Panasonic Inverter R32 Series Technical Data & Service Manual page 190

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, R32 (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 – 55 N · m
ø12.7 (1/2")
{490 – 550 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 R22 pressure, the use of ordinary
flare 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 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 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,
including distribution joint (field 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.
Insulation of the flare nuts
Attach the flare insulator (supplied) just like wrapping around
the flare nut (supplied). Match the both slits of flare insulators
for gas and liquid tubes facing upward. Tightly attach the end of
the flare insulators to the tube cradle without any space. Then
clamp the flare insulator with the clampers about 20 mm away
from both ends.
Flare insulator (for gas tube)
Facing upward
Liquid tubing
Gas tubing
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.
Tube thickness
The joint should be sealed on both liquid and gas side.
0.8 mm
0.8 mm
Silicone Sealant must be neutral cure and ammonia free. Use of silicon
containing ammonia can lead to stress corrosion on the joint and cause
0.8 mm
leakage.
Taping the flare nuts
1.0 mm
Wind the white insulating tape around the flare nuts at the gas
tube connections. Then cover up the tubing connections with
the flare insulator, and fill the gap at the union with the supplied
black insulating tape. Finally, fasten the insulator at both ends
with the supplied vinyl clamps.
Outdoor unit
side
NOTE
Tighten the clampers to prevent any condensation that may
occur as the copper tubing is exposed.
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.
Taping the Tubes
(1) At this time, the refrigerant tubes (and electrical wiring
Flare insulator
(for liquid tube)
Tube cradle
(2) Wrap the armoring tape from the bottom of the outdoor
1-11-89
Ensure to do the re-flaring of pipes before connecting to units
to avoid leaking.
Insulation material and silicone sealant. Please ensure
there are no gaps where moisture can enter the joint.
Insulator (not supplied)
Flare nut
Clamper
(supplied)
About 20 mm About 20 mm
CAUTION
if local codes permit) should be taped together with
armoring tape in 1 bundle. To prevent condensation from
overflowing the drain pan, keep the drain hose separate
from the refrigerant tubing.
unit to the top of the tubing where it enters the wall. As you
wrap the tubing, overlap half of each previous tape turn.
Without any space
Clamper
Tube cradle
Indoor unit
side
Insulating tape
(supplied)
1