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EP0004801B1 - Circuit breaker with an electromagnetic device for a fast opening operation of the movable contact - Google Patents

Circuit breaker with an electromagnetic device for a fast opening operation of the movable contact Download PDF

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Publication number
EP0004801B1
EP0004801B1 EP79400135A EP79400135A EP0004801B1 EP 0004801 B1 EP0004801 B1 EP 0004801B1 EP 79400135 A EP79400135 A EP 79400135A EP 79400135 A EP79400135 A EP 79400135A EP 0004801 B1 EP0004801 B1 EP 0004801B1
Authority
EP
European Patent Office
Prior art keywords
contact
contact arm
arm
circuit breaker
contacts
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP79400135A
Other languages
German (de)
French (fr)
Other versions
EP0004801A3 (en
EP0004801A2 (en
Inventor
Pierre Batteux
Robert Morel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Merlin Gerin SA
Original Assignee
Merlin Gerin SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Merlin Gerin SA filed Critical Merlin Gerin SA
Publication of EP0004801A2 publication Critical patent/EP0004801A2/en
Publication of EP0004801A3 publication Critical patent/EP0004801A3/en
Application granted granted Critical
Publication of EP0004801B1 publication Critical patent/EP0004801B1/en
Expired legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H77/00—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting
    • H01H77/02—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism
    • H01H77/10—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism with electrodynamic opening
    • H01H77/107—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism with electrodynamic opening characterised by the blow-off force generating means, e.g. current loops
    • H01H77/108—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism with electrodynamic opening characterised by the blow-off force generating means, e.g. current loops comprising magnetisable elements, e.g. flux concentrator, linear slot motor

