JP2004265645A

JP2004265645A - Three-phase circuit breaker

Info

Publication number: JP2004265645A
Application number: JP2003052455A
Authority: JP
Inventors: Hiroyuki Toyama; 博之外山
Original assignee: Kawamura Electric Inc
Current assignee: Kawamura Electric Inc
Priority date: 2003-02-28
Filing date: 2003-02-28
Publication date: 2004-09-24

Abstract

<P>PROBLEM TO BE SOLVED: To provide a three-phase circuit breaker miniaturizable by reasonable connection of a surge absorbing element. <P>SOLUTION: In this three-phase circuit breaker 1, power lines 2 are connected to respective wires of three-phase three-line type cable runs R, S and T; one-side ends of three surge absorbing elements Z1-Z3 are respectively connected to the power lines 2; and the other-side ends of the absorbing elements Z1-Z3 are connected together. When a lightning surge is generated in the cable runs R, S and/or T, the lightning surge between the R-S phases is absorbed by the serially connected absorbing elements Z1 and Z2; the lightning surge between the S-T phases are absorbed by the serially connected absorbing elements Z2 and Z3; and the lightning surge between the T-R phases is absorbed by the serially connected absorbing elements Z3 and Z1. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、３相回路遮断器において雷サージから電子部品を保護するための回路に関する。
【０００２】
【従来の技術】
３相回路遮断器において欠相保護機能や漏電保護機能を備えたものは欠相を検出するためや電子制御部を駆動するために電路から電源を確保している。３相３線式回路遮断器の場合、例えば、特許文献１に示されるように電子制御部の電源は３相３線式電路の２相から供給されるようになっており、３相４線式回路遮断器の場合、例えば、図３に示すように電子制御部の電源は３相４線式電路のうち電圧線の１つと中性線の２相から供給されるようになっており、両者とも電子制御部を雷サージから保護するためのサージ吸収素子を１つだけ備えていた。そのため、サージ吸収素子がケース内で占めるスペースも小さかった。
【０００３】
【特許文献１】
特開平５−３６２２号公報（第１図）
【０００４】
【発明が解決しようとする課題】
しかしながら、従来の３相回路遮断器が漏電保護機能を備えている場合、３相のうち電子制御部の電源の何れか１相が欠相すると電子制御部が動作しないので漏電が発生しても電路を遮断しないし、また、３相回路遮断器が欠相保護機能を備えている場合も同様に、電源を取っていない相が欠相しても検出せず、電路を遮断しない。そこで１相が欠相しても漏電保護が機能するためには３相から電源を確保する必要があるし、全ての電路において欠相を保護するには全ての電路に電源線を接続する必要がある。そうすると、サージ吸収素子を各相間に設ける必要があり、Ｒ相，Ｓ相，Ｔ相から成る３相３線式電路の場合、Ｒ−Ｓ相間とＳ−Ｔ相間とＴ−Ｒ間の３箇所にサージ吸収素子を設けなければならないし、Ｌ１相，Ｌ２相，Ｌ３相，Ｎ相から成る３相４線式電路の場合、Ｌ１−Ｌ２相間、Ｌ２−Ｌ３相間、Ｌ３−Ｌ１相間、Ｌ１−Ｎ相間、Ｌ２−Ｎ相間及びＬ３−Ｎ相間の６箇所にサージ吸収素子を設けなければならない。近年は遮断器の小型化が進んでいるが、サージ吸収素子は他の電子部品に比べて大きいため、遮断器の小型化は非常に困難であった。而もＬ１−Ｌ２相間、Ｌ２−Ｌ３相間及びＬ３−Ｌ１相間の電圧は高いため、これに設けられるサージ吸収素子は容量が大きいのでＬ１−Ｎ相間、Ｌ２−Ｎ相間、及びＬ３−Ｎ相間に設けられるサージ吸収素子に比べて３倍程度の容積があり、価格も高いという問題があった。
