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Vladivostok and Brussels

15 December 2017

IEC TC31, its sub-committees and some working groups, met in Russia in October, during the General Meeting of the IEC. Those of us who went to Vladivostok were impressed both by the city itself and by the venue, The Far Eastern Federal University. SC31J (installation related standards) and SC31M (non-electrical standards) held their meetings immediately before the plenary meeting of TC31.

Two items from SC31J are worth noting here:
The ongoing saga of the choice of cable entry devices for flameproof enclosures is set to continue, with some people believing that the transmission down a cable from one enclosure to another is the only concern, but others worrying about the explosion actually bursting the cable. The UK alone has put these concerns into the national published version of the standard BS EN 60079-14, with an Annex repeating the flowchart from the previous edition.

SC31J also considered liaison action with the IEC committee responsible for refrigeration and air-conditioning plant. It seems that, although the current favoured refrigerants are actually flammable, the flame speed is so slow that the rate of pressure rise, and the peak pressure are such as to allow for explosions occurring without significant destruction. Thus there is a belief that zoning on the basis of Group IIA is overly severe.

SC31M accepted the advice from IECEx that the mining equipment standard ISO/IEC 80079-38 was written with non-mandatory text, which made it unsuitable as the basis for certification. Work will commence shortly on a second edition with the specific remit to solve this problem.

The CDV text of the revision of ISO/IEC 80079-34 has passed the ballot and the FDIS text should be released for final vote early in 2018. Publication should follow between three and four months later. This version of the standard is needed sooner rather than later as it cross refers directly to clause numbers in the current version of ISO 9001. Certificates to the earlier edition of 9001 have either expired already or will run out during 2018.

The TC31 plenary meeting consists mainly of the reports from the various active groups:
The Maintenance Team for IEC 60079-18 “Ex m” will be issuing an urgent corrigendum to clarify that, although the actual units used in the calculation have changed, the pull test on encapsulated equipment with an integral cable has not.

The way the changed units have been presented caused some people to interpret that the value for the pull test had been divided by 10.

WG22 has completed its work on the new edition of IEC 60079-0. The FDIS passed the ballot in November and the standard should be published by the end of December.

The Maintenance team for IEC60079-15 also completed their work on the next edition, which has passed all the votes and should be published about the same time. This represents a considerable thinning down of the document, as all the requirements for “Ex nA” have been removed as they now appear in IEC 60079-7 as “Ex ec”. All that remains are the requirements for Restricted Breathing (Ex nR), Sealed Equipment (Ex nD) and Non-Incendive Components (Ex nD). When this standard is harmonised for ATEX, it is expected that the previous edition will lose harmonisation status around December 2020, leaving “Ex ec” as the only option for the majority of equipment designed for installation in Zone 2.

After four years without meeting, I chaired Cenelec TC31 at the new CEN-Cenelec headquarters in Brussels in November. 

A new secretariat has taken a more active interest in the work at European level. Although much of the work of the European committee is to endorse the work of the international committee, there are items that benefit from a discussion.

We agreed that each time a new IEC document came out for vote, we would give the European countries a chance to meet together to decide on a “European view” of the document, rather than risk opposing views being put forward strongly at international level.
Because of the long gap between meetings, it was necessary for me to be formally elected to continue my role as chairman. This means that, following Brexit, I will probably be one of the few British Citizens that will continue to make a direct input to discussions on European directives.

About the author

SGS Baseefa Technical Manager Ron Sinclair MBE gives his perspective on the latest developments in the world of standards every two months in Hazardex magazine.

He is chairman of BSI Committee EXL/31, responsible for the UK input to both European and International standards for Electrical Equipment for use in potentially explosive atmospheres. He is also chairman of Cenelec TC31, represents electrical standardisation interests on the European Commission’s ATEX Standing Committee and chairs the IECEx Service Facility Certification Committee.


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