Definitions

  • a known circuit breaker of the kind mentioned (US-A-3,815,059) comprises a plurality of U-shaped ferromagnetic sheets, aligned to form an open notch for housing the contact arm extending in a direction perpendicular to the plane of the sheets.
  • the electromagnetic forces generated by the fault current cause the arm to quickly drive towards the inside of the notch and the opening of the contacts with an effect of limiting the fault current.
  • the circuit breaker is of large size, it is difficult to maintain a controlled electrodynamic resistance of the contacts up to a predetermined value of the current without increasing the contact pressure, which would require an oversized operating mechanism.
  • FR-A-2,246,052 discloses an electromagnetic trip device having a coil and two armatures, one actuating the circuit breaker locking device and the other acting directly on the movable contact.
  • a saturable magnetic shunt bridges the working air gap of the armature acting on the movable contact to ensure successive action of the two armatures.
  • the device is complicated and requires an excitation coil.
  • the object of the invention is to remedy these drawbacks and to produce a circuit breaker with controlled electrodynamic resistance up to an overcurrent threshold, and quickly limiter beyond.
  • the circuit breaker according to the invention is characterized in that said magnetic circuit comprises a saturable derivative circuit comprising a pair of ferromagnetic tongues of reduced section compared to that of the wings and separated by a second air gap (e) to form in an unsaturated state a magnetic shunt with a reluctance lower than the reluctance of the main circuit and causing in saturated state the flow path in said first air gap (E) for a displacement of the contact arm towards the open position under the influence of electromagnetic forces, the passage from the unsaturated state to the saturated state of the saturable circuit taking place when a predetermined threshold (S M ) of the fault current flowing in said arm is exceeded.
  • S M predetermined threshold
  • the current flowing through the contact arm generates a magnetic flux in the magnetic circuit with a value less than the saturation value of the derived magnetic circuit. Almost the entire flow follows this derivative circuit of low reluctance and the electromagnetic device exerts on the contact arm a negligible force of attraction.
  • the branch circuit becomes saturated and the flow crosses the air gap (E) containing the contact arm which is attracted quickly.
  • the derivative circuit establishes a frank operating threshold of the electromagnetic limiting device and this threshold, defined by the section of the derivative circuit, is chosen to be substantially equal to the threshold of the electromagnetic trip, or instantaneous trip of the circuit breaker, which causes the definitive opening of the contacts to following the rapid separation generated by the electromagnetic device.
  • the circuit breaker is advantageously a multipolar circuit breaker with molded case having a toggle operating mechanism and an automatic thermal and electromagnetic trip device ensuring the opening of the contacts when a fault or short-circuit current appears.
  • the electromagnetic quick opening device becomes active when a short-circuit current appears to move the movable contact to an intermediate opening position (I), and the operating mechanism controlled by the electromagnetic trip device then takes the relay to drive the contact arm from the intermediate position (I) to the definitive opening position (O).
  • a multipolar circuit breaker with molded housing 12 having a bottom 14 and a cover 16 comprises a tripping device 15 and a toggle control mechanism 17 common to the different poles.
  • a fixed contact 18 connected to a range input 20 by a conductor 21 and a movable contact 22. carried by a contact arm 28 connected to an output pad 24 by a braid 26 and a connection strip 27.
  • a breaking chamber 34 with deionization plates 36 is associated with the contacts 18, 22, and a horn 38. connected to the conductor 21, guides the arc drawn between the contacts 18, 22 during their separation towards the breaking chamber 34.
  • the contact arm 28 is rotatably mounted in its middle 50 on an axis 48, carried by a support 30 in the form of U.
  • the ends of the axis 48 are fitted in blind holes 52 of the wings 54 of the support of U 30 (fig. 4).
  • a rotary bar 32 secures the supports 30 of the different poles and the toggle mechanism 17 communicates to the support 30 and bar 32 assembly a rotational movement around the axis of the bar 32 to open or close the contacts 18, 22.
  • the toggle control mechanism 17 is controlled by the tripping device 15 for automatic opening on fault current, or by a lever 40 passing through an opening 42 formed in the cover 16.
  • a molded case circuit breaker is well known to specialists.
  • an electromagnetic member 44 for accelerating the movable contact 22 to the open position comprises, by pole, a U-shaped ferromagnetic stirrup 46 (FIGS. 3 and 4).
  • the core 56 of the U-shaped bracket 46 is fixed and centered by lugs 58, 60 at the bottom 14 of the housing 12 and the two wings 62, 64 of the U-shaped bracket 46 extend in the opening direction of the contact 22 in planes parallel to the deflection plane of the contact arm 28, framing a section of length L of the contact arm 28, located between the axis 48 and the braid 26.
  • Each wing 62, 64 extends in the direction opening of contact 22 by an extension 66, 68 of length I less than L, the ends 70, 72 of which are folded at right angles to face each other and define an air gap of thickness less than the spacing or air gap (E) of the wings 62, 64.
  • the air gap (e) can be zero.
  • the contact arm 28 In the closed position of the contacts 18, 22, the contact arm 28 extends substantially at the ends of the wings 62, 64 of the stirrup 46 and it is easy to see that the current (I), flowing at an instant given the contact arm 28, generates in the magnetic circuit formed by the stirrup 46, which surrounds the contact arm 28, a magnetic flux which is divided into two branches (fig. 3).
  • the branch crossed by the flux ( ⁇ 2 ) comprises the main magnetic circuit in U 56. 62, 64, and the air gap (E), and the branch crossed by the flux ( ⁇ 1 ) comprises the extensions 66. 68 and l 'air gap (e) forming a circuit derived from magnetic shunt of the main circuit.
  • the section of the extensions 66, 68 is notably smaller than that of the main magnetic circuit 56, 62, 64. and this section is chosen to obtain saturation for a value of the current (1) in the contact arm 28 exceeding a predetermined threshold (S u ), corresponding to the threshold of the magnetic trip device of the trip device - mount 15.
  • S u a predetermined threshold
  • the flow ( ⁇ 2 ) borrows the branch to be gap (E) by exerting on the contact arm 28 an electromagnetic force from Laplace which attracts the contact arm 28 towards the bottom of the U-shaped stirrup 46 in the open position of the contacts 18, 22.
  • a compression spring 74 is interposed between the core 56 and the contact arm 28 for urging the latter towards the closed position of the contacts 18, 22, the ends 70, 72 serving as a stop for limiting pivoting in this direction.
  • the electromagnetic member 44 is active and causes rapid separation of the contacts 18, 22, favoring the increase in the arc voltage and the limitation of the short-circuit current.
  • the contact arm 28 is in the intermediate separation position (I) (fig. 2, thin lines), and the control mechanism 17, actuated by the electromagnetic trip device after exceeding the threshold ( S M ) takes over to move the support 30 and the contact arm 28 to the stable position (O) of permanent opening (strong lines, fig. 2), thus preventing any reclosing of the contacts 18, 22.
  • the electromagnetic member 44 for accelerating the contact arm 28 maintains an electrodynamic resistance of the contacts 18, 22 up to the overcurrent threshold (S M ), and the rapid and frank opening of the contacts after exceeding said threshold .
  • the contact arm 22 is made of a conductive material, preferably non-magnetic. If a ferromagnetic material is used, the value of the air gap (E) is modified.
  • the magnetic U-shaped circuit can of course have a different configuration and be arranged differently, for example above the contact arm 28 between the axis 48 and the contact 22.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Breakers (AREA)

Description

L'invention est relative à un disjoncteur électrique multipolaire comportant par pôle :

