7
• When brazing the refrigerant piping, perform nitrogen
replacement first, or perform the brazing (CAUTION 2) while
feeding nitrogen into the refrigerant piping (CAUTION 1), and
finally connect the indoor unit using the flare connections.
(Refer to Fig. 9)
CAUTION
• When brazing a pipe while feeding nitrogen inside the pipe,
make sure to set the nitrogen pressure to 29 psi or less using
the pressure reducing valve.
(This pressure is such that breeze is blown to your cheek.)
Not recommendable but in case of emergency
You must use a torque wrench but if you are obliged to install the
unit without a torque wrench, you may follow the installation
method mentioned below.
After the work is finished, make sure to check that there is
no gas leak.
When you keep on tightening the flare nut with a spanner, there
is a point where the tightening torque suddenly increases. From
that position, further tighten the flare nut the angle shown below:
Table 2
DANGER
• Use of oxygen could result in an explosion resulting in seri-
ous injury or death. Only use nitrogen gas.
• Refrigerant gas may produce toxic gas if it comes in contact
with fire such as from a fan heater, stove or cooking device.
Exposure to this gas could cause severe injury or death.
NOTE
• Do not use flux when brazing refrigerant piping. Therefore,
use the phosphor copper brazing filler metal (BCuP) which
does not require flux.
(Flux has an extremely negative effect on refrigerant piping
systems. For instance, if chlorine based flux is used, it will
cause pipe corrosion. Flux containing fluorine will damage
refrigerant oil.)
7.
DRAIN PIPING WORK
CAUTION
• The connection opening on the drain piping may vary
depending on the model, so check the model name and use
the right method for that model.
• Make sure all water is out before making the duct connection.
(1) Install the drain piping.
• Make sure the drain works properly.
• The diameter of the drain piping should be greater than or
equal to the diameter of the connecting pipe (vinyl tube; pipe
size : 25/32 in. ; outer dimension : 1-1/32 in.).
(not including a riser)
• Keep the drain piping short and sloping downwards at a gra-
dient of at least 1/100 to prevent air pockets from forming.
(Refer to Fig. 10)
CAUTION
Water accumulating in the drain piping can cause the
drain to clog.
• To keep the drain piping from sagging, space hanging
bracket every 3 to 5 ft..
• Use the drain hose (2) and the metal clamp (1). Insert the
drain hose (2) fully into the drain pipe connection hole and
firmly tighten the metal clamp (1) with the upper part of the
tape on the hose end. Tighten the metal clamp (1) until the
screw head is less than 1/8 in. from the hose.
(Refer to Fig. 11, 12)
• The two areas below should be insulated because conden-
sation may form there causing water to leak.
• Drain piping passing indoors
• Drain pipe connection hole
Referring the figure below, insulate the metal clamp (1) and
drain hose (2) using the included large sealing pad (5).
(Refer to Fig. 12)
Pipe size (in.)
Further tightening angle
Recommended arm
length of tool (in.)
φ
1/4
60 to 90 degrees
Approx. 5-7/8
φ
3/8
60 to 90 degrees
Approx. 7-7/8
φ
1/2
30 to 60 degrees
Approx. 9-13/16
φ
5/8
30 to 60 degrees
Approx. 11-13/16
Refrigerant piping
Part to be brazed
Taping
Pressure-reducing valve
hands
valve
Nitrogen
Nitrogen
Fig. 9
Drain pipe connection hole
Refrigerant pipes
Service drain hole
(with rubber cap)
4 in.
or more
Main drain piping
(with a slope of at least 1/100)
Fig. 10
