EP2286432A1

EP2286432A1 - Electric selective automatic switch

Info

Publication number: EP2286432A1
Application number: EP09757283A
Authority: EP
Inventors: Jozef Smrkolj
Original assignee: Hager Electro SAS
Current assignee: Hager Electro SAS
Priority date: 2008-06-05
Filing date: 2009-06-03
Publication date: 2011-02-23
Anticipated expiration: 2029-06-03
Also published as: DE102008026813A1; CN102047370B; DE102008026813B4; EP2286432B1; CN102047370A; WO2009146900A1

Abstract

The invention relates to an electric selective automatic switch, particularly a circuit breaker, having a series connection from an auxiliary trigger device (6), a normally closed first switch (8), a resistor (10), and a main trigger device (12) that is connected between a first and a second electrical connection (2, 4), a shunt current path that is connected in series to the main trigger device (12) between the first and the second electrical connections (2, 4) and that has a second switch (14), which is closed if no malfunction exists, and a normally closed third switch (16), which is connected in series to the second switch (14), and a current bridge connecting an input contact of the first switch (8) to a connection contact (18) between the second and the third switches (14, 16), wherein the main trigger device (12) is configured such that upon achieving a first threshold current the second switch (14) is opened, and upon achieving a second threshold current, which is greater than the first threshold current, additionally the third switch (16) is opened, and wherein the auxiliary trigger device (6) is configured such that the first and the third switches (8, 16) are opened after expiration of a first time duration with the second switch (14) being open, while the first switch (8) is opened after expiration of a second time duration that is shorter than the first time duration with the second and third switches (14, 16) being open.

Description

Electric selective auto switch Description

The invention relates to an electrical selective self-switch, in particular a circuit breaker. It particularly concerns an electrical selective circuit breaker with low power losses.

An electrical self-switch is known for example from DE 103 54 505 Al. If, in the case of this known electrical self-switch, the tappet of the magnet armature strikes the contact bridge in the direction of actuation, the result of the resulting elastic shock is not only an interruption of the main current path, but also a brief interruption of the auxiliary current path. This can lead to the function of the auxiliary release device not being reliably guaranteed.

From DE 28 54 616 a selective protection device is known, which is used for selective shutdown of consumers, possibly with an upstream main fuse. In this case, a switching device is provided in the current path of a main line circuit breaker, which at least partially switches the current on a provided with a magnetic triggers parallel branch when a short-circuit current, the parallel branch includes a device which after passing a predetermined value of a temporal square integral current through the Coil of the magnetic release increased so much that this triggers a switch lock, which finally opens a separation point in the current path of the main line circuit breaker.

From DE 41 183 77 Al a circuit breaker is already known, the only temporarily shuts off in the event of a short circuit and waits whether a downstream circuit breaker disconnects the short circuit. In this case, it turns on again, otherwise it turns off permanently. For this purpose, a power circuit breaker is provided, in whose main current path an overcurrent responsive thermal release such as a bimetal, a responsive short-circuiting magnetic mechanism and operated by the thermal release and the magnetic mechanism separation point are net. The magnetic mechanism and the separation point are bridged by a Nebenstromweg, in which a second thermal release such as a second bimetal, an electrical resistance and a second separation point are arranged. Behind the separation points, another current path branches off to the neutral conductor via a second magnet mechanism, it leads behind the second magnet mechanism via two parallel lines each having a third separation point and a fourth separation point, the first branch current still having a second resistance.

In addition, main circuit breakers are known according to E DIN VDE 0645, in which in a main current path, a first thermal tripping device such as a bimetal, a main switch and a magnetic tripping seese device are connected in series, the main switch is bridged by a shunt, in which a selective resistor, a second thermal trip device for selective trip and a sub-switch are connected in series, the first thermal tripping device and the second thermal tripping device acting on a derailleur which opens the main switch and the sub-switch, and wherein the magnetic trip device acts on the main switch acts.

The object of the present invention is to provide an electrical selective self-switch in which, on the one hand, it is reliably ensured that an uninterrupted flow of current in the auxiliary current path is ensured when the main tripping device is actuated, ie if the main current path is interrupted, and at the same time the power losses are minimized during normal operation.

This object is achieved by the electrical selective self-switch according to claim 1. Advantageous embodiments of the invention are specified in the subclaims.

In particular, according to the invention an electrical selective self-switch, in particular a circuit breaker is provided with a series circuit of an auxiliary trip device, a normally closed first switch, a resistor and a main tripping device, which is connected between a first and a second electrical connection, a bypass current path, the main tripping device is connected in series between the first and the second electrical connection and having a closed in the event of trouble second switch and a normally closed third switch, the second switch is connected in series, and a current bridge connecting an input contact of the first switch with a connection contact between the second and the third switch, wherein the main triggering device is designed so that upon reaching a first threshold current of the second switch and upon reaching a second threshold current, is larger than the first threshold current, in addition, the third switch is opened, and wherein the auxiliary triggering device is designed such that the first and the third switch is opened when the second switch is open after a first period of time, while with the second and third switches open the first switch is opened after a second period of time, which is shorter than the first time period.

