Window Function - WIKA PSD-4 Manual De Instrucciones

5. Commissioning, operation
5.9 Switching functions
Hysteresis function
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
■
WIKA operating instructions pressure switch, model PSD-4
Fig.: Hysteresis function
Fig.: Window function
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