“The concept of a third level of protection for intrinsic safety has existed for several decades,” said Phil Saward. “Only in recent years has it been formally adopted into the major standards systems in common use worldwide. Meanwhile, other methods of protection have filled the gap. In particular, Ex nL has provided a workable, but somewhat loosely defined alternative until its recent withdrawal from international standards. The paper therefore covers the essential differences between Ex ic and Ex nL, and discusses the pros and cons of the two techniques.”
The whitepaper 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. The paper is aimed at those who are familiar with the principles of explosion protection for electrical apparatus, but will also appeal to readers who are responsible for compliance to the ATEX Directive and relevant IEC standards. Topics covered include:
- What is Ex ic?;
- The position of Ex ic in the Intrinsic Safety family;
- Changes to the IEC standards;
- Why things are changing now;
- Background and links to the ATEX directive.
One of the most helpful elements of the whitepaper is the inclusion of a case study which demonstrates how the new Ex ic standard can fundamentally change the design of a FOUNDATION™ fieldbus network, compared with implementations that were based on the Ex n standards. This practical illustration will help readers understand the potential impact in terms of network design and hardware selection.
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