Two-Hand Operation/Synchronism - Siemens SIRIUS 3SK1 Equipment Manual

If the START button is operated for more than 2 seconds, the 3SK1 basic unit detects a wiring
short-circuit in the START button and switches to the fault state (Device = green; SF = flashing
red; Out = flashing yellow; IN = off)
Note
In the delivery state of the 3SK1 safety relays, the start type is set to "Monitored start".
Figure 4-4
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.
When 3SK1 safety relays are used, you can achieve applications up to type IIIc in compliance with
EN 574 / EN 13851 (applications up to PL e/Cat. 4 in compliance with EN 13849-1 or SILCL 3 in
compliance with IEC 62061).
Note
In the delivery state of 3SK1 safety relays, monitoring of time synchronism is deactivated.
Monitoring of time synchronism can be activated using the following adjustable parameters for
3SK112 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 exclusively support two-hand control units with 2 NO contacts.
Note
The two-hand circuit must be marked in compliance with EN 574 EN 13851. You can find
information on determining the response time in the section entitled Response times
(Page 180).
SIRIUS 3SK1 Safety Relays and 3RQ1 Positively-Driven Coupling Relays
Equipment Manual, 05/2021, A5E02526190021A/RS-AE/005
"Monitored start" start function
Safety systems - General information
„1"
„0"
4.3 Basic terminology
47