Protected mode-convertible type leakage protection plug

Abstract

The invention provides a protected mode-convertible type leakage protection plug, which comprises a shell, a plug pin, a phase line, a null line, a ground line, 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 first wire. The output end of the secondary winding of the zero-sequence current transformer is connected in parallel with the input end of an amplifying circuit. The output ends of first and second voltage comparators are connected with the first change-over switch. The common output end of the first change-over switch is connected with one end of the first wire. The other end of the first wire passes through the zero-sequence current transformer to be connected with the negative electrode of the DC output end of a first rectifier circuit. According to the technical scheme of the invention, the leakage protection plug can be selectively converted between a ground line fault current protection mode and a ground line fault voltage protection mode. In this way, the mis-tripping problem of the plug can be solved. Meanwhile, the power 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 capable of switching 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 ...

AI Technical Summary

Problems solved by technology

[0006] The object of the present invention is to provide a leakage protection plug capable of switching protection modes. The leakage protection plug can not only detect the fault current and voltage of the ground wire, but also have the leakage protection function of detecting the fault current and fault voltage of the ground wire. Carry out selective conversion, 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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