Self-sufficient control devices for explosion protection

The control devices in the Steute Ex RF BF 80 series, that have been designed for use in explosive zones, are now also wireless and self-sufficient. They will be shown at the SPS/ IPC/ DRIVES exhibition 2011.

In order to assemble these control and command devices, the enclosure merely has to be affixed to the wall or machine. No power or signal cables are needed because signals are transmitted by radio. The switching device generates the required energy all by itself. Or more accurately: the user generates the energy all by himself when he actuates the switch. A miniaturised electrodynamic energy transformer mounted on the switch plunger transforms kinetic energy to electrical energy and a signal is sent to the receiver unit by radio.

This wireless technology has long been tried and tested in both industrial applications and building automation, and has now begun to assert itself in the field of explosion protection. The steute "Energy Harvesting" technology has been approved by the appropriate authorities – with the result that the command devices in our Ex RF BF 80 series are certified for use in gas-Ex zones 1 and 2, as well as dust-Ex zones 21 and 22, in accordance with the ATEX guidelines. The plastic enclosure of our new command devices is very robust. Variants for one, two and three control elements are available, with users being able to choose from among a wide range of pushbuttons, mushroom pushbuttons, selector and key switches. The wireless protocol guarantees a high degree of transmission safety over distances of up to 30 m (indoors) or 200 m (outdoors). Several »Wireless Ex« systems can be operated within one transmission area; the exact assignation of command device to receiver unit is performed in a few simple steps during the teach-in process.

Like all steute switching devices, the Ex RF BF 80 series is extremely durable. The switching insert with its electrodynamic energy generator has been developed especially for rough industrial applications, achieving a mechanical lifetime of over one million switching cycles. At the SPS/IPC/DRIVES exhibition, steute will also be presenting other self-sufficient switching devices. And our range of Ex-switchgear has also been expanded – e.g. to include a new series of position switches for universal use.