
Chapter
6
Operating Instructions
UE 440/470
54
© SICK AG • Industrial Safety Systems • Germany • All rights reserved
8 010 432/P097/14-03-05
Electrical installation
6.2.11
External device monitoring (EDM)
Wire the external device monitoring within the control cabinet!
You must implement the external device monitoring electrically by the positive closing
action of both N/C contacts (k1, k2) when the contact elements (K1, K2) reach their de-
energised position after the protective device has responded. 24 V is then applied at the
input of the EDM. If all criteria for switching on the OSSD are fulfilled and the 24 V are not
connected, one of the contact elements is defective and the external device monitoring
prevents switch-on of the OSSD.
Spark-suppressed contactors extend the response time of the OSSDs depending on the
type of the protective wiring.
%
ATTENTION
Fig. 24: Example for
connection of the external
device monitoring
Note