What is the high voltage fuse made of? To solve this problem, we can introduce from the characteristics of high voltage fuse.
As we know, the function of a high-voltage fuse is to protect the circuit, that is, when the current in the circuit exceeds a specified value, the melt inside the fuse will produce a kind of heat to break the circuit. Therefore, for high-voltage fusing materials, the requirement is to have low melting point, easy to quench arc characteristics of materials, generally including copper, silver, zinc, lead, lead tin alloy and other materials.
High voltage fuses are made of copper, silver, zinc, lead, lead tin alloy, etc., the melting point of these materials is not the same, so different currents need to use different materials, their melting temperature corresponding to 1080℃, 960℃, 420℃, 327℃, 200℃. Instructions for the use of these different materials are as follows:
1. The melting point of zinc, lead, lead-tin alloy and other metals is relatively low, but the resistivity is larger. Therefore, to use the fuse cross-sectional area is large, the metal vapor generated when fusing is not conducive to extinguishing arc, mainly used in 1kV circuit.
2. Copper and silver have high melting points, but small resistivity and good electrical and thermal conductivity. Therefore, to use the fuse cross sectional area is small, the metal vapor generated when fusing is less, easy to extinguish-arc, can be used in high voltage, large current circuit. However, if the current is too large, long-term temperature is too high, easy to cause damage to other components in the fuse. In order to make the melt fuse quickly, it must flow through a larger current, otherwise it will prolong the fuse time, which is unfavorable to the protection equipment. In order to eliminate this shortcoming, a tin or lead pellet is often welded on the copper or silver melt to reduce the melting temperature and improve the protection performance of the melt.