  • - une paire de contacts séparables fixe et mobile,
  • - une chambre d'extinction d'un arc tiré entre les contacts- séparables,
  • - un bras de contact, en matériau conducteur, supportant le contact mobile et connecté en série avec lesdits contacts,
  • - et un dispositif électromagnétique à circuit magnétique en forme de U doté de deux ailes séparées par un premier entrefer (E) s'étendant transversalement à la direction longitudinale du bras, et susceptible d'exercer sur le bras de contact des forces électromagnétiques résultant de l'interaction du courant (I) parcourant ledit bras et du flux magnétique (4)2) engendré par ledit courant dans le cireur magnétique pour provoquer l'ouverture rapide des contacts.
The invention relates to a multi-pole electric circuit breaker comprising per pole:
  • - a pair of separable fixed and mobile contacts,
  • - a chamber for extinguishing an arc drawn between the separable contacts,
  • a contact arm, of conductive material, supporting the movable contact and connected in series with said contacts,
  • - and an electromagnetic device with a U-shaped magnetic circuit provided with two wings separated by a first air gap (E) extending transversely to the longitudinal direction of the arm, and capable of exerting on the contact arm electromagnetic forces resulting from the interaction of the current (I) flowing through said arm and of the magnetic flux (4) 2) generated by said current in the magnetic shiner to cause the rapid opening of the contacts.

Un disjoncteur connu du genre mentionné (US-A-3.815.059) comporte une pluralité de tôles ferromagnétiques en forme de U, alignées pour former une encoche ouverte de logement du bras de contact s'étendant selon une direction perpendiculaire au plan des tôles. Les forces électromagnétiques, engendrées par le courant de défaut, provoquent l'entraînement rapide du bras vers l'intérieur de l'encoche et l'ouverture des contacts avec un effet de limitation du courant de défaut. Lorsque le disjoncteur est de gros calibre, il est difficile de maintenir une tenue électrodynamique contrôlée des contacts jusqu'à une valeur prédéterminée du courant sans augmenter la pression de contact, ce qui nécessiterait un mécanisme de manoeuvre surdimensionné.A known circuit breaker of the kind mentioned (US-A-3,815,059) comprises a plurality of U-shaped ferromagnetic sheets, aligned to form an open notch for housing the contact arm extending in a direction perpendicular to the plane of the sheets. The electromagnetic forces generated by the fault current cause the arm to quickly drive towards the inside of the notch and the opening of the contacts with an effect of limiting the fault current. When the circuit breaker is of large size, it is difficult to maintain a controlled electrodynamic resistance of the contacts up to a predetermined value of the current without increasing the contact pressure, which would require an oversized operating mechanism.

On connaît, par FR-A-2.246.052, un déclencheur électromagnétique ayant une bobine et deux armatures, l'une actionnant le dispositif de verrouillage du disjoncteur et l'autre agissant directement sur le contact mobile. Un shunt magnétique saturable ponte l'entrefer de travail de l'armature agissant sur le contact mobile pour assurer une action successive des deux armatures. Le dispositif est compliqué et nécessite une bobine d'excitation.FR-A-2,246,052 discloses an electromagnetic trip device having a coil and two armatures, one actuating the circuit breaker locking device and the other acting directly on the movable contact. A saturable magnetic shunt bridges the working air gap of the armature acting on the movable contact to ensure successive action of the two armatures. The device is complicated and requires an excitation coil.

L'invention a pour but de remédier à ces inconvénients et de réaliser un disjoncteur à tenue électrodynamique contrôlée jusqu'à un seuil de surintensité, et rapidement limiteur au-delà.The object of the invention is to remedy these drawbacks and to produce a circuit breaker with controlled electrodynamic resistance up to an overcurrent threshold, and quickly limiter beyond.

Le disjoncteur selon l'invention est caractérisé par le fait que ledit circuit magnétiqué comporte un circuit dérivé saturable comportant une paire de languettes ferromagnétiques de section réduite par rapport à celle des ailes et séparées par un deuxième entrefer (e) pour former en état non saturé un shunt magnétique de réluctance inférieure à la réluctance du circuit principal et provoquer en état saturé le cheminement du flux dans ledit premier entrefer (E) pour un déplacement du bras de contact vers la position d'ouverture sous l'influence des forces électromagnétiques, le passage de l'état non saturé à l'état saturé du circuit saturable s'effectuant au dépassement d'un seuil prédéterminé (SM) du courant de défaut circulant dans ledit bras.The circuit breaker according to the invention is characterized in that said magnetic circuit comprises a saturable derivative circuit comprising a pair of ferromagnetic tongues of reduced section compared to that of the wings and separated by a second air gap (e) to form in an unsaturated state a magnetic shunt with a reluctance lower than the reluctance of the main circuit and causing in saturated state the flow path in said first air gap (E) for a displacement of the contact arm towards the open position under the influence of electromagnetic forces, the passage from the unsaturated state to the saturated state of the saturable circuit taking place when a predetermined threshold (S M ) of the fault current flowing in said arm is exceeded.

