In low-voltage distribution system, fuse is an electric appliance, which plays a role in safety protection. Fuses are widely used in protection of electrified wire netting and electric equipment. When they short out or overload, the circuit will be cut off automatically. It prevents the damages of the electrical equipment and the spread of the accident.
Fuse is made of insulating base(or support pieces), contact, melt and so on. The melt is main part of the fuse. The melt is equivalent to a special wire in the circuit. When the circuit short out or overload, the current is too large, the melt is gong to melt due to overheat, then cut off the circuit.The melt is usually made into filiform, grid or schistose. The material of melt has relatively low melting point, stable features, and easy to fuse. It usually adopts terne metal, silver plated copper, zinc, silver and other metal. In the process of the melt fuse to cut off the circuit, there is gong to produce electric arc. To extinguish electric arc safely and effectively, the melt is generally installed inside in a fuse shell. Take measures to extinguish electric arc quickly.
Fuses have advantages of simple structure, convenient use and low price, so that it widely used in low-voltage system.
