JP2008166186A

JP2008166186A - Ground-fault interrupter

Info

Publication number: JP2008166186A
Application number: JP2006356204A
Authority: JP
Inventors: Hiroyuki Toyama; 博之外山
Original assignee: Kawamura Electric Inc
Current assignee: Kawamura Electric Inc
Priority date: 2006-12-28
Filing date: 2006-12-28
Publication date: 2008-07-17

Abstract

<P>PROBLEM TO BE SOLVED: To reduce an insulation distance, particularly, between a CR snubber circuit and another constituent component. <P>SOLUTION: A ground-fault interrupter 1 includes a zero-phase current transformer 2 for outputting a signal by detecting electric leakage in main circuits 4, 4, an electric leakage detection circuit 5 for detecting electric leakage on the basis of the output signal of the zero-phase current transformer 2, a tripping mechanism 6 that opens each contact 6 provided in the main circuits 4, 4 by a magnetic force generated in a trip coil 11, into which an excitation current is made to flow, so as to trip the main circuits 4, 4 from a power supply, a thyristor 14 serially connected to the trip coil 11 so as to make an excitation current flow into the trip coil 11 on the basis of the output signal of the electric leakage detection circuit 5, and a snubber circuit 8 composed by connecting a capacitor 13 as a capacitive element and a resistor 12 as a resistance element in series. The snubber circuit 8 is connected to the thyristor 14 in parallel. The capacitor 13 is connected to the trip coil 11 side of the thyristor 14 while the resistor 12 is connected to the ground line side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、漏電遮断器において、電源に外来サージが印加された場合に、引き外し機構のトリップコイルが備えるインダクタンスによって生じる高電圧部分を減らすための技術に関する。 The present invention relates to a technique for reducing a high voltage portion caused by an inductance provided in a trip coil of a tripping mechanism when an external surge is applied to a power supply in an earth leakage breaker.

従来から、特許文献１に記載の回路遮断器のように、駆動コイルに励磁電流を流すサイリスタと並列にＣＲスナバ回路を入れて構成し、外来サージが印加された場合であっても、サイリスタが不要動作しないよう保護する技術が知られている。ここで、図２は、特許文献１と同様のＣＲスナバ回路１８を備えた漏電遮断器２０を示すブロック図である。 Conventionally, as in the circuit breaker described in Patent Document 1, a CR snubber circuit is inserted in parallel with a thyristor that supplies an exciting current to the drive coil, and even when an external surge is applied, A technique for protecting against unnecessary operation is known. Here, FIG. 2 is a block diagram showing an earth leakage breaker 20 provided with a CR snubber circuit 18 similar to that of Patent Document 1.

特開２００２−９３４４６号公報JP 2002-93446 A

しかし、特許文献１の技術のように、駆動コイル２１の磁力を利用して主電路の接点を引き外す構造では、電源に外来サージが加わった場合、駆動コイル２１が備えるインダクタンスによって瞬時電圧が生じ、駆動コイル２１とＣＲスナバ回路１８との間の接続部分が高電圧状態となる場合がある（図２の太線部分）。また特許文献１に限らず、一般的にＣＲスナバ回路１８は、駆動コイル２１側に抵抗２２を接続し、接地側にコンデンサ２３を接続して構成されているため、駆動コイル２１とＣＲスナバ回路１８との間の接続部分はもちろん、特に抵抗２２を含むコンデンサ２３までの配線部分について高電圧状態となり、他の構成部品との絶縁距離を大きく確保する必要が生じ、小型化するための高密度実装を阻害する一因となっていた。さらに近年、漏電遮断器は高遮断容量かつ小型化が進み、以前にも増してケース内の収納スペースが小さくなってきており、絶縁距離の確保がより難しくなっていた。 However, as in the technique of Patent Document 1, in the structure in which the contact of the main circuit is pulled off using the magnetic force of the drive coil 21, when an external surge is applied to the power supply, an instantaneous voltage is generated by the inductance provided in the drive coil 21. The connection portion between the drive coil 21 and the CR snubber circuit 18 may be in a high voltage state (the thick line portion in FIG. 2). The CR snubber circuit 18 is not limited to Patent Document 1 and generally has a configuration in which a resistor 22 is connected to the drive coil 21 side and a capacitor 23 is connected to the ground side, so that the drive coil 21 and the CR snubber circuit are connected. 18 and of course the wiring portion including the resistor 22 to the capacitor 23 is in a high voltage state, and it is necessary to ensure a large insulation distance from other components, and the high density for miniaturization. It was one factor that hindered implementation. Further, in recent years, the earth leakage circuit breaker has a high breaking capacity and a small size, and the storage space in the case has become smaller than before, and it has become more difficult to secure an insulation distance.

