Operation wit other refrigerants in cascade systems may be satisfactory if the proper motor and displacement combination is selected, adequate lubrication can be maintained, and if adequate compressor protection is provided.
All applications with refrigerants other than R-12, R-22 and
R-502 must be approved by the Copeland Application Engineering department.
Because of the undesirable high discharge temperatures of R-22 should not be used in single stage low temperature compressors 5 HP and larger.
Different expansion valves are required for each refrigerant, so the refrigerants are not interchangeable in a given system, and should never be mixed. If for some reason it is desirable to change from one refrigerant to another in an existing system, it is usually possible to convert the system by changing expansion valves and control settings providing the existing piping sizes and component working pressures are compatible.
In some cases the existing motor-compressor may be satisfactory for example, in converting from R-22 to R-502. If the conversion will result in higher power requirements as is the case in changing from R-12 to R-502, then it may also be necessary to change the motor-compressor.
The refrigerant charge should be held to the minimum required for satisfactory operation, since an abnormally high charge will create potential problems of refrigerant control.
R-410A Refrigerant
In 1987 the Montreal Protocol, an International environmental agreement, established requirements that began the worldwide phase out of ozone-depleting CFCs (chlorofluorocarbons).
In 1992 it was amended to establish a schedule for the phase out of HCFCs (hydrochlorofluorocarbons). HCFCs are less damaging to the ozone layer than CFCs, but still contain ozone-destroying chlorine.
The Montreal Protocol is carried out in the U.S. through Title VI of the Clean Air Act, which is implemented by EPA.
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