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Caution Before Connecting Tubes Tightly
(1) Apply a sealing cap or water-proof tape to prevent
dust or water from entering the tubes before they
are used.
(2) Be sure to apply refrigerant lubricant to the
GB
matching surfaces of the flare and union before
connecting them together. This is effective for
reducing gas leaks. (Fig. 7-4)
(3) For proper connection, align the union tube and
FR
flare tube straight with each other, then screw
on the flare nut lightly at first to obtain a smooth
match. (Fig. 7-5)
●
DE
Adjust the shape of the liquid tube using a tube
bender at the installation site and connect it to the
liquid tubing side valve using a flare.
Cautions During Brazing
IT
●
Replace air inside the tube with nitrogen gas to
prevent copper oxide film from forming during
the brazing process. (Oxygen, carbon dioxide
and Freon are not acceptable.)
PT
●
Do not allow the tubing to get too hot dur-
ing brazing. The nitrogen gas inside the tub-
ing may overheat, causing refrigerant system
valves to become damaged. Therefore allow
GR
the tubing to cool when brazing.
●
Use a reducing valve for the nitrogen cylinder.
●
Do not use agents intended to prevent the for-
mation of oxide film. These agents adversely
ES
affect the refrigerant and refrigerant oil, and
may cause damage or malfunctions.
7-2. Connecting Tubing Between Indoor and
Outdoor Units
(1) Tightly connect the indoor-side refrigerant tubing
extended from the wall with the outdoor-side tubing.
(2) To fasten the flare nuts, apply specified torque as
at right.
●
When removing the flare nuts from the tubing con-
nections, or when tightening them after connecting
the tubing, be sure to use 2 monkey wrenches or
spanners as shown. (Fig. 7-6)
If the flare nuts are over-tightened, the flare may be
damaged, which could result in refrigerant leakage
and cause injury or asphyxiation to room occupants.
●
When removing or tightening the gas tube flare nut,
use 2 monkey wrenches together: one at the gas
tube flare nut, and the other at part A. (Fig. 7-7)
●
For the flare nuts at tubing connections, be sure to
use the flare nuts that were supplied with the unit,
or else flare nuts for R410A (type 2). The refriger-
ant tubing that is used must be of the correct wall
thickness as shown in the table at right.
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DC̲Inverter̲Eng.indd 56
Apply refrigerant lubricant.
Fig. 7-4
Union
Fig. 7-5
Torque wrench
Indoor unit
Fig. 7-6
Fig. 7-7
Tightening torque
Tube diameter
(approximate)
14 – 18 N
ø6.35 (1/4")
(140 – 180 kgf
34 – 42 N
ø9.52 (3/8")
(340 – 420 kgf
49 – 61 N
ø12.7 (1/2")
(490 – 610 kgf
68 – 82 N
ø15.88 (5/8")
(680 – 820 kgf
Because the pressure is approximately 1.6 times
higher than conventional refrigerant pressure, the
use of ordinary flare nuts (type 1) or thin-walled
tubes may result in tube rupture, injury, or asphyxi-
ation caused by refrigerant leakage.
●
In order to prevent damage to the flare caused
by over-tightening of the flare nuts, use the table
above as a guide when tightening.
●
When tightening the flare nut on the liquid tube,
use a monkey wrench with a nominal handle length
of 200 mm.
56
Flare nut
Spanner
Outdoor unit
A
Tube thickness
·
m
0.8 mm
·
cm)
·
m
0.8 mm
·
cm)
·
m
0.8 mm
·
cm)
·
m
1.0 mm
·
cm)
2007/07/25 13:21:46
2007/07/25 13:21:46
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