6
CAUTION
CAUTION TO BE TAKEN WHEN BRAZING REFRIGER-
ANT PIPING
Do not use flux when brazing refrigerant piping. Therefore,
use the phosphor copper brazing filter metal (BCuP) which
does not require flux.
(Flux has extremely harmful infulence on refrigerant piping
system. For instance, if the chlorine based flux is used, it will
cause pipe corrosion or, in particular, if the flux contains flu-
orine, it will damage the refrigerant oil.)
• Before brazing local refrigerant piping, nitrogen gas shall be
blown through the piping to expel air from the piping.
If brazing is done without nitrogen gas blowing, a large
amount of oxide film develops inside the piping, and could
cause system malfunction.
• When brazing the refrigerant piping, only begin brazing after
having carried out nitrogen substitution or while inserting
nitrogen into the refrigerant piping. Once this is done, con-
nect the indoor unit with a flared or a flanged connection.
• Nitrogen should be set to 2.9 psi with a pressure-reducing
valve if brazing while inserting nitrogen into the piping.
NOTE
Use the flare nuts attached with the unit.
• Refer to Table 2 for tightening torque.
Table 2
Not recommendable but in case of emergency
You must use a torque wrench but if you are obliged to install
the unit without a torque wrench, you may
follow at the installation method mentioned below.
After the work is finished, make sure to check that there
is no gas leak.
When you keep on tightening the flare nut with a spanner,
there is a point where the tightening torque suddenly
increases. From that position, further tighten the flare nut at
the angle shown below:
Table 3
(in.)
7. DRAIN PIPING WORK
Rig the drain pipe as shown below and take measures
against condensate. Improperly rigged piping could lead to
leaks and eventually wet furniture and belongings.
(1)
Carry out the drain piping
Connect the drain hose
(1) using the attached
hose and parts, as
shown in the right
drawing.
• If converging multiple drain pipes, install according to the
procedure shown below.
Select converging drain pipes whose gauge is suitable for the
operating capacity of the unit.
(2)
After piping work is finished, check drainage flows
smoothly.
• Add approximately 1 liter of water slowly from the air out-
let and check drainage flow.
(3)
Be sure to insulate all indoor pipes
Pipe
size
Tightening
torque
(ft-lbf)
Flare
dimensions
A (in.)
Flare shape (in.)
φ
1/4”
10.5 – 12.7
0.343 – 0.358
φ
3/8”
24.1 – 29.4
0.504 – 0.520
φ
1/2”
36.5 – 44.5
0.638 – 0.654
φ
5/8”
45.6 – 55.6
0.760 – 0.776
Pipe size
Further tightening
angle
Recommended arm length
of tool
φ
1/4”
60 to 90 degrees
Approx. 5 7/8
φ
3/8”
60 to 90 degrees
Approx. 7 7/8
φ
1/2”
30 to 60 degrees
Approx. 9 13/16
φ
5/8”
30 to 60 degrees
Approx. 11 13/16
