Concealed Duct High Static Pressure
Tightening connection
Do not apply excessive torque. Otherwise, the nut
may crack depending on the conditions.
Outer dia. of copper pipe
12.7 mm (dia.)
▼ Tightening torque of flare pipe connections
Pressure of R410A is higher than that of R22.
(Approx. 1.6 times) Therefore, using a torque wrench, tighten
the flare pipe connecting sections which connect the indoor
and outdoor units of the specified tightening torque.
Incorrect connections may cause not only a gas leak, but also
a trouble of the refrigeration cycle.
Align the centres of the connecting pipes and tighten the flare
nut as far as possible with your fingers. Then tighten the nut
with a spanner and torque wrench as shown in the figure.
Half union
Externally
threaded side
Use a wrench to secure.
REQUIREMENT
Tightening with an excessive torque may crack the nut
depending on installation conditions.
Tighten the nut within the specified tightening torque.
Gas side refrigerant pipe
connection
• Turn up the pipe heat insulator to the unit side.
• Wrap the pipe with wet cloth.
Wet cloth
23-EN
CAUTION
(Unit: N•m)
Tightening torque
50 to 62 (5.0 to 6.2 kgf•m)
Flare nut
Internally
threaded side
Use a torque wrench to tighten.
Turn up pipe heat
insulator
Remove the all
brazed part.
• Remove the cup on the gas side piping by using a brazing
machine.
Do not burn the pipe heat insulator.
• Braze the attached joint part to the gas side piping and
braze the connection piping to the joint part.
Braze all around
• Turn back the pipe heat insulator and tie up with a banding
band.
Tie up with a banding
band.
Piping with outdoor unit
• For details of installation, refer to the Installation Manual of
the outdoor unit.
Evacuation
Using a vacuum pump, perform vacuuming from the charge
port of valve of the outdoor unit.
For details, follow to the Installation Manual attached to the
outdoor unit.
• Never use the refrigerant sealed in the outdoor unit for
evacuation.
REQUIREMENT
For the tools such as charge hose, etc., use those
manufactured exclusively for R410A.
– 23 –
Installation Manual
CAUTION
Remove the cap.
Attached joint part
Connection pipe
Locally procured
Ø28.6 mm
brazing
brazing