The new safety relay modules are suitable for use in areas with explosive atmospheres.

As Competence Centre of the Schmersal Group for explosion protection, Elan continuously extends and completes the programme of Ex switching appliances and control devices. Though the programme of available field devices being already comprehensive, it did not include Ex versions of safety relay modules for control cabinet mounting – until now.

This gap in the programme now is closed with as much as four different safety relay modules from the PROTECT SRB programme, which join the tried-and-tested safety technology with the requirements for explosion protection. These modules are equipped with intrinsically safe monitoring circuits (Ex i; safe separation to EN 60097-11) and are suitable for the safe signal evaluation of emergency stop devices and for guard door monitoring.

The PROTEXT SRB 101-Ex (one safety release) and SRB 200 (two safety release) series are suitable for use in Ex zones. There are variants with monitored reset function (trailing edge) as well as with automatic or manual reset function. All these versions have a stop 0 safety release and optionally can be supplied with cross-wire short detection.

The four new safety relay modules can be used in intrinsically safe circuits in combination with, amongst others, reset buttons, emergency stop control devices, interlocking devices and safety magnet switches to the ATEX-Directive 94/9/CE. Due to the explosion category “n” to EN 60079-15, they can be used in IP 54 control cabinets in Ex zone 2 (gas).

The modules have a compact design and require only 22.5 mm in case of DIN rail mounting in the control cabinet. Their red front plate immediately distinguishes them from conventional, not intrinsically safe safety relay modules. These features provide the new safety relay modules with a large application spectrum, ranging from the chemical industry over the broad field of food processing and packaging technology to the plastics technology and recycling plants. Even some aspects of metal processing must comply with the explosion protection directives, considering that the dusts from light metals such as aluminium and magnesium – two metals that are frequently used in the automotive industry – are inflammable in certain dust-air concentrations.

The Schmersal Group will present the new safety relay modules at Powtech 2008 in Nurnberg: Hall 7, Booth 7-219.