4.3 EMC評価

The manufacturer shall perform an EMC assessment of the apparatus based on the relevant phenomena in order to ensure that he meets the essential requirements. As noted above the EMCD does not require the mandatory intervention from a third party (e.g. notified body or laboratory) when carrying out the assessment.

The manufacturer is fully responsible for applying the appropriate method of assessment. Recommendations are given in this Guide to help in this process.

Where the EMC assessment establishes that the apparatus concerned is inherently benign in terms of electromagnetic compatibility (both for emission and immunity) according to Article 2(2d), the apparatus is excluded from the scope of EMCD and no further actions are necessary.

However, it is recommended to document the results of the assessment and its conclusion.

The EMC assessment needs to take into account all normal intended operating conditions of the apparatus.

In cases where the apparatus can take different configurations, the electromagnetic compatibility assessment must confirm that the apparatus meets the essential requirements, “in all possible configurations identified by the manufacturer as representative of its intended use”.

In practice, this EMC assessment has to be performed following a defined methodology.

Any conformity assessment procedure requires the manufacturer to start with an analysis of the specific risks of the product to address them in order to comply with the essential requirements because not all products present the same risks.

Once these risks are identified and the manufacturer has determined the measures to address those risks in order to comply with the essential requirements he can choose to apply the harmonised standards applicable to his product or he can choose other technical specifications.

After having identified the risks of the apparatus, three methods are possible for the EMC assessment:

a) Application of EMC harmonised standards having checked whether the chosen harmonised standard(s) covers all the phenomena relevant to the product.

b) An EMC assessment where no harmonised standards have been applied and the manufacturer applies his own methodology (other technical specifications).

c) Mixed assessment, combining the two previous methods. For example, one could use the harmonised standards to cover emission phenomena and a detailed technical EMC assessment for immunity aspects.

Harmonised standards (see the definition in the relevant chapter of the Blue Guide) provide a recognised methodology to demonstrate compliance with the essential requirements and are usually the preferred way to demonstrate compliance. The manufacturer may ask a third party to perform the EMC assessment for him or help him with part of it, but the manufacturer is and remains fully responsible for the compliance of his apparatus with the provisions of the Directive.

To re-iterate - the EMC assessment is the sole responsibility of the manufacturer; it is never the responsibility of a third party such as a Notified Body or an EMC test laboratory.

Where a manufacturer assembles a final apparatus using components from other manufacturers, the manufacturer of the final apparatus must retain

overall control and is responsible for the compliance of the final apparatus.

Where apparatus can take different configurations, the EMC assessment shall confirm that the apparatus meets the essential requirements in all of the configurations foreseeable by the manufacturer as representative of normal use in intended applications.

The manufacturer is responsible for identifying the possible configurations and the choice of the worst case(s). The use of the worst case approach needs to be documented in the technical documentation.

Harmonised standards are European standards that have been adopted on the basis of a request made by the Commission for the application of Union harmonisation legislation (for example the EMC Directive).

Compliance with the applicable harmonised standards whose reference is listed in the OJEU under the EMC Directive gives presumption of conformity with the corresponding essential requirements of the EMCD.

Each harmonised standard contains information (including a table at Annex ZZ) on how to achieve the presumption of conformity with the corresponding essential requirements of the EMC Directive.

The EMCD refers to the moment of placing on the market for each individual apparatus. This means that for apparatus which is continuously produced over a long period, the applicable standards may change in the course of time. In this case the provisions explained at 4.3.2 concerning the reference of the superseded standards and the date of cessation of Presumption of Conformity should be taken into account. The date of cessation of the superseded standard provides a transition period (usually between 18 and 36 months) during which either the old or the new harmonised standards may be used, at the choice of the manufacturer, to benefit from Presumption of Conformity.

After this time if the manufacturer wishes to continue to benefit from the Presumption of Conformity and the apparatus is not yet placed on the EU

market, the apparatus needs to conform to the later harmonised standard and a new EU Declaration of Conformity is required to include the reference to it (which is often a later edition/version with the same reference number). This will require the manufacturer to make an EMC evaluation to the later harmonised standard and he may consider it necessary to carry out some re-testing.

However, it may be that the manufacturer wishes to continue to meet the essential requirements by continuing to use of the “old” edition (that has ceased to be harmonised) plus other technical solutions if necessary. As harmonised standards are voluntary this is of course an acceptable solution, but this would not give the presumption of conformity that application of the later edition would confer. In this case, the manufacturer has the obligation to demonstrate that his products are in conformity with essential requirements with the means he has chosen.

Where new editions become available and are to be applied it does not necessarily mean that a complete EMC re-assessment of an existing product is necessary. The evaluation may be restricted to those modifications directly affecting the apparatus concerned. For example, the change may only relate to a small range in scope, or one particular clause or phenomenon.

Harmonised standards under the EMCD are drawn up and adopted by the three European Standardisation Organisations (ESO) recognised in the Standardisation Regulation:

European Committee for Standardization (CEN)

European Committee for Electro technical Standardization (CENELEC)

European Telecommunications Standards Institute (ETSI)

Detailed information on the general EU policy regarding harmonised standards is available at the web-site of the European Commission.

The list of harmonised standards published in the OJEU is regularly updated. The European Commission publish a link to the relevant edition of the OJEU on their web page relevant to the EMC Directive.

Information on standards is also available on the CENELEC, ETSI and CEN web-sites:

www.cenelec.eu

www.etsi.org

www.cen.eu

In order to obtain the text of CEN or CENELEC standards, you should contact the national members of CEN or CENELEC or the standardisation body of your country if you are located outside the territory of CEN/CENELEC members.

