"Powercross requirements for surge protection used in telecommunication systems"

In order to be able to classify surge protective devices (SPDs), uniform internationally applicable testing methods are necessary. These testing methods and the appropriate minimum requirements to the surge protection are described in the IEC 61643-21 [1] and the EN 61643-21 [3]. Because upon location of the SPD different demands are made, additionally the application standards IEC 61643-22 [2], ITU-T K.45 [6] and ITU-T K.11 [7] have to be considered. For internationally applicable surge protective devices the attention of these standards is mandatory necessary. Depending upon structure of a telecommunications system not only overvoltages but also disturbances by the power line can influence the telecommunication equipment or even destroy. The highest-energy disturbance can occur, if a direct contact between power supply line and telecommunications line, so called POWERCROSS, arises. For this, in above-mentioned Standards requirements for the SPDs are included, which protect telecommunications equipment against these disturbances.