Panasonic U-8LE1R8 Installation Instructions Manual page 36

● The ø25.4 gas main will not pass easily into the opening for
coolant pipes in the pipe cover, so make sure you connect
the ø22.22 pipe with the ø19.05 pipe outside of the outdoor
unit.
(2) Tightly connect the indoor-side refrigerant tubing extended
from the wall with the outdoor-side tubing.
(3) 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.
Indoor unit
If the flare nuts are over-tightened, the flare may be
damaged, which could result refrigerant leakage and cause
in 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.
● 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 following table.
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}
100 – 120 N · m
ø19.05 (3/4")
{1000 – 1200 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.
Torque wrench
Spanner
Outdoor unit
A
Tube thickness
0.8 mm
0.8 mm
0.8 mm
1.0 mm
1.2 mm
● In order to prevent damage to the flare caused by over-
tightening of the flare nuts, see the table 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.
● Do not use a spanner to tighten the valve stem caps. Doing
so may damage the valves.
● Depending on the installation conditions, applying excessive
torque may cause the nuts to crack.
Precautions for Packed Valve Operation
● If the packed valve is left for a long time with the valve stem
cap removed, refrigerant will leak from the valve. Therefore,
do not leave the valve stem cap removed.
Packed valve
Valve stem cap
Valve stem cap
Service port
● Use a torque wrench to securely tighten the valve stem cap.
● Valve stem cap tightening torque:
Service port
Valve stem cap
Flare nut
36
Service port
Do not apply spanner at this position.
Hexagon screw
Torque wrench
Spanner (Fixed)
Gas side
8 – 10 N · m
ø9.52 (liquid)
{80 – 100 kgf · cm}
6.9 – 11.8 N · m
ø19.05 (gas)
{69 – 118 kgf · cm}
19 – 21 N · m
ø9.52 (liquid)
{190 – 210 kgf · cm}
13 – 14 N · m
ø19.05 (gas)
{130 – 140 kgf · cm}
34 – 42 N · m
ø9.52 (liquid)
{340 – 420 kgf · cm}
100 – 120 N · m
ø19.05 (gas)
{1000 – 1200 kgf · cm}