INVENTOR V7CI-24WiFiR/U7RS-24, Installation Manual

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 Page 20 
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.
For R32/R290
refrigerantmodels, the pipe connection
points must be placed outside of room.
The connection pipes can not be reused.
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.
3. Make sure that the pipe is cut at a perfect
90° angle. Refer to Fig. 6.3 for examples of
bad cuts.
Oblique
Rough
Warped
90°
Fig. 6.3
Fig. 6.2
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) or
10m(32.8ft) of vertical suction line riser.
(See Fig. 6.2)
The outdoor unit is installed higher than
the indoor unit
6m/20ft
(
＜
36000Btu/h unit)
10m/32.8ft
(=>36000Btu/h unit)
6m/20ft
(
＜
36000Btu/h unit)
10m/32.8ft
(=>36000Btu/h unit)
 Page 21 
6. Place flaring tool onto the form.
7. Turn the handle of the flaring tool
clockwise until the pipe is fully flared. Flare
the pipe in accordance with the dimensions
shown in table 6.3.
Table 6.3: PIPING EXTENSION BEYOND FLARE
FORM
8. Remove the flaring tool and flare form,
then inspect the end of the pipe for cracks
and even flaring.
Step 4: Connect pipes
Connect the copper pipes to the indoor unit first,
then connect it to the outdoor unit. You should
first connect the low-pressure pipe, then the
high-pressure pipe.
1. When connecting the flare nuts, apply a
thin coat of refrigeration oil to the flared
ends of the pipes.
2. Align the center of the two pipes that you
will connect.
Indoor unit tubing
Flare nut
Pipe
Fig. 6.8
3. Tighten the flare nut as tightly as possible
by hand.
4. Using a spanner, grip the nut on the unit
tubing.
5. While firmly gripping the nut, use a torque
wrench to tighten the flare nut according
to the torque values in table 6.3.
Step 2: Remove burrs.
Burrs can affect 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. 6.4
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. 6.5
Flare nut
Copper pipe
Fig. 6.5
4. Remove PVC tape from ends of pipe when
ready to perform flaring work.
5. Clamp flare form on the end of the pipe.
The end of the pipe must extend beyond
the flare form.
Flare form
Pipe
Fig. 6.6
Pipe
gauge Tightening
torque
Flare dimension (A)
(Unit: mm/Inch)
Flare shape
Min. Max.
Ø 6.35
R0.4~0.8
45
°±
2
90
°
±
4
A
Ø 9.52
Ø 12.7
Ø 16
Ø 19
Ø 22
65-67 N.m
(663-683 kgf.cm)
23.2/0.91 23.7/0.93
75-85N.m
(765-867 kgf.cm)
26.4/1.04 26.9/1.06
18-20 N.m
(183-204 kgf.cm)
8.4/0.33 8.7/0.34
25-26 N.m
(255-265 kgf.cm)
13.2/0.52 13.5/0.53
35-36 N.m
(357-367 kgf.cm)
16.2/0.64 16.5/0.65
45-47 N.m
(459-480 kgf.cm)
19.2/0.76 19.7/0.78