Influence of the wall material of the lightning protected object size induced surges

The authors verify the separation distance coefficient /s/ setting of the distance according to the International standards IEC 62305, ed. 2, based on mathematical modeling. The coefficient of the separation distance is established in standards according to the empirical relationships. The authors wants to point out the possibility of more precise verification provided by real model experiments on building materials that are commonly used worldwide. For this purpose, mathematical models were carried out in collaboration with the Czech Technical University in Prague and the company DEHN + SÖHNE and compiled several artificial wall materials (air, concrete, PE and PVC). Behind them, object wiring (installation loop) was adjusted. In front of the wall, down-conductor was established. The assembly was tested by current impulse of 10/350 μs; 0.25/100 μs; 1/200 μs. The result is a set of adjustments that could be accepted by the international standardization committees for the revision of the standards IEC 62305 and the national standards STN 34 1398 and NF C 17-102.