因雷击架空线路引起的直击雷电过电压或感应过电压极易导致绝缘子闪络或击穿，形成的工频续流，高温电弧瞬间熔断导线。为了防止这一事故，需要在架空线路上安装线路过电压保护器，其作用是在雷击架空线路时，将雷电流引向保护器，并切断工频续流，避免绝缘子闪络或击穿，保护架空线路避免引发雷击断线事故。
The direct lightning overvoltage or induced overvoltage caused by lightning strikes the overhead line is very easy to cause the insulator flashover or breakdown, and the power frequency continuous flow is formed, and the high temperature arc instantly fuse the wire. In order to prevent this accident, it is necessary to install the overvoltage protector on the overhead line. The effect is to guide the lightning current to the protector when lightning strikes the overhead line, and to cut off the continuous flow of the power frequency, avoid the flashover or breakdown of the insulator, and protect the overhead line from the lightning strike.