Surge protective devices efficiency for apparatus protection in front of direct flashes to overhead low voltage lines

•Low voltage power system protection.•Safety of electrical and electronic systems within a structure.•Efficiency of surge protective device system.•Lightning simulations.•IEC standards discussion.

Aim of the paper is to give the rationale for evaluating the coordinated surge protective device (SPD) system characteristics in order to reduce the probability of damage of electrical and electronic equipment within a structure against lightning surges due to direct lightning stroke to the connected low voltage overhead lines (source of damage S3 according to IEC standard 62305). Two SPD systems are considered, namely SPD system type S, consisting of only one SPD, typically a switching type SPD, and an SPD system type L consisting of only one SPD, typically a limiting type SPD. The probability of the two SPD systems to reduce the risk of failure of apparatus is investigated and practical information are given useful for IEC standard revision.