Safety systems - General information
4.3 Basic terminology
3SK1 safety relays
36
Manual, 04/2013, A5E02526190021A/RS-AA/01
4.3.10
Two-hand operation/synchronism
Synchronous sensor operation is a special form of simultaneity of sensors.
In this case, it is not sufficient for sensor contacts 1 and 2 to be switched to the closed state
at different times, they must be closed within 0.5 seconds.
Synchronism of sensors is required, in particular, in the case of two-hand operation of
presses. This ensures that the presses only become active when the sensors are operated
simultaneously with both hands. This minimizes the risk of the operator getting a hand in the
press.
Note
In the delivery state of 3SK1 safety relays, monitoring of time synchronism is deactivated.
Time synchronism can be activated using the following adjustable parameter for 3SK11
Advanced and 3SK122 Advanced:
•
Jumper T1/PAR (NO/NC evaluation)
•
Dip switches (1) Autostart
•
Dip switches (3) 2 x single-channel
Note
The 3SK1 Advanced safety relays support exclusively two-hand control units with two NO
contacts.
4.3.11
Cascading
Cascading of safety relays is used for tripping safety relays in series.
Several safety functions can then be logically connected to a shared shutdown path. Several
enabling circuits can be created for selective shutdown of drive elements.
The connection between the individual modules must be arranged on one side only, because
cascading from the last relay to the first one would create a loop which would prevent
starting.
Cascading is implemented within a control cabinet in a single-channel configuration; this is
even permissible with SIL 3 / PL e, because cable routing within a control cabinet is
protected against short-circuits and short-circuiting to P potential (fault exclusion in
accordance with ISO 13849-2).
The 3SK1 Advanced device series offers an extremely convenient solution for cascading.
Input expansions can be easily connected to the evaluation unit by means of device
connectors.
Summary of Contents for SIRIUS 3SK1
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Page 10: ...Table of contents 3SK1 safety relays 10 Manual 04 2013 A5E02526190021A RS AA 01 ...
Page 186: ...Commissioning 3SK1 safety relays 186 Manual 04 2013 A5E02526190021A RS AA 01 ...
Page 258: ...Accessories 3SK1 safety relays 258 Manual 04 2013 A5E02526190021A RS AA 01 ...
Page 260: ...Appendix A 1 Correction sheet 3SK1 safety relays 260 Manual 04 2013 A5E02526190021A RS AA 01 ...
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