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SERVICE MANUAL
Portable Air Condi oners
3) Cleaning brazing fi ller metal and piping
• When the refrigerant system has been opened, exposure to heat may cause
the brazing fi ller metal to s ck to the inside and outside of the piping. Brazing
fi ller metal may also combine with oxygen in the air to form an oxide fi lm. In
addi on, grease and oils may s ck to the pipe during handling. All these factors
will reduce the eff ec veness of brazing. Therefore, excess brazing fi ller metal
must be removed with sand paper, and by thorough cleaning with a solvent
such as Trichlene.
4) Dry Nitrogen gas use
• During brazing, the inside of the pipe undergoes an oxida ve reac on due to
the brazing fl ame. Introduce dry nitrogen gas (0.3 gal/min (1 L/min); adjust
with the fl ow regulator) through the pinch-off tube of the refrigerant cycle to
prevent oxida on.
NOTE
:Do not get foreign ma er such as dirt, water, or oil into the piping.
5) Ver cal joints
• For ver cal joints, heat the en re brazed
fi
ng to the proper brazing temperature.
Bring the brazing fi ller metal into contact
with the fi
ng so that the brazing fi ller
metal begins to fl ow.
• Stop hea ng the fi
ng as soon as the
brazing fi ller metal has fl own into the gap
(clearance). Since the brazing fi ller metal
fl ows easily into por ons heated to the
proper temperature, the en re fi
ng
must be kept at the proper brazing tem-
perature.
Burner
45°
Tube
Brazing Filler Metal
Vercal Down Joint
Tube
Burner
45°
Brazing Filler Metal
Vercal Up Joint