In other words, according to the invention, an electrical selective self-switch is provided which can be used, in particular, as a circuit breaker which has a first and a second parallel circuit which are connected in series with each other and with a main tripping device. In this case, the first parallel circuit in its first branch on an auxiliary tripping device and a series-connected normally closed first sub-switch of a double switch, wherein its second branch forms a shunt with a normally closed first switch. The second parallel circuit has in its first branch a normally closed second partial switch of the double switch and a resistor connected in series therewith, wherein its second branch forms a shunt with a normally closed second switch. The main triggering device is designed so that upon reaching a first threshold current of the first switch and on reaching a second threshold current, which is greater than the first threshold current, in addition, the second switch is opened. The auxiliary tripping device is designed such that the first and second subswitch of the double switch and the second switch at an open first switch after a first period of time and at an open second switch after a second period of time which is shorter than the first time period, is opened.

In a practical embodiment of the invention, it is preferred that the current bridge is formed by a contact bridge, which in the operating state a first and a second fixed contact of the first switch and a third fixed contact of the third switch electrically connects to each other.

To ensure that the first switch is basically only opened by the auxiliary triggering device in order to ensure an uninterrupted current flow in the auxiliary current path, it is advantageous if the third fixed contact on the one hand and the first and second fixed contact on the other hand on opposite sides of the contact bridge are located.

In a preferred embodiment of the invention, the auxiliary trip device comprises a Bimetallbetätigereinrichtung with a located between the first terminal and the first switch first bimetal, wherein the Bimetallbetätigereinrichtung is formed so that it acts on the contact bridge mechanically acting on the switch lock, and wherein the Switching mechanism applied to the contact bridge tripping force in the opening direction of the contact between the third fixed contact and the contact bridge and the opening directions of the contact between the first fixed contact and the contact bridge and the second fixed contact and the contact bridge acts.

In this case, it is expedient for the bimetallic actuator device to have a second bimetal located between the first switch and the second connection, which is designed such that it triggers the switching mechanism independently of the first bimetal by means of the bimetallic actuator device.

Preferably, the arrangement of the first fixed contact and the second fixed contact and / or the design of the contact bridge is such that the contact bridge when the switching lock is released, after the third fixed contact has been opened, first separated from the second fixed contact and then from the first fixed contact , This embodiment causes a reliable consecutive separation of the second fixed contact first of the contact bridge and then the first fixed contact of the contact bridge.

For a mechanically safe and simple embodiment of the invention, it is particularly advantageous if the main tripping device has a magnetically actuating device acting mechanically on the contact bridge with a first In the direction of actuation movable magnet armature and a switched between the bypass path and the second coil, wherein the actuating direction of the first armature directed, exerted by the first armature release force in the opening direction of the contact between the third fixed contact and the contact bridge and in the closing direction of the contact between the first Fixed contact and the contact bridge and between the second fixed contact and the contact bridge acts.

In a preferred embodiment of the invention, a connecting line between the first fixed contact and the second fixed contact forms a pivot axis for the contact bridge when the tripping force of the first armature is applied to the contact bridge.

Further, it is preferable if the point of action of the release force exerted by the first armature between the third fixed contact on the one hand and the first and second fixed contact on the other hand.

Furthermore, it is expedient if a contact spring is provided which simultaneously generates contact forces between the third fixed contact and the contact bridge, between the first fixed contact and the contact bridge and between the second fixed contact and the contact bridge in the respective closing direction of the fixed contacts.

It when the contact spring facing away from the second fixed contact, the first and second fixed contact superior portion of the contact bridge acts on it is particularly advantageous.

In this case, it is particularly expedient for the second switch to have a movable contact which, in the event of a malfunction, electrically connects the first connection to the contact bridge, wherein preferably the movable one

Contact in the direction of actuation of the movable armature behind the

Contact bridge is arranged and pivotally mounted by means of a pivoting device, wherein the pivot axis of the pivoting device extends substantially parallel to the pivot axis of the contact bridge. For a simple mechanical implementation of the second and third switches of the electrical selective self-switch according to the invention, it is particularly advantageous if the magnetic actuator has a extending through a through hole of the contact bridge pin with a direction of actuation of the movable armature located in front of the contact bridge expansion, wherein one end of the pin of the magnetic actuator is adapted to act in the opening direction of the movable contact on this and the expansion is adapted to act in the opening direction of the contact bridge on this.

