Samson 3767 - Adjusting the Limit Contacts

42 EB8355-2EN
Operation
5.3Adjustingthelimitcontacts
The positioner version with inductive limit
contactshastwoadjustabletagsmountedon
a rotary shaft which operate the associated
proximityswitches(50).
The operation of the inductive limit contact
requiresswitchingamplierstobeconnected
intheoutputcircuit.Refertosection4.2.1.
Whenthetag(51)islocatedintheinductive
eldoftheswitch,theswitchassumesahigh
resistance.Whenitmovesoutsidetheeld,
the switch assumes a low resistance.
The limit contacts are usually adjusted to is-
sueasignalforbothendpositions.The
switchingpointscanalsobeadjustedtoin-
dicate intermediate positions.
TheswitchesAandBmustbeassignedto
the end positions of the control valve (valve
OPENorCLOSED)dependingontheoper-
ating direction and the mounting position ac-
cordingtoTable8andTable9.
Theterminals41/42and51/52canoption-
allybeassignedtotheswitchesAandBby
turningtheassociatedlabelontheterminal
block(alsoseeFig.12).
NOTICE
The tags of the limit contacts cannot
be turned by 360°. As a result, it is
important to observe the correct as-
signment of switches A and B to the
valve positions (valve CLOSED and
valve OPEN), especially when the
limit contacts are to be connected in
safety circuits.
The required switching function, i.e. whether
theoutputrelayistobepickeduporre-
leasedwhenthetagenterstheeld,mustbe
determinedattheswitchingamplier.
Fig.14:Limit contacts