EP2541574A1 - Double interrupter protective switch device - Google Patents

Abstract

The double breaking protective switching device (1) has switching contacts (10,20) which are electrically connected in series with respect to each other. The arc extinguishing chambers (13,23) are arranged adjacent to each other for erasing the arcs (14-1,14-2,24-1,24-2) generated while opening the switching contacts respectively. A common blowing loop (30) electrically connected to the switching contacts is energized only when the arcs are commutated so as to drift the arcs with respect to arc extinguishing chambers.

Description

The invention relates to a double-breaking protective switching device, in particular a circuit breaker or circuit breaker, for interrupting an electrical line in a low-voltage distribution network. Such double interrupting circuit breakers, or short double breaker, have a first switching contact and a second switching contact, which is electrically connected in series with the first switching contact on. Each of the two switch contacts has a fixed contact and a relatively movable moving contact. Since the opening of the switch contacts in the energized state, an arc is formed, each of the two switching contacts associated with a so-called arc-quenching chamber to bring the arc as quickly as possible to extinguish.

From the European patent application EP 1 548 772 A1 is a circuit breaker with double break is known, which has two spatially arranged side by side switching contacts with two associated, spatially juxtaposed extinguishing chambers. The two moving contacts are combined to form a structural unit in the form of a contact bridge, so that the current in the on state flows from the input terminal via the first fixed contact to the first moving contact, further via the contact bridge to the second moving contact and via the second fixed contact to the output terminal. This results in the disadvantage that when opening the switch contacts by moving away the contact bridge of the two fixed contacts form two arcs, which are oriented opposite to each other with respect to the current flow direction. Due to this opposite orientation, the two arcs affect each other negatively, since the faster arc generates a magnetic field which exerts a force on the slower arc, the pushes this arc away from its associated quenching chamber. To compensate for this effect, points out of the EP 1 548 772 A1 known circuit breaker on a shield, which magnetically isolated the two Vorkammerbereiche from each other. Furthermore, the circuit breaker on an arc drive in the form of a so-called Blasschleife. This Blasschleife generates a magnetic field, which positively affect the two arcs and should drive into their associated extinguishing chambers. Due to the different orientation of the two arcs, however, the structural design of the blown loop is comparatively complicated; the electromagnetic field generated by the blowing loop is only of limited suitability for driving two arcs arranged adjacently but oppositely oriented.

It is therefore the object of the present invention to provide a double-breaking protective switching device, which overcomes the disadvantages mentioned above and has an improved switching performance to drive the arcs faster in the quenching chambers and there to extinguish.

This object is achieved by the double-breaking protection device according to claim 1. Advantageous embodiments are the subject of the dependent claims.

The double-breaking protection switching device according to the invention, in particular a circuit breaker or circuit breaker, has a first switching contact and a second switching contact, which is arranged spatially next to the first switching contact and electrically connected in series with the first switching contact, wherein the first switching contact and the second switching contact in Operation of currents are flowed, which have the same direction. Furthermore, the protective switching device has a first arc extinguishing chamber for extinguishing a first arc occurring when the first switching contact is opened, and a second arc Arc quenching chamber for deleting a second arc occurring when the second switching contact opens. Furthermore, the protective switching device has a common blowing loop, which is arranged adjacent to the first switching contact and the second switching contact and electrically connected to them so that it is energized only when the first arc and / or the second arc is commutated to the Arcs in their associated arc-extinguishing chambers to drive.

In the double interrupting protective switching device according to the invention, the two juxtaposed switching contacts are traversed by currents which have the same direction. As a result, the arcs occurring upon opening of the first and second switch contacts are rectified, i. they have the same direction of orientation. This results in the advantage that the electromagnetic field generated by the faster of the two arcs has a positive effect on the other, slower arc, to the effect that the slower arc is forced towards its associated arc quenching chamber and does not remain at the contact point. By pulling the slower moving arc from the faster moving arc towards the quenching chambers, a smooth movement of the two arcs is achieved.

