Electric leakage protection plug

Abstract

The invention discloses an electric leakage protection plug, which can prevent an electric shock accident caused by electrical faults and can prevent the electric shock accident caused by accidental electrification of a ground wire. In the electric leakage protection plug, a detection winding is wound on a zero-sequence current transformer; the detection winding and a secondary winding of the zero-sequence current transformer are respectively wound on an iron core of the zero-sequence current transformer; the detection winding and the secondary winding of the zero-sequence current transformer are insulated and separated from each other; a detection loop which is formed by connecting the detection winding of the zero-sequence current transformer and a current-limiting capacitance resistance element in series is connected between the ground wire and a zero line; output ends of the secondary winding of the zero-sequence current transformer are respectively connected with a trigger electrode and a cathode of a thyristor in parallel; and an anode and the cathode of the thyristor are respectively connected with positive and negative electrodes of the output end of a rectification circuit.

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] Chinese patent document CN1142618C discloses a kind of earth leakage protection plug which can be opened and closed. The earth leakage protection plug is not only provided with a zero-sequence current transformer through which both the phase wire and the neutral wire pass, but also has a ground wire through which the earth wire passes. Line live detection sensor, so it can not only detect whether there is residual current between the phase line and the neutral line at the load end, when there is a residual current between the phase and neutral lines and reaches the preset threshold (for example: 10mA), it will It will trip immediately and cut off the phase wire, neutral wire and ground wire; and when the ground wire is accidentally electrified due to an abnormal grounding protection system, i...

AI Technical Summary

Problems solved by technology

[0003] It can be seen from the above that the prerequisite for the existing leakage protection plug to trip when the load end is faulty or the ground wire is accidentally electrified is that there must be a residual current between the load end phase and the neutral wire or there must be an accidental current flow on the load end ground wire. Therefore, the existing leakage protection plug has the following defects: when in use, whether the ground wire of the grounding protection system is missing (for example: the ground wire of the socket is empty, resulting in no grounding) and the load end of the leakage protection plug is insulated by electrical appliances When there is a fault leakage, or when the grounding protection system is abnormal (for example: short circuit of the phase wire and the ground wire) and the ground wire is accidentally electrified, it will cause the exposed metal parts of the electrical appliances to carry dangerous voltages, but they have not formed a loop, so there is no Therefore, although the exposed metal parts of electrical appliances have been charged with dangerous voltage, the existing leakage protection plugs will not automatically trip in this case, only when the human body or livestock touch these When the exposed metal parts have been electrified, a circuit is formed through the human body or livestock, resulting in residual current or ground wire accidental current, which makes the leakage protection plug trip within 0.1S and disconnects the phase wire, neutral wire, and ground wire. Although it can be tripped in time to protect the life safety of people or livestock, in this case, the existing leakage protection plug must first pass through the human body or livestock to generate residual current or ground wire accidental current and flow through the human body or livestock. It can be released to disconnect the phase wire, neutral wire and ground wire, so the existing leakage protection plug will still cause electric shock accidents to human body or livestock.

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