3-2 EB 8331-3 EN
Design and principle of operation
3.3 Additional equipment
The actuator can be equipped with mechani-
cal limit contacts or with resistance transmit-
terstoinuencethetasksofcontrolequip-
ment.
Mechanical limit contacts
Optionally, the actuator can be equipped
with two limit contacts. They consist of two
changeover switches. Their switching posi-
tions are changed independently from one
another by continuously adjustable cam
disks.
Thelimitcontactsaresuitableforretrotting.
The installation and adjustment of the me-
chanical limit contacts is described in the 'In-
stallation' section.
Resistance transmitter
Optionally, the actuator can be equipped
with resistance transmitters. They are linked
to the gear and produce a resistance signal
betweenapprox.0and1000Ω(usable
range0to900Ω)proportionaltothevalve
travel. They can be used to process the posi-
tion of the actuator stem. The resistance
transmittersaresuitableforretrotting.The
installation and adjustment of the mechani-
cal limit contacts is described in the 'Installa-
tion' section.