Air Conditioning Repair Certification (ETI) Practice Exam

The low-pressure cut-off switch plays a critical role in maintaining the operational integrity of refrigeration systems by establishing minimum operating pressure in the evaporator. This switch monitors the pressure in the refrigeration system and is designed to deactivate the compressor if the pressure drops below a certain threshold.

When the pressure is too low, it can indicate unsafe operating conditions, such as inadequate refrigerant flow or potential system damage due to a refrigerant leak. By cutting off the compressor operation, the switch prevents further issues from arising that could lead to compressor failure or other severe problems within the system.

Its function is essential for ensuring that the evaporator operates efficiently. For optimal heat exchange, the evaporator requires a specific minimum pressure; if the pressure is too low, it can lead to reduced efficiency, ice formation on evaporator coils, or damage to components. Thus, this switch is a protective feature designed to safeguard the overall health of the refrigeration system.