Leakage protection plug

Abstract

The invention discloses a leakage protection plug which can prevent electric shock accidents caused by faults of electric appliances and accidental electrification of a grounding wire. The leakage protection plug is provided with a weak current detection inductor, wherein a primary winding and a secondary winding of the weak current detection inductor are insulated from each other and coiled on an iron core of the weak current detection inductor; a detection circuit formed by connecting the primary winding and a current limiting and capacitance resisting element is connected between the ground wire and a neutral wire; second controllable silicon is arranged in a driving circuit of an electromagnetic coil; the output end of the secondary winding of the weak current detection inductor is connected in parallel with a trigger electrode and a negative electrode of the second controllable silicon respectively; a positive electrode and the negative electrode of the second controllable silicon are connected with a positive electrode and a negative electrode of the output end of a rectifying circuit respectively; and the output end of a secondary winding of a zero sequence current mutual inductor is connected in parallel with the input end of the driving circuit of the electromagnetic coil respectively.

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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