Short Report for the Directive 94/9/EC ATEX Working Group Meeting
Short report for the Directive 94/9/EC ATEX Working Group Meeting
(Meeting on 07 July 2010, Agenda Point 6)
Introduction
This report covers the period between January and June 2010. It is not intended to duplicate items in detail, which will be reported by the Technical Committees CEN TC 305 and CENELEC TC 31.
Statistics
15 standards and 1 Technical Report have been assessed (CEN: 11, ISO/IEC: 1, CENELEC/IEC: 4). Positive assessment reports could be issued for 15 projects, one report expressed complete rejection. Corrective actions or improvements were recommended in 8 assessment reports. The mentioned IEC Technical Report (electrostatics) will not be suitable to be harmonised, but it will be a very important technical specification for the ATEX field.
Electrical standards
The discussions about a standardised annex dealing with changes in the state of the art have been continued in the CEN/CLC Joint Advisory Group (JAG) ”State of the Art”, the results of which will be reported by TC 31 and TC 305. It can be expected that future Annexes ZY of harmonised ATEX standards will provide sufficient information to enable a continuous technical progress in standardisation without unnecessary impacts on conformity evaluation and existing installations.
The work on electrical standards in IEC TC31 mainly is dealing with update and maintenance.
Controversial positions have been taken concerning a draft standard, which is dealing with a systematic approach for conformity assessment of ATEX equipment in the absence of product or concept standards. One of the major questions is, if the future standard IEC 60079-33 will be suitable to be harmonised according to Directive 94/9/EC. For details see further below.
Non-electrical standards
A new interesting project is a draft standard on Explosion Isolation Flap Valves (CEN TC 305).
Two projects in IEC TC31 / SC 31M are developed on basis of existing harmonised CEN-standards:
- ISO/IEC 80079-36 Non-electrical equipment for explosive atmospheres — Basic method and requirements
- ISO/IEC 80079-37 Non-electrical equipment for use in explosive atmospheres — Protection by constructional safety ‘c’, by control of ignition source ‘b’, by liquid immersion ‘k’
A first draft for the revision of EN 1755:2000 "Safety of industrial trucks — Operation in potentially explosive atmospheres" has been presented by WG 13 of CEN TC 150. The draft had to be completely rejected. Details are given further below.
Standards covering all sorts of equipment and protective systems
ISO/IEC 80079-34 "Explosive atmospheres – Part 34: Application of quality systems for equipment manufacture", developed by SC31M has been circulated for Enquiry and will replace EN 13980.
Documents actually under discussion
EN 1755:2000 "Safety of industrial trucks — Operation in potentially explosive atmospheres" - Notes concerning the existing standard, harmonised since 2000
Triggered by the draft for a revision of EN 1755 and by reports from market surveillance the existing harmonised standard was reviewed concerning the application of the "Restricted Breathing" concept (EN 50021; replaced by EN 60079-15) by EN 1755 on trucks in Equipment Category 3G (Zone 2).
Fork lift trucks in category 3G with EN1755-"modified" nR-enclosures have electrical equipment on board, which can be evaluated as normal industrial (sparking in normal service), or providing a reduced level of protection, which is not as high as "Restricted Breathing" in conformity with EN 60079-15. The necessary level of explosion safety of this equipment is only or mainly determined by the correct selection, installation, use, calibration, and maintenance of the gas detection instruments.
EN 1755:2000 "Safety of industrial trucks — Operation in potentially explosive atmospheres" - Notes concerning the proposed revision
The document includes requirements and tests for so-called "Gas penetration resistant enclosures", which according to the proposed wording apply also to explosion protection of electrical equipment. This concept does not exist in IEC/CENELEC standards in that field. The creation of new types of protection for electrical equipment is a matter to be dealt with by the entity of experts in CENELEC / IEC TC 31.The coherence of standardisation in the field of electrical equipment for explosive atmospheres can only be maintained, if TC 31 and subcommittees handle all electrical ATEX standards.
PrEN 1755:20xx does partly not comply with CEN 414 "Safety of machinery – Rules for drafting and presentation of safety standards" (or ISO 78, which will replace it in future), and in several clauses the draft does not give sufficient support of Directive 94/9/EC.
Miscellaneous
Fuel Cells: EN 62282-3-1
IEC TC 105 has circulated IEC 105/251/CD:2009 "Fuel cell technologies – Part 3-1: Stationary fuel cell power systems – Safety ".
This sort of equipment may have internal parts, in which potential ignition sources are installed in potentially explosive atmospheres. The draft standard applies the principles of Directive 94/9/EC and relevant harmonised standards, but it is not linked to the Directive.
Hydrogen detection: ISO 26142
ISO TC 197 has distributed ISO/FDIS 26142 " Hydrogen detection apparatus — Stationary applications", which is partly overlapping with EN / IEC 60079-29-1 "Explosive atmospheres - Part 29-1: Gas detectors - Performance requirements of detectors for flammable gases".
Efforts of IEC TC 31 to avoid the duplication of standardisation have not had success. However, for the next revision of IEC 60079-291-1 it is intended to enable the integration of the additional requirements of ISO 26142, which mainly have been written for applications in Hydrogen energy systems, e.g. filling stations for vehicles or fuel cells.
Pressurized rooms "p": IEC 60079-13
IEC TC 31 has distributed 31/878/FDIS IEC 60079-13 "Explosive atmospheres - Part 13: Equipment - protection by pressurized room 'p' " for final vote. It can be assumed that this standard will not be harmonised according to Directive 94/9/EC. The applied safety concepts are comparable with EN 60079-2 for pressurized enclosures and - to some extent – with EN 50381 "Transportable ventilated rooms with or without an internal source of release". The scope of the standard EN 60079-13 is dealing with safety aspects of buildings and staff. The rooms are designed to facilitate the entry of personnel and primarily intended for installation by an end-user and verification on site.
Reciprocating Internal Combustion Engines: EN 1834
The three standards EN 1834-1, -2 and -3 are harmonised according to Directive 94/9/EC, but are not anymore harmonised according to Directive 2006/42/EC (Machinery).
The reason is the unavailability of experts for updating the standards. When maintenance of these standards cannot be provided, they will be withdrawn someday.
Protection by special protection ‘s’: IEC 60079-33
IEC TC 31 has distributed 31/875/CD, a new draft of IEC 60079-33 Ed. 1.0: Explosive atmospheres – Part 33: Equipment – Protection by special protection ‘s’.
The document gives detailed guidance, which specific rules and procedures have to be applied, if the applied explosion safety measures are not in conformity with existing concept and product standards.
Most elements do not provide additional support for Essential Requirements of Directive 94/9/EC; some will be suitable as guide, how to deviate from harmonized standards. Mainly Notified Bodies and their clients will use it for the conformity assessment procedure.
It has to be appreciated that for the option "conformity with Directives without application of harmonised standards" - given by the Blue Guide - a detailed guidance will be provided.
IEC 60079-33 will also build a bridge between the concept of the New Approach of the European Union and the global certification system IECEx in the ATEX sector.
A decision, if the final version of this standard can be harmonised according to Directive 94/9/EC, will have to be made.
Cappenberg, 2010-06-22
ATEX-Consultant
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