Midea MOU-12HDN1, Service Manual

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Precaution on Installation MLCAC-UTSM-2010-10
116 Installation
1. Precaution on Installation
1). Measure the necessary length of the connecting pipe, and make it by the following way.
a. Connect the indoor unit at first, then the outdoor unit.
Bend the tubing in proper way. Do not harm them.
Specially Notice the pipe length/height/dimension of each capacity.
Maximum pipe length
Model Max. Length Max. Elevation
12,000Btu/h 15m 8m
18,000Btu/h ~24,000Btu/h 25m 12m
30,000Btu/h 25m 15m
36,000Btu/h 30m 20m
48,000Btu/h~60,000Btu/h 50m 25m
Piping sizes
Model Liquid(mm) Gas(mm)
12,000Btu/h~18,000Btu/h 6.35 12.7
24,000Btu/h~60,000Btu/h
9.52 15.9
CAUTIONS
 Daub the surfaces of the flare pipe and the joint nuts with frozen oil, and wrench it for 3~4 rounds
 With hands before fasten the flare nuts.
 Be sure to use two wrenches simultaneously when you connect or disconnect the pipes.
Pipe gauge Tightening torque
Flare dimension A
Min (mm) Max
Flare shape
Φ 6.35
14.2
～
17.2N.m
(144 ～ 176 kgf.cm)
8.3 8.7
Φ 9.52
32.7
～
39.9N.m
(333 ～ 407kgf.cm)
12.0 12.4
Φ 12.7
49.5 ～ 60.3N.m
(504
～
616kgf.cm)
15.4 15.8
Φ 15.9
61.8 ～ 75.4N.m
(630
～
770 kgf.cm)
18.6 19.1
Φ 19
97.2
～
118.6N.m
(990 ～ 1210kgf.cm)
22.9 23.3
b. The stop value of the outdoor unit should be closed absolutely (as original state). Every time you connect it, first loosen the nuts at the part
of stop value, then connect the flare pipe immediately (in 5 minutes). If the nuts have been loosened for a long time, dusts and other
impurities may enter the pipe system and may cause malfunction later. So please expel the air out of the pipe with refrigerant before
connection.
c. Expel the air after connecting the refrigerant pipe with the indoor unit and the outdoor unit. Then fasten the nuts at the repair-points.
2) Locate The Pipe
a. Drill a hole in the wall (suitable just for the size of the wall conduit), then set on the fittings such as the wall conduit and its cover.
b. Bind the connecting pipe and the cables together tightly with binding tapes. Do not let air in, which will cause water leakage by
condensation.
c. Pass the bound connecting pipe through the wall conduit from outside. Be careful of the pipe allocation to do no damage to the tubing.
3) Connect the pipes.
4) Then, open the stem of stop values of the outdoor unit to make the refrigerant pipe connecting the indoor unit with the outdoor unit in
fluent flow.
5) Be sure of no leakage by checking it with leak detector or soap water.
6) Cover the joint of the connecting pipe to the indoor unit with the soundproof / insulating sheath (fittings), and bind it well with the tapes to
prevent leakage.