The common Blasschleife, which is assigned to the two switch contacts together, represents an additional active arc drive to drive the resulting in the case of opening the two switch contacts arcs in their respective associated arc-quenching chamber. In this case, the blowing loop is electrically connected to the two switching contacts in such a way that it is energized only after commutation of the first, more rapid arc by its associated moving contact to a guide rail assigned to the relevant arc-extinguishing chamber. This has the advantage that the Blasschleife is energized only then and thus by an electromagnetic field is generated only when needed to drive the arcs. Since the blown loop is not permanently energized, the power loss of the protective switching device can be significantly reduced. The blowing loop required for this purpose can be made structurally simple, since the two arcs have the same orientation and should be driven in the same direction.

In an advantageous development of the double-breaking protective switching device, a deletion of the first arc (14) takes place independently of time of a deletion of the second arc (24). In contrast to the known from the prior art standard double interrupters, in which both arcs must commute simultaneously, the two arcs are independent of each other in the protective switching device according to the invention and can also commutate individually. The erase performance of the protection device is thereby significantly improved.

In a further advantageous development of the double-breaking protective switching device, the blowing loop is electrically connected between a first guide rail of the first arc extinguishing chamber and a fixed contact of the second switching contact, so that the blown loop is energized only at a commutation of the first arc to the first guide rail. The blowing loop is thus electrically connected in series with the first guide rail and the fixed contact of the second switching contact. This represents an easy-to-implement possibility for electrical connection of the blown loop.

In a further advantageous development of the protective switching device, the blowing loop is arranged spatially between the first switching contact and the second switching contact. Due to the central placement of the blowing loop between the two switching contacts is a symmetrical arrangement achieved, which allows an approximate uniform distribution of the current generated by the energized Blasschleife and acting on the two arcs electromagnetic field.

In a further advantageous development, the protective switching device has a further blowing loop for driving at least one of the two arcs. To enhance the drive effect of the blown loop, another blown loop can be used. In addition to the central arrangement between the two switching contacts and other arrangements of the two blow loops are possible. In addition to an improved switching performance thus an increased degree of freedom for the structural design of the protection device is achieved.

In a further advantageous development of the protective switching device, the further blower loop is permanently energized. Thus, this Blasschleife already acts before the commutation of one of the two arcs on the respective associated guide rail, whereby the switching capacity of the protection device is further improved.

In a further advantageous development of the protective switching device, the first switching contact and the second switching contact are arranged spatially between the blowing loop and the further blowing loop. In this way, when using two blow loops as compact as possible arrangement of the individual components of the protective device can be achieved.

Figur 1

eine schematische Darstellung des Schaltbildes des erfindungsgemäßen doppelt unterbrechenden Schutzschaltgerätes;

Figuren 2A und 2B

schematische Darstellungen zweier Seitenansichten des doppelt unterbrechenden Schutzschaltgerätes;

Figur 3

eine schematische Schnitt-Darstellung des doppelt unterbrechenden Schutzschaltgerätes in einer Draufsicht;

Figuren 4A und 4B

schematische Darstellungen des doppelt unterbrechenden Schutzschaltgerätes in perspektivischer Ansicht.

In the following, an embodiment of the double-breaking protective switching device will be explained in more detail with reference to the accompanying figures. In the figures are:

FIG. 1

a schematic representation of the circuit diagram of the double-breaking protective switching device according to the invention;

FIGS. 2A and 2B

schematic representations of two side views of the double interrupting protection device;

FIG. 3

a schematic sectional view of the double interrupting protective switching device in a plan view;

FIGS. 4A and 4B

schematic representations of the double interrupting protective device in perspective view.

In the various figures of the drawing, like parts are always provided with the same reference numerals. The description applies to all drawing figures in which the corresponding part can also be recognized.

