What are high voltage fuses made of？

High-voltage fuse is a device used to protect high-voltage circuits from being damaged by overload current or short-circuit current. Its principle is to use metal conductors as melts in series in the circuit. And fuse, thereby breaking the circuit. So what does a high voltage fuse consist of?

The structure of the high-voltage fuse mainly consists of a melt, a fuse tube, a contact conductive part, a post insulator, and a base. The structural components are described as follows:

Melt: It is the core part of the fuse. It is made of good conductors such as silver or copper, and some fusible alloys are usually welded on it to improve its sensitivity. The shape and size of the melt determines the rated current and current limiting characteristics of the fuse. The melt will not melt during normal operation, but it will quickly heat up and gasify when it is overloaded or short-circuited, forming an arc and cutting off the circuit.

Fuse tube: It is the shell of the melt, which is made of heat-resistant insulating material, and has the function of extinguishing the arc when the melt is blown. The fuse tube is usually filled with fine-grained materials for arc extinguishing, such as quartz sand. The fine-grained material can absorb the energy of the arc, divide and cool the arc, and generate a large amount of gas pressure to deionize the arc, so that the arc can be extinguished quickly.

Contact conductive part: It is a metal part connecting high-voltage lines and supporting insulators, usually made of copper or copper alloy, with good electrical conductivity and mechanical strength. Contact conductive parts should ensure good contact with lines and insulators, and be able to withstand mechanical and electrical stress during normal operation and failure.

Supporting insulator: It is an insulating part that supports and fixes the conductive part and the base. It is usually made of materials such as ceramics or glass fiber reinforced plastics, and has good insulation performance and weather resistance. The supporting insulator should ensure sufficient insulation distance from the contacting conductive parts, and be able to withstand the mechanical and electrical stress during normal operation and failure.

Base: It is a fixed part installed on high-voltage switchgear or other equipment, usually made of cast iron or steel plate and other materials, with good mechanical strength and corrosion resistance. The base should ensure a solid connection to the supporting insulators and be able to withstand the mechanical and electrical stresses during normal operation and failure.