【０００５】
そこで上記問題点に鑑み、本発明の目的は、小型化することができる３相回路遮断器を提供することである。
【０００６】
【課題を解決するための手段】
上記目的を達成するために、請求項１に記載の発明によれば、３相３線式電路に用いられる３相回路遮断器において、３相３線式電路の各線に電源線を接続し、電源線に３つのサージ吸収素子の一方端を夫々接続し、３つのサージ吸収素子の他方端を一括して接続したことを特徴とする。
【０００７】
請求項２に記載の発明によれば、請求項１に記載の３相４線式欠相保護付き回路遮断器において、３相４線式電路に用いられる３相回路遮断器において、３相４線式電路の電圧線の各線に電源線を接続し、電源線に３つのサージ吸収素子の一方端を夫々接続し、３つのサージ吸収素子の他方端を一括して接続し、接続点を３相４線式電路の中性線に接続したことを特徴とする。
【０００８】
【発明の実施の形態】
３相３線式電路に用いられる３相回路遮断器は、３相３線式電路の各線に電源線を接続し、電源線に３つのサージ吸収素子の一方端を夫々接続し、この３つのサージ吸収素子の他方端を一括して接続する。そして、３相３線式電路に流れる雷サージを各相間につき２つのサージ吸収素子によって吸収する。
【０００９】
また、３相４線式電路に用いられる３相回路遮断器は、３相４線式電路の電圧線の各線に電源線を接続し、電源線に３つのサージ吸収素子の一方端を夫々接続し、３つのサージ吸収素子の他方端を一括して接続し、この接続点を３相４線式電路の中性線に接続する。そして、３相４線式電路に雷サージが発生した場合、電圧線間は２つのサージ吸収素子によって雷サージを吸収し、電圧線と中性線間は１つのサージ吸収素子によって雷サージを吸収する。
【００１０】
【実施例】
本発明に係る３相回路遮断器の第１実施例を図１の添付図面に基づいて説明する。
【００１１】
３相３線式電路Ｒ，Ｓ，Ｔに用いられる３相回路遮断器１は、３相３線式電路Ｒ，Ｓ，Ｔの各線に電源線２を接続している。電源線２にはサージ吸収素子Ｚ１〜Ｚ３の一方端が夫々接続され、この３つのサージ吸収素子Ｚ１〜Ｚ３の他方端は一括して接続している。
【００１２】
また、電源線２は電子制御部３に接続されて電源を供給するようになっている。電子制御部３は３相３線式電路Ｒ，Ｓ，Ｔを貫通させた零相変流器ＺＣＴと、３相３線式電路Ｒ，ＳＴ，の開閉接点４を開離させるためのトリップコイルＴＣが接続され、零相変流器ＺＣＴの出力によって電子制御部３が漏電を検出するとトリップコイルＴＣを駆動させて開閉接点４を開離し、３相３線式電路を遮断するようになっている。
【００１３】
ここで３相３線式電路Ｒ，Ｓ，Ｔに雷サージが発生した場合、Ｒ−Ｓ相間は直列接続されたサージ吸収素子Ｚ１，Ｚ２で雷サージを吸収し、Ｓ−Ｔ相間は直列接続されたサージ吸収素子Ｚ２，Ｚ３で雷サージを吸収し、Ｔ−Ｒ相間は直列接続されたサージ吸収素子Ｚ３，Ｚ１で雷サージを吸収する。
【００１４】
このように各相間につき２個のサージ吸収素子によって雷サージを吸収するのでサージ吸収素子１個は従来の３相４線式電路の電圧線と中性線との間に使用するものと同程度の容量の小さいものにすることができ、従来に比べて容積を１／３にすることができる。
【００１５】
尚、本実施例における３相回路遮断器は漏電保護機能付きであるが欠相保護機能付きの３相回路遮断器においても同様に実施できる。
【００１６】
本発明に係る３相回路遮断器の第２実施例を図２の添付図面に基づいて説明する。尚、第１実施例と同一部分には同一符号を付してある。
【００１７】
３相４線式電路Ｌ１，Ｌ２，Ｌ３，Ｎに用いられる３相回路遮断器１１は、３相４線式電路の電圧線Ｌ１，Ｌ２，Ｌ３の各線に電源線２を接続している。電源線２にはサージ吸収素子Ｚ１１〜Ｚ１３の一方端が夫々接続され、この３つのサージ吸収素子Ｚ１１〜Ｚ１３の他方端は一括して接続し、接続点を３相４線式電路の中性線Ｎに接続している。
【００１８】
また、電源線１２は電子制御部３に接続されて電源を供給するようになっている。電子制御部３は３相４線式電路Ｌ１，Ｌ２，Ｌ３，Ｎを貫通させた零相変流器ＺＣＴと、３相４線式電路Ｌ１，Ｌ２，Ｌ３，Ｎの開閉接点４を開離させるためのトリップコイルＴＣが接続され、零相変流器ＺＣＴの出力によって電子制御部３が漏電を検出するとトリップコイルＴＣを駆動させて開閉接点４を開離し、３相４線式電路を遮断するようになっている。
