During the last few years, many new EMC standards have been adopted; however, more and more standards are outside the scope of formal EMC legislation. The recent change in scope of IEC ACEC, CISPR and the new European EMC Directive creates new challenges for industry, as their focus will be aimed at the protection of the general broadcasting and communication services and of serving the main public interest.
During the last APEMC 2010 symposium in Beijin, a contribution was given to a workshop about the EMC developments for the European Industry. As in Europe, large changes resulted from the recent update of the EMC Directive 89/336/CE to 2004/108/CE where the entire legislation on physically large systems and large installations, called “fixed installations,” was altered.
Although the European EMC Directive explicitly states: “The equipment covered by this Directive should include both apparatus and fixed installations. However, separate provisions should be made for each. This is so because, whereas apparatus as such may move freely within the Community, fixed installations on the other hand are installed for permanent use at a predefined location, as assemblies of various types of apparatus and, where appropriate, other devices. The composition and function of such installations correspond in most cases to the particular needs of their operators,” by which exclusions are already claimed. By the last sentence, the requirements will be based on particular needs.
It further reads that: “Fixed installations, including large machines and networks, may generate electromagnetic disturbance, or be affected by it. There may be an interface between fixed installations and apparatus, and the electromagnetic disturbances produced by fixed installations may affect apparatus, and vice versa. In terms of electromagnetic compatibility, it is irrelevant whether the electromagnetic disturbance is produced by apparatus or by a fixed installation. Accordingly, fixed installations and apparatus should be subject to a coherent and comprehensive regime of essential requirements. It should be possible to use harmonized standards for fixed installations in order to demonstrate conformity with the essential requirements covered by such standards.”
On the one hand, it is assumed that “fixed installations” will cause electromagnetic disturbance and/or may be affected by other nearby systems. On the other hand, no IEC nor CE harmonized standards exist which enable RF emission, RF immunity and impulse immunity testing at close proximity on site or in-situ. Even worse, RF immunity testing at most end-user premises is prohibited by law or restricted to the ISM frequency bands only. Conducted mains tests will not be performed at all as the power cabling to the “fixed installation” has to be adapted for the sake of a “few” measurements.Here, the long system start-up and turn-down times are not being considered which might take several hours. For this reason, comparison between RF emissions measured with an active “fixed installation” and one turned-off doesn’t make sense due to the lag time between these events.
“It is not pertinent to carry out the conformity assessment of apparatus placed on the market for incorporation into a given fixed installation, and otherwise not commercially available, in isolation from the fixed installation into which it is to be incorporated. Such apparatus should therefore be exempted from the conformity assessment procedures normally applicable to apparatus. However, such apparatus should not be permitted to compromise the conformity of the fixed installation into which it is incorporated. Should apparatus be incorporated into more than one identical fixed installation, identifying the electromagnetic compatibility characteristics of these installations should be sufficient to ensure exemption from the conformity assessment procedure.”
The above gives a carte blanche to “fixed installation” contractors and subcontractors as they might leave all necessary EMC measures to the end-integrator, the one who or who’s company is bringing the full “fixed installation” under his brand name onto the market. Only for those apparatus which also will be brought as OEM on the market, the general apparatus requirements apply.
1. Apparatus which has been placed on the market and which may be incorporated into a fixed installation is subject to all relevant provisions for apparatus set out in this Directive. However, the provisions of Articles 5, 7, 8 and 9 shall not be compulsory in the case of apparatus which is intended for incorporation into a given fixed installation and is otherwise not commercially available. In such cases, the accompanying documentation shall identify the fixed installation and its electromagnetic compatibility characteristics and shall indicate the precautions to be taken for the incorporation of the apparatus into the fixed installation in order not to compromise the conformity of that installation. It shall furthermore include the information referred to in Article 9(1) and (2).
2. Where there are indications of non-compliance of the fixed installation, in particular, here there are complaints about disturbances being generated by the installation, the competent authorities of the Member State concerned may request evidence of compliance of the fixed installation, and, when appropriate, initiate an assessment. Where non-compliance is established, the competent authorities may impose appropriate measures to bring the fixed installation into compliance with the protection requirements set out in Annex I, point 1.
3. Member States shall set out the necessary provisions for identifying the person or persons responsible for the establishment of compliance of a fixed installation with the relevant essential requirements.”
In the first part, it is again assumed that a single apparatus and a “fixed installation” shall be treated the same, whereas in the following clauses exclusions are given.
