Airwell YEVFD Series, Service Manual

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Pipe installation
When doing the piping connection, please do the following:
■ Please don't let the pipe and the parts in the unit collide each other.
■ When connecting the pipes, close the valves fully.
■ Protect the pipe end against the water, impurity into the pipes (welding after being flat, or being sealed with
adhesive tape).
■ Bend the pipe as large semi-diameter as possible(over 4 times of the pipe diameter).
■ The connection between outdoor liquid pipe and the distributing pipe is flared type. Please expand the pipe with
the special tool for R410A after installing the expanding nut. But if the projecting pipe length has been adjusted
with the copper pipe gauge, you can use the original tool to expand the pipe.
■ Since the unit is with R410A, the expanding oil is ester oil, not the mineral oil.
■ When doing the flare connection, please do the following: When connecting the expanding pipe, fasten the pipes
with double-spanner. The torque refers to the former info.
Pipe outer
diameter
(mm)
A
Ø6.35 9.1
Ø9.52 13.2
Ø12.7 16.6
Ø15.88 19.7
Expanding pipe:A(mm)
Pipe outer
diameter
(mm)
When it is hard pipe
Special tool
for R410A
The former
tool
Ø6.35
0-0.5 1.0-1.5
Ø9.52
Ø12.7
Ø15.88
Projecting length of pipe to be expanded:B(mm)
■ The outdoor gas pipe and the refrigerant distributing pipe, as well the refrigerant distributing pipe and the branch
pipe should be welded with hard solder.
■ When doing the braze connection, please do the following: Brazing the pipe at the same time charge the nitrogen.
Or it will cause a number of impurity (a film of oxidation) to clog the capillary and the expansion valve, further
cause the deadly failure.
Operation procedure
■ Brazing the pipe at the same time charge the nitrogen. Or it will cause a number of impurity (a
film of oxidation) to clog the capillary and the expansion valve, further cause the deadly failure.
Seal the pipe end with adhesive tape or the stopper to
increase the resistance, fill up the pipe with nitrogen.
Only nitrogen gas
can be used
brazing
<N2>
taping
■ Protect the pipe end against the water, impurity into the pipes (welding after being flat, or
being sealed with adhesive tape).
flat
brazing
adhesive tape
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