Lightning protector for low voltage electric equipment

Abstract

The lightning protector incldues: one common-mode lightning preventing circuit, one overcurrent protector, and one lightning preventing warning device comprising three lightning preventing warning and indicating circuits in the same structure. It features that the lightning preventing warning and indicating circuit consists of one limiting resistor and one serially connected one-way conducted lightning and indicating circuit. In the lightning preventing warning and indicating circuit, current flows in only one direction and the indicating lamp of the circuit goes out along with the blow of the overcurrent protector to indicate reliably the on-off state, and this is favorable to maintenance. The structure and configuration is simple, flexible and practical.

Description

technical field [0001] The invention relates to a lightning protection device, in particular to a lightning protection device for low-voltage electrical equipment. Background technique [0002] In order to provide lightning protection for low-voltage electrical equipment, the most effective method at present is to install lightning protection devices on the AC power supply lines of the equipment. There are two main working principles of existing lightning protection devices: one is to install lightning protection components directly to the ground on the neutral line and three phase lines respectively; the other is to install lightning protection components between the zero line and the ground, Arresters are directly installed on the three phase lines and the neutral line respectively. When the former lightning protection device is in use, due to the influence of grounding resistance, when the lightning protection component is damaged, although there is a fuse connected in s...

AI Technical Summary

Problems solved by technology

When the former lightning protection device is in use, due to the influence of grounding resistance, when the lightning protection component is damaged, although there is a fuse connected in series in front of it, the fuse is not easy to blow, so the lightning protection component will explode or burn

When the latter lightning protection device works, it will also cause a fire because there is no fuse with an appropriate current capacity connected in series in front of the lightning protection element between the neutral line and the ground.

Chinese patent ZL98217538.8 (notification number CN2376112Y) discloses a kind of lightning protection device for above-mentioned problem, and it is mainly to be connected with overcurrent protector namely fuse before each piezoresistor of lightning protection components and gas discharge tube, and set There is an on-off indication circuit of the overcurrent protector, that is, the lightning protection alarm indication circuit, but the lightning protection device of this structure has imperfections. For the three-phase power supply system, due to the different phases of the three phases, after the neutral line fuse is blown, the The current can form a loop between the phase wires through the diode, causing the indicator light to not go out, making it difficult for the user or maintenance personnel to know the operating status of the lightning protection device, and providing wrong information to the maintenance personnel, thinking that the lightning protection device is operating normally. But in fact, the lightning protection device has lost the protection function of the common-mode lightning strike to the ground, so that the equipment is in a dangerous situation of being struck by lightning, and it is difficult to ensure the safe operation of the communication equipment.

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