Leakage protection plug

Abstract

A leakage protection plug comprises a shell, a bolt, phase lines, zero lines, ground lines, a zero-sequence current transformer, a test loop, an electromagnetic tripping and locking device, a ground line fault current detection circuit, a ground line fault voltage detection circuit, a first change-over switch, and a one-way conduction circuit. Two output ends of a secondary winding of the zero-sequence current transformer are respectively connected in parallel with first and second input ends of an amplification circuit. The output end of the one-way conduction circuit is connected in parallel with a third middle input end of the amplification circuit. The first change-over switch is connected between the output ends of first and second voltage comparators and the input end of the one-way conduction circuit. The leakage protection plug can be selectively switched between a ground line fault current protection mode and a ground line fault voltage protection mode. The problem that a plug may be tripped falsely is solved. Higher electrical safety is ensured for people.

Description

technical field [0001] The invention relates to the technical field of electricity safety protection, in particular to an electric leakage protection plug. 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 ground wire reaches a pr...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a leakage protection plug, which can not only detect the fault current and voltage of the ground wire, but also selectively switch the leakage protection function of detecting the fault current and voltage of the ground wire , which not only solves the problem of being unusable due to false tripping, but also reduces the after-sales maintenance rate and maintenance cost

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