Author_Institution :
Electrical Engineer, American Gas & Elec. Co., New York, N.Y.
Abstract :
This paper gives the operating experience of some thousand miles of 132-kv. transmission lines analyzed from the lightning point of view. The lightning experience during three years operation of the system is compared. In addition, the effect of ground wires, grading shields, and tower footing ground resistances is discussed from data secured under operating conditions. The comparative reliability of single- and two-circuit lines is analyzed from the data recorded. Cases of damage to insulator strings, hardware, etc., are tabulated and discussed from the point of the severity of the damage and the location on the phase wires. Yearly averages of lightning outages per 100 mi. of line per year are given for the different lines and from these figures comparisons made for the different types of line construction. A three year record is given of the percentage of lightning outages on the 1000-mi. network.