Sub-clause 2 indicates that only EMC measures or corrective actions will or need to be taken in case of complaints. However, these complaints will only be governmental addressed when these stem from citizen living in the neighborhood of that industrial premise. No governmental actions will be taken on what is called intra-system or on-premises EMC issues. These need to be solved on a case-to-case base between the end-user and the apparatus and installation suppliers. However, there are no formal EMC measurement methods available to prove “guilt” when RF emission is exceeded, other than IEC CISPR 16-2-5. Above all, IEC CISPR/B claims that: “There is particular no meaning in requiring any emission measurements within the given large system or installation. Such testing is regarded as assessing the intra-system EMC which is however NOT in the scope of standardization work in CISPR. Globally spoken, user installation testing is a rather untypical case of application and use of CISPR standards and technical reports and its practice strongly depends on national (or regional) regulation. Some states recognize user installations as substitute for the traditional type test business for equipment which cannot be tested, for certain reasons, at standardized CISPR test sites. However, even in these circumstances the national authority will determine which limits shall be used, even if it follows the advice of existing CISPR standards or technical reports.”
The latter would mean that the industry has to rely on what is called the EMC competence of the Notified Bodies and accredited test houses. Here too, any relation of correlation between the findings of these “accredited” test houses is lacking though they are tempting to unify their Way-of-Working under the “Group of Notified Bodies under the EMC Directive (ECANB).” They have issued their technical guidance Note; TGN 27, February 2010, regarding on-site tests of large products. Here, opposite to what has been recently stated by ACEC and CISPR (June 2010), conductive measurements are evoked. No reference is made to IEC CISPR-2-5 but EN 55016-2-3 (= Standard 3/10 m RF emission test method). Differences in in-situ test result with deviations over +/– 20 dB and aside are noted at exorbitant costs of 50.000,= Euro /test sequence. When in search for an intra-system solution at the end-user premises still no issue but when it comes to who’s taken the costs to solve these intra-system compatibility issues in-situ a serious point of conflict by lacking proper reference.
Annex 1: Essential Requirements Referred To
1. Protection requirements Equipment shall be so designed and manufactured, having regard to the state of the art, as to ensure that:
a. the electromagnetic disturbance generated does not exceed the level above which radio and telecommunications equipment or other equipment cannot operate as intended;
b. it has a level of immunity to the electromagnetic disturbance to be expected in its intended use which allows it to operate without unacceptable degradation of its intended use.
2. Specific requirements for fixed installations
Installation and Intended Use of Components
A fixed installation shall be installed applying good engineering practices and respecting the information on the intended use of its components, with a view to meeting the protection requirements set out in Point 1. Those good engineering practices shall be documented and the documentation shall be held by the person(s) responsible at the disposal of the relevant national authorities for inspection purposes for as long as the fixed installation is in operation.”
This last statement from the Annex of the EMC Directive comes back to the initial title; I’m sure that all my EMC colleagues have all the best in mind (when they are or have been involved with the apparatus or system design up to the level of installation). Many system concepts have been developed with most intra-system constraints in mind but without considering the additional apparatus and systems which might appear adjacent at the end-user’s premises. Good engineering practice is hard to defend in case of dispute when it goes up into court. Although some standardization groups lead industry astray, an objective internationally agreed measurement method with accompanying limit levels will support intra-system issues for in-situ fixed installations.
Fortunately, the new guidance on the EMC Directive, dated February 2010, indicates that alternative measures may be used as testing techniques to demonstrate compliance when correlation can be proven with the existing regulations. Alas, neither ACEC nor CISPR/B sees need in alternative test methods which could have a broad acceptance and which could be published as technical report (TR) rather than an international standard (for the time being).
There is a call for a better defined reference such that end-users, fixed installation suppliers and their contractors and sub-contractors know what is or will be required rather than the Eldorado which is presently created to solve every issue on an ad-hoc bases with an arbitrary result at the end. The global market has not only opened up for small apparatus and appliances but should also become uniform accessible for the “fixed installation” market.
MART COENEN (BSc ’79) has over 30 years experience in EMC in variousfields and has published many papers and publications. He has beenactively involved in international EMC standardization since 1988 andwas given the IEC 1906 award in 2006. He is the former project leader of thestandards: IEC 61000-4-6 and IEC 610004-2 but moved his focus towardsEMC in integrated circuits. He has been the convener of IEC TC47A/WG9and member of WG2.