【００１９】
ここで３相４線式電路Ｌ１，Ｌ２，Ｌ３，Ｎに雷サージが発生した場合、Ｌ１−Ｌ２相間は直列接続されたサージ吸収素子Ｚ１１，Ｚ１２で雷サージを吸収し、Ｌ２−Ｌ３相間は直列接続されたサージ吸収素子Ｚ１２，Ｚ１３で雷サージを吸収し、Ｌ３−Ｌ１相間は直列接続されたサージ吸収素子Ｚ１３，Ｚ１１で雷サージを吸収し、Ｌ１−Ｎ相間、Ｌ２−Ｎ相間、Ｌ３−Ｎ相間はサージ吸収素子Ｚ１１〜Ｚ１３で夫々吸収する。
【００２０】
このように電圧が高い電圧線間は２個のサージ吸収素子によって雷サージを吸収するのでサージ吸収素子１個は従来の３相４線式電路の電圧線と中性線との間に使用するものと同程度の容量の小さいものにすることができ、従来に比べて容積を１／４にすることができる。
【００２１】
尚、本実施例における３相回路遮断器は漏電保護機能付きであるが欠相保護機能付きの３相回路遮断器においても同様に実施できる。
【００２２】
【発明の効果】
以上説明したように請求項１に記載の発明によれば、３相３線式電路に用いられる３相回路遮断器において、３相３線式電路の各線に電源線を接続し、電源線に３つのサージ吸収素子の一方端を夫々接続し、３つのサージ吸収素子の他方端を一括して接続したことにより、コストを低減し、遮断器を小型化することができるという効果がある。
【００２３】
請求項２に記載の発明によれば、請求項１に記載の３相４線式欠相保護付き回路遮断器において、３相４線式電路に用いられる３相回路遮断器において、３相４線式電路の電圧線の各線に電源線を接続し、電源線に３つのサージ吸収素子の一方端を夫々接続し、３つのサージ吸収素子の他方端を一括して接続し、接続点を３相４線式電路の中性線に接続したことにより、コストを低減し、遮断器を小型化することができるという効果がある。
【図面の簡単な説明】
【図１】本発明の第１実施例に係る３相回路遮断器の回路図である。
【図２】本発明の第２実施例に係る３相回路遮断器の回路図である。
【図３】従来の３相４線式回路遮断器の回路図である。
【符号の説明】
１…３相回路遮断器
２…電源線
Ｒ，Ｓ，Ｔ…３相３線式電路
Ｚ１〜Ｚ３…サージ吸収素子[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a circuit for protecting electronic components from lightning surge in a three-phase circuit breaker.
[0002]
[Prior art]
In a three-phase circuit breaker having an open-phase protection function and a leakage protection function, power is secured from an electric circuit to detect an open phase and to drive an electronic control unit. In the case of a three-phase three-wire circuit breaker, for example, as shown in Patent Document 1, the power of the electronic control unit is supplied from two phases of a three-phase three-wire circuit, and three-phase four-wire In the case of a circuit breaker, for example, as shown in FIG. 3, the power of the electronic control unit is supplied from one of the voltage lines and the neutral line of the three-phase four-wire circuit, Both had only one surge absorbing element for protecting the electronic control unit from lightning surge. Therefore, the space occupied by the surge absorbing element in the case is small.
