The EMC Directive is all about electrical interference – emissions and immunity. As test house TUV puts it ‘Do not disturb. Do not be disturbed’.
When enacted in 1989, the Directive was regarded by many with horror and some degree of panic. Today, EMC is one of the constraints which designers deal with regularly and which results in better products.
When first aired, it was one of the first ‘New Approach CE Marking’ Directives. While it did not contain technical limits, it established the legal framework, referring all specifics to harmonised standards. Neither did it mandate that products had to be tested in order to comply. An alternative route to compliance was via the Technical Construction File (TCF), demonstrating the design was in accordance with the requirements. The TCF was verified by a Competent Body; another departure from established norms.
In preparation for its introduction, a five year transition period was instituted to address technical and design issues, as well as compliance and CE marking procedures. In the UK, the Department for Trade and Industry (DTI) implemented – with help from New Electronics – a nationwide EMC Awareness Campaign, targeted especially at SMEs and companies which used electronics in their products. A range of publications, articles and case studies were created, a national network of EMC Clubs was established, Services Directories were compiled and the engineering higher education sector targeted.
The EMC Directive enacted in 1989 – 89/336/EEC – came into force in January 1992, with a transition period until 1 January 1996. Minor amendments were made during the transition period, principally to align the CE marking requirements more closely with other relevant Directives. In 1999, further amendments covered some telecommunications equipment.
More changes came in December 2004, after considerable consultation. EMC Directive 2004/108/EC came into force in July 2007, with a transition period to July 2009. The principal changes were to administrative and attestation requirements. The TCF was replaced with ‘Technical Documentation’ that no longer mandated the use of a Competent Body. Instead, Notified Bodies could be used on a voluntary basis to provide additional verification of compliance, effectively an insurance policy.
In 2008, the EU introduced the New Legislative Framework; a package of measures designed to improve market surveillance, to boost the quality of conformity assessments and clarify the use of CE Marking. As a result, the 2004 Directive will be replaced in April 2016 by Directive 2014/30/EU – and these changes are likely to have serious repercussions.
Enforcement
There were always concerns about how the EMC Directive would be policed and enforced. In the UK, it is overseen by the Trading Standards Service and Ofcom. Penalties for non compliance in the UK are severe enough: £5000 fine and/or three months imprisonment. More costly is the requirement to recall or replace any non-compliant apparatus and, of course, the damage to the firm’s reputation.
Being largely complaints driven, enforcement was expected to be self regulating, with competitors watching each other. “But this did not happen,” observes Nick Wainwright, chief executive of York EMC Services. “Perhaps lack of confidence in their own efforts meant manufacturers kept their heads down.”
Anecdotal information on offences is rife, but prosecutions are extremely rare. Consequently, there has been growing frustration that the Directive has never been enforced properly. Indeed, at times, it has proved to be unenforceable.
One of the most controversial cases of non enforcement occurred in 2008, with the launch of power line adapters used in domestic broadband installations. A large number of complaints alleged these devices blocked the high frequency communications used by taxicab companies and some emergency services, as well as military, marine and amateur enthusiasts. Despite investigations by Ofcom and evidence showing that some devices far exceeded the emissions limits in the relevant standards, no prosecutions were made. The problem was Ofcom had no legal power to act once products were in service – the EMC Directive only covers products placed on the market. As a result, work started to modify the EMC Directive and the Wireless Telegraphy Act.
Market surveillance
It is little known that, for more than a decade, cross border EMC Market Surveillance investigations have been undertaken by European authorities. They have tackled a range of products known to be sources of EMC problems, including ‘energy saving lamps’, power tools, consumer entertainment systems, LED lighting products and solar panel inverters. In all cases, major shortfalls were found, both in terms of technical assessment (primarily emissions) and administration. Interestingly, the highest number of failures came from LED lighting.
The reports recommended that national bodies and industry groups address some of the worst offenders, should they so choose. Worryingly, in each investigation, the origin of products could not be determined. In certain cases, it was recommended that harmonised standards should be updated or created to encompass new product developments.
It became clear that many companies were not getting to grips with the administration involved in CE Marking. A significant percentage of the products inspected failed, or partially failed to comply, not necessarily for technical reasons, but because they had out of date, incomplete or missing Declarations of Conformance. Some had no CE mark or it was incorrectly applied.