In FIG. 1 is a circuit diagram of the double-breaking protective switching device 1 according to the invention shown schematically. The double-breaking protective switching device 1 has a first switching contact 10 and a second switching contact 20, which are electrically connected in series with each other. Furthermore, the protective switching device 1 has a short-circuit release 2, which is designed in the illustrated case as a short-circuit trip coil, and an overload release 3, which is shown here as a bimetallic strip, on. The first switching contact 10 is assigned a first arc quenching chamber 13 for extinguishing a first arc 14. Likewise, the second switching contact 20 is associated with a second arc quenching chamber 23 for extinguishing a second arc 24. The first switching contact 10 has a first fixed contact 11 and a movable relative to the first moving contact 12, which is mounted on a first moving contact carrier 16 on. Accordingly, the second switching contact 20 has a second fixed contact 21 and a relative movable second moving contact 22, which is mounted on a second moving contact carrier 26, on.

To better distinguish the arcs 14 and 24 provided in the further course with the appendix "-1" when they burn between the fixed contact 11 and 21 and the moving contact 12 and 22, so for example. "14-1" or "24 -1". If the first arc 14 or the second arc 24 is commutated by the respective fixed contact 12 or 22 to a first guide rail 15 or second guide rail 25 assigned to it, then the reference symbol is given the appendix "-2", ie, for example, "14 -2 "or" 24-2 ".

The first fixed contact 11 is connected on the one hand via the short-circuit release 2 with an input terminal 4 of the protective switching device 1 electrically conductive. Via a first contact horn 18, the first fixed contact 11 is further electrically conductively connected to the first arc quenching chamber 13. Furthermore, the first moving contact 12 is electrically conductively connected via the first moving contact carrier 16 to the second fixed contact 21 of the second switching contact 20. The second fixed contact 21 is further electrically conductively connected via a second contact horn 28 to the second arc quenching chamber 23. The second moving contact 22 is electrically conductively connected via the second moving contact carrier 26 and the overload release 3 to an output terminal 5 of the protective switching device 1.

If the double-breaking protection device 1 is triggered - either by the short-circuit release 2 or by the overload release 3 - a switching mechanism (not shown) is unlatched, as a result of which the first switching contact 10 and the second switching contact 20 are opened via the mechanism. Initially, a first arc 14-1, which first burns between the first fixed contact 11 and the first moving contact 12, and a second arc 24-1, which initially between the second fixed contact 21 and the second moving contact 22 burns. If the first moving contact 12 is moved away from the first fixed contact 11 by further pivotal movement of the first moving contact carrier 16, the first arc 14-1 commutates from the fixed contact 12 onto the first guide rail 15 which is electrically conductively connected to the first arc extinguishing chamber 13 is. The first arc 14-2 now burns between the first fixed contact 11 and the first guide rail 15. Accordingly, the second arc 24 commutes in a further pivotal movement of the second Bewegkontakt carrier 26 from the second moving contact 22 on the second guide rail 25, which with the second arc Extinguishing chamber 23 is electrically connected. The second arc 24-2 burns in the course between the second fixed contact 21 and the second guide rail 25th

Furthermore, a blowing loop 30 is electrically connected to the first switching contact 10 and the second switching contact 20 in such a way that it is energized only after the first arc 14 has been commutated onto the first guide rail 15. For this purpose, the blowing loop 30 is electrically conductively connected with its first end to the first guide rail 15. With its second end, the blowing loop 30 is electrically conductively connected to the second fixed contact 21 of the second switching contact 20. As long as the first arc 14 is not yet commutated, the current flows from the first fixed contact 11 via the first arc 14-1 to the first moving contact 12 and further via the first moving contact carrier 16 to the second fixed contact 21. Only after the commutation of the first arc 14th the current flows from the first fixed contact 11 via the commutated first arc 14-2 to the first guide rail 15 and further via the Blasschleife 30 to the second fixed contact 21. The Blasschleife 30 is executed in the simplest case as a simple conductor loop. However, if space permits inside the protective switching device 1, it is also possible to form the blowing loop 30 as a multi-turn coil.

