DIN VDE 0845 Beiblatt 1:2010-11

This supplement applies for measures against overvoltage in information technology equipment (IT installations) and contains applicable supplementary and further information. The following components shall be observed for the overvoltage protection of information technology equipment: - telecommunication lines (signal lines and antennae lines are considered telecommunication lines); - installations for information technology (information technology devices) for the connection and the course of the line; - buildings with IT installations; - power supply and remote power installations (devices); - power supply lines; - grounding installations. Overvoltage for the purpose of this supplement is: - transient influence, caused by - atmospheric discharge (lightening, thunderstorms); - switching operations; - electromagnetic influence; - low-frequency fields of adjacent electrical power supply and traction current systems. Furthermore, this supplement contains supplementary and further information on the overvoltage protection devices which are employed for the overvoltage protection of information technology equipment. Corresponding normative specifications are included in the standards DIN EN 61663-1 (VDE 0845-4-1) and DIN EN 61663-2 (VDE 0845-4-2) as well as DIN EN 61643-21 (VDE 0845-3-1). Information for the use of overvoltage protection devices are contained in Technical Report IEC/TR 61643-22. Overvoltage protection for the purposes of these standards is the protection against overvoltage and overcurrents, which are produced on telecommunication, signal, antennae and power supply lines, for example, by the effect of lightening. These overvoltages and overcurrents are described, amongst others, by the parameters peak value, rise time, time to half-value of the wave tail and specific energy. These parameters are widely fluctuating, statistically distributed values and are not entirely ascertainable. They are dependent, for instance, on the factors disturbance source, site, characteristics of the lines and type of installation. The responsible Committee is Subcommittee UK 767.6 "Schutz von Einrichtungen der Informationstechnik gegen Überspannung und niederfrequente Felder" ("Protection of information technology installations against overvoltage and low frequency fields") of the DKE (German Commission for Electrical, Electronic and Informational Technologies) at DIN and VDE.