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"Engineers are often unaware that the DoC is a living document. It will change during the product's life, either because harmonised standards have evolved of the product has." Nick WainwrightWider ranging responsibilities
The incoming 2014 EMC Directive has the potential to address a number of the non-compliance and enforcement issues. For example, it now specifies: ‘Procedure for dealing with apparatus presenting a risk at national level’, which should be sufficient to tackle the power line adaptor case outlined above and similar situations. Incidentally, EN50561-1 – the first in a new family of CENELEC standards covering high frequency products – has been published and will come into force in October 2015.
The impact of the 2014 EMC Directive on manufacturers is described as ‘relatively slight’ by the CE Marking Association.
However, it does require all manufacturers to act; for new products and those still on the market, the Declaration of Conformity (DoC) must be reissued and, from 20 April, refer to the new EMC Directive 2014/30/EU.
“It is the administration that catches out most people,” Wainwright warns. “Engineers are often unaware that the DoC is a living document. It will change during the product’s life, either because harmonised standards have evolved or the product has.”
A crucial change is the whole supply chain now has legal responsibilities – including importers and distributors. “For example, it is the importer’s responsibility to ensure, not only that a CE mark is applied to the product, but they are also satisfied that proper conformity assessment procedures have been followed and that the DoC is readily available and correct,” explains Wainwright.
“Under the new Directive, if a non-compliant product reaches the end user, a number of offences will have been committed within the supply chain.”
Further, the 2014 Directive also tackles rebranding. “If you rebrand a product, you are now deemed to be the manufacturer, with all that entails regarding CE marking,” Wainwright warns. The regulations on product labelling and accompanying documentation have also been tightened.
What’s next?
There are still unknowns. Tim Williams, managing director of EMC consultancy Elmac Services asks ‘what about when the importer is the end user, buying directly from the Far East? What about development boards that become the basis of end products?’. Wainwright is convinced the lack of the threat of enforcement is one of the most serious shortfalls in the Directive’s implementation.
“This has undermined the whole effort,” he claims, noting there should be considerably more publicity of the cross border Market Surveillance reports and, especially, their outcomes, such as products being withdrawn from the market, as well as complaints and prosecutions. “Improved awareness will help the industry self regulate,” he maintains.
There are exceptions, such as in automotive, railways and other transport sectors. Here, the ‘customers’ – car makers and service providers – are unofficial regulators, demanding compliance. Williams concurs: “Companies that comply with the EMC Directive do so not through fear of penalties, but because customers demand it.”
Designing for EMC One of the major benefits of the EMC Directive, according to Elmac’s Tim Williams, is the positive impact on electronics design. “It’s the biggest deal; engineers won’t do something that costs time and money if they don’t have to.” And, as one of Wainwright’s managers is fond of saying, ‘engineers do what you inspect, not what you expect!’. EMC still does not feature on the syllabus of electronics engineering courses, so engineers are learning on the job. “Most medium to large companies have in house knowledge and expertise and this ‘rule-of-thumb’ approach is passed on, with varying degrees of success,” Williams explains. Wainwright agrees. “Two decades on, we are still having the same conversations: what is EMC and what do we have to do? More than half the products that we see in our laboratories will fail at least one of the tests.” He believes EMC simply isn’t sufficiently embedded into the development cycle, resulting in uncertainty as to whether the product will pass the tests. “I often hear EMC referred to as a ‘black art’; sentiments that don’t readily appeal to young engineers. It’s true that you can’t see EMC and measuring it takes skill and expertise but, in the end, it all comes down to good engineering practices.” But, while technology has marched forward, EMC best practice remains largely the same, embedded in the three maxims of filtering, shielding and PCB layout, says Williams. Increases in CPU clock speeds to GHz levels have demanded considerably more attention to high frequency design at the board level. “Signal integrity and EMC have a natural synergy, they are the same sides of a coin and designing for one will help the other,” Williams explains. Meanwhile, EMC training and consultancies and test houses continue to thrive as new engineers need to understand more about EMC and, especially, why their products fail. |
Protecting the spectrum The proliferation of radar, radio communications, GHz ICs, microwaves, mobile phones and, more recently, low power RF wireless devices means the electromagnetic spectrum is under constant pressure. Efforts to limit and allocate frequency usage, as well as establish standards and national regulations, have had limited success. While the EMC Directive has looked to protect the electromagnetic spectrum, it has been part of wider measures to facilitate a single European market of goods and services. Although safety was not the aim of the legislation, it was recognised as an important issue that could be used to leverage better design practices and motivate companies to comply. While there is no shortage of evidence of serious safety issues arising from EMC interference, it has been more commonly experienced as a nuisance. |
Author profile
Louise Joselyn was New Electronics’ editor during the EMC Awareness Campaign and when the EMC Directive was implemented.
