What is Pressure Switch Differential?

Pressure Switch Differential (commonly referred to as range)

Differential is the difference in pressure between the trip point (cut-out) and the reset point (cut-in). It can be adjustable or nonadjustable (fixed) depending on the make and model of the pressure switch.

Example: If the cut-in is 30 psi and the cut-out is 50 psi, the differential is 20 psi (50 minus 30 psi).

Adjustable Differential

This means that the actuation range can be adjusted in the field.

It’s not common but you may have someone refer to differential as “dead-band”. The dead-band is the difference between the actuation point and the re-actuation point in a pressure switch. For example: if a pressure switch is set to operate at 60 psi on increasing pressure, the switch will actuate when pressure rises to that point. As the pressure drops to 40 psi, the switch actuates again (this is the re-actuation point). The dead-band of this switch is 20 psi (the difference between the set point of 60 psi and the re-actuation point of 40 psi).