Haier MRV 5-RC AB052MAERA, Service Manual

Page: 88 / 243

85
Pipe installation
Important
• 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 connecting the expanding pipe, fasten the pipes with double-spanner. The torque refers to the former info.
• 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.
• Weld 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.
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)
Operation procedure
• Weld 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.
• Protect the pipe end against water and impurities (welding after being flatted, or being sealed with adhesive tape).
• The refrigerant pipe should be clean. The nitrogen should flow under the
pressure of about 0.5MPa and when charging the nitrogen, stop up the
end of the pipe by hand to enhance the pressure in the pipe, then loose
the hand (meanwhile stop up the other end).
• When connecting the pipes, close the valves fully.
• When welding the valve and the pipes, use the wet cloth to cool down the
valve and the pipes.
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
Adhesive tape
Flat
Brazing
1st side
Hand
2nd side
Source valve
0.2MPa