En fonctionnement normal du disjoncteur, le courant parcourant le bras de contact engendre un flux magnétique dans le circuit magnétique de valeur inférieure à la valeur de saturation du circuit magnétique dérivé. La quasi-totalité du flux emprunte ce circuit dérivé de faible réluctance et le dispositif électromagnétique exerce sur le bras de contact une force d'attraction négligeable. Lors d'un court-circuit le circuit dérivé se sature et le flux traverse l'entrefer (E) contenant le bras de contact qui est attiré rapidement. Le circuit dérivé établit un seuil franc de fonctionnement du dispositif électromagnétique limiteur et ce seuil, défini par la section du circuit dérivé, est choisi sensiblement égal au seuil du déclencheur électromagnétique, ou déclencheur instantané du disjoncteur, qui provoque l'ouverture définitive des contacts à la suite de la séparation rapide engendrée par le dispositif électromagnétique.In normal operation of the circuit breaker, the current flowing through the contact arm generates a magnetic flux in the magnetic circuit with a value less than the saturation value of the derived magnetic circuit. Almost the entire flow follows this derivative circuit of low reluctance and the electromagnetic device exerts on the contact arm a negligible force of attraction. During a short circuit, the branch circuit becomes saturated and the flow crosses the air gap (E) containing the contact arm which is attracted quickly. The derivative circuit establishes a frank operating threshold of the electromagnetic limiting device and this threshold, defined by the section of the derivative circuit, is chosen to be substantially equal to the threshold of the electromagnetic trip, or instantaneous trip of the circuit breaker, which causes the definitive opening of the contacts to following the rapid separation generated by the electromagnetic device.

Le disjoncteur est avantageusement un disjoncteur multipolaire à boîtier moulé ayant un mécanisme de manoeuvre à genouillère et un déclencheur automatique thermique et électromagnétique assurant l'ouverture des contacts lors de l'apparition d'un courant de défaut ou de court-circuit. Le dispositif électromagnétique d'ouverture rapide devient actif lors de l'apparition d'un courant de court-circuit pour déplacer le contact mobile en une position (I) intermédiaire d'ouverture, et le mécanisme de manoeuvre piloté par le déclencheur électromagnétique prend ensuite le relais pour entraîner le bras de contact de la position (I) intermédiaire vers la position (O) d'ouverture définitive.The circuit breaker is advantageously a multipolar circuit breaker with molded case having a toggle operating mechanism and an automatic thermal and electromagnetic trip device ensuring the opening of the contacts when a fault or short-circuit current appears. The electromagnetic quick opening device becomes active when a short-circuit current appears to move the movable contact to an intermediate opening position (I), and the operating mechanism controlled by the electromagnetic trip device then takes the relay to drive the contact arm from the intermediate position (I) to the definitive opening position (O).

D'autres avantages et caractéristiques ressortiront plus clairement de l'exposé qui va suivre d'un mode de réalisation de l'invention, donné à titre d'exemple non limitatif et représenté aux dessins annexés, dans lesquels :

  • la figure 1 est une coupe longitudinale d'un pôle de disjoncteur, représenté en position F de fermeture et équipé d'un dispositif électromagnétique d'ouverture selon t'invention ;
  • la figure 2 analogue à la figure 1, montre le pôle en position 1 intermédiaire de séparation (traits fins) et en position O d'ouverture (traits forts) ;
  • la figure 3 est une vue en perspective du dispositif électromagnétique selon l'invention ;
  • la figure 4 est une vue partielle en plan de la figure 1, montrant le dispositif électromagnétique traversé par le bras de contact.
Other advantages and characteristics will emerge more clearly from the description which follows of an embodiment of the invention, given by way of nonlimiting example and represented in the appended drawings, in which:
  • Figure 1 is a longitudinal section of a circuit breaker pole, shown in the closed position F and equipped with an electromagnetic opening device according to the invention;
  • Figure 2 similar to Figure 1, shows the pole in intermediate position 1 of separation (fine lines) and in position O of opening (strong lines);
  • Figure 3 is a perspective view of the electromagnetic device according to the invention;
  • Figure 4 is a partial plan view of Figure 1 showing the electromagnetic device through which the contact arm passes.

