Flaring Work And Pipe Connection - Mitsubishi Electric MXZ-3DM50VA Installation Manual

2. OUTDOOR UNIT INSTALLATION
2-1. CONNECTING WIRES FOR OUTDOOR UNIT
1) Remove the service panel.
2) Loosen terminal screw, and connect indoor/outdoor unit connecting wire (B) from
the indoor unit correctly on the terminal block. Be careful not to make mis-wiring.
Fix the wire to the terminal block securely so that no part of its core is appeared,
and no external force is conveyed to the connecting section of the terminal block.
3) Firmly tighten the terminal screws to prevent them from loosening. After tighten-
ing, pull the wires lightly to confirm that they do not move.
4) Perform 2) and 3) for each indoor unit.
5) Connect power supply cord (A).
6) Fix indoor/outdoor unit connecting wire (B) and power supply cord (A) with the
cable clamps.
7) Close the service panel securely. Make sure that 3-2. PIPE CONNECTION is
completed.
• After making connections between both power supply cord (A) and indoor/
outdoor unit connecting wire (B), be sure to fix both cable and wire with cable
clamps.
Indoor/outdoor unit
connecting wire
Terminal block
N L
N L
Terminal block
<INDOOR UNIT>

3. FLARING WORK AND PIPE CONNECTION

3-1. 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 diameter Nut
Clutch Clutch
(mm) (mm)
type tool type tool
for R410A for R22
ø6.35 (1/4") 17
ø9.52 (3/8") 22
0 to 0.5 1.0 to 1.5
ø12.7 (1/2") 26
ø15.88 (5/8") 29
3-2. PIPE CONNECTION
1) Apply a thin coat of refrigeration oil (G) to the flared ends of the pipes and the
pipe connections of the outdoor unit. Do not apply refrigeration oil on screw
threads. Excessive tightening torque will result in damage on the screw.
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 refrigerant
leakage.
• Be sure to wrap insulation around the piping. Direct contact with the bare
piping may result in burns or frostbite.
3-3. 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.
<OUTDOOR UNIT>
Terminal block for
power supply
Terminal block
N L
N L
POWER SUPPLY
Terminal block
~/N 230 V 50 Hz
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
34.3 to 41.2 350 to 420
49.0 to 56.4 500 to 575
2.0 to 2.5
73.5 to 78.4 750 to 800
15 mm
35 mm
Lead wire
• Be sure to attach each screw to its correspondent terminal when
securing the cord and/or the wire to the terminal block.
• Make earth wire a little longer than others. (More than 35 mm)
• For future servicing, give extra length to the connecting wires.
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.
Terminal block for power supply
3DM50VA
Service panel
No good
Good
Tilted Uneven Burred
Fig. 2
Flaring tool
Clutch type Wing nut type
Fig. 4
Inside is shin-
ing without any
Smooth all
scratches.
around
Even length
all around
Fig. 6
En-4