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(2) Safety drain
There is no need to provide a trap for the safety drain pipe. If the safety drain pipe is
connected to the main drain pipe, make the connection below the trap on the main drain
pipe.
Unit
Drain pipe (main)
Drain pipe (safety)
•
Once installation is complete, check the flow of the drain water.
5. PIPE INSTALLATION
WARNING
During installation, make sure that the refrigerant pipe is attached firmly before you
run the compressor.
Do not operate the compressor under the condition of refrigerant piping not attached
properly with 2-way or 3-way valve open. This may cause abnormal pressure in the
refrigeration cycle that leads to breakage and even injury.
During the pump-down operation, make sure that the compressor is turned off before
you remove the refrigerant piping.
Do not remove the connection pipe while the compressor is in operation with 2-way or
3-way valve open. This may cause abnormal pressure in the refrigeration cycle that
leads to breakage and even injury.
When installing and relocating the air conditioner, do not mix gases other than the
specified refrigerant (R410A) to enter the refrigerant cycle.
If air or other gas enters the refrigerant cycle, the pressure inside the cycle will rise to
an abnormally high value and cause breakage, injury, etc.
If refrigerant leaks while work is being carried out, ventilate the area. If the refrigerant
comes in contact with a flame, it produces a toxic gas.
CAUTION
Be more careful so that foreign matter (oil, water, etc.) does not enter the piping than
with refrigerant R410A models. Also, when storing the piping, securely seal the open-
ings by pinching, taping, etc.
While brazing the pipes, be sure to blow dry nitrogen gas through them.
5.1. Flare connection (Pipe connection)
WARNING
• 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 a hazardous gas if the refrigerant comes into contact with a flame.
5.1.1. Flaring
• Use special pipe cutter and 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
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.
(4) Protect the pipes by pinching them or with tape to prevent dust, dirt, or water from
entering the pipes.
Check if [L] is flared uniformly
and is not cracked or scratched.
B
Die
A
Pipe
En-6
Dimension A [mm]
Pipe outside diameter
0
Dimension B
[mm]
Flare tool for R410A,
-
0.4
[mm (in.)]
clutch type
6.35 (1/4)
9.1
9.52 (3/8)
13.2
12.70 (1/2)
0 to 0.5
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 measure the dimension A.
Width across
Pipe outside
Width across flats
flats
diameter [mm (in.)]
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
5.1.2. Bending pipes
•
If pipes are shaped by hand, 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
difficult 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.
5.1.3. Pipe connection
CAUTION
• Be sure to install the pipe against the port on the indoor unit correctly. If the centering
is improper, the flare nut cannot tighten 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
connecting 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.
(1) Detach the caps and plugs from the pipes.
(2) Centering the pipe against port on the indoor unit, turn the flare nut with your hand.
Flare nut
Connection pipe
(small)
Flare nut
Connection pipe
(large)
(3) When the flare nut is tightened 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.)
CAUTION
• Hold the torque wrench at its grip, keeping it at a right angle with the pipe, in order to
tighten the flare nut correctly.
• 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 a hazardous gas if the refrigerant comes into contact with a flame.
• Connect the piping so that the control box cover can easily be removed for servicing
when necessary.
• In order to prevent water from leaking into the control box, make sure that the piping
is well insulated.
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