High-voltage fuse is an important current protector, which plays a role in protecting electrical equipment and preventing circuit faults in the circuit. When a short-circuit current or overload current occurs in the circuit, it will quickly fuse to cut off the current, thereby protecting each device in the circuit.
High-voltage fuses are mainly composed of three parts: melt, shell and support. The melt is a key component in controlling the fusing characteristics, and its material and shape determine the fusing characteristics. Melt materials are generally divided into two categories: low melting point and high melting point. Low melting point materials such as lead and lead alloys have low melting points and are easy to fuse, but have high resistivity, so they require larger cross-sectional sizes. On the contrary, high melting point materials such as copper and silver, although they are not easy to melt, can use smaller cross-section sizes because of their low resistivity. The shape of the melt can also affect the fusing characteristics. Common shapes are wire-shaped and ribbon-shaped.
High-voltage fuses have inverse delay characteristics, that is to say, when the overload current is small, the fusing time is longer; when the overload current is large, the fusing time is short. This means that within a certain overload current range, when the current returns to normal levels, the fuse will not blow and can continue to be used.
High-voltage fuses are widely used in small-capacity devices from 3 to 35kV, including protection lines, transformers, motors and voltage transformers. It can not only protect various electrical equipment, but also protect household appliances, playing an important role in protecting the power system.