Siemens SIRIUS 3TK2826 Manual page 31

DIP Parameter
switch
8 Startup after
power failure
Safety shutdown mat operation
All safety shutdown mats and safety edges operating in a 4-wire configuration that work in
accordance with the principle of cross-circuit tripping can be connected to the 3TK2826
safety relay. Deactivation of the 3TK2826 is triggered by a cross-circuit of the two sensor
leads T1/Y12, T2/Y22.
The 3TK2826 evaluation unit can only be started if the T1/Y12 and T2/Y22 lead connection
has been established by contact blocks of the safety shutdown mat and there is no cross-
circuit of the signal leads due to tripping of the signaling device. This means that the device
remains in a safe state in the event of a discontinuity of the signal leads, or assumes the
safe state while switched through.
If the safety shutdown mat resistance is < 1000 Ω for the mat and the connecting leads, safe
evaluation is performed in accordance with DIN EN 1760-1 and DIN EN 1760-2.
Function of the cascading input (terminal 1)
1. Safe combination of safety relays
3TK2826 safety relay
Manual, 08/2007, GWA NEB 926 1579-02 DS 02
Function
The parameters of the 3TK2826 device can be defined so that the enabling circuits switch
automatically to the active position after a power failure, i.e. without actuation of the start button
Y33.
Requirements:
Y12, Y22 or the cascading input 1 are set to "monitored start".
•
The switch-on condition at the sensor inputs and at the cascading input is satisfied.
•
The START button was actuated before the power failure and this was valid, i.e. the
•
enabling circuits were in the active position.
In this application, a higher-level safety relay switches off the 3TK2826 via the cascading
input.
Example:
an EMERGENCY STOP circuit is to deactivate the entire installation as a higher-level
circuit.
Several function groups (e.g., protective doors) that deactivate locally can be operated as
subordinate units.
WARNING
Application/safety relay safety category
When faults are ruled out (protected laying of the control lead), the application's safety
category corresponds to that of the higher-level safety relay.
Configuration / project engineering
9.3 Explanation of the device's functions
31