Haier MRV SII AU042FNEUA Service Manual page 35

Note:
1. When connecting the pipe and the outdoor, please pay attention to the outdoor pipe dimension.
2. When adjusting the diameter among pipes and among the units, please must execute at the branch pipe side.
3. When welding with hard solder, please must blow nitrogen. If not, a number of oxide will be produced and cause
heavy damage.Besides,to prevent water and dust into the pipe, please make the brim as outer roll.
Adhesive side
Heat insulation
■ Gas pipe and liquid pipe should be heat insulated separately.
■ The material for gas pipe should endure the high temperature over
120°C.That for liquid pipe should be over 70°C.
■ The material thickness should be over 10mm, when ambient temp.
is 30°C, and the relative humidity is over 80%, the material thickness
should be over 15mm.
■ He material should cling the pipe closely without gap, then be
wrapped with adhesive tape. The connection wire can not be put
together with the heat insulation material and should be far at
20cm.
Fix the refrigerant pipe
■ In operation, the pipe will vibrate and expand or shrink. If not being fixed, the refrigerant will focus on one part to cause the
broken pipe.
■ To prevent the central stress, fix the pipe for every 2-3m.
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 and water, impurities (welding after being flatted, 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.
Expanding pipe: A(mm)
Pipe outer diameter
■ 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.
Prepare on field
A
(mm)
Ø6.35 9.1
Ø9.52 13.2
Ø12.7 16.6
Ø15.88 19.7
Cut off pipe with the cutter
Seal the connection and wrap the
heat insulator with adhesive tape
Liquid pipe
least
Projecting length of pipe to be expanded: B(mm)
Pipe outer diameter
(mm)
Ø6.35
Ø9.52
Ø12.7
Ø15.88
33
Cut off at the middle
Connection wire
over 20cm
Adhesive tape
Gas pipe
Heat insulator
When it is hard pipe
Special tool The former
for R410A tool
0-0.5 1.0-1.5