PNOZsigma safety relays

The multifunctional PNOZsigma relay allows a smaller number of units to be used in applications that previously required the use of numerous different models of safety relay, meaning that stockholdings can be reduced substantially. The PNOZsigma relays also provide LEDs on the front that give much better diagnostic data than their predecessors, helping with troubleshooting and therefore reducing machine downtime.

The PNOZsigma relays require less cabinet space, the slimmest model being just 12.5 mm wide, and it is now possible to install six safety outputs within a width of 30 mm. Typically, the relays deliver the same functionality in 50% of the space required previously. Improved switching capacity also leads to further cost savings, and all models feature a semiconductor output for status indication purposes.

Several of the PNOZsigma relays have a user-selectable reset mode, operating mode and time functions, the configuration of which is performed by means of switches on the front panel rather than by wired connections. This means that the set-up is quicker, the chance of errors is reduced, and the tamper-proof technology is safer (if the switch position is altered, the relay will shut down the safety circuit — and it will remain shut down even if the switch is moved back to its original position).

If additional contacts are required, expansion modules can be mounted alongside the base relay and connected by means of a jumper connector. Quicker, easier and less error prone than wiring the units together, this way of expanding the number of contacts also avoids the sacrificing of a safety output.