Sur les figures, un disjoncteur multipolaire à boîtier moulé 12 ayant un fond 14 et un couvercle 16, comporte un dispositif de déclenchement 15 et un mécanisme 17 de commande à genouillère communs aux différents pôles. Dans chaque pôle est disposé un contact fixe 18 relié à une plage d'entrée 20 par un conducteur 21 et un contact mobile 22. porté par un bras de contact 28 connecté à une plage de sortie 24 par une tresse 26 et une barrette de raccordement 27. Une chambre de coupure 34 à tôles de désionisation 36 est associée aux contacts 18, 22, et une corne 38. connectée au conducteur 21, guide l'arc tiré entre les contacts 18, 22 lors de leur séparation vers la chambre de coupure 34. Le bras de contact 28 est monté à rotation en son milieu 50 sur un axe 48, porté par un support 30 en forme de U. Les extrémités de l'axe 48 sont emboîtées dans des trous borgnes 52 des ailes 54 du support de U 30 (fig. 4). Un barreau rotatif 32 solidarise les supports 30 des différents pôles et le mécanisme à genouillère 17 communique à l'ensemble supports 30 et barreau 32 un mouvement de rotation autour de l'axe du barreau 32 pour ouvrir ou fermer les contacts 18, 22. Le mécanisme de commande à genouillère 17 est piloté par le dispositif de déclenchement 15 pour une ouverture automatique sur courant de défaut, ou par une manette 40 traversant une ouverture 42 ménagée dans le couvercle 16. Un tel disjoncteur à boîtier moulé est bien connu des spécialistes.In the figures, a multipolar circuit breaker with molded housing 12 having a bottom 14 and a cover 16, comprises a tripping device 15 and a toggle control mechanism 17 common to the different poles. In each pole is placed a fixed contact 18 connected to a range input 20 by a conductor 21 and a movable contact 22. carried by a contact arm 28 connected to an output pad 24 by a braid 26 and a connection strip 27. A breaking chamber 34 with deionization plates 36 is associated with the contacts 18, 22, and a horn 38. connected to the conductor 21, guides the arc drawn between the contacts 18, 22 during their separation towards the breaking chamber 34. The contact arm 28 is rotatably mounted in its middle 50 on an axis 48, carried by a support 30 in the form of U. The ends of the axis 48 are fitted in blind holes 52 of the wings 54 of the support of U 30 (fig. 4). A rotary bar 32 secures the supports 30 of the different poles and the toggle mechanism 17 communicates to the support 30 and bar 32 assembly a rotational movement around the axis of the bar 32 to open or close the contacts 18, 22. The toggle control mechanism 17 is controlled by the tripping device 15 for automatic opening on fault current, or by a lever 40 passing through an opening 42 formed in the cover 16. Such a molded case circuit breaker is well known to specialists.

Selon l'invention, un organe électromagnétique 44 d'accélération du contact mobile 22 vers la position d'ouverture comprend par pôle un étrier 46 ferromagnétique en forme de U (fig. 3 et 4). L'âme 56 de l'étrier en U 46 est fixée et centrée par des ergots 58, 60 au fond 14 du boîtier 12 et les deux ailes 62, 64 de l'étrier en U 46 s'étendent en direction d'ouverture du contact 22 dans des plans parallèles au plan de débattement du bras de contact 28, en encadrant un tronçon de longueur L du bras de contact 28, situé entre l'axe 48 et la tresse 26. Chaque aile 62, 64 se prolonge dans la direction d'ouverture du contact 22 par une extension 66, 68 de longueur I inférieure à L, dont les extrémités 70, 72 sont repliées en équerre pour se faire face et définir un entrefer (e) d'épaisseur inférieur à l'écartement ou entrefer (E) des ailes 62, 64. L'entrefer (e) peut être nul.According to the invention, an electromagnetic member 44 for accelerating the movable contact 22 to the open position comprises, by pole, a U-shaped ferromagnetic stirrup 46 (FIGS. 3 and 4). The core 56 of the U-shaped bracket 46 is fixed and centered by lugs 58, 60 at the bottom 14 of the housing 12 and the two wings 62, 64 of the U-shaped bracket 46 extend in the opening direction of the contact 22 in planes parallel to the deflection plane of the contact arm 28, framing a section of length L of the contact arm 28, located between the axis 48 and the braid 26. Each wing 62, 64 extends in the direction opening of contact 22 by an extension 66, 68 of length I less than L, the ends 70, 72 of which are folded at right angles to face each other and define an air gap of thickness less than the spacing or air gap (E) of the wings 62, 64. The air gap (e) can be zero.

