Leakage protection plug

Abstract

The invention discloses a leakage protection plug, which not only can prevent electrical shock caused by electrical equipment faults, but also can prevent electrical shock caused by accidental electrification of an earth wire. The leakage protection plug is also provided with a weak electric current detection sensor, wherein the weak electric current detection sensor is provided with an iron core, a primary winding and a secondary winding, the primary winding and the secondary winding of the weak electric current detection sensor are both wound on the iron core and are insulatively separated, a detection circuit formed by connecting the primary winding of the weak electric current detection sensor and a flow resistance capacitance resistance element in series is connected between the earth wire and a zero line, and an output end of the primary winding of the weak electric current detection sensor and an output end of a secondary winding of a zero sequence current mutual inductor are respectively connected with an input end of a drive circuit of an electromagnetic coil in parallel.

Description

Technical field [0001] The present invention relates to the technical field of electrical safety protection, in particular to a leakage protection plug. Background technique [0002] Chinese patent document CN1142618C discloses a leakage protection plug with a ground wire that can be opened and closed. The leakage protection plug is not only provided with a zero-sequence current transformer through which the phase wire and the neutral wire pass, but also a ground wire through which the ground 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 the residual current between the phase and the neutral line reaches the preset threshold (for example: 10mA), it can It will trip immediately to cut off the phase, neutral, and ground wires; and when the ground wire is accidentally charged due to an abnormality in the grounding protection system, it can also detect whether ther...

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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