Mitsubishi Electric Mr.Slim MUZ-A09NA Service Manual page 4

INFORMATION FOR THE AIR CONDITIONER WITH R410A REFRIGERANT
• This room air conditioner adopts HFC refrigerant (R410A) which never destroys the ozone layer.
• Pay particular attention to the following points, though the basic installation procedure is same as that for R22 air condition-
ers.
As R410A has working pressure approximate 1.6 times as high as that of R22, some special tools and piping parts/materials
are required. Refer to the table below.
Take sufficient care not to allow water and other contaminations to enter the R410A refrigerant during storage and installa-
tion, since it is more susceptible to contaminations than R22.
For refrigerant piping, use clean, pressure-proof parts/materials specifically designed for R410A. (Refer to 2. Refrigerant pip-
ing.)
Composition change may occur in R410A since it is a mixed refrigerant. When charging, charge liquid refrigerant to prevent
composition change.
Refrigerant
Composition (Ratio)
Refrigerant handling
Chlorine
Safety group (ASHRAE)
Molecular weight
Boiling point (°F)
Refrigerant
Steam pressure [77°F] (PSIG)
Saturated steam density [77°F] (lb./ft.
Combustibility
ODP 1
GWP 2
Refrigerant charge method
Additional charge on leakage
Kind
Refrigeration oil Color
Smell
1: Ozone Depletion Potential: based on CFC-11
2: Global Warming Potential: based on CO2
The incompatible refrigeration oil easily separates from
refrigerant and is in the upper layer inside the suction
muffl er.
Raising position of the oil back hole enables to back the
refrigeration oil of the upper layer to flow back to the
compressor.
Compressor
New Specification
Suction muffler
Oil back hole
refrigeration oil
Refrigerant
New refrigerant
R410A
HFC-32: HFC-125 (50%: 50%)
Pseudo-azeotropic refrigerant
Not included
A1 / A1
72.6
-60.5
225.82
3
) 3.995
Non combustible
0
1730
From liquid phase in cylinder
Possible
Incompatible oil
None
None
Since refrigerant and refrigeration oil are compatible with
each other, refrigeration oil goes back to the compressor
through the lower position oil back hole.
Compressor
4
Previous refrigerant
R22
R22 (100%)
Single refrigerant
Included
A1
86.5
-41.4
136.34
2.772
Non combustible
0.055
1700
Gas phase
Possible
Compatible oil
Light yellow
None
Current Specification
Suction muffler
Oil back hole
Refrigeration oil /Refrigerant