Protection-mode-convertible electric leakage protection plug

Abstract

The invention provides a protection-mode-convertible electric leakage protection plug which is composed of plug pins, phase wires, zero wires, ground wires, a zero sequence current transformer, a test loop, an electromagnetic tripping and latching device, a ground wire fault current detection circuit, a ground wire fault voltage detection circuit, first and second conversion switches, first and second amplification circuits and a unidirectional conduction circuit. The secondary winding output end of the zero sequence current transformer is connected with the input end of the first amplification circuit. The unidirectional conduction circuit is connected with the third intermediate input end of the second amplification circuit. The secondary winding output end of a ground wire live detection inductor is connected with the input end of the second amplification circuit via the second conversion switch. The trigger output end of the second amplification circuit is connected with the control electrode of a second silicon controlled rectifier. According to the electric leakage protection plug, a ground wire fault current protection mode and a ground wire fault voltage mode can be convertibly selected so that a problem of mis-tripping of the electric leakage protection plug can be solved and electricity utilization is ensured to be safer for people.

Description

technical field [0001] The invention relates to the technical field of electricity safety protection, in particular to a leakage protection plug with switchable protection modes. Background technique [0002] Existing leakage protection plugs can be divided into two types of products: ground fault current detection and protection and ground fault voltage detection and protection according to the detection and protection methods for live wires. [0003] Chinese patent document CN1142618C discloses a leakage protection plug capable of detecting ground wire fault current. The leakage protection plug can detect whether there is a fault current in the ground wire when the ground wire is accidentally electrified due to an abnormal ground protection system, and the ground wire fault current reaches When the preset threshold value is reached, it will immediately cut off the phase wire, neutral wire and ground wire. It can be seen from this that, as long as the fault current of the ...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a leakage protection plug with a convertible protection mode, which can not only detect the fault current and voltage of the ground wire, but also charge the ground wire for detecting the fault current and voltage of the ground wire The protection function is selectively converted, which not only solves the problem that the leakage protection plug cannot be used normally due to false tripping, but also reduces the after-sales maintenance rate and maintenance cost of the product

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