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(Unit : mm)
B
A
09~22 model
252
24 model
277
3.5. Pipe installation
• Do not use mineral oil on a flared part. Prevent mineral oil from getting into the
system as this would reduce the lifetime of the units.
• While welding the pipes, be sure to blow dry nitrogen gas through them.
■ Flaring
(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 the
burrs.
(3) Insert the flare nut onto the pipe and flare the pipe with a flaring tool.
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 R32(R410A) flare tool, or the conventional (for R22) flare tool.
When using the conventional flare tool, always use an allowance adjustment gauge and
secure the A dimension shown in the following table.
Check if [L] is flared uniformly and
is not cracked or scratched.
Pipe outside
Flaring tool for
diameter
R32 or R410A, clutch type
ø 6.35 mm (1/4")
ø 9.52 mm (3/8")
ø 12.70 mm (1/2")
0 to 0.5
ø 15.88 mm (5/8")
ø 19.05 mm (3/4")
■ Bending pipes
(1) When bending the pipe, be careful not to crush it.
(2) To prevent breaking of the pipe, avoid sharp bends.
Bend the pipe with a radius of curvature of 70 mm or more.
(3) If the copper pipe is bend the pipe or pulled to often, it will become stiff. Do not
bend the pipes more than three times at one place.
■ Flare connection
(1) Detach the caps and plugs from the pipes.
• Be sure to apply the pipe against the port on the indoor unit and the outdoor unit
correctly. If the centering is improper, the flare nut cannot be 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.
(2) Centering the pipe against port on the outdoor unit, turn the flare nut with your
hand.
AIR
Drain pipe mounting hole
Dimensions
B
399
409
CAUTION
Die
A
Pipe
A (mm)
Conventional (R22) Flaring tool
Clutch type
Wing nut type
1.0 to 1.5
1.5 to 2.0
CAUTION
To prevent gas leakage,
coat the flare surface with
alkylbenzene oil (HAB).
Do not use mineral oil.
(3) Tighten the flare nut of the connection pipe at the outdoor unit valve connector.
2-way valve
(Liquid)
3-way valve
(Gas)
(4) When the flare nut is tightened properly by your hand, use a torque wrench to
finally tighten it.
Torque wrench
Flare nut
Holding
wrench
Flare nut
Connection pipe
• Hold the torque wrench at its grip, keeping it in the right angle with the pipe, in order
to tighten the flare nut correctly.
Tightening torque [N·m (kgf·cm)]
Flare nut [mm (in.)]
6.35 (1/4) dia.
9.52 (3/8) dia.
12.70 (1/2) dia.
15.88 (5/8) dia.
19.05 (3/4) dia.
• Fasten a flare nut with a torque wrench as instructed in this manual. If fastened too
tight, the flare nut may be broken after a long period of time and cause a leakage of
refrigerant.
• 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 3-way valves open. This may cause abnormal pres-
sure in the refrigeration cycle that leads to breakage and even injury.
3.6. Sealing test
WARNING
• Before operating the compressor, install the pipes and securely connect them.
Otherwise, if the pipes are not installed and if the valves are open when the compressor
operates, air could enter the refrigeration cycle. If this happens, the pressure in the
refrigeration cycle will become abnormally high and cause damage or injury.
• After the installation, make sure there is no refrigerant leakage. If the refrigerant
leaks into the room and becomes exposed to a source of fire such as a fan heater,
stove, or burner, it produces a toxic gas.
• Do not subject the pipes to strong shocks during the sealing test. It can rupture the
pipes and cause serious injury.
• Do not block the walls and the ceiling until the sealing test and the charging of the
refrigerant gas have been completed.
• For maintenance purposes, do not bury the piping of the outdoor unit.
• After connecting the pipes, perform a sealing test.
• Make sure that the 3-way valves are closed before performing a sealing test.
• Pressurize nitrogen gas to 4.15 MPa to perform the sealing test.
• Add nitrogen gas to both the liquid pipes and the gas pipes.
• Check all flare connections and welds. Then, check that the pressure has not decreased.
• Compare the pressures after pressurizing and letting it stand for 24 hours, and check
that the pressure has not decreased.
* When the outdoor air temperature changes 5 °C, the test pressure changes
0.05 MPa. If the pressure has dropped, the pipe joints may be leaking.
• If a leak is found, immediately repair it and perform the sealing test again.
• After completing the sealing test, release the nitrogen gas from both valves.
• Release the nitrogen gas slowly.
Connection pipe
(Liquid)
Connection pipe
(Gas)
Flare nuts
Connection pipe
(liquid)
90°
CAUTION
16 to 18 (160 to 180)
32 to 42 (320 to 420)
49 to 61 (490 to 610)
63 to 75 (630 to 750)
90 to 110 (900 to 1100)
CAUTION
CAUTION
En-7
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