Electric leakage protection device

Abstract

The invention discloses an electric leakage protection device which is not only capable of preventing the accidents of electric shocks caused by faults of electrical appliances but also capable of preventing the accidents of electric shocks caused by accidental electrification of earth wires. The electric leakage protection device is provided with a first resistor-capacitor unit, an earth wire fault voltage detector and an induction ring; a detection coil of the earth wire fault voltage detector is wound on an iron core of the earth wire fault voltage detector; a detection circuit formed by the first resistor-capacitor unit and the detection coil of the earth wire fault voltage detector which are connected in series is connected between an earth wire and a null line; one end of the first resistor-capacitor unit is connected with the earth wire and the other end is connected with one end of the detection coil of the earth wire fault voltage detector; the other end of the detection coil of the earth wire fault voltage detector is connected with the null line; and the detection ring passes through a closed induction circuit formed by the earth wire fault voltage detector and a zero-sequence current transducer.

Description

technical field [0001] The invention relates to the technical field of electricity safety protection, in particular to an electric leakage protection device. Background technique [0002] Chinese patent document CN1142618C discloses a leakage protection plug, which is provided with a zero-sequence current transformer through which both the phase line and the neutral line pass to detect the residual current between the phase and the neutral line, and the ground line There is a ground fault voltage detector to detect the fault current flowing through the ground wire. When the residual current between the phase and neutral wires or the fault current on the ground wire reaches the preset threshold (for example: 10mA), It trips instantly, cutting phase, neutral and ground. It can be seen that when in use, when the ground wire of the ground protection system is missing (for example: no ground due to a virtual connection of the ground wire of the socket) and the electrical applian...

AI Technical Summary

Problems solved by technology

It can be seen that when in use, when the ground wire of the ground protection system is missing (for example: no ground due to a virtual connection of the ground wire of the socket) and the electrical appliances on the load line of the leakage protection device have leakage due to insulation failure or abnormality of the ground protection system (for example: When the ground wire is accidentally electrified, it will cause dangerous voltage on the shell of Class I electrical appliances, but they have not yet produced residual current or ground fault current, so the existing leakage protection device is in this case. Under normal circumstances, it will not trip automatically. Only when people touch the energized shells, residual current or ground fault current will be generated, so that the leakage protection device will trip within 0.1S, and the phase wire, neutral wire, The ground wire is disconnected. Although it can trip in time to protect people's lives, it can only implement power-off protection after people get an electric shock. Therefore, the existing leakage protection device still has the problem of people getting an electric shock.

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