Single-pressure controls connect to one of the two pressure lines in a refrigeration system and make or break an electrical connection when pressures exceed or drop below the setpoint. They feature a control unit that helps protect the sensitive components and allows the user to view and adjust the setpoint. They are commonly used with the low-pressure side to control the compressor and act as a low-limit safeguard. They can also act as an overpressure safeguard on the high-pressure line.

Single-pressure encapsulated switches install into HVAC systems and react to changes in refrigerant pressure by making or breaking an electrical connection. They are compact and self-contained but are less protected than standard pressure controls and sensors.