If the low-pressure gauge of a vapor-cycle cooling system stays in a vacuum after evacuation, what is the likely issue?

When the low-pressure gauge of a vapor-cycle cooling system remains in a vacuum after the evacuation process, it indicates that there is a significant issue preventing the proper circulation of refrigerant within the system. A blockage in the system could result in an inability for the refrigerant to flow correctly, leading to the gauge reading low pressure or achieving a vacuum state, as there isn’t enough refrigerant to create the necessary pressure.

In a properly functioning vapor-cycle system, evacuation should result in a complete removal of moisture and air, followed by a pressure increase once the system is charged with refrigerant. If a blockage exists, refrigerant circulation is impeded, and the gauge reflects this by indicating a vacuum state instead of the anticipated pressure once it’s charged.

This scenario can arise from issues such as ice buildup, contaminants within the system, or obstructions in the lines that could prevent the refrigerant from moving freely. Correct identification of a blockage as the cause is critical for ensuring efficient operation of the cooling system and for troubleshooting any further issues that may arise.