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ATEX and IECEx Certification of Products – the implications of IEC 60079-32-1 and IEC 60079-32-2

Ron Sinclair MBE

General Manager – SGS Baseefa

2 © SGS SA 2012 ALL RIGHTS RESERVED

ATEX 94/9/EC

The ATEX Equipment Directive applies to all equipment with a potential ignition source intended to be installed in a hazardous area in the EEA

Conformity is required with the Essential Health and Safety Requirements (EHSRs) of the directive

The EHSRs require to be fleshed out. This is the role of harmonised standards which are subject to revision and development

Harmonised Standards are listed in the Official Journal, along with supersession dates


ATEX 94/9/EC

Preliminary Observation to the EHSRs:

Technological knowledge, which can change rapidly, must be taken into account as far as possible and be utilized immediately.

Therefore if a revision to a standard imposes additional restrictions, these should be applied when the new standard is published (or after an agreed overlap period for harmonisation) • This does not imply that existing installed equipment

needs to be changed


IECEx Certification

The IECEx Certification System has three schemes • IECEx Product Certification • IECEx Service Facility Certification • IECEx Personnel Competence Certification

The IECEx Product Certification Scheme overlaps with ATEX 94/9/EC

Service Facility and Personnel Competence Certification are relevant to ATEX 1999/92/EC


IECEx Product Certification

Scheme rules provide for certification to the current published standard, or one edition previous • The intent of allowing one edition previous is to allow for a

product nearing completion of certification when the standard changes, not enforcing a standard upgrade unnecessarily

• It is anticipated that new equipment will be compliant with the current standard

• A manufacturer is not forced to have an existing product recertified to a later standard. The intent is that the market should apply the necessary pressure, rather than the rules of the scheme


ATEX and IECEx

Most electrical equipment is certified within both schemes • IECEx for worldwide sales and to give the European

purchaser confidence in the certification • ATEX to meet the legal requirements for sale in Europe • Typically the manufacturer opts for IECEx, then gratefully

accepts an ATEX Certificate as “free issue”

Non-electrical equipment will come within the scope of IECEx once ISO 80079-36 and -37 are published


ATEX and IECEx

Legal obligation under ATEX to comply with the latest standards

Commercial pressure under IECEx to comply with the latest standards

Typical harmonisation overlap under ATEX is three years from publication

Most manufacturers normally look for an upgrade between 3 months and 30 months after the new standard is published


IEC TS 60079-32-1 IEC 60079-32-2

One of the motivations for developing the new “electrostatics” standards was to put in place criteria that could be referenced in IEC 60079-0, rather than have electrostatic test requirements in that standard

Because 60079-32-1 is a TS, it cannot be given a mandatory reference in a standard used for certification

60079-32-2 is under development (currently at CDV) to be the document that is referenced in 60079-0


IEC TS 60079-32-1 IEC 60079-32-2

The CDV text of 60079-32-2 is almost identical to Annex G of 60079-32-1 • Whereas Annex G refers directly to earlier clauses in

60079-32-1 for acceptance criteria, 60079-32-2 uses the construction: “The pass/fail criteria given in the standard which calls for the test method apply. If specific pass/fail criteria are not given, guidance is provided in IEC TS 60079-32-1.”

What follows assumes that there will not be significant changes between the CDV text and the published standard, and that the calling standard will be 60079-0


Surface Resistance

Although expressed slightly differently, the current edition of 60079-0 puts the boundary between “insulating” and “dissipative” enclosure material at:

109 Ω measured at (50 ± 5) % relative humidity; or 1011Ω measured at (30 ± 5) % relative humidity 60079-32-1 puts the boundary at: 1011Ω measured at (25 ± 5) % relative humidity 60079-32-2, without setting the boundary value, has

the test performed at (25 ± 5) % relative humidity


Surface Resistance

This causes conflict between the existing published 60079-0, used for certification, and 60079-32-1, used for all other purposes • 60079-32-2 says:

For some tests, different limits measured at 50 % RH have been applied in the past in the absence of a dehumidified test chamber. This approach has now been discontinued; such test conditions should only be used in exceptional cases and in agreement with the end user, with appropriate limits being put on the conditions of use.

• This is not a true statement, as the practice will not have been discontinued until 60079-0 is amended.


Surface Resistance

IEC TC31 WG22 has a choice It can align the next edition of 60079-0 with 60079-

32-1 and 60079-32-2 It can use the basic methodology of 60079-32-2 by

reference but state that the test shall be done at either (50 ± 5) % relative humidity or at (30 ± 5) % relative humidity (with appropriate pass criteria)

Either option has both positive and negative consequences


Surface Resistance

IEC TC31 has taken the decision at the highest level that changes to standards that would impose significant costs on manufacturers should only be made if there is a clear technical justification • Changing the test condition to (25 ± 5) % relative humidity

requires all existing products to be retested if they relied on the previous criteria in 60079-0

• Retesting at (25 ± 5) % relative humidity will be comparatively expensive as a dehumidified room will be required

• There is no evidence to show that the current criteria have caused an explosion


Surface Resistance

IEC TC31 has taken the decision at the highest level that, as far as possible, only one standard should cover any particular technical aspect. • The 61241 series of standards for equipment intended to

be used in the presence of combustible dusts was amalgamated into the 60079-0 series specifically because some requirements that should have been identical had started to diverge

There is, therefore, a direct conflict between the two high level standardisation requirements • Some National Committees will want one solution, others

will want the other


Capacitance

The test requirements in 60079-0 and 60079-32-2 are almost identical but do have the critical difference in relative humidity

Products previously tested at (50 ± 5) % relative humidity will require retesting at (25 ± 5) % if the full testing specification is adopted from 60079-32-2 in the revision of 60079-0

The same option to vary the condition would apply as for surface resistance, with the same commercial and safety arguments


A “Get Out” ?

60079-32-2 clause 4.1: If the test methods cannot be applied for any reason, alternative approaches can be applied under the condition that at least the same level of safety is achieved • Define “Cannot” • Define “Any reason” • Define “The same level of safety”

The role of ExTAG and ExNB

Documents

ATEX and IECEx Certification of Products – the ...electrostat-ex.iopconfs.org/IOP/media/uploaded/EVIOP/event_456/P6... · ATEX and IECEx Certification of Products – the implications