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downstream protective stages is to discharge the residual impulse currents of the lightning flood wave and to reduce the surges induced by the electromagnetic field to an acceptable level for downstream equipment. While single-stage or two-stage protection concepts are designed for small-sized electrical installations, e.g. a radio base station, a three-stage protection concept has proven to be an economical and technical optimum for medium-sized and

The Safe Protection Concept Safe lightning and surge protection is based on the lightning protection zones concept described in IEC 62305-4 (EN 62305-4). The relevant organising principle of dividing the object to be protected into protection zones (known as lightning protection zones (LPZ)) and defining the zone boundaries can be applied both to protect a detached house and a large-scale installation (e.g. a data processing centre). First the outside area

strength of the parts of the installation and the terminal devices. These requirements are fulfilled with the DEHN Surge Arrester Family Coordinated Surge Protection for Power Supply Systems Wave form 10/350 μs I (kA) Lightning impulse current 200 200 kA Peak value 100 As Charge 6.25 MJ/ Specific energy 100 0 700 350 Lightning impulse current 10/350 μs

The Lightning Flood Wave When lightning hits an installation, high impulse currents and impulse voltages come up within conductive systems which can be compared to an enormous “flood wave“. If this “flood wave“ is not broken, important electrical consumers will be destroyed. The impact of this “flood wave“ is described and defined in lightning protection standard series IEC 62305 (EN 62305). The lightning flood wave is similar to an impulse current reaching