Abstract: The disconnector of the present invention comprises: a current transformer that detects a current flowing through electric wires; a rectifying part that rectifies the current outputted from the current transformer; a charging part that charges the current outputted from the rectifying part; a switching part that disconnects the electric wires upon driving; and a trigger part that drives the switching part when the charge stored in the charging part becomes a predetermined drive area. In this regard, the drive area is set larger than the charge that can be stored in the charging part by a lightning surge current. The disconnector of the present invention and the overvoltage protectors may be combined to constitute the overvoltage protection device.

Abstract: Problems can be solved about reducing the maximum voltage, reducing the size and cost, and so on. According to the invention, three or more discharge units are connected in series between two conductors. Two or more clamping type overvoltage protective units (hereinafter referred to as “clamping units”) are connected in parallel to the discharge units except one or more of the discharge units. The overall operating voltage of the discharge units arranged in parallel to all the clamping units is set lower than any voltage obtained by subtracting from the operating voltage of each clamping unit, the spark-over voltages of the other discharge units connected in parallel to the clamping unit. The overall operating voltage of the discharge units connected in parallel to all the clamping units is set higher than the operating voltage of each discharge unit connected in series to any one of the clamping units.

Abstract: An object of the present invention is to provide a disconnector that satisfies applying a lightning surge current, blocking a follow current, being capable of short circuit breaking, and being compact in size and an overvoltage protection device combining the disconnector with overvoltage protectors. The disconnector of the present invention comprises: a current transformer that detects a current flowing through electric wires; a rectifying part that rectifies the current outputted from the current transformer; a charging part that charges the current outputted from the rectifying part; a switching part that disconnects the electric wires upon driving; and a trigger part that drives the switch when the charge stored in the charging part becomes a predetermined drive area. In this regard, the drive area is set larger than the charge that can be stored in the charging part by a lightning surge current.