Mitsubishi Electric MXZ-2HA40VF2 Notice D'installation page 9

3-2. FLARING WORK
1) Cut the copper pipe correctly with pipe cutter. (Fig. 1, 2)
2) Completely remove all burrs from the cut cross section of pipe. (Fig. 3)
• Aim the copper pipe downward while removing burrs to prevent burrs
from dropping in the pipe.
3) Remove flare nuts attached to indoor and outdoor units, then put them on
pipe having completed burr removal. (Not possible to put them on after
flaring work.)
4) Flaring work (Fig. 4, 5). Firmly hold copper pipe in the dimension shown
in the table. Select A mm from the table according to the tool selected.
5) Check
• Compare the flared work with Fig. 6.
• If flare is noted to be defective, cut off the flared section and do flaring
work again.
A (mm)
Pipe
Clutch
Nut
Clutch
diameter
type tool
(mm)
type tool
(mm)
for R32,
for R22
R410A
ø6.35
17
(1/4")
ø9.52
22
(3/8")
0 to 0.5 1.0 to 1.5
ø12.7
26
(1/2")
ø15.88
29
(5/8")
3-3. PIPE CONNECTION
• The connected pipe size differs depending the models and the capacities
of indoor units.
Indoor unit capacity 25 ~ 50
Liquid pipe size ø6.35
Gas pipe size ø9.52
• Use tightening torque table above as a guideline for indoor unit side union
joint section, and tighten using two wrenches. Excessive tightening dam-
ages the flare section.
1) Do not apply refrigeration oil on screw threads. Excessive tightening torque
will result in damage on the screw.
2) For connection, first align the center, then tighten the first 3 to 4 turns of
flare nut by hand.
3) Tighten the flare nut with a torque wrench as specified in the table.
• Over-tightening may cause damage to the flare nut, resulting in refrigerant
leakage.
• Be sure to wrap insulation around the piping. Direct contact with the bare
piping may result in burns or frostbite.
3-4. INSULATION AND TAPING
1) Cover piping joints with pipe cover.
2) For outdoor unit side, surely insulate every piping including valves.
3) Using piping tape (E), apply taping starting from the entry of outdoor unit.
• Stop the end of piping tape (E) with tape (with adhesive agent attached).
• When piping have to be arranged through above ceiling, closet or where
the temperature and humidity are high, wind additional commercially sold
insulation to prevent condensation.
Tightening torque
Wing nut
type tool N•m kgf•cm
for R22
13.7 to 17.7 140 to 180
1.5 to 2.0
34.4 to 41.2 350 to 420
49.1 to 56.9 500 to 580
2.0 to 2.5
73.5 to 78.5 750 to 800
Copper
pipe
Fig. 1
Copper pipe
Burr
Spare reamer
Pipe cutter
Fig. 3
Copper pipe
Die
Flare nut
Fig. 5
WARNING
When installing the unit, securely connect the refrigerant pipes
before starting the compressor.
CAUTION
When there are the ports which are not used, make sure their
nuts are tightened securely.
Indoor unit connection
Flare nut
Internal thread side
Tighten the flare nut
with a torque wrench.
Outdoor unit connection
Tighten the flare nut
with a torque wrench.
No good
Good
Tilted Uneven Burred
Fig. 2
Flaring tool
Clutch type Wing nut type
Fig. 4
Inside is shin-
Smooth all
ing without any
around
scratches.
Even length
all around
Fig. 6
Union joint
External thread side
Grip the nut on the
union joint with a spanner.
En-7