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[For 1 Rear piping, 2 Right piping and 3 Bottom piping]
• The drain hose and drain cap are used as they are.
[For 4 Left bottom piping, 5 Left piping and 6 Center piping, 7 Left rear
piping]
• Remove the drain cap and drain hose. Mount the drain cap and drain hose to the drain
port on its opposite side.
Right side
Drain cap
Insert the drain cap until it butts
against the drain port.
3.3.4. Cut-out for piping on front cover
[For 2 Right piping, 3 Bottom piping, 4 Left bottom piping and 5 Left pip-
ing]
• Use a metal shears or other cutting tool to cut along the groove in the plastic for the
piping that will coming out of the front cover.
For 3 Bottom piping
For 2 Right piping
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 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.
Left side
Drain hose
Drain cap
Drain hose
Insert the drain hose until it butts
against the drain port.
For 5 Left piping
For 4 Left bottom piping
CAUTION
CAUTION
Thicknesses of Annealed Copper Pipes (R410A)
Pipe outside diameter [mm (in)]
6.35 (1/4)
9.52 (3/8)
12.70 (1/2)
15.88 (5/8)
19.05 (3/4)
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 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 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).
4.3. Flare connection (pipe connection)
Tighten the flare nuts with a torque wrench using the specified tightening method.
Otherwise, 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.
Die
A
Pipe
Dimension A [mm]
Pipe outside
Flare tool for R410A,
diameter [mm (in)]
clutch type
6.35 (1/4)
9.52 (3/8)
12.70 (1/2)
15.88 (5/8)
19.05 (3/4)
When using conventional (R22) 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 measure the dimension A.
It is recommended that a R410A flaring tool is used.
Thickness [mm]
0.80
0.80
0.80
1.00
1.20
CAUTION
CAUTION
WARNING
Check if [L] is flared uniformly and
B
is not cracked or scratched.
L
Dimension B
9.1
13.2
0 to 0.5
16.6
19.7
24.0
0
[mm]
-
0.4
En-4
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