そこで、本発明では上記課題を鑑み、特にＣＲスナバ回路と他の構成部品との絶縁距離を小さくして、小型化できる漏電遮断器の提供を課題とする。 In view of the above problems, an object of the present invention is to provide an earth leakage circuit breaker that can be miniaturized by reducing the insulation distance between the CR snubber circuit and other components.

上記課題を解決するため、請求項１の発明に係る漏電遮断器は、主回路の漏電を検出して信号を出力する零相変流器と、零相変流器の出力信号に基づき漏電を検出する漏電検出回路と、励磁電流を流したトリップコイルで生じる磁力により主回路を引き外す引き外し機構と、トリップコイルに直列接続され、漏電検出回路の出力信号に基づきトリップコイルに励磁電流を流すスイッチング手段と、容量性素子と抵抗素子とを直列接続してなり、スイッチング手段に並列接続されるスナバ回路と、を備えてなり、スナバ回路が、容量性素子側を、スイッチング手段のトリップコイル側に接続して構成される。 In order to solve the above-mentioned problem, a leakage breaker according to the invention of claim 1 includes a zero-phase current transformer that detects a leakage of a main circuit and outputs a signal, and a leakage current based on an output signal of the zero-phase current transformer. A leakage detection circuit to detect, a tripping mechanism that trips the main circuit by the magnetic force generated by the trip coil that has passed the excitation current, and a series connection to the trip coil, and an excitation current to flow to the trip coil based on the output signal of the leakage detection circuit A switching device, and a snubber circuit in which a capacitive element and a resistance element are connected in series, and connected in parallel to the switching device. The snubber circuit has a capacitive element side on the trip coil side of the switching means. Connected to and configured.

請求項１の発明によれば、スナバ回路と他の構成部品との絶縁距離を抵抗素子周辺で部分的に小さくできるので、その空きスペースを利用して構成部品の高密度実装及び配置が可能となり、よって漏電遮断器を小型化できる。 According to the first aspect of the present invention, since the insulation distance between the snubber circuit and the other component parts can be partially reduced around the resistance element, it is possible to mount and arrange the component parts at high density using the empty space. Therefore, the earth leakage circuit breaker can be reduced in size.

本発明に係る漏電遮断器の実施の形態を図１の添付図面に基づいて説明する。
漏電遮断器１は、主回路４，４の漏電を検出して信号を出力する零相変流器２と、零相変流器２の出力信号に基づき漏電を検出する漏電検出回路５と、励磁電流を流したトリップコイル１１で生じる磁力により主回路４，４に設けた接点６を開放して主回路４，４を電源から引き外す引き外し機構６と、トリップコイル１１に直列接続され、漏電検出回路５の出力信号に基づきトリップコイル１１に励磁電流を流すスイッチング手段としてのサイリスタ１４と、容量性素子としてのコンデンサ１３と抵抗素子としての抵抗１２とを直列接続してなるスナバ回路８と、を具備している。 An embodiment of an earth leakage breaker according to the present invention will be described with reference to the attached drawing of FIG.
The earth leakage circuit breaker 1 includes a zero-phase current transformer 2 that detects a leakage of the main circuits 4 and 4 and outputs a signal; a leakage detection circuit 5 that detects an earth leakage based on the output signal of the zero-phase current transformer 2; A tripping mechanism 6 that opens the contacts 6 provided in the main circuits 4 and 4 by the magnetic force generated in the trip coil 11 through which an exciting current is passed to disconnect the main circuits 4 and 4 from the power source, and the trip coil 11 are connected in series. A thyristor 14 serving as a switching means for supplying an exciting current to the trip coil 11 based on an output signal from the leakage detection circuit 5; a snubber circuit 8 formed by connecting a capacitor 13 serving as a capacitive element and a resistor 12 serving as a resistive element in series; Are provided.