In this case, it is expedient for the magnetic actuator device to be designed in such a way that, upon actuation of the first magnet armature, the contact between the contact bridge and the movable contact is opened prior to the contact between the third stationary contact and the contact bridge.

If, in a further advantageous embodiment, the magnetic actuator device has a core which is provided with a short-circuit ring facing the first magnet armature, vibration of the magnet armature is avoided by the eddy currents occurring in the short-circuit ring in the event of a fault or when operating with alternating current. Finally, in a further preferred embodiment, the reliability is increased by the fact that the magnetic actuator has a second movable in the direction of actuation armature, which preferably has a greater mass than the first armature, and in addition to the first armature an accelerated at an increased induction in the magnetic actuator Movement causes in the direction of actuation. By providing the additional second magnet armature, the contact between the contact bridge and the third fixed contact is abruptly opened in the case of a short circuit, ie at high induction in the magnetic actuator device as a result of a high overcurrent that a resulting there arc even at the in this Error case increased current flow reliably and quickly cleared.

Further, it is preferred if the auxiliary triggering device is configured such that upon manual switching on, first the second switch, then the first switch and subsequently the third switch is closed. The invention will be explained in more detail by way of example with reference to the drawing; in this shows

1A is a functional diagram of the electrical selective self-switch according to the invention and a detailed view of the first and second fixed contacts lying one behind the other in the direction A;

Fig. IB is a circuit diagram of the electrical selective self-switch according to the invention in trouble-free operation;

FIG. 2A is a functional diagram of the electrical selective self-switch according to the invention in the event of an overcurrent; FIG.

2B is a circuit diagram of the electrical selective self-switch according to the invention in the case of an overcurrent.

3A is a functional diagram of the electrical selective self-switch according to the invention in the case of a short-circuit current.

3B is a circuit diagram of the electrical selective self-switch according to the invention in the case of a short-circuit current.

4A is a functional diagram of the electrical selective self-switch according to the invention in the switched-off state;

4B is a circuit diagram of the electrical selective self-switch according to the invention in the off state;

FIG. 5A shows a functional sketch of a further embodiment of the electrical selective self-switch according to the invention in the case of trouble-free operation; FIG. and

Fig. 5B is a circuit diagram of the further embodiment of the electrical selective self-switch according to the invention in trouble-free case.

6 is a circuit diagram of a main circuit breaker during the short-circuit with a Selektivauslöser and 7 shows the arrangement according to the invention of a selective resistor in the magnetic circuit of a striking coil.

In Fig. IA and IB, the structure of the schematically illustrated electrical selective self-switch according to the invention in the switched-on operating state and an associated equivalent circuit diagram are shown. As shown in Fig. IB, the self-switch according to the invention comprises a first electrical connection 2 and a second electrical connection 4, between which an auxiliary tripping device 6, a first switch 8, a resistor 10 and a main tripping device 12 are connected in series. Furthermore, the electrical selective self-switch according to the invention has a bypass current path which is connected in series with the main triggering device 12 between the first terminal 2 and the second terminal 4 and which has a second switch 14 closed in the event of a malfunction and a third switch 16 normally closed which is connected in series with the second switch 14. Furthermore, the input contact of the first switch 8 is connected by a current bridge with a connection contact 18 between the second switch 14 and the third switch 16.

Fig. IA shows the structure of the electrical selective self-switch according to the invention in the switched-on operating state. Here, a pivotally movable contact bridge 20 connects a first fixed contact 22, which forms the input contact of the first switch 8, a second fixed contact 24 which is connected to the resistor 10, and a third fixed contact 26, which via the bypass current path with the main triggering device 12 in connection stands, electrically with each other. For this purpose, the contact bridge 20 bears against a contact point 28 at its first end 30 on the second fixed contact 26 and establishes an electrical connection between the main triggering device 12 and the first connection 2 via the second switch 14. In the vicinity of its other end 32, the contact bridge 20 is supported via a compression spring 34 against an abutment 38 provided on a switching lock 36. The abutment 38 and the third fixed contact 26 lie on the same side of the contact bridge 20. On the side facing away from this side of the contact bridge 20 this lies in a between the point of attack of the compression spring 34 and the third fixed contact 26 on the first fixed contact 22 and second fixed contact 24 and thus provides an electrical connection between the first, second and third fixed contact 22, 24 and 26 ago. As shown in the detailed illustration of FIG. 1A, which shows the spatial arrangement of the first fixed contact 22 and the second fixed contact 24 in the direction A perpendicular to the plane of the drawing, the first fixed contact 22 is on the same side of the contact bridge 20 as the second fixed contact 24. Hier However, the second fixed contact 24 may be spaced slightly further from the abutment 38 than the first fixed contact 22. In the operating state, the first contact bridge 20 is supported by the pressure of the spring 34 against the first fixed contact 22 and the third fixed contact 24 and is dependent on the force of Spring 34 is pivoted counterclockwise about a pivot axis X connecting the first fixed contact 22 and the second fixed contact 24 in the detailed illustration of FIG. 1A, so that the first end 30 of the contact bridge 20 with the contact point 28 is pressed against the third fixed contact 26. The compression spring 34 thus brings on all three fixed contacts 22, 24 and 26 a required pressure force, which brings the first contact bridge 20 against the fixed contacts 22, 24 and 26 for fixed abutment.

