Mitsubishi Electric MFZ-KJ12NA Notice D'installation page 10

4. FLARE CONNECTION, PIPE CONNECTION
4-1. FLARE CONNECTION
1) Cut the copper pipe as straight as possible with a pipe cutter. (Fig. 1, 2)
2) Remove all burrs from the cut section of the pipe, ensuring that precautions
are taken to avoid getting metal shavings into the piping. (Fig. 3)
3) Remove flare nuts attached to indoor and outdoor units, then put them on
pipe.
4) Flaring work (Fig. 4, 5). Firmly hold copper pipe in the dimension shown in the
table. Select A inch (mm) from the table according to the tool you use.
5) Check
• Compare the flared work with Fig. 6.
• If flare is defective, cut off the section and repeat procedure.
A inch (mm)
Pipe
B inch
Clutch Clutch
diameter
(mm)
type tool type tool
inch (mm)
for R410A for R22
ø 1/4 21/32
(6.35) (17)
ø 3/8
7/8 (22)
0.04 to
(9.52)
0 to 0.02
0.06
(0 to 0.5)
ø 1/2 1-1/32
(1.0 to 1.5)
(12.7) (26)
ø 5/8 1-5/32
(15.88) (29)
4-2. PIPE CONNECTION
• Fasten flare nut with a torque wrench as specified in the table.
• When fastened too tight, flare nut may eventually break and cause refrigerant
leakage.
• Be sure to wrap insulation around the piping. Direct contact with the bare
piping may result in burns or frostbite.
Indoor unit connection
Connect both liquid and gas pipings to indoor unit.
• Do not apply refrigeration oil on screw threads. Excessive tightening torque
will result in damage on the screw.
• For connection, first align the center, then tighten the first 3 to 4 turns of flare
nut by hand.
• Use tightening torque table above as a guideline for indoor unit side union
joint section, and tighten using two wrenches. Excessive tightening damages
the flare section.
Outdoor unit connection
Connect pipes to stop valve pipe joint of the outdoor unit following the same
procedure detailed in indoor unit connection.
• For tightening, use a torque wrench or spanner.
WARNING
When installing the unit, securely connect the refrigerant pipes before
starting the compressor.
EN-9
Tightening torque
Wing nut
ft-lb
type tool N•m
(kgf•cm)
for R22
10 to 13 13.7 to
0.06 to
(140 to 180) 17.7
0.08
25 to 30 34.4 to
(1.5 to 2.0)
(350 to 420) 41.2
36 to 42 49.1 to
0.08 to
(500 to 580) 56.9
0.10
54 to 58 73.5 to
(2.0 to 2.5)
(750 to 800) 78.5
Copper
pipe
Fig. 1
Copper pipe
Burr
Spare reamer
Flaring tool
Clutch type Wing nut type
Fig. 4
Smooth all around
Inside is
shining
without any
scratches.
Even length
all around
Fig. 6
Good No good
90°
Tilted Uneven Burred
Fig. 2
Pipe cutter
Fig. 3
Copper pipe
Die
Flare nut
B
Fig. 5