Monday, December 26, 2011

Ready-Made Connecting devices (cables) under EMC directive?

EMC test with stripline
Image via Wikipedia
During the revision of the EMC directive 89/336/EEC, back in 2003, one of the most controversial proposals was the inclusion of “Ready-made connecting devices” within the scope of the EMC directive.

Ready-made connecting devices would encompass passive product, typically 3rd party in nature, designed to interconnect and be connected to apparatus covered within the scope of the directive, in effect classifying such connecting devices as apparatus themselves within the scope of the directive.

Products such as network cables, Audio / Video cables, and other interconnecting cables and adaptors would come under such classification and be subject to the protection requirements of the EMC directive (to paraphrase; must not interfere with others and must operate in the presence of interference without significant loss of performance) , thus requiring testing and marking as any other apparatus would.

It was argued that the term, “Ready-made connecting devices”, itself was ambiguous and unclear. Eventually it was decided that the devices represented no major interference potential, and because of the costs manufactures would incur for testing and marking, it was removed from the scope of the directive.

With the current revision and alignment of the EMC Directive with New Legislative Framework (NLF), the EMC directive 204/108/EC once again is subject to modification, and potential scope expansion. One such change being circulated for inclusion is that ready-made connecting devices be considered again and brought under the regime of the EMC directive.

In a proposal from the German Administration (BNetza), it is argued that in light of experience gained since 2003, the non interference claims argument cannot be maintained. The proposal claims there is no longer any serious doubt that insufficiently shielded connecting devices greatly increase the interference potential of TV and Cable networks in particular. The proposal cites several reports with data supporting this conclusion. One such report shows a  peak 30dB difference in screening effectiveness between two types tested, from most to least shielding, and notes that cable connectors can contribute around 10 dB of difference. See   ”The Concise Report of the CENELEC/ETSI Joint Working Group on the digital dividend" of 12 August 2010 (section 7.3)

The proposal suggests  that the following requirement be added to the new EMC directive;
Ready-made connecting devices, although incapable of generating electromagnetic disturbance in isolation, may generate or transmit electromagnetic disturbance when connected to an apparatus and should therefore be considered to be apparatus for the purposes of this Directive.

With ready-made connecting devices being defined as;
ready-made connecting devices' intended for connection to an apparatus by an end user for the transmission of signals, which are placed on the market separately from such apparatus, and which are liable to generate or transmit electromagnetic disturbance when connected to it.

This addition would then subject cables and connectors to the same technical requirements as any other product under the EMC directive, regardless of the component’s active or passive nature.

Thursday, December 15, 2011

EN 55013 modified and draft going for vote

Under construction

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EN 55013 is the EMC emissions standard for broadcast receivers and associated equipment. The standard is aligned with the European Union’s EMC directive as published in the official journal. The EMC directive is a CE marking directive, and compliance with this directive is compulsory for most electrical / electronic products prior to placing on the European market.

Previously reported in a post back in the summer of 2009, EN 55013, QP vs RMS, it was noted that the EU commission was holding off publishing reference to the newest edition of EN 55013, 2009, in the Official Journal.

The CENELEC technical committee, CLC/TC 210, had decided that the standard should not be published, without the link to the EMC Directive, and accordingly has set up a task force to seek a resolution.

It was agreed that the new draft common modifications should be circulated under UAP. The current project name is EN 55013:201X

The CLC/TC 210 Secretary proposed that the following explanation appear in the forward to the draft common modifications, furthermore this is not to be included in the final publish standard, should the draft be accepted:

“The text of CISPR/I/296/FDIS, the future CISPR 13 ed 5.0, received a positive vote in CENELEC, but was not ratified due to technical objections raised by the EMC Consultant. These would have prevented the listing of the standard in the Official Journal of the European Union as a harmonised standard providing a presumption of conformity with the protection requirements of the EMC Directive 2004/108/EC. The following draft includes common modifications to address these objections, and they have been agreed by the EMC Consultant and the responsible committee, TC210. It is submitted to UAP.”

It is expected that in light of the upcoming CISPR 32, perhaps appearing within a couple years, that EN 55013 will then be deleted. At that time, the use of the QP detector will have become obsolete and replaced by the RMS/Average detector.

It should be noted that the UK is not in favor of issuing the document under UAP, nor is Italy. The UK proposes to wait and see what happens with CISPR 32. The draft will be submitted under UAP none the less.

Wednesday, December 14, 2011

The last word on Power Line telecom (PLT) in the EU, EN 55022:2006 applies in full, maybe….


Image by Sigfrid Lundberg via Flickr

Power Line communication devices continue to be a controversial subject, with respect to the Electromagnetic Compatibility of such devices. We have been following this subject for both the United States, and for Europe. The latest round comes from across the pond with the rejection (negative vote) of the European Norm targeted to cover the testing of these devices, prEN 50561-1:201X. For background on this topic, see my past article “An update on PLT, Power Line Telecommunications, in Europe”.

Due to the negative vote on prEN 50561-1:201X, and a lack of a specific standard covering the emissions testing for PLT devices, EN 55022:2006 applies in full for these devices as of October 1st. It should be noted that many newer high speed advanced PLT devices cannot pass the requirements of EN 55022:2006 at this time.

This conclusion will be confirmed by a note published in the Official Journal reference to harmonized standards under the EMC directive.

CENELEC may offer a second vote, indicating that the choice is between EN 50561-1 and EN 55022. If this vote fails, no further option exists.

What does this mean for product on the market? Are recalls required for non compliant devices? What about new product placed on the market? The Commission is expected to accept a reasonable Date of Withdrawal (DoW) as proposed by working group 11, and until that date, manufacturers should still be able to continue placing product on the market using the Declaration of Conformity and Notified Body TCF path. The EU market authorities are “encouraged” to accept this.

The group of European Notified Bodies are meeting to discuss, and will consider the Technical Guidance Note (TGN) on the matter, after the meeting. Is this the end of the debate? Time will only tell, and we’ll continue to post when we learn more.