Mitsubishi Electronics MS-GA50VB Air Conditioner User Manual


 
6. 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 suffi cient care not to allow water and other contaminations to enter the
R410A refrigerant during storage and installation, since it is more susceptible to
contaminations than R22.
3 For refrigerant piping, use clean, pressure-proof parts / materials specifi cally
designed for R410A. (Refer to 2. Refrigerant piping.)
4 Composition change may occur in R410A since it is a mixed refrigerant. When
charging, charge liquid refrigerant to prevent composition change.
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?
Description
Gauge manifold No
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.
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
No 1/2
Flare tool Yes
Clamp bar hole has been enlarged to reinforce
the spring strength in the tool.
Flare gauge New
Provided for fl aring work (to be used with R22
fl are tool).
Vacuum pump
adaptor
New
Provided to prevent the back fl ow of oil. This
adapter enables you to use existing vacuum
pumps.
Electronic scale
for refrigerant
charging
New
It is diffi cult to measure R410A with a charging
cylinder because the refrigerant bubbles due to
high pressure and high-speed vaporization.
No: Not substitutable for R410A Yes: Substitutable for R410A
Be sure to fi x the indoor/outdoor unit
connecting wire A and power supply cord K
using this cord clamp.
Remove two fi xing
screws to open the
service panel.
Be sure to put the left portion
into the square hole of the
service panel.
Fixing screws
Service panel
WARNING
Be sure to attach the service panel of the outdoor unit securely. If it is not attached
correctly, it could result in a fi re or an electric shock due to dust, water, etc.
Copper pipe
Good
90
o
No good
Tilted Uneven Burred
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.
1
Pipe cutting
Cut the copper pipe correctly with pipe cutter.
6-2 FLARING WORK
Main cause of gas leakage is defect in fl aring work.
Carry out correct fl aring work in the following procedure.
Burr
Copper pipe
Spare
reamer
Pipe
cutter
3
Putting nut on
Remove fl are nuts attached to indoor and outdoor
units, then put them on pipe having completed
burr removal.
(not possible to put them on after fl aring work)
Flare nut for R410A pipe differs from R22 pipe.
Refer to the following table for detail.
mm Inch R410A R22
ø6.35 1/4 17 17
ø12.7 1/2 26 24
Flare nut
Copper pipe
Smooth all around
Even length
all around
Inside is shining without any scratches.
5
Check
Compare the fl ared work with fi gure below.
If fl are is noted to be defective, cut off the fl ared section and do fl aring work again.
4
Flaring work
Carry out fl aring work using fl aring tool as shown below.
Outside diameter
A (mm)
Flare tool for R410A
clutch type
Conventional fl are tool
Clutch type Wing nut type
ø6.35 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 2.0 to 2.5
Firmly hold copper pipe in a die in the dimension shown in the table above.
Die
Copper pipe
Flare nut
Die
Copper pipe
York
Flaring tool
Wing nut typeClutch type
A
A
K