A list of members of CENELEC is available at: http://www.cenelec.eu/

ETSI standards can be downloaded from the ETSI web-site without cost and are sometimes distributed by National standards bodies or third parties.

Further guidance for the application of harmonised standards is given in Annex 2.

The selection of the relevant harmonised standards is the responsibility of the manufacturer.

When the manufacturer chooses to apply harmonised standards he shall select them in the following precedence order:

Product-specific standards (if available)

Product family standards (if available)

Generic standards

Product-specific (family) standards are those written by ESO’s taking into account the environment, operating and loading conditions of the equipment and are considered the best to demonstrate to compliance to the Directive.

Generic standards could be used in the absence of either product-specific or product-family standards. They are divided into generic environments but do not contain specific guidance of how to operate and load equipment during the testing phase of an EMC assessment.

It may be necessary to apply several harmonised standards to cover all essential requirements of the Directive. Each harmonised standard identifies the essential requirements which it covers in an annex.

The main aspects that are generally required to be covered are:

Radiated disturbances

Conducted disturbances at mains and telecommunication ports

Immunity to continuous radiated and conducted disturbances

Immunity to transient phenomena

Applying several standards may be necessary to address all relevant phenomena in all relevant frequency ranges. For multi-function apparatus, it may also be necessary to select standards relevant to all primary functions.

Useful practical information on the selection of the appropriate CENELEC standards may be found in the CENELEC Guide 34 ” Guide to the drafting and use of harmonized and nonharmonized EMC standards” which is available on the CENELEC website. This guide explains the general structure of the EMC standardisation and the respective roles of EMC standards, e.g. basic standards, generic and product (family) standards.

applied A manufacturer may wish to declare the conformity of his apparatus directly to the essential requirements, without reference to harmonised standards, by addressing the EMC risks with other means. If the manufacturer chooses not to follow the harmonised standards, he has the obligation to demonstrate that his products are in conformity with the essential requirements by the use of other means of his own choice (Blue Guide, paragraph 4.1.3 Conformity with the essential requirements: Other possibilities). This assessment needs to follow a technical methodology to ensure that the requirements of the EMC Directive are met. The manufacturer will need to provide clear evidence of compliance.

This option allows flexibility for technical development, crucial when manufacturers of new or innovative apparatus for which standards do not exist, or cannot be used, want to assess their apparatus according to the essential requirements.

This is usually the case where:

There are no harmonised standards or where they do not cover all the essential requirements applicable to the apparatus;

The apparatus uses technologies, incompatible with or not yet taken into account by harmonised standards, and generic standards are not applicable;

The manufacturer uses test methods not covered by the harmonised standards;

The manufacturer may want to apply any other standards or specifications not harmonised in the context of the EMCD;

The apparatus is physically too large to be tested in the facility described in the harmonised standard or where “in-situ” testing is foreseen and not adequately covered by a harmonised standard.

The assessment required for a particular apparatus will depend on several factors, such as:

Nature of the apparatus (apparatus characteristics);

Intended use;

Location of use; EMC environment

Types of disturbances created by or affecting the apparatus;

Environmental conditions;

Performance criteria for immunity.

The EMCD requires the manufacturer to document all steps taken and decisions made to check the conformity of the apparatus for those aspects for which the manufacturer has chosen this method of assessment. It may encompass (but is not limited to) the following:

Description and definition of the apparatus operating conditions and its intended purpose. This should also cover the power supply voltage and frequency aspects relevant to the apparatus;

Specification, descriptions and classification of the environments in which the apparatus will be used. This may cover also aspects relevant for apparatus that may be moved and must have emission and immunity characteristics appropriate for several environments. This selection is the responsibility of the manufacturer based on knowledge of the electromagnetic environment and awareness of the statistical aspects involved;

Clear specification of relevant sources and effects of the electromagnetic phenomena covered and compatibility levels applied;

Specification of the performance criteria of the apparatus. These should be set taking into account of the reasonable expectations of the user;

Test levels with regard to the immunity of the apparatus;

Limits adopted for emission, etc.;

Reference to available documents such as any harmonised standards, recommendations;

Indication of any deviations made to available reference documents.

These deviations may concern the phenomena considered, tests methods, test facilities or test levels, etc.;

EMC design considerations and/or calculation results;

Statistical evaluations, theoretical studies or other examinations carried out, presenting background theory, arguments, results and conclusion.

This may include information on the levels of occurrence and statistical distribution of the disturbances;

Description on how components are selected;

Information on shielding, cable screening and routing, filters, ferrites etc;

Any description of the solutions adopted in order to comply with the essential requirements, including the list of the relevant technical specifications applied;

Any specification of general or specific requirements taken to limit emission of disturbances;

Assessment of whether compliance with the essential requirements is ensured in residential areas or not. If this is not the case the restriction of use shall be clearly established;

Assessment of whether any specific precautions have to be taken when the apparatus is assembled, installed, maintained or used, in order to ensure that, when put into service, the apparatus is in conformity with the essential requirements;

Worst case selection criteria for series of apparatus with similarities;

Detailed guidance on the selection of electromagnetic phenomena to be assessed in the EMC assessment is given in Annex 3 to this Guide.

Reference sources of information for the manufacturers undertaking this method of assessment may continue to include harmonised standards, their drafts as well as standards related to EMC but not harmonised under the Directive e.g. basic EMC standards.

To-reiterate, where this route is chosen the apparatus does not benefit from a presumption of conformity.