Specifications

Installation of indoor unit EDUS281104
94 Installation of indoor / outdoor unit
3PN06240-3E
9
7-4 Brazing refrigerant piping
• Before brazing local refrigerant pipe, nitrogen gas shall be
blown through the pipe to expel air from the pipe.
If your brazing is done without nitrogen gas blowing, a large
amount of oxide film develops inside the pipe, and could
cause system malfunction.
• When brazing the refrigerant pipe, only begin brazing after
having carried out nitrogen substitution or while inserting
nitrogen into the refrigerant pipe. Once this is done, connect
the indoor unit with a flared or a flanged connection.
• Nitrogen should be set to 2.9psi. with a pressure-reducing
valve if brazing while inserting nitrogen into the pipe.
DANGER
• Use of oxygen may cause an explosion resulting in serious
injury or death. Only use nitrogen gas.
NOTE
• Do not use flux when brazing refrigerant pipe. 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. If the flux contains fluorine, it will
damage the refrigerant oil.)
8. DRAIN PIPING WORK
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〈〈〈〈
〈〈Rig the drain pipe as shown below and take measures
against condensate. Improperly rigged pipe could lead to
leak and eventually wet furniture and belongings.〉〉
〉〉〉〉
〉〉
(1) Rig drain pipe
• The diameter of the drain pipe should be greater than or
equal to the diameter of the connecting pipe (vinyl tube; pipe
size: 1 in.; outer dimension: 1 1/4 in.). (This does not apply to
rise.)
• Keep the drain pipe short and sloping downwards at a gradi-
ent of at least 1/100 to prevent air pockets from forming.
• If the drain pipe cannot be sufficiently set on a slope,
execute the drain raising pipe.
• To keep the drain pipe from sagging, space hanging wires
every 3.28 ~ 4.92ft .
• Use the attached drain hose (1) and metal clamp (2).
Insert the drain hose into the drain socket, up to the white
tape. Tighten the clamp until the screw head is less than
3/16 in. from the hose.
• Be sure to insulate the 2 below indicated spots.
If uninsulated, there is always the possibility of conden-
sate forming and leaking.
• The drain pipe inside the building
• Drain socket
• Wrap the attached sealing pad (10) (Large) over the clamp
and drain hose to insulate, as shown in the drawing below.
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〈〈
〈NOTE FOR DRAIN RAISING PIPE〉
〉〉
〉
• Install the drain raising pipe at a height of less than 21 5/8 in..
• Install the drain raising pipe at a right angle to the indoor unit
and no more than 11 13/16 in. from the unit.
Nitrogen
Refrigerant
pipe
Part to be
brazed
Taping
Pressurereducing valve
hands
valve
Nitrogen