company news about Working principle of DC high-speed fuse

        A complete high-speed fuse is mainly composed of pure silver (99.995%) fuse link, high-strength flame-retardant insulated composite pipe body, conductive connection terminal and internal arc extinguishing quartz sand. After the fuse (fuse) is connected to the electrical circuit, the silver fuse is a low resistance excellent conductor under normal load, only consumes a small amount of electrical energy, and can work stably for a long time under normal power supply conditions.

       When the overload fault current occurs in the electrical system, the current through the fuse (fuse) increases rapidly, and the current density through the fuse link increases, resulting in a rapid rise in the temperature in the middle of the fuse link. When the temperature reaches 960 ° C, the fuse link begins to melt from solid to liquid, and all of it melts into the surrounding quartz sand gap, thus cutting off the fault current in the circuit. The whole process takes about tens of seconds, Because the fuse (fuse) is relatively insensitive to the overload current, the circuit breaker or thermal relay is usually used for overload protection.

        When there is a huge short-circuit current in the circuit, the current passing through the fuse link increases rapidly in a very short time, resulting in the thin neck of the fuse link being directly melted from the solid state and vaporized in a very short time, producing a strong grid arc ion gas, limiting the smooth passage of the short-circuit current, and quickly extinguishing and disconnecting the high-temperature and high-voltage arc bridge under the tight surrounding quartz sand and forced cooling, and cutting off the passage of the short-circuit current, To achieve the effect of safe high-speed disconnection, the whole process only takes a few milliseconds.