Outdoor Condenser Installation Manual

En-7
3.5.2. Pipe connection

Brazing
CAUTION
• If air or another type of refrigerant enters the refrigeration cycle, the internal
pressure in the refrigeration cycle will become abnormally high and prevent the unit
from exerting its full performance.
• Apply nitrogen gas while brazing the pipes. If a pipe is brazed without applying
nitrogen gas, an oxidation lm will be created.
This can degrade performance or damage the parts
in the unit (such as the compressor or valves).
Nitrogen gas pressure: 6 inHg (0.02 MPa)
(= pressure felt su󰀩ciently on the back of the hand)
• For brazing material, use phosphor copper
that does not require ux. Do not use ux to
braze pipes. If the ux is the chlorine type, it will
cause the pipes to corrode.
Furthermore, if the ux contains uoride, it will adversely a󰀨ect the refrigerant pipe
system such as by degrading the refrigerant.
If uoride is contained, quality of refrigerant deteriorates and a󰀨ects the refrigerant
piping system.

Flaring
CAUTION
• Do not use mineral oil on a ared part. Prevent mineral oil from getting into the
system as this would reduce the lifetime of the units.
• While brazing the pipes, be sure to blow dry nitrogen gas through them.
• Use special pipe cutter and 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 the cuttings will not enter the pipe and remove any
burrs.
(3) Insert the are nut (always use the are nut attached to the indoor and outdoor
units respectively) onto the pipe and perform the are processing with a are tool.
Leakage of refrigerant may result if other are 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 ared uniformly and
is not cracked or scratched.
B
Pipe
A
Die
Pipe outside diameter
[in (mm)]
Dimension A [in (mm)]
Dimension B [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 are tools to are R410A pipes, the dimension A should
be approximately 0.020 in (0.5 mm) more than indicated in the table (for aring with
R410A are tools) to achieve the specied aring. Use a thickness gauge to measure
the dimension A.
Width across ats
Pipe outside diameter
[in (mm)]
Width across ats 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)

Bending pipes
CAUTION
• To prevent breaking of the pipe, avoid sharp bends. Bend the pipe with a radius of
curvature of 3-15/16 in (100 mm) to 5-7/8 in (150 mm).
• If the pipe is bent repeatedly at the same place, it will break .
• If pipes are shaped by hand, be careful not to collapse them.
• Do not bend the pipes at an angle of more than 90°.
• When pipes are repeatedly bent or stretched, the material will harden, making it
di󰀩cult to bend or stretch them anymore.
• Do not bend or stretch the pipes more than three times.
Pressure regulating valve
Cap
Brazing area
Nitrogen gas

Connecting pipes
CAUTION
• Be sure to install the pipe against the port on the indoor unit and the outdoor unit
correctly. If the centering is improper, the are nut cannot be tightened smoothly. If
the are nut is forced to turn, the threads will be damaged.
• Do not remove the are nut from the outdoor unit pipe until immediately before
connecting the connection pipe.
• After installing the piping, make sure that the connection pipes do not touch the
compressor or outer panel. If the pipes touch the compressor or outer panel, they
will vibrate and produce noise.
(1) Detach the caps and plugs from the pipes.
(2) Center the pipe against the port on the outdoor unit, and then turn the are nut by
hand.
(3) Tighten the are nut of the connection pipe at the outdoor unit valve connector.
3-way valve (Liquid)
3-way valve (Gas)
Flare nut
Connection pipe
(Liquid)
Flare nut
Connection pipe
(Gas)
(4) After tightening the are nut by hand, use a torque wrench to fully tighten it.
CAUTION
• Hold the torque wrench at its grip, keeping it in a right angle with the pipe, in order
to tighten the are nut correctly.
• Fasten a are nut with a torque wrench as instructed in this manual. If fastened too
tight, the are nut may be broken after a long period of time and cause a leakage of
refrigerant.
• Outer panel may be distorted if fastened only with a wrench. Be sure to x the
elementary part with a spanner and fasten with a wrench. (Refer to the following
gure.)
• Do not apply force to the blank cap of the valve or hang a wrench, etc., on the cap. It may
cause leakage of refrigerant.
90°
Flare nut
Torque
wrench
Holding
wrench
Torque wrench
To prevent gas leakage, coat the
are surface with refrigerator oil.
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)

Handling precautions for the valves
• Mounted part of blank cap is sealed for protection.
• Fasten blank cap tightly after opening valves.
Table A
Blank cap [in (mm)] Tightening torque [lbf·ft (N·m)]
1/4 (6.35) 14.8 to 18.4 (20 to 25)
3/8 (9.52) 14.8 to 18.4 (20 to 25)
1/2 (12.70) 18.4 to 22.1 (25 to 30)
5/8 (15.88) 22.1 to 25.8 (30 to 35)
3/4 (19.05) 25.8 to 29.5 (35 to 40)
9379113069-02_IM.indb 7 6/11/2021 10:26:44 AM