A comparative review of NEC versus IEC concepts and practices

New Article 505 of the 1996 National Electrical Code/spl copy/[NEC] introduces a concept of zone electrical area classification similar to that of the International Electrotechnical Commission's [IEC] Standard 79-10 [79-10]. This tutorial paper comparatively reviews the most common electrical installation concepts and practices in classified locations as defined by NEC Divisions and IEC Zones. In addition, it makes a comparative review of sections in Articles 500 and 501 to show that the concepts of zone classified installations were already recognized in earlier editions of the NEC for locations classified by division.