Service Manual
37
Installation of Indoor, Outdoor Unit
Pipe bending
Annealed copper pipe with small diameter (ø6.35 or ø9.52) can be easily bent manually. In this case, secure large
R(radius) for the bend section and gradually bend pipe. If annealed copper pipe is large in diameter (ø15.88 or
ø19.05), bend pipe with bender. Use bender appropriate for the pipe diameter.
Brazing
In refrigerant piping, bending (in particular, acute bending) must be minimized to reduce piping resistance. Bending
is, however, necessary in some places by virtue of the installation position of devices auxiliary to the packaged air
conditioner, or of the building structure, piping distance or finishing appearance. If a more acute bend is required
than that attainable by pipe bender, perform brazing using ready-made elbow. Aside from this function, brazing also
serves to connect straight pipes, generally using ready-made sockets. While brazing, protect piping against heat
with wet cloth to avoid damaging valve packing or burning thermal insulator with burner heat. While brazing, blow
inert gas (nitrogen gas or carbonic gas) to prevent formation of oxidation film in copper piping; otherwise, the refrig-
erant circuit will clog. The blowing of nitrogen gas (or carbonic gas) through 3-way valves is described in the follow-
ing:
Refrigerant piping(Flare piping)
When connecting piping, be sure to keep piping dry(keep piping away from water), clean (keep piping away from
dust) and airtight (avoid refrigerant leakage).
When connecting piping on rainy days or making a through-hole in wall, take due care to prevent water or plaster
from entering piping.
Water enters
Plaster enters
• This procedure is designed to prevent formation of oxidation film by filling piping with inert gas. Note that exces-
sive gas pressure will generate pinholes at brazed points.
(Nitrogen gas: Supply pressure 0.05~0.1kg/cm2G)
• When supplying inert gas, be sure to open one end of piping.
CAUTION
