Samson 3768, Монтаж и эксплуатация

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28 EB 8356 EN
Operation – Adjusting the limit contacts
5 Operation – Adjusting the
limit contacts
Two adjustable tags (51) are located on the
rotary axis which activate the associated
proximity switches (50).
The operation of the inductive limit switches
requires switching amplifiers to be connected
in the output circuit (see section 4).
When the tag (51) is located in the inductive
field of the switch, the switch assumes a high
resistance. When it moves outside the field,
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 mount -
ing position of the limit switch according to
Table 8 and Table 9. The terminals 41/42
and 51/52 can optionally be assigned to
the switches A and B by turning the associat-
ed label on the terminal block (see Fig. 8).
Î
The tags of the limit contacts cannot be
turned by 360°. As a result, it is import -
ant to observe the correct assignment of
switches A and B to the valve positions
(valve CLOSED and valve OPEN), espe -
cially when the limit contacts are to be
connected in safety circuits.
Î
The required switching function, i.e.
whether the output relay is to be picked
up or released when the tag enters the
field, must be determined by jumpers for
either load current or no-load current at
the switching amplifier.
Fig. 9: Limit switch