[0003]
[Patent Document 1]
JP-A-5-3622 (FIG. 1)
[0004]
[Problems to be solved by the invention]
However, when the conventional three-phase circuit breaker has a leakage protection function, if any one of the three phases of the power supply of the electronic control unit loses phase, the electronic control unit does not operate. Similarly, when the three-phase circuit breaker is provided with an open-phase protection function, the circuit is not interrupted even if the power-off phase is not detected, and the electric circuit is not interrupted. Therefore, even if one phase is lost, it is necessary to secure the power supply from three phases in order for the leakage protection to function, and to protect the open phase in all the electric circuits, it is necessary to connect the power supply lines to all the electric circuits There is. Then, it is necessary to provide a surge absorbing element between each phase, and in the case of a three-phase three-wire circuit composed of R, S, and T phases, three points between the RS phase, between the ST phases, and between the TR phases. In the case of a three-phase four-wire circuit composed of L1, L2, L3, and N phases, between the L1 and L2 phases, between the L2 and L3 phases, between the L3 and L1 phases, and L1- Surge absorbing elements must be provided at six locations between the N phases, between the L2-N phases, and between the L3-N phases. In recent years, circuit breakers have been miniaturized, but since the surge absorbing element is larger than other electronic components, miniaturization of the circuit breaker has been extremely difficult. Since the voltage between the L1 and L2 phases, between the L2 and L3 phases, and between the L3 and L1 phases is high, the surge absorbing element provided therein has a large capacity, and therefore, between the L1 and N phases, between the L2 and N phases, and between the L3 and N phases. There is a problem that the volume is about three times as large as the surge absorbing element provided and the price is high.
[0005]
In view of the above problems, an object of the present invention is to provide a three-phase circuit breaker that can be reduced in size.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the invention, in a three-phase circuit breaker used for a three-phase three-wire circuit, a power line is connected to each line of the three-phase three-wire circuit. One end of each of the three surge absorbing elements is connected to the power supply line, and the other ends of the three surge absorbing elements are connected together.
[0007]
According to the second aspect of the present invention, in the three-phase four-wire circuit breaker with the three-phase four-wire circuit according to the first aspect, A power supply line is connected to each of the voltage lines of the wire-type circuit, one ends of the three surge absorbing elements are connected to the power supply lines, respectively, and the other ends of the three surge absorbing elements are collectively connected. It is characterized in that it is connected to the neutral conductor of the phase 4 wire type electric circuit.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
In a three-phase circuit breaker used for a three-phase three-wire circuit, a power line is connected to each line of the three-phase three-wire circuit, and one end of each of three surge absorbing elements is connected to the power line. The other ends of the surge absorbing elements are connected together. Lightning surge flowing through the three-phase three-wire circuit is absorbed by two surge absorbing elements for each phase.
[0009]
In the three-phase circuit breaker used for the three-phase four-wire circuit, a power line is connected to each of the voltage lines of the three-phase four-wire circuit, and one end of each of the three surge absorbing elements is connected to the power line. Then, the other ends of the three surge absorbing elements are collectively connected, and this connection point is connected to the neutral wire of the three-phase four-wire circuit. When a lightning surge occurs in a three-phase four-wire circuit, two surge absorbing elements absorb lightning surge between the voltage lines, and one surge absorbing element absorbs lightning between the voltage line and the neutral line. I do.
[0010]
【Example】
First Embodiment A three-phase circuit breaker according to a first embodiment of the present invention will be described with reference to the accompanying drawings in FIG.
[0011]
The three-phase circuit breaker 1 used for the three-phase three-wire circuits R, S, and T has a power line 2 connected to each of the three-phase three-wire circuits R, S, and T. One end of each of the surge absorbing elements Z1 to Z3 is connected to the power supply line 2, and the other ends of the three surge absorbing elements Z1 to Z3 are collectively connected.
[0012]
The power supply line 2 is connected to the electronic control unit 3 to supply power. The electronic control unit 3 includes a zero-phase current transformer ZCT that penetrates the three-phase three-wire circuits R, S, and T, and a trip coil for opening and closing the switching contacts 4 of the three-phase three-wire circuits R, ST. When the electronic control unit 3 detects a leakage based on the output of the zero-phase-sequence current transformer ZCT, the trip coil TC is driven to open and close the on-off contact 4 to cut off the three-phase three-wire circuit. I have.
[0013]
Here, if a lightning surge occurs in the three-phase three-wire circuit R, S, T, the surge absorption element Z1, Z2 connected in series between the R-S phases absorbs the lightning surge, and the series connection between the S-T phases. The surge absorbers Z2 and Z3 absorb lightning surges, and the surge absorbers Z3 and Z1 connected in series between the TR phases absorb lightning surges.
[0014]
As described above, the lightning surge is absorbed by the two surge absorbing elements for each phase, so that one surge absorbing element is almost the same as that used between the voltage line and the neutral line of the conventional three-phase four-wire circuit. Can be reduced, and the volume can be reduced to 1/3 of the conventional one.
