5
Adjusting the limit switch
The positioner version 3760-X1XXXX is
equipped with an inductive limit switch to
signal, for example, a travel end position.
The travel of the plug stem is transmitted to
the metal tag of the proximity switch over
the pin (5) and lever (3).
For operation of the inductive limit switch, a
switching amplifier (section 3.2.1) must be
connected to the output circuit.
Normally, the limit switch is adjusted to pro-
vide a signal when the valve has reached
one of its end positions. However, you may
also adjust to signal intermediate travel po-
sitions.
Adjusting the switching point:
Prior to adjusting the limit switch, the start-
ing point and upper range value of the
positioner need to be adjusted.
1. The yellow switching point indicator (7)
must be within the area of the notch
mark (6). If this is not the case, turn ad-
justment screw (4).
2. Move control valve to the desired
switching position. Turn adjustment
screw (4) until the switching point is
reached. This will be indicated by the
switching amplifier.
The switching element and the levers re-
quired to operate it are slightly sensitive to
temperature changes. To ensure reliable
switching, both the switching hysteresis and
the displacement of the switching point due
to temperature fluctuations need to be taken
into account when adjusting the positioner.
The terminal used to connect the limit switch
(41/42 or 51/52) can be written on the ad-
hesive function label inside the positioner
cover.
Mark the adjusted switching function, i.e.
switching at either open or closed valve on
the other label.
EB 8385 EN
19
Adjusting the limit switch
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