Protection model of an horizontal lightning conductor in the case of earth discontinuity

In this paper, we present some results of investigations carried out in the capture zones of an horizontal lightning conductors in the case of discontinuous earth. The conductor may be situated as well as in the upper or the lower earth part. The capture zones were determined in the case of lightning conductor situated between the high voltage rod and the discontinuity (interface) and also in the case of high voltage rod situated between the lightning conductor and the discontinuity. In some situations the lightning conductor capture zones are smaller than defined by the electro-geometrical model. We attribute this result to the great field intensity at the discontinuity, which reduce the lightning conductor discharge capture effect. This is in concordance with the results concerning the electrical strength of such air gaps without lightning conductors.