• Wrap the pipes of the indoor unit that are visible from the outside with decorative tape.
Pipe (Top)
Cloth tape
(Accessories)
2
Right piping
3
Bottom piping
Bind with vinyl tape
Drain hose (Bottom)
1
Rear piping
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