In addition, the electrical selective self-switch according to the invention has a movable contact 40 which electrically connects the first terminal 2 to the contact bridge 20 in the event of a fault. The movable contact 40 is mounted with its first end 42 in a pivot bearing 44 and is located with a contact point 46 at its second end 48 to the contact bridge 20 at. The pivot axis of the pivot bearing 44 lies substantially parallel to the pivot axis X of the contact bridge 20. The movable contact 40 is arranged on the same side of the contact bridge 20 as the first fixed contact 22 and the second fixed contact 24, wherein the movable contact 40 against the Contact bridge 20 is pressed by a compression spring 50, which is supported on an abutment 52. The movable contact 40 thus connects the first terminal 2 with the contact bridge 20 and thus forms the closed second switch 14. The third fixed contact 26 opposite a fixed housing stop 54 is provided, to which the first end 30 of the contact bridge 20 during a movement the contact bridge 20 abuts against the force of the compression spring 34 in a clockwise direction in order to limit a deflection of the contact bridge 20. In the following, the main triggering device 12 will be described in more detail. This has a coil 56 which is connected in series between the second terminal 4 and the shunt current path to the second switch 14 and the third switch 16. The main tripping device 12, which is designed as a magnetic actuator device or magnet system, further comprises a coil core 58 located within the coil 56, a pin 60 and a first magnet armature 62. In addition, a second armature 64 is provided, which is also displaceable in the release direction B within the coil 56 and acts on the pin 60. At rest, the second armature 64 is supported under the force of a compression spring 66 against a stop 68 fixed to the housing. Furthermore, the core 58 is provided on its side facing the first armature 62 end face with a short-circuit ring 70, wherein formed in the short-circuit ring 70, which is made of a highly electrically conductive material, eddy currents that prevent the formation of vibrations in the main triggering device 12 so that there is no unwanted noise. This is particularly advantageous in AC operation, since then the armature is held vibration-free at the core 58 during the triggering of the self-switch.

The pin 60 is axially slidably mounted within the core 58 in the release direction A and is biased by the compression spring 66 against the release direction B. The forward end of the pin 60 protrudes axially from the core 58 toward the contact bridge 20 and the movable contact 40 and forms a striker for actuating the movable contact 40, the point of action of the pin 60 between the pivot bearing 44 of the movable contact 40 and the compression spring 50 is located. In this case, the pin 60 extends through a through hole 72 of the contact bridge 20, wherein at the front end of the pin 60 in the direction of actuation B of the first armature 62 in front of the contact bridge 20, a widening or a section of enlarged diameter 74 is arranged, the larger as the through hole 72 of the contact bridge 20 is. Upon movement of the pin 60 in the direction of actuation B of the magnet armature 62, the widening 74 abuts against the contact bridge 20 to this about the pivot axis X, which is formed by the first and second fixed contact 22 and 24 against the force of the compression spring 34 counterclockwise to move and to open the contact of the contact bridge 20 with the third fixed contact 26. The widening 74 is arranged on the pin 60 such that first of all the contact between the movable cone clock 40 and the contact bridge 20 is opened before the contact between the contact bridge 20 and the third fixed contact 26 is opened.

The rear end of the pin 60 is supported in a blind hole of the second magnet armature 64 against the first magnet armature 62. The pin 60 penetrates an axial bore in the first armature 62. The first magnet armature 62 is axially displaceably guided within the blind hole of the second armature 64 and is supported on its side facing away from the magnet armature 64 against a collar 75 of a portion of the pin 60 with an enlarged diameter from.

In the following, the auxiliary release device 6 will now be described. This has a Bimetallbetätigereinrichtung with a first bimetal 76, which is connected between the first terminal 2 and the first fixed contact 22 of the first switch 8. In a current flowing through the auxiliary current path, the first bimetal 76 is heated and bends with it, whereupon the switching mechanism 36 is triggered in a known manner after a delay time correlated with the current intensity. In the case of triggering the switching mechanism 36, the switching mechanism 36 moves in the direction of the arrow C shown in Fig. 4A, wherein the second end 32 of the contact bridge 20 pivots in a clockwise direction about the axis X until the first end 30 to rest against the third fixed contact 26 located housing fixed stop 54 device. During this movement of the switching mechanism 36 and the abutment 38 is moved in the direction of the arrow C, so that the pivotal movement of the contact bridge 20 without compression of the spring 34 takes place, so the force of the spring 34 does not increase additionally.

