Mitsubishi Electric MXZ-2F33VF Mode D'emploi page 8

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.
Pipe
Clutch
Nut
diameter
type tool
(mm)
(mm)
for R32,
R410A
ø6.35
17
(1/4")
ø9.52
22
(3/8")
0 to 0.5
ø12.7
26
(1/2")
ø15.88
29
(5/8")
3-3. PIPE CONNECTION
• 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) Apply a thin coat of refrigeration oil (G) to the flared ends of the pipes and
the pipe connections of the outdoor unit.
2) Align the center of the pipe with that of the pipe connections of the outdoor
unit, then hand tighten the flare nut 3 to 4 turns.
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 refriger-
ant 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.
En-7
A (mm) Tightening torque
Clutch Wing nut
type tool type tool N•m
for R22 for R22
13.7 to 17.7 140 to 180
1.5 to 2.0
34.3 to 41.2 350 to 420
1.0 to 1.5
49.0 to 56.4 500 to 575
2.0 to 2.5
73.5 to 78.4 750 to 800
Copper pipe
Burr
Spare reamer
kgf•cm
Die
Flare nut
When installing the unit, securely connect the refrigerant pipes
before starting the compressor.
When there are the ports which are not used, make sure their
nuts are tightened securely.
To avoid risk of fire, flare connection should be installed
outdoors.
Reusable mechanical connectors and flared joints are not
allowed indoors.
When connecting the refrigerant piping by brazing, rather
than using flare connections, complete all brazing prior to
connecting indoor unit to outdoor unit.
No good
Good
Copper
pipe
Tilted Uneven Burred
Fig. 1
Flaring tool
Pipe cutter
Clutch type Wing nut type
Fig. 3
Inside is shin-
Smooth all
ing without any
around
scratches.
Copper pipe
Fig. 5
WARNING
CAUTION
WARNING
Fig. 2
Fig. 4
Even length
all around
Fig. 6