AirStage AO54FJ, Service Manual

Page: 136 / 169

07-08
1. Preparing pipes
Diameter and thickness of copper pipes is shown below.
Nominal Outer diameter Thickness
diameter (inch) (mm) (mm)
1/4 ø 6.35 0.8
3/8 ø 9.52 0.8
1/2 ø 12.70 0.8
5/8 ø 15.88 1.0
3/4 ø 19.05 1.2
Flare nut tightening torque
Nominal Tightening Torque
diameter (inch)
1/4 14.0 to 18.0 N m
3/8 33.0 to 42.0 N m
1/2 50.0 to 62.0 N m
5/8 63.0 to 77.0 N m
3/4 80.0 to 98.0 N m
7-3 PRECAUTIONS FOR INSTALLATION
(1) Use the designated size ( diameter & thickness )
of refrigerant pipes.
(2) Those pipes purchased locally may contain dust
inside. Please blow out the dust by dried inert gas
when using.
(3) Be careful to avoid the dust or water falling into the
pipe when performing piping process and piping
installation.
(4) When processing the pipe, make the number of
bending portion as few as possible, and the bending
radius as large as possible.
(5) To process the branch, do not use T-shaped pipe,
which causes an uneven refrigerant flow. Use the
optionally available standard branch kit.
(6) If the diameter of the required pipe is different from
the branch unit, either cut it out or use the reducer.
(7) Keep the permissible length of every piping limitation
to prevent a defect or cooling/heating failure.
(8) When replacing the unit, never use piping which has
been used for previous installations.
Only use the new piping.
(1) Confirm that there are not scratches or waster, etc.,
on the flare and union surface.
(2) When using lubrication oil on the inside and outside
of flare, always use small amount and must the same
lubrication oil as used in the refrigerant circuit. Use of
different oil will cause the lubrication oil to deteriorate
and a compressor failure. Also too much oil may
introduce water inside refrigerant circuit because the
synthetic oil is highly hygroscopic.
Brazing work must be carried out while blowing dry
nitrogen gas through the pipes, so that an oxidized
layer does not form on the inner surface of the pipes.
Separation Tube
(Standard parts)
T - tube
Pressure hose
Bello ws v alve
Rubber stopper
Nitr og en gas
2. Flare connection
3. Brazing work
Nitrogen Gas is used
Example) Inside state of welded pipe section
Nitrogen Gas is used but not
sufficient (Oxygen gas still exists
inside the pipe)
Nitrogen Gas is not used
Material: JIS H3300 C1220T-O or equivalent
Allowable tensile stress 33 (N/mm )
2