5.1 必須要件

"Fixed installation" means a particular combination of several types of apparatus and, where applicable, other devices, which are assembled, installed and intended to be used permanently at a predefined location

Owing to their characteristics, fixed installations are not subject to certain rules of free movement within the Union. Therefore, they are not subject to the requirements for CE marking, DoC or for formal EMC assessment before putting into service. However, fixed installations have to comply with the essential

requirements and other specific requirements (Annex I of the Directive) which are applicable to them.

Measures are prescribed in the EMCD to enable the competent authorities to handle complaints concerning disturbance generated by fixed installations.

(Article 19 (2)).

A fixed installation may be assembled by the incorporation of several apparatus including specific apparatus as described in Article 19.1 (see 2nd paragraph) and other devices outside the scope of the EMCD.

Apparatus incorporated in a fixed installation is subject to all provisions applicable to apparatus under the EMCD. However, there is a possibility of some exemption for apparatus under certain conditions as detailed in Article 19(1) of the EMCD (See also sections 1.6.2 and 5.4 of this Guide).

The specific essential requirements in Annex II.2 of the Directive require that fixed installations shall be installed taking into account good engineering practices and the information provided by the respective manufacturers regarding the intended use of the components that make up the fixed installation, in order to comply with the essential requirements set out in Annex II.1.

The two basic requirements relating to the use of components and to good engineering practice can be summarised as follows:

Intended use of components

This means that all the EMC instructions given by the manufacturer for all the component sub-parts used in the fixed installation have to be taken into account.

This applies to any sub-part, whether those parts are large machines, apparatus, components not subject to the EMCD, specific apparatus for the fixed installation, etc.

Since a fixed installation is installed in a pre-defined location the instructions for use should ensure that the components are installed in this specific location.

For example, these instructions may concern:

– the specified environment (especially the EMC environment);

– the required use of additional auxiliary devices (protection devices, filters etc);

– the specifications and length of the cables required for external connections;

– the conditions for use;

– Any special precautions for EMC (equipotential earthing etc.).

Good engineering practice

Good engineering practice comprises of suitable technical behaviour taking account recognised standards and codes of practice applicable to the particular fixed installation. The “good engineering practices” referred to in Annex I, 2 mean practices which are good for EMC purposes at the specific site in question.

General information on good engineering practice within the context of installations is available in several EMC handbooks, courses and technical reports.

For example some technical reports published by standardisation bodies deal with installation and mitigation guidelines for EMC.

Good engineering practice, particularly in the field of EMC, are in constant evolution. Whilst there is a need to have regard for the ‘state of the art’ practices it does not necessarily follow that they are relevant for all installations. Standards for installations cannot cover all specific local conditions: therefore it is necessary to be aware of some guiding principles when aiming to demonstrate installation according to good engineering practices:

Emissions: take appropriate actions to mitigate the source of disturbances by EMC design, e.g. by the addition of filters or of absorption devices etc.

Coupling and radiation: take appropriate actions in respect of distances, equipotential earthing, selection of cables, screening etc.

Immunity: take appropriate actions to ensure that sensitive equipment is protected against the various types of disturbances that might be expected.

When applying the essential requirements to a defined fixed installation, it is essential to define the borderlines/geographical limits of this fixed installation in order to distinguish it clearly from the external environment. In an analogy with apparatus, it is fundamental to identify:

– The ports/interfaces where conducted (high or low frequency) disturbances may cross the borderline from or towards the fixed installation (power supply port, control and telecommunication ports etc.);

– The coupling mechanism with the external environment;

– The radiation towards or from the external environment.

It should be noted that it is not the purpose of the EMCD to ensure electromagnetic compatibility between specific equipment inside the borders of the defined fixed installation.