Synopsis
The protection of electrical apparatus for use in flammable atmospheres is embracing a new technique: Ex ic. As a logical extension of the existing intrinsic safety concept, it formalises the application of intrinsic safety in Zone 2 hazardous areas, but users and manufacturers alike are wrestling with the details. The discussion centres as much on the withdrawal of the Ex nL technique, as on the application of Ex ic which replaces it. The paper deals primarily with the impact on countries that follow IEC and ATEX practice, but there are parallels with the ‘non- incendive’ technique that is adopted in North America.