A Method for Making Low-Voltage Lightning Arrester Have Automatic Disengagement Function

Abstract

The invention relates to a method for enabling a low-voltage lightning arrester to have an automatic disconnection function, which belongs to the field of lightning arresters. It is provided with a built-in hot-melt detachment component on the lower end surface of the lower plate of the low-voltage arrester body; Hot-melt medium layer; between the front end of the metal core wire of the grounding lead and the lower end surface of the lower plate, there is a set with a first spring; when an internal fault occurs in the low-voltage arrester, the temperature of the upper and lower plates rises; After the temperature of the plate exceeds the melting temperature point of the low-temperature hot-melt medium layer, under the action of the pre-stored elastic force of the first spring, the metal core wire of the grounding lead falls off from the lower end surface of the lower pole plate, disconnecting it from the lower pole of the low-voltage arrester. The contact between the boards makes the faulty low-voltage arrester out of operation and realizes the automatic disengagement function. It can be widely used in the fields of design, manufacture or operation and maintenance of low-voltage surge arresters with working voltages below 1kV to 0.5kV.

Description

technical field [0001] The invention belongs to the field of lightning arresters, in particular to a lightning arrester used for overvoltage protection of a low-voltage power system. Background technique [0002] Surge arrester is an electrical device used to protect electrical equipment from transient overvoltage (lightning strike, operation, steep wave) and quickly cut off power frequency continuous current. It is usually connected in parallel with the protected line or equipment. [0003] Its internal main components are non-linear resistors (such as zinc oxide resistors), which are in a high-resistance state under normal power frequency voltage due to their good non-linearity, and the arrester will not operate. When the overvoltage occurs, the action resistance sheet of the arrester is turned on, and the overvoltage shock current absorbs part of the energy through the resistance sheet and then leaks into the ground, thereby reducing the amplitude of the overvoltage, redu...

AI Technical Summary

Problems solved by technology

[0014] Existing external hot-melt disconnectors or thermal-explosive disconnectors are only suitable for high- and medium-voltage systems, and cannot be applied to low-voltage systems below 1kV

The reason is that the rated voltage / operating voltage of the arrester in the low-voltage system is low, the air gap between the two electrodes cannot be broken down, and the arc cannot be generated in the thermal explosion disconnector, resulting in the thermal explosion disconnector being unable to pass through the detonation heat. Explosive components to achieve the purpose of "disconnecting" the ground lead

However, because the heat-melt disconnector is used externally, the heat generated by the fault current cannot be transmitted to the disconnector, so the disconnector cannot operate

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