En position de fermeture des contacts 18, 22, le bras de contact 28 s'étend sensiblement au niveau des extrémités des ailes 62, 64 de l'étrier 46 et il est facile de voir que le courant (I), parcourant à un instant donné le bras de contact 28, engendre dans le circuit magnétique formé par l'étrier 46, qui entoure le bras de contact 28, un flux magnétique qui se répartit en deux branches (fig. 3). La branche traversée par le flux (Φ2) comprend le circuit magnétique principal en U 56. 62, 64, et l'entrefer (E), et la branche traversée par le flux (Φ1) comprend les extensions 66. 68 et l'entrefer (e) formant un circuit dérivé de shunt magnétique du circuit principal. La section des extensions 66, 68 est notablement plus petite que celle du circuit magnétique principal 56, 62, 64. et cette section est choisie pour obtenir une saturation pour une valeur du courant (1) dans le bras de contact 28 dépassant un seuil prédéterminé (Su), correspondant au seuil du déclencheur magnétique du dispositif de déclenche- mont 15. Lorsque le circuit dérivé à entrefe, (e) est saturé, le flux (Φ2) emprunte la branche à entrefer (E) en exerçant sur le bras de contact 28 une force électromagnétique de Laplace qui attire le bras de contact 28 vers le fond de l'étrier en U 46 en position d'ouverture des contacts 18, 22. Un ressort de compression 74 est intercalé entre l'âme 56 et le bras de contact 28 pour solliciter ce dernier vers la position de fermeture des contacts 18, 22, les extrémités 70, 72 servant de butée de limitation du pivotement dans ce sens.In the closed position of the contacts 18, 22, the contact arm 28 extends substantially at the ends of the wings 62, 64 of the stirrup 46 and it is easy to see that the current (I), flowing at an instant given the contact arm 28, generates in the magnetic circuit formed by the stirrup 46, which surrounds the contact arm 28, a magnetic flux which is divided into two branches (fig. 3). The branch crossed by the flux (Φ 2 ) comprises the main magnetic circuit in U 56. 62, 64, and the air gap (E), and the branch crossed by the flux (Φ 1 ) comprises the extensions 66. 68 and l 'air gap (e) forming a circuit derived from magnetic shunt of the main circuit. The section of the extensions 66, 68 is notably smaller than that of the main magnetic circuit 56, 62, 64. and this section is chosen to obtain saturation for a value of the current (1) in the contact arm 28 exceeding a predetermined threshold (S u ), corresponding to the threshold of the magnetic trip device of the trip device - mount 15. When the derivative circuit with gap, (e) is saturated, the flow (Φ 2 ) borrows the branch to be gap (E) by exerting on the contact arm 28 an electromagnetic force from Laplace which attracts the contact arm 28 towards the bottom of the U-shaped stirrup 46 in the open position of the contacts 18, 22. A compression spring 74 is interposed between the core 56 and the contact arm 28 for urging the latter towards the closed position of the contacts 18, 22, the ends 70, 72 serving as a stop for limiting pivoting in this direction.

L'organe électromagnétique 44 fonctionne de la manière suivante :

  • En position (F) de fermeture des contacts 18, 22 (fig. 1), le ressort 74 assure la pression de contact et le maintien du bras de contact 28 dans l'entrefer (E) à un niveau égal ou légèrement supérieur à celui des extrémités des ailes 62, 64. Pour des intensités de courants peu élevées comprises entre le courant nominal (ln) et le seuil (SM) de fonctionnement du déclencheur magnétique, la majorité du flux magnétique (Φ1), engendré dans l'étrier 46 par le passage du courant dans le bras 28, passe dans le circuit dérivé à entrefer (e) dont la réluctance est inférieure à celle du circuit principal à entrefer (E) plus grand. Le flux (Φ2) dans l'entrefer (E) est négligeable, et le bras de contact 28 n'est soumis à aucune force de Laplace. Durant cette première phase, l'organe électromagnétique 44 est inactif et maintient une tenue électrodynamique des contacts 18, 22, jusqu'au seuil (SM) de surintensité. Le courant de surcharge est détecté d'une manière connue par le déclencheur thermique du dispositif de déclenchement 15, qui assure l'ouverture automatique du disjoncteur au bout d'un temps prédéterminé.
The electromagnetic member 44 operates in the following manner:
  • In position (F) of closing the contacts 18, 22 (fig. 1), the spring 74 ensures the contact pressure and the maintenance of the contact arm 28 in the air gap (E) at a level equal to or slightly higher than that of the ends of the wings 62, 64. For low current intensities between the nominal current (l n ) and the operating threshold (S M ) of the magnetic trip device, the majority of the magnetic flux (Φ 1 ), generated in l caliper 46 by the passage of current in the arm 28, passes in the derivative circuit with air gap (e) whose reluctance is lower than that of the main circuit with air gap (E) larger. The flow (Φ 2 ) in the air gap (E) is negligible, and the contact arm 28 is not subjected to any Laplace force. During this first phase, the electromagnetic member 44 is inactive and maintains an electrodynamic resistance of the contacts 18, 22, up to the overcurrent threshold (S M ). The overload current is detected in a known manner by the thermal trip device of the trip device 15, which ensures the automatic opening of the circuit breaker after a predetermined time.

