Use maintenance of Fuse cutout
The fuse in the low-voltage power distribution system is a kind of electrical appliance that plays a role of safety protection. The fuse is widely used in power grid protection and electrical equipment protection. When the grid or electrical equipment has a short-circuit fault or overload, it can automatically cut off the circuit to avoid electrical appliances. The equipment is damaged to prevent the accident from spreading.
The fuse consists of an insulating base (or support), contacts, melt, etc. The melt is the main working part of the fuse. The melt is equivalent to a special wire in series in the circuit. When the circuit is short-circuited or overloaded, the current increases sharply and the melt melts due to overheating, thereby cutting off the circuit. The melt is often made into filaments, grids or flakes. The melt material has the characteristics of relatively low melting point, stable characteristics, and easy fusing. Metals such as lead-tin alloy, silver-plated copper sheet, zinc, silver, etc. are generally used. In the process of melting and cutting off the circuit, an arc will be generated. In order to extinguish the arc safely and effectively, the melt is generally installed in the fuse housing and measures are taken to quickly extinguish the arc.
The fuse has the advantages of simple structure, convenient use, low price, etc., and is widely used in high-voltage and low-voltage systems.
In view of the excellent short-circuit protection performance of the fuse, it is widely used in high and low-voltage power distribution systems and control systems and electrical equipment. As a short-circuit and over-current protector, it is one of the most commonly used and most important protection devices.
In the application, attention should be paid to the use of fuse precautions, daily inspection and maintenance.
Precautions for the use of fuse:
1. The protection characteristics of the fuse should be compatible with the overload characteristics of the protected object, and considering the possible short-circuit current, a fuse with the corresponding breaking capacity should be selected;
2. The rated voltage of the fuse should be adapted to the line voltage level, and the rated current of the fuse should be greater than or equal to the rated current of the melt;
3. The rated current of the melt of the fuses at all levels in the line should be matched accordingly, and the rated current of the previous melt must be greater than the rated current of the next melt;
4. The melt of the fuse should be matched with the melt as required, and it is not allowed to increase the melt at will or replace the melt with other conductors.