Connecting Tubing Between Indoor And Outdoor Units - Sanyo R410A Installation Instructions Manual

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 match-
ing surfaces of the flare and union before connecting
them together. This is effective for reducing gas leaks.
(Fig. 5-4)
(3) For proper connection, align the union tube and flare
tube straight with each other, then screw in the flare
nut lightly at first to obtain a smooth match. (Fig. 5-5)
● 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
● 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.)
● Do not allow the tubing to get too hot during
brazing. The nitrogen gas inside the tubing may
overheat, causing refrigerant system valves to
become damaged. Therefore allow 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
affect the refrigerant and refrigerant oil, and may
cause damage or malfunctions.
5-2. 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
connections, or when tightening them after connect-
ing the tubing, be sure to use 2 adjustable wrenches
or spanners as shown. (Fig. 5-6)
If the flare nuts are over-tightened, the flare may be
damaged, which could result refrigerant leakage and
cause in injury or asphyxiation to room occupants.
● 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 refrigerant
tubing that is used must be of the correct wall thick-
ness as shown in the table at right.
Torque wrench
Indoor unit
Tube diameter
ø1/4" (ø6.35 mm)
ø3/8" (ø9.52 mm)
ø1/2" (ø12.7 mm)
ø5/8" (ø15.88 mm)
ø3/4" (ø19.05 mm)
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 asphyxia-
tion 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
an adjustable wrench with a nominal handle length
of 7-7/8 in.
33
Apply refrigerant
lubricant
Fig. 5-4
Flare nut
Union
Fig. 5-5
Spanner
Outdoor unit
Fig. 5-6
Tightening torque,
Tube thickness
approximate
·
120 – 160 lbs inch
·
(140 – 180 kgf cm)
·
300 – 360 lbs inch
·
(340 – 420 kgf cm)
·
430 – 530 lbs inch
·
(490 – 610 kgf cm)
·
590 – 710 lbs inch
·
(680 – 820 kgf cm)
·
870 – 1040 lbs inch
·
(1000 – 1200 kgf cm)
t1/32"
(0.8 mm)
t1/32"
(0.8 mm)
t1/32"
(0.8 mm)
t5/128"
(1.0 mm)
over t5/128"
(over 1.0 mm)