Midea MUEU-18HRFNX-QRD0W, Service Manual

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 6. Refrigerant Pipe Installation 
6.2 The procedure of connecting pipes
1.Choose the pipe size according to the specification table.
2.Confirm the cross way of the pipes.
3.Measure the necessary pipe length.
4.Cut the selected pipe with pipe cutter
•
Make the section flat and smooth.
Oblique
Rough
Warped
90
5. Insulate the copper pipe
•
Before test operation, the joint parts should not be
heat insulated.
6. Flare the pipe
•
Insert a flare nut into the pipe before flaring the
pipe
•
According to the following table to flare the pipe.
Pipe diameter
(inch(mm))
Flare dimension A (mm/inch)
Flare shape
Min Max
1/4" (6.35) 8.4/0.33 8.7/0.34
R0.4~0.8
45
°±
2
90
°
± 4
A
3/8" (9.52) 13.2/0.52 13.5/0.53
1/2" (12.7) 16.2/0.64 16.5/0.65
5/8" (15.9) 19.2/0.76 19.7/0.78
3/4" (19) 23.2/0.91 23.7/0.93
7/8" (22) 26.4/1.04 26.9/1.06
•
After flared the pipe, the opening part must be seal
by end cover or adhesive tape to avoid duct or exog-
enous impurity come into the pipe.
7. Drill holes if the pipes need to pass the wall.
8. According to the field condition to bend the pipes so
that it can pass the wall smoothly.
9. Bind and wrap the wire together with the insulated pipe
if necessary.
10. Set the wall conduit
11. Set the supporter for the pipe.
12. Locate the pipe and fix it by supporter
•
For horizontal refrigerant pipe, the distance be-
tween supporters should not be exceed 1m.
•
For vertical refrigerant pipe, the distance between
supporters should not be exceed 1.5m.
13. Connect the pipe to indoor unit and outdoor unit by
using two spanners.
•
Be sure to use two spanners and proper torque to
fasten the nut, too large torque will damage the
bellmouthing, and too small torque may cause
leakage. Refer the following table for different pipe
connection.
Pipe Diameter
Torque
Sketch map
N.
m(lb.ft)
1/4" (6.35)
15~16
(11~11.8)
3/8" (9.52)
25~26
(18.4~19.18)
1/2" (12.7)
35~36
(25.8~26.55)
5/8" (15.9)
45~47
(33.19~34.67)
3/4" (19)
65~67
(47.94~49.42)
7/8" (22)
75-85
(55.3-62.7)