Indoor/Outdoor Unit Connection Finishing And; Flaring Work - Mitsubishi Electric MCFH-A24WV Manual De Instalación

6. INDOOR/OUTDOOR UNIT CONNECTION FINISHING AND TEST RUN
6-1 Tools dedicated for the air conditioner with R410A refrigerant
The following tools are required for R410A refrigerant. Some R22 tools can be substituted for R410A tools.
The diameter of the service port on the stop valve in outdoor unit has been changed to prevent any other
refrigerant being charged into the unit. (Cap size has been changed from 7/16 UNF with 20 threads to 1/2 UNF
with 20 threads.)
R410A tools Can R22 tools be used?
Gauge manifold No
Charge hose No
Gas leak detector No
Yes
Torque wrench
No
Flare tool Yes
Flare gauge New
Vacuum pump adaptor New
Electronic scale for re-
New
frigerant charging
No: Not substitutable for R410A Yes: Substitutable for R410A
6-2

FLARING WORK

• Main cause of gas leakage is defect in flaring work.
Carry out correct flaring work in the following procedure.
1. Pipe cutting
• Cut the copper pipe correctly with pipe cutter.
Description
R410A has high pressures beyond the measurement range of existing
gauges.
Port diameters have been changed to prevent any other refrigerant from
being charged into the unit.
Hose material and cap size have been changed to improve the pressure
resistance.
Dedicated for HFC refrigerant.
1/4
5/8
Clamp bar hole has been enlarged to reinforce the spring strength in the
tool.
Provided for flaring work (to be used with R22 flare tool).
Provided to prevent the back flow of oil. This adapter enables you to use
existing vacuum pumps.
It is difficult to measure R410A with a charging cylinder because the refrig-
erant bubbles due to high pressure and high-speed vaporization.
No good
Good
Copper pipe
Tilted
90°
2. Burrs removal
• Completely remove all burrs from the cut cross section of
pipe.
• 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. Putting nut on
• 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)
• Flare nut for R410A pipe differs from R22 pipe. Refer to the
following table for detail.
mm inch
ø6.35 1/4
ø15.88 5/8
4. Flaring work
• Carry out flaring work using flaring tool as shown below.
Burred
Uneven
Outside Flare tool for
R410A clutch type
diameter
ø6.35 mm 0 to 0.5
ø15.88 mm 0 to 0.5
• Firmly hold copper pipe in a die in the dimension shown in
the table above.
5. Check
• Compare the flared work with figure below.
• If flare is noted to be defective, cut off the flared section
and do flaring work again.
10
Copper pipe
Burr
Flare nut
R410A R22
17 17
29 27
Flaring tool
Die
Copper pipe
Clutch type
Wing nut type
A (mm)
Conventional flare tool
Clutch type Wing nut type
1.0 to 1.5 1.5 to 2.0
1.0 to 1.5 2.0 to 2.5
Smooth all around Inside is shining without any scratches.
Even length
all around
Spare
reamer
Pipe
cutter
Copper pipe
A
York
Die
Copper pipe
Flare nut