Pilz PNOZsigma PNOZ s4 Emergency Stop Safety Relay, 48 → 240V ac/dc, Dual-Channel, 3 Safety Contacts

To ensure complete safety in these environments, a safety relay can be added to your circuit to allow you full control and monitoring of your working environment. A safety relay will run regular checks down your circuit by sending pulses back and forth to confirm whether any (for example) wiring was implemented incorrectly or any welding has occurred along the circuit. Once the relay has detected this, it would then shut down the area by cutting off the power, until the fault can be determined and fixed. Most recent safety relays feature intuitive LED displays that will alert users to any faults, this is of course useful to prevent harm to users and also proactively engage in maintenance before any machinery is damaged beyond repair, so certain cost savings can be associated when using a safety relay.

Some safety relays have specific functions and only work with certain devices like E-STOPs, some work better with other devices like safety curtains. More than one safety relay can be used to give you total monitoring of your circuit, ensuring you and your employees safety.