Mitsubishi MLP-444WU Installation Manual page 22

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 inch (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.
A inch (mm)
Pipe
B inch
Clutch type Clutch type
diameter
(mm)
tool for tool for
inch (mm)
R410A R22
ø1/4 21/32
(6.35) (17)
ø3/8 7/8
0.04 to
(9.52) (22)
0 to 0.02
0.06
(0 to 0.5)
ø1/2 1-1/32
(1.0 to 1.5)
(12.7) (26)
ø5/8 1-5/32
(15.88) (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 brake after a long period and cause refriger-
ant 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.
• Apply a thin coat of refrigeration oil on the seat surface of pipe.
• 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.
Outdoor unit connection
Connect pipes to stop valve pipe joint of the outdoor unit in the same manner
applied for indoor unit.
• For tightening, use a torque wrench or spanner and use the same tightening torque
applied for indoor unit.
3-4. INSTALLING THE PIPE COVER
Make sure to install the pipe cover. Incorrect installation results in water leakage.
• No insulation is needed on the pipe connecting part of the indoor side for this unit.
The pipe cover gathers the water condensed around the pipe connecting part.
1) Install the pipe band removed in 3-1. to secure the connecting pipes.
* The pipe band should hold down the insulating material of connecting pipe. In-
sulating material should protrude 3/8 in. (10 mm) or more than the pipe band, as
shown in the illustration on the right.
2) Install pipe cover.
When using pipe with super insulating material
(about ø1-7/8 in. (ø48 mm) liquid pipe, ø2 in. (ø51 mm) gas pipe)
1) Make sure that the plate is turned over, and the concave part is facing upward.
(Refer to 3-1.)
2) Use band provided with the unit. (Do not use the pipe band attached to the
unit)
3) Connecting pipe exit of pipe cover is precut. Cut it along the line.
4) Install pipe cover.
Note:
Install pipe cover and pipe band securely. Incomplete installation will cause water
to drip from the unit, soaking and damaging household goods.
En-9
Tightening torque
Wing nut
ft-lb
type tool N•m
(kgf•cm)
for R22
10 to 13
13.7 to 17.7
0.06 to
(140 to 180)
0.08
25 to 30
(1.5 to 2.0)
34.3 to 41.2
(350 to 420)
36 to 42
49.0 to 56.4
0.08 to
(500 to 575)
0.10
54 to 58
(2.0 to 2.5)
73.5 to 78.4
(750 to 800)
Copper
pipe
Fig. 1
Copper pipe
Burr
Spare reamer
Pipe cutter
Fig. 3
A
Copper pipe
Die
Flare nut
Fig. 5
When installing the unit, securely connect the refrigerant
pipes before starting the compressor.
Insulating material
should protrude 3/8 in.
(10 mm) or more than
the edge of pipe band
[When using pipe with super
insulating material]
Insulating material
should protrude 3/8 in.
(10 mm) or more than
the edge of pipe band
Band (accessory part)
Fixing screw
No good
Good
90°
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
WARNING
Pipe band
Insulating material
should protrude 3/8 in.
(10 mm) or more than
the edge of pipe band
Pipe cover
Fixing screw
Insulating material
should protrude 3/8 in.
Cut
(10 mm) or more than
the edge of pipe band
Pipe cover