Insulating The Refrigerant Tubing - Panasonic R410A Mode D'emploi

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 (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 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.

5-3. Insulating the Refrigerant Tubing

Tubing Insulation
● Thermal insulation must be applied to all units tubing,
including distribution joint (local 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.
Taping the flare nuts
Wind the white insulation 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 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
Gas tubing
Fig. 5-7
13
Heat Insulation
CAUTION
Be sure to perform heat insulation on the drain, liquid and
gas piping. Imperfection in heat insulation work leads to
water leakage.
(1) Use the heat insulation material for the refrigerant piping
which has an excellent heat-resistance (over 120°C).
Overlap with heat
insulator for piping.
Band
(Accessory)
Indoor
unit
(2) Precautions in high humidity circumstance.
This air conditioner has been tested according to the "JIS
Standard Conditions with Mist" and have been confirmed
that there are no faults. However, if it is operated for a long
time in high humid atmosphere (dew point temperature:
more than 23°C), water drops are liable to fall. In this case,
add heat insulation material according to the following
procedure:
• Heat insulation material to be prepared... Adiabatic
glass wool with thickness 10 to 20 mm.
• Stick glass wool on all air conditioners that are located
in ceiling atmosphere.
• In addition to the normal heat insulation (thickness:
more than 8 mm) for refrigerant piping (gas piping: thick
piping) and drain piping, add a further of 10 mm to 30
mm thickness material.
Wall seal
● When the outdoor unit is installed on a higher position than
the indoor unit, install the trap so as not to instill rain water
into the wall by transmitting in piping.
● Stuff the space among piping, the electric wire, and the drain
hose with putty and seal the penetration wall hole. Make
sure that rain water do not instill into the wall.
Pipe down
Indoor
unit
Drain pipe
* Put the incision at the trap part of the heat insulator (for water
drain)
Heat insulator for piping
(Local supply)
Heat insulator
(Accessory)
Fig. 5-8
Putty
Pipe
Trap
Incision
Fig. 5-9