The road to CE compliance

The CE marking (Europe)

The manufacturer or his authorized representative is required to attest that the protection requirements of the European Directive have been met. European Directives are the laws that manufacturers must meet before they are permitted to affix CE Marking to their products. The Directives are about EMC (ElectroMagnetic Compatibility) and health and safety regulations. The CE Declaration Of Conformity is required, whether the manufacturer self-certifies to harmonized standards or not.

This requires 2 things:

• He issues a Declaration Of Conformity (DOC) which must be kept available to the enforcement authority for 10 years following the placing of the apparatus on the market. The Declaration of Conformity is the procedure by which a manufacturer upholds and declares that the product satisfies the provisions of the Directives that apply to them.

• He affixes the CE mark to the apparatus or to its packaging, instructions or guarantee certificate.

The Declaration of Conformity (DOC)

The CE Declaration Of Conformity must include the following components:

• A description of the apparatus to which it refers. This is the product identification.

• A reference to the specifications under which conformity is declared, and where appropriate to the national measures implemented to ensure conformity.
  In other words, the EU Directives complied with.

• Standards used to verify compliance with the Directives

• An identification of the signatory empowered to bind the manufacturer or his authorized representative. Normally this will be either the director or the technical director.

• The manufacturer’s name and address.

• If a Notified Body was used to prove compliance:

  • Name of the Notified Body (= third party independent testing house or laboratory authorized by the EU Member States to perform the conformity assessment tasks specified in the Directives).

  • Reference to the EC type examination certificate of a Notified Body

Compliance with the EMC Directive

There are several routes to EMC compliance:

Self-certification by the manufacturer

Self-certification to harmonized standards (BS and EN standards of CENELEC = European Standards body / ETSI = European Telecommunication Standards Institute) that apply to the product range. Most products which are within the scope of European product legislation can be self-certified by the manufacturer and exporter and do not require intervention of a Notified Body.
The potential advantage of certifying against standards, from the manufacturer’s point of view, is that there is no mandatory requirement for testing by an independent test house. The only requirement is that the manufacturer makes a declaration of conformity which references the standards against which compliance is claimed.
Of course, the manufacturer will normally need to test the product to assure himself that the product actually does meet the requirements of the standards, but this could be done in-house.
A technical file is still required.

Product examination by a Notified Body

A chosen Notified Body (third party independent test lab) issues an EC-Type Examination certificate to the applicant containing:

• the name and address of the applicant

• the conclusions of the examination

• the conditions for its validity

• the necessary data for identification of the approved design

This is the very expensive route that is taken mainly by big companies that can afford it.
A technical file containing, among others, the examination certificate is required.

No testing at all for special products

The manufacturer can generate a technical construction file without doing any testing or certificates in the following cases:

• When existing standards cannot be applied because of the nature of the apparatus or because it incorporates advanced technology which is beyond their breadth of concept.

• When testing, the product is impractical because of the size or extent of the apparatus, or because of the existence of many fundamentally similar installations.

• When the apparatus is so simple that testing is not necessary (no radiation or immunity issues expected)

• When the apparatus already meets standards that have not been harmonized but are nevertheless believed to meet the essential requirements

• When the apparatus is derived from a previous product that has already been tested and certified, and the differences have no effect on the test results for requirements that have to be met.

Technical Construction File (TCF)

The technical construction file is to be held at the disposal of the relevant competent authorities for inspection purposes, or by the Notified Body for EC-type examination as soon as the apparatus is placed on the market and for 10 years thereafter.

The Technical Construction File demonstrates the technical basis for conformity of the product to the requirements of the Directive. The manufacturer must implement internal measures to ensure that the product remains in conformity. The file is intended essentially for national surveillance authorities.

The main elements comprising a Technical Construction File are:

• Declaration of Conformity containing:

  • A general description of the product

  • Conceptual design

  • Manufacturer's drawings, diagrams of components, sub-assemblies, circuits, etc…

  • Descriptions and explanations necessary for the understanding of the said drawings and diagrams and the general functioning of the product.

  • Detailed technical data for essential aspects of the products

  • A list of standards referred to and descriptions of the solutions adopted to meet the Essential Requirements of the Directives

  • Results of design calculations made, examinations carried out etc…

  • Test reports

  • Certificate and inspection reports

  • In case of series production, the internal conditions that have been observed to safeguard compliance with the Directive.
    

• CE User manual with user safety information.
  A User manual is often an essential safety requirement.
  The User manual must contain all the information required for the correct and safe use of a product, including:

  • Information on risks

  • Identification and discouragement of hazardous applications

  • Instructions on how the product can be put to safe use

  • Details of who is authorized to perform certain actions

  • Identification of appropriate safety precautions to be taken

Product classification

Class A = industrial conducted and radiated emission limits
Class B = domestic conducted and radiated emission limits (most strict Class)
An apparatus that is in compliance with the domestic (Class B: most strict) limit line can also be installed in an industrial (Class A) environment.