If the first end 30 of the contact bridge 20 abuts the stop 54, the further movement of the switching mechanism 36 in the direction of the arrow C causes the contact bridge 20 to come away from the first fixed contact 22 and from the second fixed contact 24, so that the first switch 8 opens becomes. In this case, when the positioning of the first fixed contact 22 and of the second fixed contact 24 is offset in the release direction C, first the second fixed contact 24 can be detached from the contact bridge 20, after which the first fixed contact 22 is detached from the contact bridge 20, so that the circuit is finally disconnected , Now, the function of the electric selective self-switch according to the invention will be described in detail.

Occurs in an accident, an overcurrent between the first terminal 2 and the second terminal 4 via the low-resistance shunt path, the coil 56 induces a magnetic force on the first armature 62, the latter in the release direction B against the force of the spring 66 against the collar 75th of the pin 60 and then the pin 60 against the force of the spring 66 in the release direction B against the movable contact 40 in its point of action, whereby the contact between the movable contact 40 and contact bridge 20 is opened, as in Figs. 2A and 2B shown. Here, the extension 74 is attached to the pin 60 so that the contact bridge 20 still forms a contact with the third fixed contact 26 and is not opened. For the equivalent circuit shown in FIG. 2B, this means that the second switch 14 is open while the first switch 8 and the third switch 16 remain closed. Thus, in the event of overcurrent, the bimetal 76 of the bimetallic actuator of the auxiliary trip device 6 is connected in series with the coil 56 of the main tripping device 12 and a parallel circuit of resistor 10 and a shunt current path with the third switch 16 shorting the resistor 10 by this shunt current path. Here, the current flowing through the first bimetal 76 leads to a heating of the first bimetal 76, whereby after a first period of time the switching mechanism 36 is opened in the manner described above. In this case, the overcurrent corresponds to a first threshold current, which is adjustable in terms of apparatus (for example, by a corresponding dimensioning of the ratio between the spring force of the spring 66 and the force of the coil 56) by the electrical selective self-switch.

In the event of a short-term exceeding of the first threshold current below the first time duration, the contact between the movable contact 40 and the contact bridge 20 is closed again, whereby the first bimetal 76 is again short-circuited by the shunt current path with the first switch 14. Thus, it comes with a short-term increase in the operating current not to trigger the switching mechanism 36. This function has the purpose that the electrical selective self-switch can be provided as a main switch, with an occurrence of an overcurrent first by lying after the main switch fuses of End consumers can be eliminated without the working as a main switch electrical selective selector switch disconnects the entire supply of a variety of end users.

In the case of a short-circuit current, however, the electrical selective self-switch is intended to actuate the switching mechanism 36 within a very short time, that is to say a second time duration, which is substantially shorter than the first time duration. This case is shown in Figs. 3A and 3B. Due to a short-circuit current, which in addition to the movable contact 40 by means of the expansion 74, the contact bridge 20 moves in the direction of actuation B and thus the contact between contact bridge 20 and third fixed contact 26 is opened, there is an opening of the second switch 14 and the third switch 16, as shown in the equivalent circuit diagram in Fig. 3B. Thus, the short-circuit current flows via the first bimetal 76, the first switch 8 and the current-limiting resistor 10 via the coil 56 to the second terminal 4. The short-circuit current causes a sudden heating of the first bimetal 76, whereby the switching mechanism 36 is actuated immediately. In the case of a short-circuit disconnection, the second magnet armature 64 has the task of opening the contact fixed immediately after contact opening without the interposition of any kinematics parts sufficient to effectively limit the arc current acting on the third fixed contact 26, so that the Arc is safely deleted. In the event of the occurrence of a high short-circuit current, therefore, the second magnet armature 64 is abruptly moved in the release direction B and acts on the system of the rear end of the pin 60 directly on the pin 60 and shifts it in the triggering direction abruptly against the contact bridge 20th

A further exemplary embodiment of the electrical selective self-switch according to the invention is shown in FIGS. 5A and 5B. Here, the auxiliary tripping device 6 on a Bimetallbetätigereinrichtung having in addition to the first bimetal 76, a second bimetal 78 which is formed so that it causes independent of the first bimetal 76 by means of the Bimetallbetätigereinrichtung triggering the switching mechanism 36. In this case, the second bimetal 78 is connected between the second fixed contact 24 and the coil 56. The second bimetal 78 thus becomes active only in the event of a short circuit or when a second threshold current is exceeded, since below one second threshold current, the second bimetal 78 and the resistor IO is shorted to the third switch 16 by the shunt current path. In this case, the second bimetal 78 has the function of opening, with a time constant, the switching mechanism 36, which is substantially smaller than the time constant of the first bimetal 76.

