PNOZsigma safety relays are slimline all-rounders

Pilz has already published a PNOZclassic-to-PNOZsigma checklist to help customers identify the right PNOZsigma relay to use when replacing Classic relays, and the company's technical support engineers can provide advice by telephone, email or fax in the event of any queries about replacing Classic relays, Pilz X range relays or, indeed, safety relays from other manufacturers.

For maintenance engineers, one of the advantages of the multi-functional PNOZsigma relays is that a much smaller number of products are capable of being used in applications that previously required the use of numerous different models of safety relay. This versatility means that stockholdings can be reduced substantially. Furthermore, the PNOZsigma relays benefit from LEDs on the front that give much better diagnostic data than their predecessors, which helps with troubleshooting and therefore reduces machine downtime.

Machine builders and system integrators will appreciate the above advantages, plus they will find that the slimline PNOZsigma relays require less cabinet space. For example, the slimmest model is just 12.5mm wide, and it is now possible to install six safety outputs within a width of just 30mm. Typically the relays deliver the same functionality in 50 per cent of the space required previously. Furthermore, improved switching capacity leads to further cost savings, and all models feature a semiconductor output for status indication purposes.

When safety-related control systems are being upgraded, the slimline PNOZsigma relays are easier to install in existing control cabinets than traditional safety relays.

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 - which is the case when wiring an expansion module to a traditional safety relay.