
Operating Instructions
Chapter
7
UE 440/470
8 010 432/P097/14-03-05
© SICK AG • Industrial Safety Systems • Germany • All rights reserved
67
Application and switching
examples
Application A
Application B
Marginal conditions
$
Both OSSDs are monitored for cross circuits.
$
The connection cables of the dual channel safety switches are
installed in separate sheathing lines or protected.
$
The operating mode selector switch has a 1-of-4 evaluation (i.e.
expectations of the availability of the signals).
$
EDM and contactors are wired within the control cabinet.
$
The connection cables of both reset buttons are installed in
separate sheathing lines or protected.
Result
The UE 470 reaches a value of
21
)
% PFD at SIL 3 in
application A with the specified
marginal conditions after
10 years.
The UE 470 reaches a value of
21
)
% PFD at SIL 3 in
application B with the specified
marginal conditions after
10 years.
In accordance with Standard EN 963, the machine cycle contact BDC must be
implemented with two independent signals (e.g. two 1-channel NO contacts). The following
information is provided there: "The means for setting the acceptance point, at which the
protective effect is nullified during the closing stroke, must be a position signal and a
pressure signal or a suitable alternative; these are triggered when the tools are closed and
the machine begins to apply the force of pressure."
Fig. 44: Connection of the
hazardous point protection
with PSDI mode
Note