Outdoor telecommunications networks typically have cable lengths of 300 m and more. Sometimes communication lines may even have a total cable length of several kilometers. The corresponding test impulse given by the applicable standard shows the typical waveform 10/700 μs – 5/320 μs as this waveshape is the most representative of actual surges encountered in the field. Coupling via arrestors is the preferred coupling method for unshielded outdoor symmetrical communication lines. The coupling network also has the task of splitting the surge current into multiple pairs in multiconductor cables.
Learn more...