Service manual

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.
New refrigerant Previous refrigerant
Refrigerant
Refrigerant R410A R22
Composition (Ratio) HFC-32: HFC-125 (50%: 50%) R22 (100%)
Refrigerant handling Pseudo-azeotropic refrigerant Single refrigerant
Chlorine Not included Included
Safety group (ASHRAE) A1 / A1 A1
Molecular weight 72.6 86.5
Boiling point (°F) -60.5 -41.4
Steam pressure [77°F] (PSIG) 225.82 136.34
Saturated steam density [77°F] (lb./ft.
3
) 3.995 2.772
Combustibility Non combustible Non combustible
ODP
1 0 0.055
GWP 2 1730 1700
Refrigerant charge method From liquid phase in cylinder Gas phase
Additional charge on leakage Possible Possible
Refrigeration oil
Kind Incompatible oil Compatible oil
Color None Light yellow
Smell None None
1: Ozone Depletion Potential: based on CFC-11
2: Global Warming Potential: based on CO2
New Specification Current Specification
Compressor
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.
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
Suction muffler
Oil back hole
refrigeration oil
Refrigerant
Compressor
Suction muffler
Oil back hole
Refrigeration oil /Refrigerant