Lors de l'apparition de courants de court-circuit dont l'intensité est supérieure à celle du seuil (SM) du déclencheur magnétique, le shunt magnétique formé par le circuit magnétique dérivé à languettes 66, 68 de section réduite se sature, et la majorité du flux (Φ2) engendré par le courant de court-circuit traverse l'entrefer (E). Le bras de contact 28, est soumis à des forces électromagnétiques de Laplace résultant de l'interaction du flux (Φ2) et du courant-parcourant le bras 28. Les forces électromagnétiques importantes provoquent l'attraction rapide du bras 28 vers l'âme 56 de l'étrier 46 à l'encontre de la force du ressort 74, le bras 28 pivotant sur l'axe 48 dans le sens des aiguilles d'une montre. Durant cette deuxième phase, l'organe électromagnétique 44 est actif et provoque la séparation rapide des contacts 18, 22, favorisant l'accroissement de la tension d'arc et la limitation du courant de court-circuit. A la fin de la deuxième phase, le bras de contact 28 se trouve dans la position (I) intermédiaire de séparation (fig.2, traits fins), et le mécanisme de commande 17, actionné par le déclencheur électromagnétique après dépassement du seuil (SM) prend le relais pour déplacer le support 30 et le bras de contact 28 vers la position (O) stable d'ouverture définitive (traits forts, fig. 2), empêchant ainsi toute refermeture des contacts 18, 22.When short-circuit currents appear whose intensity is greater than that of the threshold (S M ) of the magnetic trip device, the magnetic shunt formed by the derivative magnetic circuit with tabs 66, 68 of reduced section becomes saturated, and the majority of the flux (Φ 2 ) generated by the short-circuit current passes through the air gap (E). The contact arm 28 is subjected to Laplace electromagnetic forces resulting from the interaction of the flux (Φ 2 ) and the current-flowing through the arm 28. The large electromagnetic forces cause the rapid attraction of the arm 28 towards the soul. 56 of the stirrup 46 against the force of the spring 74, the arm 28 pivoting on the axis 48 in a clockwise direction. During this second phase, the electromagnetic member 44 is active and causes rapid separation of the contacts 18, 22, favoring the increase in the arc voltage and the limitation of the short-circuit current. At the end of the second phase, the contact arm 28 is in the intermediate separation position (I) (fig. 2, thin lines), and the control mechanism 17, actuated by the electromagnetic trip device after exceeding the threshold ( S M ) takes over to move the support 30 and the contact arm 28 to the stable position (O) of permanent opening (strong lines, fig. 2), thus preventing any reclosing of the contacts 18, 22.

L'organe électromagnétique 44 d'accélération du bras de contact 28 assure le maintien d'une tenue électrodynamique des contacts 18, 22 jusqu'au seuil (SM) de surintensité, et l'ouverture rapide et franche des contacts après dépassement dudit seuil. Le bras de contact 22 est en matériau conducteur, de préférence non magnétique. Dans le cas d'emploi d'un matériau ferromagnétique la valeur de l'entrefer (E) est modifiée. Le circuit magnétique en U peut bien entendu avoir une configuration différente et être disposé différemment, par exemple au-dessus du bras de contact 28 entre l'axe 48 et le contact 22.The electromagnetic member 44 for accelerating the contact arm 28 maintains an electrodynamic resistance of the contacts 18, 22 up to the overcurrent threshold (S M ), and the rapid and frank opening of the contacts after exceeding said threshold . The contact arm 22 is made of a conductive material, preferably non-magnetic. If a ferromagnetic material is used, the value of the air gap (E) is modified. The magnetic U-shaped circuit can of course have a different configuration and be arranged differently, for example above the contact arm 28 between the axis 48 and the contact 22.

Claims (5)

1. A multipolar electric circuit breaker comprising per pole :
- a pair of separable fixed (18) and movable (22) contacts,
- an arc-control chamber (34) of an arc drawn between the separable contacts,
- a contact arm (28) in electrical conductive material carrying the movable contact, and series connected to said contacts (18, 22),
- and an electromagnetic device (44) with a U-shaped magnetic main circuit (46) having two wings (62, 64) separated by a first air gap (E) extending transversely to the longitudinal direction of arm (28) and susceptible to exert on the contact arm electromagnetic forces generated by the Interaction of the current (I) flowing in said arm (28) and the magnetic flux (4)0 generated by said current in the magnetic circuit (46) to provoke the rapid contacts opening, characterized by the fact that said magnetic circuit comprises a saturable shunt circuit (66. 68) comprising a pair of ferromagnetic tongues (66, 68) of reduced section relatively to that of the wings (62, 64) and separated by a second air gap (e) to constitute in a non saturated state a magnetic shunt of lower reluctance than the main circuit reluctance and to provoke in a saturated state the magnetic flux flow across said first air gap (E) for moving the contact arm (28) towards the opened position by the electromagnetic forces, the passage of the saturable circuit from the non saturated state to the saturated state occurring when the fault current flowing in said arm is higher than a predetermined threshold (SM).
2. Electric circuit breaker according to claim 1, characterized by the fact that a compression spring (74) positioned insides the U-shaped magnetic circuit (46) urges contact arm (28) in the closed position with a suitable contact pressure up to said predetermined current threshold (SM).
3. Electric circuit breaker according to one of the claims 1 and 2, characterized by the fact that the associated wings (62, 64) and tongues (66, 68) of the magnetic circuit (46) are symmetrical to the median oscillation plane of said movable contact and that the extremities (70, 72) of said tongues are bended at right angles to constitute abutments limiting the contact arm (28) pivotment. -
4. Electric circuit breaker according to any one of the claims 1 to 3, comprising an operating toggle mechanism (17) having a trip lever to actuate the movable contact (22) between the closed (F) and opened (O) contact positions (18, 22) and an automatical trip device (15) associated to the operating mechanism for the simultaneous contact (18, 22) opening when the current is higher than said predetermined threshold (SM), characterized by the fact that after passing said threshold (SM) said electromagnetic device (44) moves the contact arm (28) at high speed towards an intermediate contact (18, 22) separation position (I) and that thereafter the operating mechanism (17) monitored by the trip device (15) works in relay of the electromagnetic device (44) to move the contact arm (28) from the intermediate position (I) towards the final opened position (O).
5. Electric circuit breaker according to claim 4, characterized by the fact that the saturation threshold (SM) of the saturable shunt circuit corresponds substantially to the trip threshold of the instantaneous trip device (15) so that the circuit breaker has controlled electrodynamic holding of the contacts (18, 22) when the electromagnetic device is In an inactive position, up to said thresholds (SM) and thereafter a fault current limitation due to the high speed contact arm (28) movement towards the intermediate position (I) by the electromagnetic forces generated by the electromagnetic device (44) after passing said thresholds (SM).
EP79400135A 1978-03-31 1979-03-05 Circuit breaker with an electromagnetic device for a fast opening operation of the movable contact Expired EP0004801B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR7809833 1978-03-31
FR7809833A FR2421458A1 (en) 1978-03-31 1978-03-31 MULTIPOLAR CIRCUIT BREAKER WITH ELECTROMAGNETIC DEVICE FOR QUICK OPENING OF THE MOBILE CONTACT

