NORSTAT Safety Relays - Handbuch (Seite 39)

application guide safety relays from riese electronic page 37
Safety circuits with safety relays
Safety circuits with safety relays is a young technology. Before the safety relays were established on the
safety marked all safety circuits had to be realized with conductors.
That means a defined number of conductors were connected together so that safety application were
realized .
Example:
electronic conductor circuit
Application only for very simple machines and under restrictions
Main
switch
Emergency
stop
Main power
supply
End user
Example of a machine control unit with two emergency stop conductors. Allowed to use
only with restrictions
Emergency stop
Start
Today not longer used
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