When charging an R-12 refrigeration system using a water-cooled condenser, to which pressure must you first charge with vapor?

When charging an R-12 refrigeration system using a water-cooled condenser, to which pressure must you first charge with vapor?

• A. At least 25 psig
• B. At least 30 psig
• C. At least 35 psig
• D. At least 40 psig

Answer: (C)

Charging an R-12 refrigeration system with vapor requires maintaining a minimum pressure in the system to ensure proper refrigerant flow and prevent issues such as liquid floodback and compressor damage. R-12, which operates under specific pressure-temperature relationships, requires the initial vapor charge to reach a certain minimum pressure to effectively transfer the refrigerant into the high-pressure side of the system. In this context, charging to at least 35 psig is essential to create enough pressure differential between the vapor in the cylinder and the condenser, promoting efficient flow of refrigerant. This level of pressure is crucial for the refrigerant to properly enter the system and subsequently condense effectively in the condenser coils. Lower pressures could lead to inadequate vapor flow, potentially resulting in compressor issues or inefficient system operation. This understanding of pressure requirements is vital for safe and efficient system charge, ensuring that the refrigeration cycle functions optimally without risking damage to system components or compromising performance.

Charging an R-12 refrigeration system with vapor requires maintaining a minimum pressure in the system to ensure proper refrigerant flow and prevent issues such as liquid floodback and compressor damage. R-12, which operates under specific pressure-temperature relationships, requires the initial vapor charge to reach a certain minimum pressure to effectively transfer the refrigerant into the high-pressure side of the system.

In this context, charging to at least 35 psig is essential to create enough pressure differential between the vapor in the cylinder and the condenser, promoting efficient flow of refrigerant. This level of pressure is crucial for the refrigerant to properly enter the system and subsequently condense effectively in the condenser coils.

Lower pressures could lead to inadequate vapor flow, potentially resulting in compressor issues or inefficient system operation. This understanding of pressure requirements is vital for safe and efficient system charge, ensuring that the refrigeration cycle functions optimally without risking damage to system components or compromising performance.