The present invention thus provides an electrical selective self-switch which selectively opens in the event of an overcurrent occurring after a period of time sufficient for subsequent electrical self-switches of end-users to shut off before the main switch operating as an electrical selective self-switch turns off, and which in Case of a short-circuit current abruptly the contact between the first terminal 2 and second terminal 4 separates. Here, the electric self-switch according to the invention has the advantage that in normal operation, the current between the first terminal 2 and second terminal 4 substantially only flows through the coil 56 of the main triggering device 12, since the first bimetal 76 or the second bimetal 78 through the bypass current path with the second Switch 14 and the third switch 16 are short-circuited. Thus, the power consumption of the electric selective self-switch according to the present invention is minimized. Furthermore, the electric selective self-switch of the present invention has the advantage that before switching off by the switching mechanism 36, an uninterrupted flow of current in an auxiliary current path for controlling the switching mechanism 36 is ensured, whereby a fault in the function of the auxiliary release device is avoided.

In the following, an advantageous embodiment of the resistor 10 and the coil 56 will be described, which will be explained with reference to FIGS. 6 and 7 for better illustration of the principle of operation by a simplified main fuse. However, the arrangement and configuration of the selective resistor 101 and the beating coil 102 are applicable to a resistor 10 configured as a coil and the coil 56.

For current limiting in the event of a short circuit, resistors in the range of 0.5 ohms are used in the main circuit breaker. During the turn-off time of a few tens of milliseconds, the selective resistor has to be able to handle powers of the order of 100 kilowatts non-destructively.

This requires considerable dimensions of the selective resistance as z. B. in the European application WO 03/065398 Al described in detail. There, a resistor body of doped ceramic is recommended as a selective resistor. In addition to coils wound from resistance wire, folded or wound current limiting resistors are known as flat strips of resistance material.

Apart from the measures which are required to avoid the unwanted magnetic field of such arrangements, the space in "miniature circuit breaker'Oft also not available.

Basically disadvantageous is that the magnetic field of the bobbin in short circuits of z. B. 5 times rated current is sufficient to open the main contact, but not to keep it open during the delayed shutdown. Due to the current limiting of the selective resistor, the current in the impact coil is reduced to approximately 3 times the rated current - the magnetic excitation is no longer sufficient to hold the armature against the force of the closing spring of the main contact. The consequence of this is that the main contact closes momentarily to reopen immediately. This alternating process, referred to in the art as "woodpeckers", is undesirable.

Therefore, according to the present invention, a selective resistor, which may be the resistor 10 shown in FIGS. 1 to 5, is used, which is wound as a coil of resistive material over the beating coil of the main circuit which may be the coil 56.

As a result, the use of the free space between the bobbin and the housing walls of the main circuit breaker for accommodating the selective resistor is possible.

This simple measure ensures that, due to the additional number of turns of the selective resistor in series with the impact coil, even with limited residual current, greater flux in the magnetic field is achieved. circle is available as the operating current of the electromagnet. The magnet armature keeps the main contact safely open during the delay time and that until the Selective bimetal unlocks the switch lock of the main circuit breaker and this interrupts the circuit.

The Selektivauslöser forms together with the impact coil a structural unit, which is enclosed by a common magnetic yoke and additionally has a magnetic core, a magnet armature and a selective bimetal.

Preferably, the magnetic yoke is formed so that it not only serves to conduct the magnetic flux, but also acts as a magnetic and thermal shield against adjacent devices. The magnetic yoke, which also carries the selective bimetal, encloses on four sides in a box-shaped manner both the impact coil and the coil-shaped selective resistance and is spatially arranged on both sides between the latter and the housing walls of the main automatic circuit breaker.

It is advantageous if the complete selective release, so housed together with the impact coil on the same side in the energy flow direction of main and break contact circuit technology.

In addition, the winding direction of selective resistance and impact coil is chosen so that complement their magnetic effect in current flow.

In Fig. 6 is the arrangement of the selective resistor 101 on the impact coil 102 can be seen from the circuit diagram of the main circuit breaker. Likewise, the circuit-technical position of the selective release can be recognized as a parallel circuit. The illustrated switching state corresponds to the fault case "short circuit" during the delay time.

