The EMC-Directive, 89/336/EEC, of the EU has been repealed and replaced by a more refined Directive, 2004/108/EC. One important change is that the so called Modular Approach is not applicable for certification of a system. One important consequence is that a machine that includes two or more EMC-relevant subunits or subsystems is considered to be apparatus that must comply with the provisions of the EMC-Directive.

89/336/EEC – the old EMC-Directive

The guidelines of the former EMC-Directive, 89/336/EEC, gave the following advice:

For systems and installations, it is up to the manufacturer of the system or the person taking the installation into service to ensure that the provisions of the directive are observed and the EMC requirements complied with. Either a system or a modular approach may be used to demonstrate compliance.

The TCF route is thus not required for verifying a system and/or an installation if all subunits and subsystems comply with the EMC requirements (modular approach), presuming that the referenced standards are relevant for intended environments and that installation guidelines are followed. Since the CE mark does not indicate which directives or standards have been referred to, this will need to be covered in the Declaration of Conformity or another document.

2004/108/EC – the new EMC-Directive

The guidelines of the new EMC-Directive contain these guiding principles:

1.2.2 Combination of finished appliances (systems)

A combination of several finished appliances which is made commercially available as a single functional unit intended for the end-user is considered to be apparatus. Such a system, within the sense of the EMC Directive, is combined, and/or designed and/or put together by the same person (the “manufacturer”) and is intended to be placed on the market for distribution as a single functional unit for end-use and to be installed and operated together to perform a specific task. All provisions of the EMC Directive, as defined for apparatus, apply to the combination as a whole.

It should be noted that combining two or more CE marked finished appliances does not automatically produce a “compliant” system e.g.: a combination of CE marked Programmable Logic Controllers and motor drives may fail to meet the protection requirements.

3.4.1.1 CE marking of systems

A system which is only placed on the market as a whole need carry only one CE marking, which may be placed on any one of the constituent parts or units. However the manufacturer may, if he wishes, place additional CE marking on the other parts of the system. This could be appropriate, for example, if the user were able to easily separate the constituent parts and make use of them separately. Additional CE marking does not incur the need for separate conformity assessment or additional declarations of conformity for the constituent parts.

If separate use could lead to a part or unit failing to comply with the protection requirements, a suitable warning should be included in the instructions for use, for example: The units of this system are intended to be used together, and must not be operated separately.

If the manufacturer places any part of the system on the market separately, the relevant provisions of the Directive, conformity assessment, documentation and CE marking, apply separately to that part or unit, in addition to the requirements for the system as a whole.

Author:  PG Nilsson