CE certification: navigating the EMC standards landscape

If you want to sell a product in the European Union, it typically must be CE marked (Communauté Européenne). Electrical and electronic devices are no exception. An essential aspect here is electromagnetic compatibility, which is a recurring topic in our blog and in our customer support.The European Union has issued a set of directives for the free movement of goods throughout the EU territory that sets minimum product requirements. The ‘CE’ marking certifies conformity. The EMC Directive (2014/30/EU) regulates electromagnetic interference of electrical and electronic equipment. Each EU state may draw individual legislation from this at a national level. Germany, for example, made this standard national law in 2016 with their EMVG act (Gesetz über die elektromagnetische Verträglichkeit von Betriebsmitteln) which governs the electromagnetic compatibility of equipment.
Dr. Heinz Zenkner, an EMC expert at Würth Elektronik has authored a two-part paper on this topic. It examines "EMC compliance for CE of electrical and electronic products" [link to paper]. Whilst his paper is beyond the scope of this blog post, a few points should be addressed here nonetheless.
The EMC directive regulates both the provision and use of equipment on the market, focusing on two principal aspects: 

1. Devices that may cause electromagnetic interference, and
2. Devices whose operation is susceptible to electromagnetic interference.

Radio shielding and protection against interference emission via electrical lines

Devices positioned at a certain distance from a particular product, as defined by the relevant standards, or connected via the power supply network (or other cables described in the standards), must not have their functionality impaired by the product. This assumes that the affected device can resist the electromagnetic phenomena, i.e. interference, as required by the EMC Act. Both the devices as well as any fixed installations are under the law’s jurisdiction.

Product immunity to electromagnetic interference

Products must also function as intended when electromagnetic interference is present. This may be caused by natural phenomena or by other electronic devices. For this protection requirement, a distinction is made in corresponding standards between the following phenomena: 
Immunity to interference from:

• electromagnetic fields
• electrostatic discharges
• transmitted transient energy
• high frequency conducted energy
• temporary power cuts and voltage fluctuations

Depending on the product, further product-specific emission and immunity requirements are added, which are detailed in the applicable standards. All requirements share the common goal of preventing electromagnetic interference between devices and evaluating and minimizing functional damage. Of course, the basic requirements for the devices do not ensure absolute protection. Type of technology, physical conditions and economic efficiency must be considered too. In order to ensure sufficient scope for future technical developments in relation to the principal procedure of CE conformity testing, the EMC Act outlines the requirements in the most general terms.
The EMC Act defines a number of exceptions where it is superseded by other laws. These include:

• Equipment covered by Directive 2014/53/EU on radio equipment
• Aerospace products, components and equipment
• Radio equipment (please note the exact definition in the EMVG)
• Automotive vehicles
• Medical devices
• Marine equipment

Furthermore, the EMC Act does not apply to "non-critical" equipment such as cables, batteries without active components, headphones, loudspeakers without amplifiers, plugs and sockets without additional electronic components etc. In the previously mentioned paper (available in German language only), Zenkner describes in detail which electrical equipment falls under the EMC Act and which does not.

Which EMC standards apply?

Testing electromagnetic properties is complex. The range of products is vast, and yet compliance must be reproducible and comparable. This results in a standards framework that describes measurement and test methodologies, limits, test severity levels, application areas and product-specific requirements. The framework includes basic-, generic- and product standards. For generic and product standards, the corresponding basic standards are referenced in relation to testing, so that extensive descriptions of structure and performance of the tests do not have to be covered. Only the correspondingly necessary product-specific variations are explained in the product standards.
EN 55035 - Immunity to interference of multimedia equipment
The EN 55035 standard, which specifies immunity requirements for multimedia devices, considers products in terms of interfaces (Fig. 1). Therefore, all interfaces (ports), including the housing, are assigned test procedures. 

Figure 1. Interface-oriented perspective of a product, for which its housing is considered an EMC interface.
 

EN 55032 - Interference emission of multimedia devices

The EN 55032 standard specifies the standards for interference emission in relation to electromagnetic compatibility of multimedia devices and equipment. 
Zenkner's paper also covers the following important aspects:
 

• Under what operating conditions and configurations must a device be tested?
• Who is responsible for CE marking and conformity?
• What must be considered for the declaration of conformity?

Lastly, Figure 2 illustrates the process of obtaining CE conformity with regard to EMC.

Figure 2. Process flowchart for CE conformity for electromagnetic compatibility.
 

Central source of EMC conformity information for CE certification of electronic products at www.we-online.com/EMV-CE.