DIN CLC/TS 61643-22:2017-06

This prestandard contains the German version of the European Technical Specification TS 61644-22:2016 and is identical to the International Standard IEC 61643-22:2004. It contains a specification for the selection of and application principles for surge protective devices (SPDs) for use in telecommunication and signal processing networks and for those surge protective devices that contain a combination of power supply protection and telecommunication or signal line protection in one enclosure. Two basic circuit types of surge protective devices are taken into account: SPD with voltage-limiting component and SPD with voltage- and current-limiting component in one enclosure. In this prestandard the technologies are described in the main part and in the informative Annexes A and B. Definitions, requirements and test methods are given in IEC 61643-21 and/or DIN EN 61643-21 (VDE 0845-3-1). The decision to use SPDs is based on an analysis of the risks that are seen by the network or system under consideration. Because telecommunications and signalling systems may depend on long lengths of wire, either buried or aerial, the exposure to overvoltages from lightning, power line faults and power line/load switching, can be significant. If these lines are unprotected, the resultant risk to information technology equipment (ITE) can also be significant. Other factors that may influence the decision to use SPDs are local regulators and insurance stipulations. This prestandard provides indications for evaluating the need for SPDs, the selection, installation and dimensioning of SPDs (risk analysis and management). It also provides guidance on achieving coordination between SPDs and between SPDs and ITE installed on telecommunication and signal lines. When attempting to attain proper coordination the waveshape of the impinging surge (impulse or AC), the ability of the equipment to withstand an overvoltage/overcurrent without damage, the installation, for example the distance between SPDs and between SPDs and ITE, and the SPD voltage-protection levels and response times of the SPD should be checked. Compared to the previous edition of this prestandard the following changes and additions have been made: a) the normative references have been updated; b) revision of the specifications for the use of multiservice surge protective devices in Clause 8; c) specifications for comparison between the classifications of surge protective devices in EN 61643-11 and EN 61643-21 in 7.3.3; d) addition of a new Annex F to take into account new transmission systems such as PoE; e) addition of a new Annex G to include EMC requirements for surge protective devices; f) addition of a new Annex H with decision criteria in which cases a connection can be considered an "internal port"; g) addition of a new Annex I on the subject of maintenance cycles of surge protective devices; h) addition of a new Annex J on the influence of an increase in the earth potential. i) addition of a new Annex K with references to risk management based on EN 62305-2. The responsible committee is DKE/UK 767.6 "Schutz von Einrichtungen der Informationstechnik gegen Überspannungen und niederfrequente Felder" ("Protection of equipment for information technology against overvoltage and low-frequency fields") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.