スナバ回路８は、サイリスタ１４に並列接続されている。コンデンサ１３は、サイリスタ１４のトリップコイル１１側に、抵抗１２が接地ライン側に接続されている。 The snubber circuit 8 is connected to the thyristor 14 in parallel. The capacitor 13 is connected to the trip coil 11 side of the thyristor 14 and the resistor 12 is connected to the ground line side.

本漏電遮断器１において、過大な外来サージ電圧が電源に印加された場合、トリップコイル１１が備えるインダクタンスによって位相遅れの電圧が生じ、トリップコイル１１とスナバ回路８との間の接続部分が高電圧状態になる（図１の太線部分）。スナバ回路８においては、トリップコイル１１側に接続されたコンデンサ１３までの配線部分が高電圧状態となる。 In this earth leakage circuit breaker 1, when an excessive external surge voltage is applied to the power supply, a phase lag voltage is generated by the inductance provided in the trip coil 11, and the connection portion between the trip coil 11 and the snubber circuit 8 is a high voltage. It will be in a state (thick line part of Drawing 1). In the snubber circuit 8, the wiring portion to the capacitor 13 connected to the trip coil 11 side is in a high voltage state.

本漏電遮断器１によれば、過大な外来サージ電圧が電源に印加された場合、スナバ回路８において高電圧状態となる配線部分を、トリップコイル１１側のコンデンサ１３までとして、比較的短くできる（図１と図２の太線部分を比較参照）。よって、他の構成部品との絶縁距離を大きく確保する必要が生じるような高電圧状態となる接続部分を減らし、より小型化できる。 According to the earth leakage circuit breaker 1, when an excessive external surge voltage is applied to the power supply, the wiring portion that becomes a high voltage state in the snubber circuit 8 can be made relatively short to the capacitor 13 on the trip coil 11 side ( (Refer to the bold lines in FIGS. 1 and 2). Therefore, it is possible to reduce the number of connection portions that are in a high voltage state where it is necessary to ensure a large insulation distance from other components, thereby further reducing the size.

尚、本発明は上記実施形態に限定されるものではなく、以下に示すように本発明の趣旨を逸脱しない範囲で各部の形状並びに構成を適宜に変更して実施することも可能である。
（１）スナバ回路は、コンデンサと抵抗とからなる無極性に限らず、コンデンサにダイオードを並列接続した有極性のものとしても良い。
（２）スイッチング素子は、サイリスタに限らず、いわゆるトランジスタやＦＥＴ等で構成しても良い。 In addition, this invention is not limited to the said embodiment, As shown below, it is also possible to implement by changing suitably the shape and structure of each part in the range which does not deviate from the meaning of this invention.
(1) The snubber circuit is not limited to nonpolarity composed of a capacitor and a resistor, but may be a polar circuit in which a diode is connected in parallel to the capacitor.
(2) The switching element is not limited to a thyristor, and may be a so-called transistor or FET.

本発明に係る漏電遮断器のブロック図である。It is a block diagram of the earth-leakage circuit breaker which concerns on this invention. 従来の漏電遮断器のブロック図である。It is a block diagram of the conventional earth-leakage circuit breaker.

Explanation of symbols

１・・漏電遮断器、２・・零相変流器、４・・主回路、５・・漏電検出回路、６・・接点、８・・スナバ回路、１１・・トリップコイル、１２・・抵抗、１３・・コンデンサ、１４・・サイリスタ。 1 .... Leakage circuit breaker, 2 .... Zero phase current transformer, 4 .... Main circuit, 5 .... Leakage detection circuit, 6 .... Contact, 8 .... Snubber circuit, 11 .... Trip coil, 12 .... Resistance , 13 · Capacitor, 14 · Thyristor.

Claims

A zero-phase current transformer that detects the leakage of the main circuit and outputs a signal;
A leakage detection circuit for detecting leakage based on the output signal of the zero-phase current transformer;
A tripping mechanism that pulls off the main circuit by the magnetic force generated by the trip coil through which the excitation current is passed;
Switching means connected in series to the trip coil, and passing an exciting current to the trip coil based on the output signal of the leakage detection circuit;
A capacitive element and a resistive element connected in series, and a snubber circuit connected in parallel to the switching means,
The snubber circuit
The capacitive element side is connected to the trip coil side of the switching means,
An earth leakage circuit breaker characterized by that.