所谓过负荷是指当导线中通过电流量超过了安全载流量时，导线的温度不断升高，这种现象就叫导线过负荷。
The so-called overload refers to the phenomenon that the temperature of the conductor increases continuously when the current in the conductor exceeds the safe carrying capacity. This phenomenon is called conductor overload.
当导线过负荷时，加快了导线绝缘层老化变质。当严重过负荷时，导线的温度会不断升高，甚至会引起导线的绝缘发生燃烧，并能引燃导线附近的可燃物，从而造成火灾。
When the conductor is overloaded, the aging and deterioration of the insulating layer of the conductor are accelerated. When the conductor is seriously overloaded, the temperature of the conductor will continue to rise, even cause the insulation of the conductor to burn, and can ignite the combustibles near the conductor, thus causing fire.