Configuration / Project Engineering; General Remarks - Siemens SIRIUS 3TK2826 Manual

Configuration / project engineering

9.1

General remarks

SIRIUS safety relays and the safety chain
A safety chain generally consists of the Sense, Evaluate and Deactivate functions.
Sensing
This involves sensing a safety requirement, e.g. when an EMERGENCY STOP facility is
actuated or a hazardous area protected by sensors such as light arrays or laser scanners is
entered.
Evaluation
This involves detecting a safety requirement and safely initiating the reaction, e.g. the
undelayed deactivation of the SIRIUS safety relay's enabling circuits.
Deactivation
This involves the reaction in an emergency or under a risk, e.g. by deactivating hazarouds
drives via subsequently connected contactors.
Result
Within this safety chain, SIRIUS safety relays act in the areas of evaluation and deactivation.
3TK2826 safety relay
Manual, 08/2007, GWA NEB 926 1579-02 DS 02
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