Application examples
108366_en_01
PHOENIX CONTACT
9.2.2
Series connection with central reset for all safety switches
Application description
Switch chain
The application example shows three PSR-CT safety switches connected in series for mon-
itoring safety equipment. The switch chain is connected to a safety relay. The safety relay
evaluates the signals of the switch chain and switches connected actuators.
Central manual, monitored
start
The safety relay is wired for operation with autostart.
All safety switches are equipped with a reset button for manual, monitored start.
If at least one safety equipment item is opened and closed again, the safety function is reset
centrally via the reset button of the safety switches.
Notes
Phoenix Contact components used
–
3 x PSR-CT safety switch
–
Safety relay: PSR-MC40-3NO-1DO-24DC-..
WARNING: Loss of functional safety
Make sure that all safety switches and the safety relay have the same ground potential.
WARNING: Risk due to unexpected machine startup
Cross-circuit between output FOA1 and the cable of the reset button can result in auto-
matic machine startup.
•
Avoid cross-circuit between FOA1 and the cable from the reset button by means of
design measures, e.g., protected cable installation.
•
See fault exclusion according to EN ISO 13849-2.
Also observe the documentation for all other devices used together with the safety switch.