Connecting Tubing Between Indoor And Outdoor Units; Insulating The Refrigerant Tubing - Panasonic Inverter R32 Series Technical Data & Service Manual

1
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.
When removing the flare nuts from the tubing connections,
●
or when tightening them after connecting the tubing, be sure
to use a torque wrench and a spanner.
Torque wrench
Indoor unit
If the flare nuts are over-tightened, the flare may be damaged,
which could result in refrigerant leakage and cause injury or
asphyxiation to room occupants.
When removing or tightening the gas tube flare nut, use 2
●
adjustable wrenches together: one at the gas tube flare nut,
and the other at part A.
A
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.
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
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 a
●
adjustable wrench with a nominal handle length of 200 mm.
● When tightening the flare nut with the adjustable wrench, do
not apply to the valve cap with the other one.
If doing so, the valve will be damaged.
Service port
Valve cap
● Depending on the installation conditions, applying excessive
torque may cause the nuts to crack.
Spanner
Outdoor unit
A
Tightening torque
Tube thickness
(approx.)
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}
Flare nut
Precautions when operating the 3-way valve for piping
installation
● If the 3-way valve is left for a long time with the valve cap
removed, refrigerant will leak from the valve. Therefore, do
not leave the valve cap removed.
3-way valve
Valve shaft
Valve cap
● Use a torque wrench to securely tighten the valve cap.
● Tightening torque:
Service port
ø6.35 (Liquid side)
ø9.52 (Liquid side)
ø12.7, ø15.88 (Gas side)

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 (purchased separately).
Two tubes arranged together
Inter-unit control
wiring
* 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.
● When cooling in the low outdoor air, the low-pressure side
pressure may decrease.
Additional Precautions For R32 Models.
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.
1-11-12
Service port
Valve
Tightening torque (approx.)
10.7 – 14.7 N • m {107 – 147 kgf • cm}
14.0 – 20.0 N • m {140 – 200 kgf • cm}
20.6 – 28.4 N • m {206 – 284 kgf • cm}
48.0 – 59.8 N • m {480 – 598 kgf • cm}
Gas tube
Liquid tube
Armoring tape
Insulation