Mitsubishi Electric MFZ-KA50VA / SUZ-KA50VA [9/24] Indoor outdoor unit connection finishing and test run

Mitsubishi Electric MFZ-KA50VA / SUZ-KA50VA [9/24] Indoor outdoor unit connection finishing and test run
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5. INDOOR/OUTDOOR UNIT CONNECTION FINISHING AND TEST RUN
INSTALLATION INFORMATION FOR THE AIR CONDITIONER WITH R410A
REFRIGERANT
This room air conditioner adopts an HFC refrigerant (R410A) which will never destroy the ozone layer.
Pay particular attention to the following points, though the basic installation procedure is same as that for
R22 air conditioners.
1 As R410A has a working pressure approx. 1.6 times as high as that of R22, some special tools and piping
parts / materials are required. (Refer to the table below.)
2 Take sufficient care not to allow water and other contaminations to enter the R410A refrigerant during stor-
age and installation, since it is more susceptible to contaminations than R22.
3 For refrigerant piping, use clean, pressure-proof parts / materials specifically designed for R410A.
4 Composition change may occur in R410A since it is a mixed refrigerant. When charging, charge liquid refrig-
erant to prevent composition change.
5-1 TOOLS DEDICATED FOR THE AIR CONDITIONER WITH R410A RE-
FRIGERANT
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? Description
R410A has high pressures beyond the measurement range of existing
gauges.
Gauge manifold No
Port diameters have been changed to prevent any other refrigerant from
being charged into the unit.
Charge hose No
Hose material and cap size have been changed to improve the pressure
resistance.
Gas leak detector No Dedicated for HFC refrigerant.
Torque wrench Yes 1/4 and 3/8
Flare tool Yes
Clamp bar hole has been enlarged to reinforce the spring strength in the
tool.
Flare gauge New Provided for flaring work (to be used with R22 flare tool).
Vacuum pump adaptor New
Provided to prevent the back flow of oil. This adapter enables you to use
existing vacuum pumps.
New
It is difficult to measure R410A with a charging cylinder because the refrig-
erant bubbles due to high pressure and high-speed vaporization.
No: Not substitutable for R410A Yes: Substitutable for R410A
Electronic scale for re-
frigerant charging
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.
4. Flaring work
Carry out flaring work using flaring tool as shown below.
A (mm)
Outside Conventional flare tool
diameter Clutch type Wing nut type
ø6.35 mm 0 to 0.5 1.0 to 1.5 1.5 to 2.0
ø9.52 mm 0 to 0.5 1.0 to 1.5 1.5 to 2.0
ø12.7 mm 0 to 0.5 1.0 to 1.5 1.5 to 2.0
Flare tool for
R410A clutch type
mm R410A
ø6.35 17
ø9.52 22
ø12.7 26
5-2 FLARING WORK
Main cause of gas leakage is defect in flaring work.
Carry out correct flaring work in the following procedure.
Copper
pipe
Good
No good
Tilted
Uneven
Burred
90°
Burr
Copper pipe
Spare
reamer
Pipe cutter
1. Pipe cutting
Cut the copper pipe correctly with pipe cut-
ter.
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.
Flare nut
Copper pipe
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.
Smooth all around
Even length
all around
Inside is shining without any
scratches.
A
Die
Copper pipe
Flare nut
Die
Copper pipe
Yo r k
Flaring tool
Wing nut type
Clutch type
01HM05A309_RAC-IM_en.pm6 4/6/05, 1:38 PM9

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