The low-pressure cutout switch serves what main purpose?

The primary purpose of a low-pressure cutout switch is to control the compressor based on suction pressure. This switch monitors the pressure in the suction line, which is the line that carries refrigerant back to the compressor after it has absorbed heat from the evaporator. If the suction pressure drops below a certain threshold—indicating insufficient refrigerant or potential issues such as low load conditions—the low-pressure cutout switch will open, stopping the compressor to prevent damage.

This function is crucial for the safe and efficient operation of refrigeration systems. By cutting off the compressor when suction pressure falls too low, the switch protects the system from issues like compressor overheating or damage due to inadequate lubrication, which can occur if the refrigerant flow is reduced or if there is a leak in the system. This regulation helps maintain overall system health and ensures efficient operation by preventing scenarios that could lead to equipment failure.

Other options relate to different functions. For example, stopping the compressor during high pressure or maintaining constant refrigerant flow pertains to other components or conditions in a refrigeration system. Regulating evaporator temperatures can also be influenced by other controls and does not directly relate to the specific role of the low-pressure cutout switch.