Midea MCA3I-09FNXD0 Owner's Manual page 34

CAUTION
If the outdoor unit is installed higher than the
indoor unit:
-It is recommended that vertical suction risers
not be upsized. Proper oil return to the
compressor should be maintained with suction
gas velocity. If velocities drop below7.62m/s
(1500fpm (feet per minute)), oil return will be
decreased. An oil trap should be installed every
6m(20ft) of vertical suction line riser.
(See Fig. 7.2)
Fig. 7.2
The outdoor unit is installed higher than the indoor unit
Refrigerant Piping Connection Instructions
CAUTION
The branching pipe must be installed
•
horizontally. An angle of more than 10° may
cause malfunction.
DO NOT install the connecting pipe until
•
both indoor and outdoor units have been
installed.
Insulate both the gas and liquid piping to
•
prevent water leakage.
Step1: Cut pipes
When preparing refrigerant pipes, take extra
care to cut and flare them properly. This will
ensure efficient operation and minimize the
need for future maintenance.
1. Measure the distance between the indoor
and outdoor units.
2. Using a pipe cutter, cut the pipe a little
longer than the measured distance.
CAUTION
DO NOT deform pipe while cutting. Be extra
careful not to damage, dent, or deform the pipe
while cutting. This will drastically reduce the
heating efficiency of the unit.
1. Make sure that the pipe is cut at a perfect
90° angle. Refer to Fig. 7.3 for examples of
bad cuts.
90°
Oblique
Fig. 7.3
Rough Warped
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