Mitsubishi Electric MFZ-KW25VG Notice D'installation page 10

3. OUTDOOR UNIT INSTALLATION
3-1. CONNECTING WIRES FOR OUTDOOR UNIT
1) Open the service panel.
2) Loosen terminal screw, and connect indoor/outdoor unit connecting wire (A) 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 tightening, pull
the wires lightly to confirm that they do not move.
4) Connect power supply cord (K).
5) Fix indoor/outdoor unit connecting wire (A) and power supply cord (K) with the cord
clamp.
6) Close the service panel securely.
<KW25, 35>
Terminal block
Cord clamp
EN
• Make earth wire a little longer than others. (More than 100 mm)
• For future servicing, give extra length to the connecting wires.
• Be sure to attach each screw to its correspondent terminal when securing the cord
and/or the wire to the terminal block.
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)
• Put the end of the copper pipe to downward direction as you remove burrs in order
to avoid to let burrs drop in the piping.
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 you use.
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 diameter Nut
type tool
(mm) (mm)
for R32,
R410A
ø6.35 (1/4") 17
ø9.52 (3/8") 22
0 to 0.5
ø12.7 (1/2") 26
ø15.88 (5/8") 29
3-3. PIPE CONNECTION
• In case of reconnecting the refrigerant pipes after detaching, make the flared part of
pipe re-fabricated.
• Fasten flare nut with a torque wrench as specified in the table.
• When fastened too tight, flare nut may break after a long period 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.
• 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.
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 (G), apply taping starting from the entry of outdoor unit.
• Stop the end of piping tape (G) with tape (with adhesive agent attached).
• When piping have to be arranged through above ceiling, closet or where the tempera-
ture and humidity are high, wind additional commercially sold insulation to prevent
condensation.
EN-9
<KW50, 60>
Indoor/outdoor
Terminal block
unit connect-
ing wire (A)
Power supply
cord (K)
Cord clamp
Always fix the power supply
cord on this side.
A (mm)
Clutch
Clutch Wing nut
type tool type tool
for R22 for R22
14 to 18
1.5 to 2.0
34 to 42
1.0 to 1.5
49 to 61
2.0 to 2.5
68 to 82
35 mm
Lead wire
Burr
Tightening torque
N•m kgf•cm
140 to 180
340 to 420
490 to 610
680 to 820
Reusable mechanical connectors and flared joints are not al-
lowed indoors.
When connecting the refrigerant piping by brazing, rather than
using flare connections, complete all brazing prior to connecting
indoor unit to outdoor unit.
15 mm
Power supply cord (K)
Good
Copper
pipe
Fig. 1
Copper pipe
Spare reamer
Pipe cutter
Fig. 3
Clutch type
Smooth all
around
Copper
Die
pipe
Even length
Flare nut
all around
Fig. 5
When installing the unit, securely
connect the refrigerant pipes be-
fore starting the compressor.
WARNING
No good
Tilted Uneven Burred
Fig. 2
Flaring tool
Wing nut type
Fig. 4
Inside is shining
without any
scratches.
Fig. 6
WARNING