CEI, the institutional body recognized by the Italian State and the European Union (EU Regulation No. 1025/2012) in the field of technical standardization in the electrotechnical, electronic and telecommunications sector, provides the Queries Service in order to provide clarifications and answers on the correct interpretation of the technical and regulatory publications of the CEI

Only the questions with these requirements will be considered:

Questions related to consultancy on products, systems, projects and technical solutions will not be taken into consideration, as this type of activity does not fall within the scope of the Query Service or among the institutional tasks of the CEI.

The questions will be examined by the competent CEI Technical Committees and the answers will be provided in times compatible with the activities of the Technical Committees and could also be planned in conjunction with the meetings scheduled by the Technical Committees themselves.

Some of the questions of general interest are published below, with the relative answers prepared by the CEI, which can be consulted free of charge by users. To facilitate the selection, the questions are searchable by topic, by text search(title, summary and purpose) or by code of standard. When searching by code of the standard, the abbreviations CEI or EN must be omitted (example: type 60439-1 for the CEI EN 60439-1 standard or 64-15 for the CEI 64-15 standard).


Before submitting a new question, check our FAQ page, you could find the answer to your problem and go on with your work promptly.

Answers to old questions are only in Italian.

Filter answers by subject

Select a subject in the list in order to find out all the replies concerning the chosen subject in the FAQ page.

Search by standard number

Digit the standard number (e.g. 64-8 if CEI or 61335-1 when EN) and click the searching button.

Search by words

Digit one or more words you think proper for searching in the questions or in the replies (e.g. explosive atmosphere, lightnings, etc) and click the searching button.

Haven't you found the reply you are looking for?

Shouldn't you find the reply to your question in the FAQ page, please click the here below button and send your new question.

Your request will be sent to the proper Technical Committee and later will be available, nameless, in the FAQ page together with the relevant reply.