Get in the zone! [zone equipment installation]

The first project in the United States that has been designed and constructed utilizing the Zone method of classification and the methods of explosion protection allowed for Zones is a new oil field on the North Slope of Alaska. The Zone method of classification and the Increased Safety (Type e) method of protection for Zone-1 areas are used at this facility. The lack of necessary components, difficulties with wiring methods allowed by NEC Article 505, and the incompatibility of existing wiring methods with the new products have all been experienced. Despite these difficulties, the author is convinced that the Zones are here to stay and will be found to provide a safe and cost-effective installation. However, proof of safer and cheaper installations will have to be determined in the future, after some experience and results have been established with which to make comparisons. Some problems encountered are presented here with solution methods and an indication of some of the holes remaining in the process of design and installation for Zone-rated projects. Recommendations are also made for products and changes to codes and standards required for Zones to be truly viable as a method of design and construction.