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9.1 Type of Limit Cut-Off
The type of limit switch cut-off is dependent on the type of valve and the limit position:
Force/stroke-dependent cut-off (cf. 9.2)
Stroke-dependent cut-off (cf. 9.3)
Basic Rule:
For a through-valve, first set the CLOSED position force/stroke-dependent, then the OPEN position stroke-
dependent. For a 3-way valve set both limit positions force/stroke-dependent.
Other arrangements are possible. Please observe the data of your valve. Cutting off the limit switch incorrectly may
cause damage to the valve.
9.2 PSL 201-214
9.2.1 Force/Stroke-Dependent Limit Switch Cut-Off
For force-dependant limit switch cut-off, the limit switches can be set by using the compression „s“ of the spring disc
coupling (Figure 7).
edge notch in
TOP limit position Position of rest BOTTOM limit position
Figure 7: Standard coupling
Using the handwheel on the actuator, drive the valve into the limit position until the valve cone touches the
valve seat. This happens when the valve stem nut starts to move axially and the spindle pushes against the disc
spring force.
Mark the position on one of the drive support pedestals at the rotation protection piece.
Continue to drive the actuator in the same direction until the disc springs are compressed to the required
amount (see the specific data sheet for the drive) as denoted on the spring/force diagram.
Slacken-off the fixing screw on the corresponding switching cam (Figure 8: Adjusting switching cams), move the
cam towards the limit switch until it clicks, and re-tighten the fixing screw.
Check the setting by repeating the drive action to close the valve and check that the spring discs are compressed
to the correct stroke. Re-adjust the cam if required.
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