While the protection of personnel and equipment is a primary concern, at the same time, flexibility and productivity are points that must also be considered as engineers design safety systems. Issues such as these are now being addressed by the new Allen-Bradley Guardmaster SensaGuard family of coded, non-contact interlock switches from Rockwell Automation, which are category 4/SIL 3 rated.
Intended for machine guarding with part or full body access, SensaGuard is particularly suitable for machines with multiple access doors that have to be monitored to this safety level. The devices feature the latest generation of RFID technology for coding and offer a long sensing range (typically 15-25mm) and tolerance to misalignment.
The switches can be connected to various standard Allen-Bradley Guardmaster safety relays via its two Safety PNP outputs and one auxiliary PNP output. These include the Minotaur MSR126, MSR127, MSR200/300 family, SmartGuard and Safety I/O Blocks. Both plastic and stainless steel versions carry an IP69K environmental rating and come with electronic short circuit and over voltage protection built-in.
SensaGuard uses standard size mountings and proximity switch brackets, making it easy to retrofit to existing installations. Its Cat 4/SIL 3 rating is maintained even when multiple units are connected in series. LED indicators located on the switch body give a visual indication of door status, and extended built-in diagnostics ease troubleshooting. A wide range of other Allen-Bradley Guardmaster safety devices, such as light curtains, E-stops and interlock switches, can also be easily connected in series to create dynamic machine guarding systems.