Midea MOU-55FN8-RD0 - Refrigerant Piping Connection Instructions

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Refrigerant Piping
Connection
Table 7.2
Permitted length
Piping
length
Total piping length 18K+18K 30/98’ L+Max
(L1, L2)
24K+24K
30K+30K
50/164’
(farthest distance from
the line pipe branch)
15/49’ L1, L2
(farthest distance from
the line pipe branch)
10/32.8’ L1-L2
Drop
height
Drop height between
indoor and outdoor unit
20/65.6’ H1
Drop height between
two indoor units
0.5/1.6’ H2
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. 7.5 for examples of bad cuts
Oblique Rough Warped
90°
Fig. 7.5
Step 2: Remove burrs.
Burrs can aect the air-tight seal of refrigerant
piping connection. They must be completely
removed.
1. Hold the pipe at a downward angle to
prevent burrs from falling into the pipe.
2. Using a reamer or deburring tool, remove
all burrs from the cut section of the pipe.
Pipe
Reamer
Point down
Fig. 7.6
Step 3: Flare pipe ends
Proper flaring is essential to achieve an airtight
seal.
1. After removing burrs from cut pipe, seal
the ends with PVC tape to prevent foreign
materials from entering the pipe.
2. Sheath the pipe with insulating material.
3. Place flare nuts on both ends of pipe.
Make sure they are facing in the right
direction, because you can’t put them on
or change their direction after flaring. See
Fig. 7.7
Flare nut
Copper pipe
Fig. 7.7