International installation methods based on NEC and IEC standards

Abstract

The installation standard IEC/EN 60079–14 [1] was revised and the new edition (edition 4) was published in December 2007. In this edition, the requirements for Electrical installations in hazardous areas (other than mines) including areas endangered by combustible dust were merged for the first time. With the introduction of Equipment Protection Levels (EPL), new options for the selection criteria for electrical equipment are given. The risk assessment carried out may make it possible to use equipment with a higher or even a lower EPL as required for the corresponding zone. Work on the next edition has been started to eliminate some weak points and to add new techniques. In US the IEC based zone classification system was introduced into the NEC [2] in its 1996 edition and, in 2007 OSHA introduced the zone classification system as an alternative to the traditional division classification system. Articles 505 and 506 in the NEC have allowed IEC type equipment to be used within the U.S, however this equipment must also meet the ordinary location standards of the U.S. and any variations in the national adoption of the IEC standards. Due to U.S. national variations to IEC standards, lack of adoption of some IEC standards, including IEC60079–14, and differences in electrical installation practice, there are significant differences in what is done in installations in the U.S. and what is done in the IEC world. However, while there are great differences existing, there are also opportunities for global organizations to attempt to provide modifiable global solutions both now and in the future.