Leakage circuit breakers

Abstract

The invention relates to a leakage circuit breaker. The leakage circuit breaker comprises a shell and an electric transmission mechanism, wherein the electric transmission mechanism comprises a stepping motor, an eccentric wheel and a transmission rod; and a control circuit comprises a central processing unit, a leakage detection sensor, a trip driving circuit and a stepping motor. When the central control unit detects that mutation leakage current exists in an A phase power supply, a B phase power supply or a C phase power supply, and when the mutation leakage current is more than a first preset value, and the central control unit controls a tripper to execute the tripping action by the trip driving circuit, so that the power supply is shut off; after 20-60 seconds, the central control unit controls the rotation of the stepping motor by the driving circuit, the stepping motor drives an operation handle of the tripper to move by the eccentric wheel and the transmission rod, and the tripper is switched on to conduct the power supply; and when gradual change leakage current exists in the A-phase power supply, the B-phase power supply and the C-phase power supply, and the current is larger than a second preset value, the central control unit controls the tripper to trip, so that the power supply is shut off.

Description

technical field [0001] The invention relates to a leakage circuit breaker. Background technique [0002] Chinese patent literature announcement number CN200941549Y discloses a small motor protection device. The transformer converts the current signal of the main circuit of the motor into a small signal current, and sends it to the single-chip microcomputer after the signal conversion circuit and the signal conditioning circuit. The single-chip microcomputer performs leakage sampling, Three-phase current sampling, and sequentially judge whether there is leakage, phase loss, short circuit, locked rotor, three-phase unbalance, overload, and then drive the LED display module to display through the display driving circuit, and cut off the input power of the motor through the output control circuit. Chinese patent document publication number CN1622414A discloses also a kind of earth leakage circuit breaker. [0003] The disadvantage of the above-mentioned prior art is that it can...

AI Technical Summary

Problems solved by technology

[0003] The disadvantages of the above-mentioned prior art are that it is impossible to automatically trip and close automatically according to the slowly changing leakage current and sudden leakage current in the power supply circuit, which brings inconvenience to the use.

The disadvantage of this scheme is that the monitoring of the slowly changing and abruptly changing leakage current is realized by using an analog circuit, and the reliability is low, and the scheme cannot realize the functions of automatic tripping and closing in combination with the slowly changing and abruptly changing leakage current.

The disadvantage of this scheme is that the analog circuit is used to realize the monitoring and closing control of the slowly changing and sudden leakage current, which is susceptible to interference and has low reliability.

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