A leak in the evaporator shell of an R134A system is likely to cause what protective action?

• A. Activate the high-pressure switch
• B. Set off the refrigerant monitor alarm
• C. Trigger the low-temperature cutout
• D. None of the above

Answer: (B)

A leak in the evaporator shell allows refrigerant to escape, and systems that have a refrigerant monitoring setup respond to that kind of release by sounding an alarm. The refrigerant monitor is specifically designed to detect refrigerant vapors or concentrations and alert personnel, often triggering safety shutdown procedures as needed. A high-pressure switch would react to abnormally high system pressure, which isn’t the typical consequence of a leak. A low-temperature cutout would trip if the evaporator temperature dropped too low, not because of a leak. So the protective action most likely is the refrigerant monitor alarm being activated.