In the FIGS. 2A and 2 B is the double-breaking protection device 1 shown schematically in two side views. The first switching contact 10 and the second switching contact 20 are arranged lying one behind the other in this view and are separated by an insulating housing intermediate part 6 from each other. Likewise, the first arc extinguishing chamber 13 and the second arc extinguishing chamber 23, which are also arranged lying one behind the other in this view, separated by the housing intermediate part 6 from each other. The housing intermediate part 6 also has a cutout 7, in which in the fully assembled state, an actuating element (not shown) of the protective switching device 1 is added. A first prechamber region of the protective switching device 1, in which the first switching contact 10 is arranged, is shielded laterally outwardly by a first cover element 17. Likewise, a second cover member 27 is arranged such that it shields a second pre-chamber region of the protective switching device 1, in which the second switching contact 20 is arranged, to the other side to the outside.

FIG. 3 schematically shows a sectional view of the double interrupting protective switching device 1 along the section line CC in FIG. 2B , The protective switching device 1 is shown at a time, since the two switching contacts 10 and 20 are opened, wherein the first arc 14 and the second arc 24 have already commutated. In this illustration, especially the position of the blowing loop 30 between the two arcs 14 and 24 can be clearly seen. As soon as the first arc 14 commutates on the guide rail 15 assigned to it, the blowing loop 30 is energized. The resulting electromagnetic field is in the field of Blasschleife 30, and the two arc-quenching chambers 13 and 23 by two in FIG. 3 from top to bottom extending field line arrows 31 shown. Outside the two arc quenching chambers 13 and 23, the field lines 31 of the electromagnetic field in arcuate paths around the Blasschleife 30 around. Since the first arc 14 and the second arc 24 have the same orientation direction, the electromagnetic field caused by the blowing loop 30 acts equally on both arcs: according to the "right-hand rule" for determining the direction of the Lorentz force on a current-carrying electrical conductor (here the arcs 14 and 24), the first arc 14 and the second arc 24 are urged toward their associated first and second arc quenching chambers 13 and 23. In this way, the blowing loop 30 contributes to the improvement of the erasing power and thus to the improvement of the switching capacity of the protective switching device 1.

In the FIGS. 4A and 4B is the double-breaking protection device 1 is shown schematically in a perspective view. The housing intermediate part 6 (see FIGS. 2A and 2 B ) was omitted for reasons of clarity. The basic structure of the protective switching device 1, ie the arrangement of the two switching contacts 10 and 20 and the two arc quenching chambers 13 and 23, corresponds to that of the in the FIGS. 2A . 2 B and 3 illustrated protective switching device 1.

In the FIGS. 4A and 4B the protective switching device 1 is shown at a time, since the first switching contact 10 and the second switching contact 20 are already open and the first arc 14-2 and the second arc 24-2 already from the respectively associated first fixed contact 12 and the second fixed contact 22nd are commutated to their respective associated first guide rail 15 and to the second guide rail 25.

To the in the FIGS. 4A and 4B shown time, the current flow in the interior of the protective switching device 1 is not interrupted, but is maintained by the first arc 14-2 and the second arc 24-2. Of the Current flows, starting from the input terminal 4 of the protective switching device 1, via the short-circuit release 2 designed as a short-circuit release and a first fixed contact carrier 19 to the first fixed contact 11. Since the first switching contact 10 is already open and the first arc 14 has already commutated to the guide rail 15 flows the current from the first fixed contact 11 not to the first moving contact 12, but via the first contact horn 18 and the first arc 14-2 to the first guide rail 15. The free, the first arc-quenching chamber 13 remote from the end of the first guide rail 15 is electrically conductive with a first end of Blasschleife 30 connected.

A second end of the blowing loop 30 is electrically conductively connected to a carrier element 8 of the protective switching device. Accordingly, the electric current flows from the first guide rail 15 via the blowing loop 30 to the carrier element 8 connected to the second end of the blowing loop 30. The carrier element 8 is integrally connected to a second fixed contact carrier 29. At a side facing away from the carrier element 8 end of the second fixed contact carrier 29 of the second fixed contact 21 and the second contact horn 28 are electrically connected to the second fixed contact carrier 29. Since the second switching contact 20 is already open and also the second arc 24-2 is already commutated to the second guide rail 25, the electric current from the carrier element 8 and the second fixed contact carrier 29 does not flow via the second switching contact 20, but on the second contact horn 28 and the second arc 24-2 to the second guide rail 25. The second guide rail 25 is connected to one of the second arc-quenching chamber 23 remote end electrically connected to the output terminal 5 of the protective switching device 1.

