User Manual

Application examples
13.2 Examples of two-hand operation console applications
SIRIUS ACT 3SU1 pushbuttons and signaling devices
270 System Manual, 02/2015, A5E03457306020A/RS-AB/002
Configuration
Figure 13-3 Two-hand operation to SIL 3 or PL e with a safety relay
Operating principle
By imposing the condition of simultaneous pressing of
both pushbuttons, the operator is restricted to the two
-
hand operation console and is thus unable to reach
into the danger zone. The safety relay only switches
the enabling circuits when bo
th signals are active with-
in 500 ms and the feedback circuit is closed.
If one of the two pushbuttons is released, the safety
relay immediately switches the machine off in a safety
-
related manner.
After the emergency stop is actuated, the Start button
must be used to restart.