Some questions of insulation coordination in distributive networks in regions with hills and mountaines in Croatia

Paper describes some experiences dealing with insulation coordination in various kinds of MV distributive networks situated in regions with hills and mountaines in Croatia. It was noticed the great number of faults due to lightnings and switching operations in long time period, so various kinds of protective measures including measuring verifications have been undertaken. In the last improvements of protection against various kind of overvoltages have been applied new international regulations in s.c. high-altitude insulation coordination.