[0015]
Although the three-phase circuit breaker in the present embodiment has a leakage protection function, the present invention can be similarly applied to a three-phase circuit breaker with a phase loss protection function.
[0016]
Second Embodiment A three-phase circuit breaker according to a second embodiment of the present invention will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals.
[0017]
The three-phase circuit breaker 11 used for the three-phase four-wire circuit L1, L2, L3, and N connects the power supply line 2 to each of the voltage lines L1, L2, and L3 of the three-phase four-wire circuit. One end of each of the surge absorbing elements Z11 to Z13 is connected to the power supply line 2, and the other ends of the three surge absorbing elements Z11 to Z13 are collectively connected, and the connection point is connected to a neutral three-phase four-wire circuit. Connected to line N.
[0018]
The power supply line 12 is connected to the electronic control unit 3 to supply power. The electronic control unit 3 separates the zero-phase current transformer ZCT penetrating the three-phase four-wire circuits L1, L2, L3, and N, and the switching contacts 4 of the three-phase four-wire circuits L1, L2, L3, and N. When the electronic control unit 3 detects a leakage current based on the output of the zero-phase current transformer ZCT, the trip coil TC is driven to open and close the on-off contact 4 and cut off the three-phase four-wire circuit. It is supposed to.
[0019]
Here, if a lightning surge occurs in the three-phase four-wire circuit L1, L2, L3, N, the surge absorption elements Z11 and Z12 connected in series absorb the lightning surge between the L1 and L2 phases, and the lightning surge between the L2 and L3 phases. Lightning surge is absorbed by the series-connected surge absorbing elements Z12 and Z13, and lightning surge is absorbed by the series-connected surge absorbing elements Z13 and Z11 between the L3 and L1 phases, between the L1 and N phases, between the L2 and N phases, and between L3 and L3. The -N phase is absorbed by the surge absorbing elements Z11 to Z13, respectively.
[0020]
As described above, a lightning surge is absorbed between two voltage lines having a high voltage by two surge absorbing elements. Therefore, one surge absorbing element is used between a voltage line and a neutral line of a conventional three-phase four-wire circuit. The capacity can be made as small as that of the conventional one, and the volume can be reduced to １／ of that of the conventional one.
[0021]
Although the three-phase circuit breaker in the present embodiment has a leakage protection function, the present invention can be similarly applied to a three-phase circuit breaker with a phase loss protection function.
[0022]
【The invention's effect】
As described above, according to the first aspect of the present invention, in a three-phase circuit breaker used for a three-phase three-wire circuit, a power line is connected to each line of the three-phase three-wire circuit, and the power line is connected to the power line. By connecting one ends of the three surge absorbing elements and connecting the other ends of the three surge absorbing elements collectively, there is an effect that the cost can be reduced and the circuit breaker can be downsized.
[0023]
According to the second aspect of the present invention, in the three-phase four-wire circuit breaker with the three-phase four-wire circuit according to the first aspect, A power supply line is connected to each of the voltage lines of the wire-type circuit, one ends of the three surge absorbing elements are connected to the power supply lines, respectively, and the other ends of the three surge absorbing elements are collectively connected. The connection to the neutral conductor of the phase four-wire system has the effects of reducing costs and miniaturizing the circuit breaker.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of a three-phase circuit breaker according to a first embodiment of the present invention.
FIG. 2 is a circuit diagram of a three-phase circuit breaker according to a second embodiment of the present invention.
FIG. 3 is a circuit diagram of a conventional three-phase four-wire circuit breaker.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... 3 phase circuit breaker 2 ... Power supply line R, S, T ... 3 phase 3 wire type electric circuit Z1-Z3 ... Surge absorption element

Claims

In a three-phase circuit breaker used for a three-phase three-wire circuit, a power line is connected to each line of the three-phase three-wire circuit, and one end of each of three surge absorbing elements is connected to the power line. A three-phase circuit breaker, wherein the other ends of the three surge absorbing elements are connected together.

In a three-phase circuit breaker used for a three-phase four-wire circuit, a power line is connected to each of the voltage lines of the three-phase four-wire circuit, and one ends of three surge absorbing elements are connected to the power line, respectively. A three-phase circuit breaker, wherein the other ends of the three surge absorbing elements are collectively connected, and the connection point is connected to a neutral wire of the three-phase four-wire circuit.