Switching Functions - WIKA PSA-31 Mode D'emploi

6. Commissioning, operation

6.8 Switching functions

Hysteresis function
EN
If the system pressure fluctuates around the set point, the hysteresis
keeps the switching status of the outputs stable. With increasing system
pressure, the output switches when reaching the switch point (SP).
Contact normally open (HNO): active
■
Contact normally closed (HNC): inactive
■
With system pressure falling again, the output will not switch back
before the reset point (RP) is reached.
Contact normally open (HNO): inactive
■
Contact normally closed (HNC): active
■
Window function
The window function allows for the control of a defined range.
When the system pressure is between window High (FH) and window
Low (FL), the output switches on.
Contact normally open (FNO): active
■
Contact normally closed (FNC): inactive
■
When the system pressure is outside window High (FH) and window
Low (FL), the output does not switch on.
Contact normally open (FNO): inactive
■
Contact normally closed (FNC): active
■
22 WIKA operating instructions pressure switch model PSA-31 for sanitary applications
Fig.: Hysteresis function
Fig.: Window function