DRIVING HIGH SURGE CURRENTS INTO LONG CABLES - MORE BEGETS LESS

Reality checks can and should be applied to proposals for characterizi ng the surge environment and application of surge-protective devices ( SPDs) to end-user, low-voltage power systems, One such check is the fa ct that driving a large current with steep front toward an SPD install ed at the far end of a branch circuit cable could require such a high voltage that the connections at the near end of the cable will flashov er, limiting the stress applied to the far-end SPD, Tests and numerica l modeling were performed to support this thesis, The results of real- world measurements and modeling, presented in the paper, are in good a greement and validate each other, From that point on, the model allows parametric variations of cable length and surge current amplitude and waveform, of which several examples are presented.