When switched on, the main contact 103 and the isolating contact 104 are closed. The operating current flows through the main contact 103 and the impact coil 102 to the electrical load. In the event of a fault in the event of a short circuit, the magnet armature 105 shown in FIG. 7, excited by the magnetic field of the impact coil 102, opens the main contact 103.

The isolating contact 104 remains closed, so that the main contact 103 is bridged by the parallel circuit of the selective release.

In this case, the short-circuit current is limited by the selective resistor 101.

This residual current flows through both the selective bimetal 106 and through the selective resistor 101 and the impact coil 102. The residual current generates an additional, magnetic induction in the selective resistor which amplifies both the attractive force of the magnet armature 105 when opening the main contact 103 in the magnetic circuit of the beating coil also ensures a sufficient holding force of the armature 105 on the magnetic core 108 during the delay time.

During this time, the selective bimetal 106 bends and unlatches the switching mechanism, which then opens the isolating contact 104, keeps the main contact 103 open and thus interrupts the circuit to be protected. If during the delay time the circuit elsewhere, so z. B. is interrupted by a downstream circuit breaker, the main circuit breaker remains switched on and ensures the availability of the rest of the system.

In Fig. 7 is a horizontal section through the main automatic circuit breaker in plan view is shown schematically. From this, the spatial arrangement of the selective resistor 101 on the impact coil 102 can be seen and the formation of the magnetic yoke 107 as thermal and magnetic shielding within the housing 1 10 relative to adjacent devices recognizable.

In the event of a fault, the flux in the magnetic circuit is generated both by the number of turns of the selective resistor 101 and by the windings of the beating coil 102, so that the residual current limited by the selective resistance is certainly sufficient to release the armature 105 during the deceleration. to hold time to the magnetic core 108 and thus to fix the main contact 103 against the force of the closing spring 109 in the open position.

Thus, therefore, a Selektivauslöser is provided for a main circuit breaker, which is arranged in series connection of selective bimetal and selective resistor as a parallel circuit to the main contact and bypasses this in the event of a fault "short circuit". The selective resistor 101 is formed as a coil and arranged in the magnetic circuit of the beating coil 102 for their magnetic support in the force effect when opening and keeping open the main contact 103.

The selective resistor 101 limited in functional combination both the short-circuit current and amplified with the remaining residual current, the flooding in the magnetic circuit together with the impact coil 102nd

The selective resistor 101 is arranged spatially between the magnet yoke 107 and the impact coil 102, enclosing and covering it at least partially.

The selective release is circuitally arranged together with the impact coil 102 on the same side in the energy flow direction of the main contact 103 and isolating contact 104.

The Selektivauslöser forms together with the impact coil 102, the magnetic core 108, the armature 105, the selective resistor 101, the selective bimetal 106 and the yoke 107 a structural unit, wherein the yoke which on the housing walls 1 10 over a large area abuts the attachment for the base of the selective bimetal 106 offers.

The arrangement of the formed as a coil selective resistor 101 to the impact coil 102 according to the invention on the resistor 10 shown in FIGS. 1 to 5 and the coil 56 is applicable.

Claims

claims

1. Electrical selective self-switch, in particular circuit breaker, comprising a series connection of an auxiliary tripping device (6), a normally closed first switch (8), a resistor (10) and a main tripping device (12) between a first and a second electrical Connection (2, 4) is connected, a bypass current path, which is connected in series with the main tripping device (12) between the first and the second electrical connection (2, 4) and a closed in the event of trouble second switch (14) and a normally closed third switch (16) connected in series with the second switch (14) and a current bridge connecting an input contact of the first switch (8) to a connection contact (18) between the second and third switches (14 , 16), wherein the main triggering device (12) is designed so that upon reaching a first threshold current the second switch (14) and upon reaching a second threshold current which is greater than the first threshold current, in addition the third switch (16) is opened, and wherein the auxiliary tripping device (6) is designed so that the first and the third switch ( 8, 16) is opened when the second switch (14) is open after a first period of time has elapsed, while with the second and third switches (14, 16) open, the first switch (8) is opened after a second period of time has elapsed, which is shorter than the first time Time is.

2. Electrical selective self-switch according to claim 1, characterized in that the current bridge is formed by a contact bridge (20) in the operating state, a first and a second fixed contact (22, 24) of the first switch (8) and a third fixed contact (26 ) of the third switch (16) electrically interconnects.

3. Electrical selective self-switch according to claim 1 or 2, characterized in that the third fixed contact (26) on the one hand and the first and second fixed contact (22, 24) on the other hand on opposite sides of the contact bridge (20) are located.

