company news about Characteristics of fast acting fuse

Inverse time limit current protection characteristics

        The fuse has anti time delay characteristics, that is, when the overload current is small, the fusing time is long; When the overload current is large, the fusing time is short. Therefore, within a certain overload current and overload time range, the fuse will not fuse and can be used continuously. Fuses have different fusing characteristic curves, which can be applied to the needs of different types of protection objects.

Current limiting characteristic

        The melt of the fast fuse is a rectangular sheet with a series of round holes and narrow necks, and is filled with quartz sand arc extinguishing medium. The section area at the narrow neck of the round hole is small, and the thermal capacity is small. When a short circuit fault occurs, the fault current has not reached the expected short circuit current, it is fused, and the arc is separated into many small segments by quartz sand. This not only limits the increase of short-circuit current, but also accelerates the extinction of arc.

Strong breaking capacity

        When a short circuit fault occurs, the narrow neck of the round hole is first fused, the arc is separated into many small segments by quartz sand, and the arc is quickly extinguished. As quartz sand is insulated, the fuse will become an insulator immediately after the arc is extinguished, breaking the circuit. Therefore, the quick fuse has strong breaking capacity, which can be up to 50kA.

The impact energy borne by the loaded equipment is small

        In case of short circuit fault, the impact energy borne by the load equipment is W=I ² In Rt formula, I - short circuit current; R - resistance of circuit; T - time from the occurrence of short circuit fault to the disconnection of the circuit. The breaking time of fast fuse is short, and it has a good current limiting effect, so the impact energy borne by the load equipment is small.