Earthing failure creepage protector

Abstract

An electric-leakage tripping apparatus for grounding fault is composed of a major-switch, a load-switch, a zero-sequence current transformer, and a control circuit in which a leakage-signal amplifier is contained. The operating mechanism of the leakage tripping apparatus has the following features: a major-switch control spring is used to retract the close restrain to the major-switch, a load-switch control spring is used to open the load-switch, a travel block is secured with a reset button, a punchy spring interposed between a basis and the travel block is used to retract the close restrain to the major-switch applied by the travel block. The travel block has restrict elements to unilaterally restrict the major-switch and the load-switch respectively. The travel block chooses one utmost position and restrains the close of one switch. In the case of electric leakage or grounding fault, the apparatus can break quickly and can provide reliable protection to the user and the load-apparatus even if the fault is not eliminated.

Description

technical field [0001] The invention relates to a leakage protection device when a grounding loop fails, in particular to a leakage protection device capable of rapidly disconnecting a power supply and a load. Background technique [0002] The ground failure leakage protection device is a safety device installed between the power supply and the load to protect the lives of personnel. Its function is that when the ground loop of the load fails or there is no ground loop, and leakage occurs at the same time, once the human body touches the leakage body Cut off the power circuit to protect life. There are many kinds of earth failure leakage protection devices, but they are basically composed of a main circuit breaker, a zero-sequence current transformer, a leakage signal amplifier, a relay for controlling the action of the main circuit breaker and an actuator. Its working principle is that when the reset button is pressed, if the load end is normal, the main circuit breaker sw...

AI Technical Summary

Problems solved by technology

But it has the problem that the disconnection recovery force is restricted by the magnetic field strength of the cut-off stroke distance, that is to say, the relay must rely on the electromagnet to generate magnetic force to make the main circuit breaker action beyond a certain distance overcome the disconnection recovery force. As we all know, a certain point The magnetic field intensity decreases sharply with the increase of the distance from the point to the magnetic pole. At the beginning of the closing action of the main circuit breaker, the magnetic attraction force it receives is the smallest. In order to complete the closing action, the opening restoring force cannot be designed too large, otherwise the magnetic The suction force cannot overcome the restoring force to close the main circuit breaker, which causes the acceleration of the disconnection action to be very small. Although the disconnection action is one, it fails to reduce the action time to the greatest extent. Therefore, the objective of this solution is that the disconnection speed is not fast. Defects

[0005] In addition, the existing technology only performs disconnection control on one end of the power supply, and does not perform disconnection control on the load end. The disadvantage of this leakage protection method is that when there is a leakage fault at the load end and someone is touching the leakage body Under normal circumstances, once other people press the reset button for a long time, the fault will be aggravated, and the person who gets an electric shock will be more dangerous

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