W 27-3 Ex: the photoelectric series in standard-compliant protective housings for the Ex-zone
Waldkirch, April 2005 – The new W 27-3 Ex is the standard-compliant solution for object detection in Zone 2 (gas) and Zone 22 (non-conductive dusts) Ex-zones. Standard-compliant means: the sensor and its metal protective housing comply with Categories 3G and 3D of the 94/9/EU (ATEX) directive – thus users need have no worries about the mechanical strength of the device stipulated in the directive (and often underestimated). For all the Ex-protection provided, sensor performance is not neglected: long ranges, rapid commissioning and high operational reliability make the W 27-3 Ex an EXcellent automation solution.
The W 27-3 Ex series meets the requirements of Category 3G and 3D, based on the 94/9/EU Directive. The relevant standards demand, among other things, that the housings of such electrical equipment must have a mechanical strength corresponding to test criteria in order to achieve the Ex-protection Category. The responsibility for standard-compliant design is transferred to the user (at the latest) on purchase and operation of the device, and the user must then make a major effort to determine and guarantee the mechanical strength of the device. These costs and risks are completely absent when the W 27-3 Ex is used. At the same time, users have a complete series at their disposal, with which they can solve their tasks individually, efficiently, reliably and standard-compliantly.
Ex-photoelectric switches: rapid commissioning thanks to intensive red light
Long operating ranges with large functional reserves and rapid commissioning – made possible by a new, intensive red-light transmission LED – are vital features of the two Ex-photoelectric switches in the series. The WL 27-3Ex photoelectric reflex switch offers an operating range of 0.1 - 11 m; the WSE 27-3Ex through-beam system can be used over distances of 0 - 25 m. Whether on the reflector or the receiver – alignment of both devices is considerably simpler with the new transmission LED and the bright light spot it generates.
Ex-photoelectric proximity switch with precise background suppression
The WTB 27-3Ex photoelectric proximity switch is available for applications in which an object requires direct detection, and reliable suppression of the scanning background is essential. The sensor, with its infrared light transmission LED, offers scanning distances of 100 – 1,600 mm. Background suppression ensures that objects or pulses present directly behind the target object do not impair the reliable functioning of the proximity switch.
EXcellent in the Ex-zone
The W 27-3 Ex series is principally used on machines and plants in the potentially explosive Zone 2 (gas) or Zone 22 (non-conductive dusts) areas in, among other sectors, the chemical, pharmaceutical, petrochemical and paint industries, in mills or cement works, or wood processing plants. A wide variety of automation tasks can be quickly, easily and reliably solved with the sensors thanks to their standard-compliant housing, standardised mechanical and electrical connector technology, and their rapid and simple alignment and parameterisation.