EUCHNER CETx-AR-xxx-AH-xxx (Unicode) - Manual (Page 28)

Operating Instructions Safety Switch CET.-AR-...-AH-...
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Fig. 11: Connection example for separate operation, version with door monitor-
ing output, start button, feedback loop and plug connector RC18
Connection of several CET-AR in a switch chain
Important:
Ì An AR switch chain may contain a maximum of 20 safety switches.
Ì In the case of series connection of more than 11 devices, the PFH
d
can be
calculated according to one of the stated methods in EN ISO 13849-1:2008,
Section 4.5.1.
Ì If the simplified method according to Section 6.3 of EN ISO 13849:2008-12
is used for validation, the Performance Level (PL) might be reduced when
more than 11 devices are connected in series.
Important:
The subsystem CET-AR complies with PL e in accordance with EN 13849-1. To
integrate the subsystem in a category 3 or 4 structure, it is necessary to monitor
the downstream load (the feedback loop must be monitored).
On the use of the CET-AR with feedback loop, this switch must be in the last
position in the switch chain (see Figure 12).
These examples show only an excerpt that is relevant for connection of the CET
system. The example illustrated here does not show complete system planning.
The user is responsible for safe integration in the overall system.
The series connection is shown here based on the example of the version with plug
connectors 2 x M12. The series connection of the version with plug connector RC18
has similar behavior, but is realized using additional terminals in a control cabinet.
The switches in the version with plug connectors 2 x M12 are connected one after
the other with the aid of pre-assembled connection cables and Y-distributors. If
a safety guard is opened or if a fault occurs on one of the switches, the system
shuts down the machine. A higher level control system cannot, however, detect
which safety guard is open or on which switch a fault has occurred with this con-
nection technology.
The safety outputs are permanently assigned to the respective safety inputs of the
downstream switch. OA must be connected to IA and OB to IB. If the connections
are interchanged (e.g. OA to IB), the unit will switch to fault state.
GND
DC 24 V
CET-AR
START
-F1 -F2
Feed-
back
loop
Connected
load
Safety
outputs
RC 18 plug connector
(19-pin)
IB
3
UB
6
OA
4
OB
5
OUT
10
IA
2
0V UB
19
RST
7
OUT D
8 0V UCM
18
LED 1
15
LED 2
16
UCM
1
Y
13