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 / model of pressure switch.

Example: Cut-in 30 psi Cut-out 50 psi - Differential 20 psi (50-30 psi)

Adjustable differential simply 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, the switch actuates again (this is the reactivation point). The dead-band of this switch is 20 psi (the difference between the set point of 60 and the reactivation point of 40 psi).