IEC 60079-0 5th edition one year later. Explosive Dust Atmospheres: IEC EN 61241 parts 0 and 1 turn to series IEC 60079 parts 0 and 31

摘要

One year after its publication, the International Standard IEC 60079-0 5^th edition has not been harmonized as European CENELEC standard yet (even if the harmonization is almost imminent). In order to attest the presumption of conformity to the Directive 94/9/EC, the future EN 60079-0 5^th edition will be previously published in the list of the Official Journal of the European Union. Consequently, there is the risk to give rise to two different "state of the art" levels: an international understanding on one side and an European reading (ATEX) on the other side, with considerable difficulties for the manufacturers in the relations with the non-European countries, and for the end-users and installation firms, due to the possible confusion deriving from two different marking systems and the difficult understanding of the various symbols. This paper means to analyze the evolution of the "state of the art", involving the manufacturer in the evaluation of equipment conformity. Between the various innovations, the 5^th edition includes the integration of explosive dust atmospheres in the IEC 60079 series. One year after the publication the completion process is complete, for the enclosures protection method, with the publication of IEC 60079-31 (equipment dust ignition protection by enclosure "t"), attesting the withdraw of IEC 61241-1. This paper intends to compare some requirements of IEC 61241 standard, parts 0 and 1, with those of IEC 60079 standard, part 0 and 31, in order to ascertain if after one year it is actually possible to affirm that there is a new "state of the art". We intend to concentrate the analysis on the requirements to prevent the dust entry on the enclosures - especially for those provided with gaskets assuring an IP protection -, on the type an duration of the tests and, at last, on the execution sequence of such tests, as it affects the service life of the protection features. It is necessary to come to an unambiguous-n clarification, both for the manufacturer's planning of the equipment evaluation and for the communication with the end-user that will face a further change in the marking.