Residual current circuit breaker

Abstract

The present invention discloses a residual current circuit breaker of a test circuit, which has the advantages of simple structure, small size and accurate electric leakage test. The residual current circuit breaker comprises the following components: an open and close part which switches on and off a main circuit; a zero-phase current transformer which is traversed by all phase conductor of the main circuit; an electric leakage detecting circuit which determines the generation of the current leakage according to the output current of the electric leakage detecting coil of the zero-phase current transformer; an operating time setting circuit for setting the operating time of the electric leakage detecting circuit; a breaking device for breaking and switching off the open and close part according to the output signal of the electric leakage detecting circuit, which represents the generation of electric leakage; a power source circuit which supplies the electric power to the electric leakage detecting circuit; and a test circuit which is provided with a test switch which supplies the test current to the test coil of the zero-phase current transformer, wherein the test circuit is installed with a unit which operates together with the test switch and is set to a preset operating time irrespectively with the setting of the operating time setting circuit.

Description

[0001] This application is a divisional application of the application of the same name with the application number 200410090718.0 filed on November 8, 2004 Technical field [0002] The present invention relates to a leakage circuit breaker used to detect leakage in a power distribution system connected to a motor and various other loads so as to prevent the spread of accidents in the future, and particularly relates to the improvement of the test circuit. Background technique [0003] In order to correctly perform the operation test of the leakage circuit breaker, various efforts have been made so far in the leakage test circuit of the leakage circuit breaker. One example is shown in Patent Document 1. Figure 7 The structure of the earth leakage circuit breaker shown in Patent Document 1 is shown in. [0004] Figure 7 The leakage circuit breaker in has multiple rated voltages, for example, there are three rated voltages of 100, 200 and 400V. The earth leakage circuit breaker 1...

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Problems solved by technology

[0010] However, in such a conventional device, since it is necessary to set the number of current-limiting resistance elements and selection switches corresponding to the type of rated voltage used, the installation space of the test circuit increases and the number of parts decreases. increase, there is a problem that the manufacturing cost increases

[0011] Moreover, especially when the rated voltage is high, a large voltage is often applied between the contacts when the test switch is turned on, so it is necessary to increase the contact interval of the test switch to improve the withstand voltage, so there is still the problem of increasing the size of the switch.

[0012] In an earth leakage circuit breaker having such a latter test circuit, when the rated voltage used is high, the voltage applied to the current-limiting resistance element during the test operation is high and the power consumption is large

For this reason, in the prior art, a current-limiting resistance element with a large power wattage is used, and the current-limiting resistance element is divided into several in series, thereby sharing power consumption

[0013] Therefore, in such conventional devices, since it is necessary to use a current-limiting resistance element with a large wattage or divide the current-limiting resistance element into a plurality in series to share the power consumption, the installation space of the test circuit becomes large and the number of parts increases, thereby There is a problem of rising manufacturing costs

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