Zero missing and zero breaking automatic protection device

Abstract

The invention discloses an automatic zero-off and zero-off protection device, which belongs to the technical field of electric power protection devices. Including the control part circuit and the detection part circuit, the control part circuit includes the auxiliary contact of the shunt circuit breaker and the relay; the detection part circuit includes the relay KC, the stop button SB1 of the shunt circuit breaker QF and the leakage protector RCD; it also includes The alarm part circuit is composed of the power supply E, the dynamic auxiliary contact QF3 of the shunt circuit breaker QF, the alarm R and the switch K, which are electrically connected in sequence. The invention is simple in structure, easy to use, strong in safety, high in intelligence, strong in versatility, low in cost, basically requires no maintenance, and is convenient to change or connect circuits on site; it is especially suitable for three-phase four-wire transformers and three-phase four-wire power supplies used on the device.

Description

technical field [0001] The invention belongs to the technical field of power protection devices. Background technique [0002] At present, due to various situations and reasons, the zero line of the lighting transformer is blown out, such as the zero line in the metering box in the JP cabinet is blown out, the zero line on the low voltage side of the transformer is blown out, etc., which will bring extremely serious consequences. . Because the unbalanced load will lead to the unbalanced three-phase voltage, if the zero line is disconnected, the unbalanced three-phase load voltage will be more serious, which will change the working characteristics of electrical equipment, and the equipment will not work if the voltage is too low. Excessive voltage shortens the life of equipment, causing many users to burn out electrical equipment, and even cause fires, causing serious economic losses to users, unnecessary compensation liabilities and economic losses to power supply companies...

AI Technical Summary

Problems solved by technology

[0002] At present, due to various situations and reasons, the zero line of the lighting transformer is blown out, such as the zero line in the metering box in the JP cabinet is blown out, the zero line on the low voltage side of the transformer is blown out, etc., which will bring extremely serious consequences.

Because the unbalanced load will lead to the unbalanced three-phase voltage, if the zero line is disconnected, the unbalanced three-phase load voltage will be more serious, which will change the working characteristics of electrical equipment, and the equipment will not work if the voltage is too low. Excessive voltage shortens the life of equipment, causing many users to burn out electrical equipment, and even cause fires, causing serious economic losses to users, unnecessary compensation liabilities and economic losses to power supply companies, and seriously affecting the power supply companies. Brand

Moreover, once the neutral line is disconnected, the electrical equipment that uses protection to connect to zero will lose its protective effect. Once the equipment leaks electricity, it will cause personal electric shock. personal electric shock accident

[0003] According to the actual situation that the zero line is disconnected in the three-phase four-wire low-voltage power distribution system, and the neutral point potential shift causes many accidents due to overvoltage, we need to research and develop a kind of easy-to-manufacture detection and protection of missing and broken neutral lines. device to ensure the safety of electricity in the low-voltage power distribution system

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