Class A

Commercial, industrial or business environment, EXCLUSIVE of a device which is marketed for use by the general public or is intended to be used in the home.
Equipment not specified in one of the 3 other classes (B, C, D) shall be considered as Class A equipment.
Products are self-verified for compliance.
In some countries, such equipment may be subjected to restrictions on its sale and/or use.
The limits for Class A equipment are derived for typical commercial establishments for which a 30m protection distance is used.
The Class A limits may be too literal for domestic establishments and some residential areas.

• Balanced 3-phase equipment are Class A devices

Class B

Portable tools marketed for use in a residential environment (domestic use), NOTWITHSTANDING its use in a commercial, industrial or business environment.
Products require certification.
Such equipment should not be subjected to restrictions on its sale and is generally not subject to restrictions in its use.
The limits for Class B equipment are derived for typical domestic establishments for which a 10m protection distance is used.

Class C

Lighting equipment (including dimmers)

Class D

Equipment having a special wave shape of input current and an active input power less than or equal to 600W:

• Personal computers and personal computer monitors.

• Television receivers

EMC measurements

EMC measurements are inherently less accurate than most other types of measurement.
Field strength measurements can be in error by up to 10dB. It is always wise to allow a margin of about this magnitude between your measurements and the specification limits, not only to cover measurement uncertainty, but also tolerances arising in production.

Conducted emissions limits for EN

There are 3 kinds of detector in common use in RF emissions measurements : 

• Peak : For military specifications, but not at all for the CISPR emissions standards.

• Quasi peak (QP) detector de-emphasizes the peak response at low pulse repetition frequencies, which are less annoying on radio reception than high pulse repetition frequencies.

• Average (AVG) detector is 10dB below the QP for Class B and 13dB below the QP for Class A. The average detector will penalize continuous emissions with respect to pulsed interference. Pulsed interference registers a low level on an average detector.

The conducted emissions limit for EN Class A and EN Class B, Group 1 (≤ 20kVA):

Radiated emissions limits for EN

The limits for radiated emissions depend on the kind of chamber wherein the tests are performed. The kind of chamber also defines the distance between the measuring antenna and the device.
The tests that were done for the F500 and F600 were performed in a fully anechoic chamber.
Only QP (Quasi peak) detection is used for radiated emission.

The radiated emissions limit for EN Class A and EN Class B, Group 1 (≤ 20kVA):

Other standards

Germany (VDE)

The German RF emission standard VDE0871 (VDE = Verband Deutscher Elektrotechniker) for broad and narrow-band interference is stricter than the EN standards and extends from 150kHz down to 9kHz for some classes of equipment. Whereas EN 5022 has no requirement below 150kHz.

USA (FCC)

In the US, radio frequency interference requirements are controlled by the FCC (Federal Communications Commission), which is an independent government agency responsible for regulating interstate and international communications by radio, television, satellite, and cable.

Before being able to market his equipment in the US, a manufacturer must either obtain certification from the FCC if it is a personal computer or associated peripheral, or must verify that the device complies with the applicable limits. Certification requires FCC approval before marketing is allowed, while verification merely requires that the manufacturer satisfies himself that the equipment meets the technical requirements.

The FCC limits are stricter than the EN limits, especially for Class B (domestic) equipment.
FCC and VDE levels differ somewhat from the harmonized European EN levels (CISPR) and are included for comparison. All radiated emission levels are normalized to a measuring distance of 10m.
You should also bear in mind that there are detailed differences in the measurement methods between FCC, VDE, and CISPR standards.

Conducted emissions limits for VDE, FCC and EN

All values are measured with the CISPR 16 quasi-peak detector, but note that EN 55011, EN 55013, EN 55022 and EN 50081 also require conducted emissions to be measured with an average detector.
The limits for the average measurement are 13dB (Class A, business, commercial and industrial use) and 10dB (Class B, residential use) below the quasi-peak limits.

The conducted emissions limit for FCC Class A and FCC Class B:

Radiated emissions limits for VDE, FCC and EN

For ease of measurement and analysis, radiated emissions are assumed to predominate above 30MHz and conducted emissions are assumed to predominate below 30MHz.
There is of course no magic changeover at 30MHz. But typical cable lengths tend to resonate above 30MHz, leading to anomalous conducted measurements. Measurements of radiated fields below 30MHz will of necessity be made in the near field if closer to the source than λ/2, which gives results that do not necessarily correlate with real situations.

Radiated emissions limit for FCC Class A and Class B:

References

• EMC for Product Designers by Tim Williams, Newnes (1992)

• CE Conformity Marking and New Approach Directives by Ray Tricker, Butterworth-Heinemann (2000)

• A review of EMI standards, part 2 – radiated emissions by Timothy Hegarty, Texas Instruments, Jul 5, 2018

• https://www.researchgate.net/figure/Conducted-Emission-CISPR-22-Standard_fig1_309340604

• EN Class A and B limits : https://www.elitetest.com/blog/2022-05/introduction-cispr-11-emc-testing

• FCC Class A and B limits : https://learnemc.com/emc-regulations-and-standards