Publications (3)

Publication Number Publication Date
EP0004801A2 EP0004801A2 (en) 1979-10-17
EP0004801A3 EP0004801A3 (en) 1979-10-31
EP0004801B1 true EP0004801B1 (en) 1982-02-03

Family

ID=9206613

Family Applications (1)

Application Number Title Priority Date Filing Date
EP79400135A Expired EP0004801B1 (en) 1978-03-31 1979-03-05 Circuit breaker with an electromagnetic device for a fast opening operation of the movable contact

Country Status (6)

Country Link
US (1) US4219790A (en)
EP (1) EP0004801B1 (en)
JP (1) JPS54161074A (en)
CA (1) CA1101025A (en)
DE (1) DE2962017D1 (en)
FR (1) FR2421458A1 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2547122B1 (en) * 1983-06-03 1985-07-05 Merlin Gerin SELECTIVE ELECTRONIC TRIGGER ASSOCIATED WITH A LIMITING CIRCUIT BREAKER
US4594567A (en) * 1984-09-28 1986-06-10 Siemens-Allis, Inc. Circuit breaker contact arm assembly having a magnetic carrier
DE3708807A1 (en) * 1987-03-18 1988-10-06 Licentia Gmbh ELECTRICAL CIRCUIT BREAKER WITH AN ELECTRO-DYNAMIC OPENING CONTACT SYSTEM
JPS63308820A (en) * 1987-06-10 1988-12-16 Fuji Electric Co Ltd Contact device for circuit breaker
US4835501A (en) * 1987-09-11 1989-05-30 Cooper Industries, Inc. Current limiting assembly for circuit breakers
FR2788164B1 (en) * 1998-12-30 2001-02-16 Schneider Electric Ind Sa ELECTRICAL SWITCHING APPARATUS WITH A CONTACT MEMBER PROVIDED WITH A SLOT

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE827821C (en) * 1950-01-21 1952-01-14 Voigt & Haeffner Ag Instantaneous magnetic overcurrent release
US3263042A (en) * 1963-02-18 1966-07-26 Westinghouse Electric Corp Electric control device with electromagnetic contact-biasing means
FR2185853B1 (en) * 1972-05-26 1977-12-30 Merlin Gerin
US3815059A (en) * 1972-12-01 1974-06-04 Westinghouse Electric Corp Circuit interrupter comprising electromagnetic opening means
DE2348613C2 (en) * 1973-09-27 1975-11-06 Siemens Ag, 1000 Berlin Und 8000 Muenchen Circuit breakers, especially circuit breakers
US4056798A (en) * 1975-09-23 1977-11-01 Westinghouse Electric Corporation Current limiting circuit breaker
US4132968A (en) * 1977-09-06 1979-01-02 Westinghouse Electric Corp. Current limiting circuit breaker with improved magnetic drive device

Also Published As

Publication number Publication date
FR2421458A1 (en) 1979-10-26
FR2421458B1 (en) 1980-09-05
EP0004801A3 (en) 1979-10-31
JPS6142371B2 (en) 1986-09-20
EP0004801A2 (en) 1979-10-17
DE2962017D1 (en) 1982-03-11
JPS54161074A (en) 1979-12-20
US4219790A (en) 1980-08-26
CA1101025A (en) 1981-05-12

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