WIKA WUD-26 - Handbuch (Seite 18)

Operating instructions/Betriebsanleitung, WUD-2x
11611057.01 GB/D 11/2013
18
Switch function
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 (NO): active
■ Contact normally closed (NC): inactive
With system pressure falling again, the output will not switch back before the
reset point (RP) is reached.
■ Contact normally open (NO): inactive
■ Contact normally closed (NC): active
Delay times (0 ... 50 s)
This makes it possible to filter out unwanted system pressure peaks of a short
duration or a high frequency (damping). The system pressure must be present
for at least a certain pre-set time for the output to switch on. The output does
not immediately change its status when it reaches the switching event (SP),
but rather only after the pre-set delay time (DS).
If the switching event is no longer present after the delay time, the switch
output does not change. The output only switches back when the system
pressure has fallen down to the reset point (PR) and stays at or below the
reset point (RP) for at least the pre-set delay time (DR).
If the switching event is no longer present after the delay time, the
switch output does not change.
7. Initial start-up and operation GB