Abstract :
CONTINUING a 4-year operating record of an extensive 132-kv transmission system under lightning conditions, this paper presents and discusses the record for 1930 and 1931. Operating experience is given on yearly line outages due to lightning, severity, and frequency of lightning storms over the system, frequency of double circuit outages, extent of line and station apparatus damage, effect of tower footing resistance in reducing lightning outages, reduction in tower footing resistances by the use of driven ground rods and counterpoises, effect on lightning outages by overinsulation, relative magnitudes of single-phase, 2-phase, and 3-phase line faults, and location of lightning flashovers on the line in reference to top, middle, and bottom conductors.
