In March of this year, the European Commission published an updated “Guide for the EMC (Electromagnetic Compatibility) Directive”. Although published some four years after the 2014 adoption of the recast EMC Directive, said recast was a key driver for the update – not least because the recast aligns the Directive with the New Legislative Framework and introduces obligations for importers and distributors for the first time. Interestingly enough, however, the updated Guide offers little of substance regarding these changes – it instead refers readers to the Blue Guide* on more than one occasion – but offers new and salient advice on longer standing issues. These issues include what constitutes “inherently benign equipment”, “custom built evaluation kits” and “components/sub-assemblies” as well as what, in practice, an EMC assessment might look like and further clarification pertaining to the use of harmonized standards. This article discusses the advice presented.
Inherently benign equipment
Recital 12 of the EMC Directive states that the Directive “should not regulate equipment which is inherently benign in terms of electromagnetic compatibility”. Recital 12 therefore provides opportunity for exclusions, something that the earlier, 2010 version of the Commission Guide discussed while also suggesting that inherent benevolence is conditional upon electrical equipment being:
- Incapable of generating or contributing to electromagnetic emissions which exceed a level allowing radio and telecommunications equipment and other equipment to operate as intended; and
- Able to operate without unacceptable degradation in the presence of electromagnetic disturbance normally present in its intended environment.
These conditions are also documented in the new Guide together with a list of examples, as follows:
- Cables and cabling, cables accessories, considered separately;
- Equipment containing only resistive loads without any automatic switching device; e.g. simple domestic heaters with no controls, thermostat, or fan;
- Batteries and accumulators (without active electronic circuits);
- Corded headphones, loudspeakers without amplification, guitar inductive sensors without active electronic parts;
- Pocket lamps (including those containing LEDs) without active electronic circuits;
- Induction motors without electronic circuits;
- Quartz watches (without additional functions, e.g. radio receivers);
- Home and building switches which do not contain any active electronic components;
- Passive antennas;
- Electromagnetic relays without active electronic parts;
- Electromagnetic locks without active electronic parts;
- Cathode ray tubes;
- Protection equipment which only produces transitory disturbances of short duration during the clearing of a short-circuit fault or an abnormal situation in a circuit and which do not include active electronic components, such as fuses and circuit breakers without active electronic parts or active components; and
- High voltage types of equipment in which possible sources of disturbances are due only to localised insulation stresses which may be the result of the ageing process and are under the control of other technical measures included in non-EMC product standards, and which do not include active electronic components.
The 2018 Guide also makes a new point:
If a product under assessment is not included in the list of examples above and the EMC assessment establishes that the apparatus concerned is inherently benign in terms of electromagnetic compatibility (both for emission and immunity), the EMCD [the EMC Directive] shall not apply. However, it is recommended to document the results of the assessment and its conclusion.
Custom built evaluation kits
The new Guide offers an interpretation of what constitutes such kits for the first time. It does so by outlining criteria for determining what is “custom built” and, subsequently, an “evaluation kit”. The guidance is:
i. A kit that has been built on the basis of a specific request from a specific customer or from a group of customers involved in a joint research and development project as for all or certain characteristics of the evaluation kit; or
ii. A kit that has been built for the specific requirements of a specific customer or a group of customers involved in a joint research and development project as for all or certain characteristics of the evaluation kit.
A printed circuit board with an integrated circuit and support components to produce a working circuit for evaluation and development.
- Destined for professionals (customers), to be used solely at research and development facilities
Research and development facilities meaning public or private research and development bodies.
- For research and development purposes
Evaluation kits to be used in testing for further development/improvement of the function of the equipment under research and development.
A non-exhaustive list of examples of evaluation kits that do not benefit from the custom built evaluation kit exemption is presented.
These are discussed in Section 1.5.3 of the new Guide. It is stated that under Article 3.2.1 of the EMC Directive:
…components/sub-assemblies are covered by the EMCD, if the following two criteria are satisfied:
(a) intended for incorporation into an apparatus by the end-user; and
(b) liable to generate electromagnetic disturbance or the performance of which is liable to be affected by such disturbance.
Based on the definitions of “placing on the market” and “making available on the market” (Article 3 of the EMCD), as interpreted by the Blue Guide, supplying a product is only considered as making available on the Union market, when the product is intended for end user on the Union market. Thus, the first criterion (paragraph (a)), which refers to the end user and hence to the end use, is satisfied once the components/sub-assemblies are considered as being “placed on the market”.
The second criterion (paragraph (b)) is satisfied if the components/sub-assemblies are liable to generate electromagnetic disturbance or is liable to be affected by such disturbance. At least any of the two situations need to be satisfied. Benign components/sub-assemblies are excluded, thus not covered by the EMCD.
Performing a practical EMC assessment
The new Guide suggests that an EMC assessment is to be performed following a “defined methodology” with the Commission’s advice being that:
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 the 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.
This is interesting as it introduces commentary around risk analysis, in keeping with risk analysis being a new requirement under technical documentation in the EMC Directive.
Use of harmonised standards
The 2018 Guide offers the following as advice:
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 on how to achieve the presumption of conformity with the corresponding essential requirements of the EMC Directive.
In addition, the 2018 Guide offers the following clarification pertaining to product-specific, product family and generic standards:
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 European Standards Organisations taking into account the environment, operating and loading conditions of the equipment and are considered the best to demonstrate 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 harmonized standards to cover all essential requirements of the Directive. Each harmonized 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.
While the updated “Guide for the EMC Directive” does not differ greatly to what was documented in the earlier, 2010 Guide, the new interpretation presented by the Commission when it comes to inherently benign equipment, custom built evaluation kits and components/sub-assemblies is noteworthy, equally the order of preference presented regarding harmonized standards. It is, however, important to remember that the guidance is not legally binding. The new Guide is available here.
*The document is the “Blue Guide on the implementation of EU product rules 2016”, obtainable here.