To reduce overvoltage load on a lightning proof transformer 9 in lightning stroke in electric facilities which protect the electrical equipment 11 in a structure 12 against lightning strokes by placing the lightning proof transformer 9 in an input power line 5 from a pole transformer 3, having a class B grounding conductor 4.
A lightning protective system is constituted as follows: in the electrical facilities, which supplies power to the electric equipment 11 in the structure 12 with the lightning proof transformer 9 placed in the input power line 5 from the pole transformer 3 having the class B grounding conductor 4, a lightning stroke point (lightning rod or the like) 13 on the structure 12 and the grounding point 17 of the class B grounding conductor 4 from the pole transformer 3 outside the structure are connected with each other through a lightning protection grounding conductor 20, installed in isolation from the structure 12 and the ground. Thus, lightning currents, flowing under the ground between the grounding point 17 and the structure 12, are intensively let through the lightning protection grounding conductor 20. As a result, the overvoltage load on the lightning proof transformer 9 is reduced and the discharge withstand current rating load on the earth lightning arrester of the lightning proof transformer 9 is reduced or the earth lightning arrester can be omitted.
OTSUKI KAZUJI
NAKAI YOSHIKO
KUDO TAKASHI
| JPH11176591A | 1999-07-02 | |||
| JPS58216396A | 1983-12-16 | |||
| JP2002271964A | 2002-09-20 | |||
| JPH0831668A | 1996-02-02 |
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