ESCO Air Conditioning Practice Exam

The primary function of a low pressure cut off switch in an air conditioning system is to prevent evaporator icing. This switch monitors the pressure within the evaporator and is designed to turn off the compressor if the pressure drops below a certain threshold. When the pressure is too low, it may indicate that the refrigerant is not properly circulating, which can lead to an excessively cold evaporator and, subsequently, icing.

Ice formation can severely impede airflow and reduce the efficiency of the system, leading to potential damage to components and compromised system performance. By cutting off the compressor operation when low pressure is detected, the switch helps maintain appropriate conditions within the evaporator, ensuring that it operates effectively without the risk of icing. This crucial safety mechanism protects the system's integrity and functionality.

While a low pressure cut off switch helps maintain system efficiency indirectly by preventing icing, its primary role is focused on protecting the evaporator environment rather than directly addressing compressor efficiency or regulating discharge pressure.