PURPOSE: To reduce damage due to thunderbolt by stretching a drop wire, having upper end connected to the top part of a transmission steel tower, vertically downward in parallel with the axis of the steel tower and grounding the lower end thereof thereby shunting the lightning current when the overhead ground wire or the steel tower is struck by a thunderbolt.
CONSTITUTION: Upper ends of drop wires 3, 4 are fixed to an arm metal 2 arranged on top of a transmission steel tower 1 in which an overhead ground wire 11 is stretched on the top and transmission lines 12-14 are stretched thereunder through insulators 15. The drop wires 3, 4 are stretched downward in parallel with the axis of the steel tower 1 and the lower ends thereof are connected with an underground ground wire 5. When the steel tower 1 or the overhead ground wire 11 is struck by a thunderbolt, lightning current is shunted through the steel tower 1 and the drop wires 3, 4. Consequently, potential rise of the steel tower with respect to the transmission line is suppressed at the time of thunderbolt resulting in prevention of reverse flashover in an insulator unit.
KAWASHIMA TAKAO
INOUE ATSUSHI
IIDA TAKAYASU
TOENEC CORP
| JPS641414A | 1989-01-05 | |||
| JPH01122316A | 1989-05-15 |