Connecting Tubing Between Indoor And Outdoor Units - Panasonic S-12MU1U6 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 matching
surfaces of the fl are 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 fl are
tube straight with each other, then screw in the fl are
nut lightly at fi rst 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 fl are.
Cautions During Brazing
●
Replace air inside the tube with nitrogen gas to
prevent copper oxide fi lm 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
formation of oxide fi lm. 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 fl are nuts, apply specifi ed torque as at
right:
●
When removing the fl are nuts from the tubing
connections, or when tightening them after connecting
the tubing, be sure to use 2 adjustable wrenches or
spanners as shown. (Fig. 5-6)
If the fl are nuts are over-tightened, the fl are may be
damaged, which could result refrigerant leakage and
cause in injury or asphyxiation to room occupants.
●
For the fl are nuts at tubing connections, be sure to use
the fl are nuts that were supplied with the unit, or else
fl are nuts for R410A (type 2). The refrigerant tubing
that is used must be of the correct wall thickness as
shown in the table at right.
VRF_Indoor_US.indb 72 VRF_Indoor_US.indb 72
Apply refrigerant
lubricant
Fig. 5-4
Union
Fig. 5-5
Torque wrench
Indoor unit
Fig. 5-6
Tightening torque,
Tube diameter
approximate
120 – 160 lbs·inch
ø1/4" (ø6.35 mm)
(140 – 180 kgf·cm)
300 – 360 lbs·inch
ø3/8" (ø9.52 mm)
(340 – 420 kgf·cm)
430 – 480 lbs·inch
ø1/2"(ø12.7 mm)
(490 – 550 kgf·cm)
590 – 710 lbs·inch
ø5/8" (ø15.88 mm)
(680 – 820 kgf·cm)
870 – 1040 lbs·inch
ø3/4" (ø19.05 mm)
(1000 – 1200 kgf·cm)
Because the pressure is approximately 1.6 times
higher than conventional refrigerant pressure, the use
of ordinary fl are nuts (type 1) or thin-walled tubes may
result in tube rupture, injury, or asphyxiation caused by
refrigerant leakage.
●
In order to prevent damage to the fl are caused by
over-tightening of the fl are nuts, use the table above
as a guide when tightening.
●
When tightening the fl are nut on the liquid tube, use
an adjustable wrench with a nominal handle length of
7-7/8 in.
72
Flare nut
Spanner
Outdoor unit
Tube thickness
1/32"
(0.8 mm)
1/32"
(0.8 mm)
1/32"
(0.8 mm)
5/128"
(1.0 mm)
over 5/128"
(1.0 mm)
2011/09/30 12:23:13 2011/09/30 12:23:13