O
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 below.
Tightening torque
Tube diameter
(approximate)
14 – 18 N · m
ø6.35 (1/4")
(140 – 180 kgf · cm)
34 – 42 N · m
ø9.52 (3/8")
(340 – 420 kgf · cm)
49 – 61 N · m
ø12.7 (1/2")
(490 – 610 kgf · cm)
68 – 82 N · m
ø15.88 (5/8")
(680 – 820 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.
O
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.
O
When tightening the fl are nut on the liquid tube, use an
adjustable wrench with a nominal handle length of 200 mm.
5-3. Insulating the Refrigerant Tubing
Tubing Insulation
O
Thermal insulation must be applied to all units tubing, including
distribution joint (fi eld supply).
* For gas tubing, the insulation material must be heat resistant
to 120°C or above. For other tubing, it must be heat resistant
to 80°C or above.
Insulation material thickness must be 10 mm or greater.
If the conditions inside the ceiling exceed DB 30°C and RH
70%, increase the thickness of the gas tubing insulation mate-
rial by 1 step.
Two tubes arranged together
Liquid tubing
Insulation
CAUTION
If the exterior of the outdoor unit valves has been finished
with a square duct covering, make sure you allow
sufficient space to access the valves and to allow the
panels to be attached and removed.
Taping the are nuts
Wind the white insulation tape around the fl are nuts at the gas
tube connections. Then cover up the tubing connections with the
fl are insulator, and fi ll the gap at the union with the supplied black
insulation tape. Finally, fasten the insulator at both ends with the
supplied vinyl clamps. (Fig. 5-8)
Tube thickness
0.8 mm
0.8 mm
0.8 mm
1.0 mm
Insulation material
The material used for insulation must have good insulation
characteristics, be easy to use, be age resistant, and must not
easily absorb moisture.
After a tube has been insulated, never try to bend it into a
narrow curve because it can cause the tube to break or crack.
Never grasp the drain or refrigerant connecting outlets when
moving the unit.
5-4. Taping the Tubes
(1) At this time, the refrigerant tubes (and electrical wiring if local
(2) Wrap the armoring tape from the bottom of the outdoor unit to
(3) Clamp the tubing bundle to the wall, using 1 clamp approx.
Gas tubing
Fig.5-7
Do not wind the armoring tape too tightly since this will decrease
the heat insulation effect. Also ensure that the condensation drain
hose splits away from the bundle and drips clear of the unit and the
tubing.
23
Flare insulator (supplied)
Flare union
Unit side
Flare nut
CAUTION
codes permit) should be taped together with armoring tape in
1 bundle. To prevent condensation from overfl owing the drain
pan, keep the drain hose separate from the refrigerant tubing.
the top of the tubing where it enters the wall. As you wrap the
tubing, overlap half of each previous tape turn.
each meter. (Fig. 5-9)
Insulated tubes
NOTE
Insulation tape (white)
(supplied)
Tube insulator
(not supplied)
Heat resistant
120°C or above
Fig.5-8
Clamp
Drain hose
Fig.5-9