If an R-12 system is mistakenly charged with R-22, what effect could this have?

If an R-12 system is mistakenly charged with R-22, what effect could this have?

• A. Overcool the system
• B. Overload the compressor motor
• C. Enhance cooling efficiency
• D. Prevent freezing

Answer: (B)

Charging an R-12 refrigeration system with R-22 can lead to significant problems, particularly concerning the compressor motor. R-12 and R-22 have different physical and thermodynamic properties, including pressure levels, saturation temperatures, and refrigerant flow characteristics. When R-22 is introduced into an R-12 system, the compressor, which is designed to operate with R-12's specific pressure and temperature characteristics, can be subjected to pressures that exceed its design limits. This mismatch can result in the compressor motor being overloaded. Overloading occurs because the compressor may attempt to work harder to compress the higher-pressure R-22, leading to excessive heat production and increased electrical demands. This can cause the motor to overheat and potentially fail, resulting in costly repairs or system replacement. The other options do not correctly represent the outcome of introducing R-22 into an R-12 system. Overcooling or enhancing cooling efficiency is unlikely since the system is not calibrated for R-22, and it may not function properly at all. Preventing freezing is also not applicable, as the introduction of a different refrigerant will disrupt the system's intended operating conditions. Thus, the primary concern with this scenario is the risk of compressor overload due to operating under unsuitable conditions

Charging an R-12 refrigeration system with R-22 can lead to significant problems, particularly concerning the compressor motor. R-12 and R-22 have different physical and thermodynamic properties, including pressure levels, saturation temperatures, and refrigerant flow characteristics.

When R-22 is introduced into an R-12 system, the compressor, which is designed to operate with R-12's specific pressure and temperature characteristics, can be subjected to pressures that exceed its design limits. This mismatch can result in the compressor motor being overloaded. Overloading occurs because the compressor may attempt to work harder to compress the higher-pressure R-22, leading to excessive heat production and increased electrical demands. This can cause the motor to overheat and potentially fail, resulting in costly repairs or system replacement.

The other options do not correctly represent the outcome of introducing R-22 into an R-12 system. Overcooling or enhancing cooling efficiency is unlikely since the system is not calibrated for R-22, and it may not function properly at all. Preventing freezing is also not applicable, as the introduction of a different refrigerant will disrupt the system's intended operating conditions. Thus, the primary concern with this scenario is the risk of compressor overload due to operating under unsuitable conditions