Certification to IEC 60079 based standards

Both in Canada and the United States the principal of classifying hazardous locations into zones, based upon the IEC 60079 system, has now been adopted and used as one of the accepted practices.

Prevailing API Recommended Practices (RP) as well as National Electric Code (NEC) and Canadian Electric Code (CEC) wiring requirements take precedence in the United States and Canada over normal IEC practices. This means that there are some subtle differences when selecting cable glands for use in hazardous locations classified as Zones.

There are additional testing requirements contained in the national standards, which include oil resistance tests for cable glands, and also cable pull-out resistance tests that involve greater tensile loads than those stipulated in IEC 60079-0.

In order to provide protection against ingress of dust and moisture, the North American system specifically requires testing of cable glands to ensure that the integrity of NEMA ratings for enclosures is maintained, so cable glands must also undergo supplementary NEMA enclosure rating tests, regardless of any IEC 60529 ingress protection ratings.

For these reasons it is not possible to mix products and equipment from the IEC ‘world’  with those required to be installed to an API, NEC, or CEC installation code, whether it be using area classification with class and divisions or with class and zones.

The tables below give examples of Cable Gland products which meet the ANSI / UL 514B, ANSI / UL 60079 and hence API, NEC, and CEC requirements for class and zone installations with their typical marking shown alongside.

Class I Zone 1 Flameproof AEx d Enclosures

Class I Zone 2 Flameproof AEx d Enclosures

Class I Zone 1 & 2 Increased Safety AEx e Enclosures