Tubing Insulation - Panasonic Inverter R32 Series Technical Data & Service Manual

1
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.
Tube diameter
ø6.35 (1/4")
ø9.52 (3/8")
ø12.7 (1/2")
ø15.88 (5/8")
Because the pressure is approximately 1.6 times higher than
conventional refrigerant R22 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 200 mm.
Insulating the Refrigerant Tubing

Tubing Insulation

Must ensure that pipe-work shall be protected from physical damage.
Thermal insulation must be applied to all units tubing, includ-
ing 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 material 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.
Ensure to do the re-flaring of pipes before connecting to units to
avoid leaking.
To prevent the ingress of moisture into the joint which could have the
potential to freeze and then cause leakage, the joint must be sealed
with suitable silicone and insulation material. The joint should be sealed
on both liquid and gas side.
Insulation material and silicone sealant. Please ensure
there are no gaps where moisture can enter the joint.
Silicone Sealant must be neutral cure and ammonia free. Use of silicon
containing ammonia can lead to stress corrosion on the joint and cause
leakage.
Tightening torque
Tube thickness
(approximate)
14 – 18 N · m
0.8 mm
(140 – 180 kgf · cm)
34 – 42 N · m
0.8 mm
(340 – 420 kgf · cm)
49 – 55 N · m
0.8 mm
(490 – 550 kgf · cm)
68 – 82 N · m
1.0 mm
(680 – 820 kgf · cm)
Gas tubing
Fig.1-11-40
Taping the fiare 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. 1-11-41)
Flare union
Unit side
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.
CAUTION
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.
Taping the Tubes
(1) At this time, the refrigerant tubes (and electrical wiring if local
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.
(2) Wrap the armoring tape from the bottom of the outdoor unit to
the top of the tubing where it enters the wall. As you wrap the
tubing, overlap half of each previous tape turn.
(3) Clamp the tubing bundle to the wall, using 1 clamp approx.
each meter. (Fig. 1-11-42)
1-11-76
Flare insulator (Supplied)
Insulation tape
(Supplied)
Tube insulator
Flare nut
(Field supply)
Heat resistant
120°C or above
Fig.1-11-41
Clamp
Drain hose
Insulated tubes
Fig.1-11-42