In the representations of the FIGS. 4A and 4B is also easy to see how the first switching contact 10 is electrically conductively connected to the second switching contact 20, that the first switching contact 10 and the second switching contact 20 are flowed through in a normal operating state of streams having the same direction. For this purpose, the first moving contact carrier 16 is electrically conductively connected to the carrier element 8 of the protective switching device 1 via a flexible strand 9-1. Since the first switching contact 10 and the second switching contact 20 are arranged symmetrically side by side, the electrically conductive connection of the first Bewegkontaktträgers 16 with the second fixed contact carrier 29 causes a parallel orientation of the current flow through the first switching contact 10 and the second switching contact 20. The second Bewegkontaktträger 26 further connected via a further flexible wire 9-2 with the formed as a thermo-bimetal overload release 3 electrically conductive. This current conduction makes it possible for the first switching contact 10 and the second switching contact 20 to flow in a normal operating state of currents which have the same direction, and nevertheless to arrange the two switching contacts 10 and 20 in an identical manner next to one another.

Even if the first Bewegkontaktträger 16 and the second Bewegkontaktträger 26 are not directly electrically connected to each other, it is still possible to operate the two Bewegkontaktträger 16 and 26 by means of a common switching mechanism (not shown) together. For this purpose, the two moving contact carriers 16 and 26 have a common pivot axis and correspondingly arranged receiving openings for coupling the common switching mechanism.

LIST OF REFERENCE NUMBERS

1

Protection device

2

Short-timer

3

Overload release

4

input port

5

output port

6

Housing intermediate part

7

cutout

8th

support element

9

flexible wire

10

first switching contact

11

first fixed contact

12

first moving contact

13

first arc quenching chamber

14

first arc

15

first guardrail

16

first moving contact carrier

17

first cover element

18

first contact horn

19

first solid contact carrier

20

second switching contact

21

second fixed contact

22

second moving contact

23

second arc quenching chamber

24

second arc

25

second guardrail

26

second moving contact carrier

27

second cover element

28

second contact horn

29

second hard contact carrier

30

Blasschleife

31

field line

Claims (7)

Double-breaking protective switching device (1), in particular circuit breaker or circuit breaker, with a first switching contact (10), - A second switching contact (20), which is arranged spatially next to the first switching contact (10) and electrically connected in series with the first switching contact (10), wherein the first switching contact (10) and the second switching contact (20) during operation of currents be flown through, which have the same direction, a first arc extinguishing chamber (13) for extinguishing a first arc (14) which occurs when the first switching contact (10) is opened, - A second arc-quenching chamber (23) for extinguishing a second arc (24) occurring when opening the second switching contact (20), wherein the first arc quenching chamber (13) and the second arc-quenching chamber (23) are arranged spatially next to each other . - A common Blasschleife (30), which is adjacent to the first switching contact (10) and the second switching contact (20) and electrically connected with these, that it is energized only when the first arc (14) and / or the second arc (24) is commutated to drive the arcs (14, 24) into their associated arc quenching chambers (13, 23). Protective switching device (1) according to claim 1, wherein a deletion of the first arc (14) takes place temporally independent of a deletion of the second arc (24). Protective switching device (1) according to one of the preceding claims, wherein the blowing loop (30) electrically between a first guide rail (15) of the first arc-extinguishing chamber (13) and a fixed contact of the second Switching contact (20) is connected, so that the blown loop is energized only at a commutation of the first arc (14) on the first guide rail (15). Protective switching device (1) according to one of the preceding claims, in which the blowing loop (30) is arranged spatially between the first switching contact (10) and the second switching contact (20). Protective switching device (1) according to one of the preceding claims, which has a further blowing loop for driving at least one of the two arcs (14, 24). Protective switching device (1) according to claim 4, wherein the further Blasschleife is permanently energized. The protective switching device (1) according to claim 4, wherein the first switching contact (10) and the second switching contact (20) are arranged spatially between the blowing loop (30) and the further blowing loop.

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