PSX Differential pressure switch for air up to 5000 Pa

The pressure that is connected to P1 (hipressure point) is compared with the pressure connected to P2. When the differential pressure exceeds the setpoint value the contact changes. When the pressure switch is used to supervise a fan one of the pressure connections can be left open, atmospheric pressure.The setpoint value is set using the knob under the lid. The setpoint value is visible through the lid. The hysteresis is preset in the factory before delivery. The lid is secured with a single screw to facilitate mounting and service.