4. An electrical selective self-switch according to claim 1, 2 or 3, characterized in that the auxiliary tripping device (6) bimetallbetä- tiger device having a between the first terminal (2) and the first switch (8) located first bimetallic strip (76), wherein the Bime- tallbetätigereinrichtung is formed so that it acts on a contact bridge (20) mechanically acting switching cam (36), and wherein the switching mechanism (36) on the contact bridge (20) exerted release force in the opening direction of the contact between the third fixed contact (26) and the contact bridge (20) and the opening directions of the contacting between the first fixed contact (22) and the contact bridge (20) and the second fixed contact (24) and the contact bridge (20) acts.

5. An electrical selective self-switch according to claim 4, characterized in that the Bimetallbetätigereinrichtung between the first switch (8) and the second terminal (4) located second bimetallic strip (78) which is designed so that it is independent of the first bimetal ( 76) by means of the bimetallic actuator causes a triggering of the switching mechanism (36).

6. Electrical selective self-switch according to claim 4 or 5, characterized in that the arrangement of the first fixed contact (22) and the second fixed contact (24) and / or the design of the contact bridge (20) is such that the contact bridge (20) during Triggering the switch latch (36) after the third fixed contact (26) has been opened, first separated from the second fixed contact (24) and then from the first fixed contact (22).

7. Electrical selective self-switch according to one of claims 2 to 6, characterized in that the main tripping device (12) mechanically acting on the contact bridge (20) Magnetbetätigereinrichtung with a first movable in the direction of actuation armature (62) and between the shunt current path and the second terminal (4) switched coil (56), wherein the actuating direction (B) of the first armature (62) directed, by the first armature (62) applied tripping force in the opening direction of the contact between the third fixed contact (26) and the contact bridge (20) and in the closing direction of the contact between the first fixed contact (22) and the contact bridge (20) and between the second fixed contact (24) and the contact bridge (20) acts.

8. An electrical selective self-switch according to claim 7, characterized in that a connecting line (X) between the first fixed contact (22) and the second fixed contact (24) forms a pivot axis for the contact bridge (20) when the tripping force of the first armature (62 ) is applied to the contact bridge (20).

9. Electrical selective self-switch according to one of claims 7 to 8, characterized in that the point of action of the first armature (62) applied tripping force between the third fixed contact (26) on the one hand and the first and second fixed contact (22, 24) on the other lies.

10. Electrical selective self-switch according to one of claims 7 to 9, characterized in that a contact spring (34) is provided which simultaneously in the operating state contact forces between the third fixed contact (26) and the contact bridge (20), between the first fixed contact (22 ) And the contact bridge (20) and between the second fixed contact (24) and the contact bridge (20) in the respective closing direction of the fixed contacts (22, 24, 26) generated.

1 1. An electric selective self-switch according to claim 10, characterized in that the contact spring (34) facing away from the third fixed contact (26), the first and second fixed contact (22, 24) projecting portion of the contact bridge (20) acts on these.

12. Electrical selective self-switch according to one of claims 2 to

1 1. characterized in that the second switch (14) has a movable contact (40) which connects the first terminal (2) with the contact bridge (20) in the case of trouble-free.

13. Electrical selective self-switch according to claim 12, characterized in that the movable contact (40) in the actuating direction (B) of the first armature (62) behind the contact bridge (20) and pivotally mounted by means of a pivoting device (44), wherein the Pivot axis of the pivoting device (44) substantially parallel to the pivot axis (X) of the contact bridge (20).

14. An electric selective self-switch according to claim 12 or 13, characterized in that the magnetic actuator means extending through a through hole (72) of the contact bridge (20) extending pin (60) with an actuating direction (B) of the first armature (62) in front of the Contact (20) located expansion (74), wherein a front end of the pin (60) of the Magnetbetätigereinrichtung is adapted to act in the opening direction of the movable contact (40) on this and the widening (74) is suitable, in the opening direction of Contact bridge (20) to interact with these.

15. An electrical selective self-switch according to one of claims 7 to

14, characterized in that the Magnetbetätigereinrichtung is configured such that upon actuation of the first armature (62) taktierung between the contact bridge (20) and the movable contact (40) before contacting between the third fixed contact (26) the contact bridge (20) is opened.

16. Electrical selective self-switch according to one of claims 7 to

15, characterized in that the Magnetbetätigereinrichtung has a core (58) which is provided with a first magnet armature (62) facing shorting ring (70).

17. Electrical selective self-switch according to one of claims 7 to

16, characterized in that the magnet actuation device has a second in the actuating direction (B) movable armature (64), which preferably has a greater mass than the first armature (62), and at an increased induction in the Magnetbetätigereinrichtung in addition to first armature (62) causes an accelerated movement in the direction of actuation (B).

18. Electrical selective self-switch according to one of the preceding claims, characterized in that the auxiliary tripping device is designed such that at a manual power on first the second switch (14), then the first switch (8) and subsequently the third switch (16) is closed.