EP1081726B1 - Multipole switching device - Google Patents

Abstract

The device has at least one input and one output terminal per pole path connected together via a connecting line with at least one current measurement device. At least one connecting line contains a switch with rails (1,2) for carrying away a spark between fixed (8) and movable (9) contacts. At least one adjacent line (10) is arranged so that its magnetic field (4',5') augments that (4) in the line with the switch when a spark (3) is present.

Description

The invention relates to a multi-pole switching device in which each Polstrecke has at least one input terminal and an output terminal, which are electrically connected to each other via a connecting line and at least one measuring device for detecting the current flowing in this connection line is provided, wherein at least one Polstrecke is provided in whose connecting line is a switching contact with a fixed and a movable contact piece is connected, which contact pieces are electrically conductive, resulting between the contact pieces arcs of these contact pieces leading rails connect.

When switching devices with such functioning as a spark-extinguishing device rails as quick as possible away movement of the resulting upon separation of the movable from the fixed contact piece arc is desirable. Due to the flow of current in the contact pieces, the rails and the arc creates a magnetic field which exerts forces on the arc, which tries to move them in the manner mentioned away from the contact pieces. To accelerate this movement, it is already known to enhance the magnetic field triggering this movement by providing conductors through which current flows.

From FR-A-2 627 324 a single-phase residual current circuit breaker according to the preamble of claim 1 with a neutral connected is described, wherein the housing has two parallel chambers. In the first chamber, a summation current transformer, a trigger relay connected thereto and a neutral circuit and in the second chamber, a phase conductor circuit comprising a switching contact and a spark-quenching chamber and a mechanism for manually switching on and off the switch housed. The neutral circuit has leads disposed immediately adjacent to one another and so that the currents flowing in them flow in opposite directions, thereby causing the magnetic fields generated by these currents to compensate each other, thus avoiding any influence on the trigger relay. The disadvantage here is that the path-movement of the light boulder is not accelerated.

It is an object of the present invention to provide a multi-pole switching device of the type mentioned, in which the acceleration of the arc movement by amplifying the arc-causing magnetic field is realized with very little effort.

According to the invention this is achieved in that the connecting line of at least one Polstrecke, which is adjacent to the switching contact having Polstrecke, at least partially so guided that the magnetic field generated by the current flowing in their current magnetic field amplifies that magnetic field, which in the of the contact pieces and the area circumscribed to the rails is caused by the current flowing in the presence of an arc between the contact pieces and the rails in the rails and the arc.

The connecting line between the input and output terminal of a Polstrecke is an already existing component of the switching device, which only has to be slightly modified to implement the invention. This modification is in the insertion of a line piece, such as e.g. Conductor rope, or even if such is already present in the connection line, in the change in the spatial arrangement, which may, if necessary, be accompanied by a slight extension of this conductor cable. Overall, however, all these measures lead to only minor material overhead and can be easily installed in existing designs of switching devices.

To be particularly favorable, it has been found that the connecting line runs at least in sections approximately parallel to the area circumscribed by the contact pieces and the rails in the region of their boundary.

The magnetic field caused by the current in the connecting line thus runs in the same direction as the magnetic field generated by the current in the rails and the arc, so that the gain of this magnetic field to be achieved is achieved particularly effectively.

According to a particularly preferred embodiment of the invention can be provided that the connecting line is designed in the form of a conductor loop and arranged so that the surface spanned by it lies approximately parallel to the circumscribed by the contact pieces and the rails surface and this area covers at least partially.

As a result, a particularly good amplification of the magnetic field generated by the current in the rails and the arc can be achieved with relatively little cost of materials.

In this context, it has proved to be favorable that the surface defined by the conductor loop covers the surface circumscribed by the contact pieces and the rails, at least in the region of the contact pieces and in the region of the sections immediately adjacent thereto.

In order to keep the caused by an arc wear of the contact points low, it is necessary to conduct away the arc from the region of the contact points, which is achieved with this arrangement way of the conductor loop. Once the arc is set in motion, no or very little force is needed to maintain this movement. However, this small force already exerts the magnetic field generated by the current in the rails and the arc alone, so that the target of the rapid arc extinction is already achieved with the arrangement just mentioned.

It has been found that it is sufficient in the usual use of the switching device in low and medium voltage networks to perform the conductor loop with one turn, since the currents are sufficiently high here to flow through a conductor loop with only one turn, the invention to be achieved magnetic field gain cause.

In a further development of the invention, the multi-pole switching device according to the invention with two pole sections can be designed as a combination of circuit breaker and residual current circuit breaker, in which the previously general and not on a particular multi-pole Switching device described limited invention principle is realized. In this particular switching device, the first provided for connecting the phase conductor of a single-phase power supply network Polstrecke the measuring devices of a circuit breaker (overcurrent detector and short-circuit current detector) and one of these measuring devices via a switching mechanism controlled switching contact and to the fixed or the movable contact piece this switching contact subsequent, electrically conductive rails and has the second provided for connecting the neutral conductor of a single-phase power supply network Polstrecke the components of a fault current detection circuit (summation current transformer and connected to the secondary winding evaluation circuit). The connecting lines of both this neutral pole path and the phase conductor Polstrecke are guided through the toroidal core of the summation current transformer and the evaluation device acts on the arranged in the phase conductor Polstrecke switching mechanism. It can be provided that the connecting line of the neutral conductor Polstrecke is formed by a conductor, which is designed in the form of a conductor loop and arranged so that the surface spanned by it is approximately parallel to the area circumscribed by the contact pieces and the rails surface and this area covered at least in the region of the contact pieces and in the region of these immediately adjacent sections of the rails.

As already discussed above, so that the magnetic field gain to be achieved is achieved particularly effectively with relatively little effort.

• Fig. 1 zwei stromführende Schienen 1,2 mit einem zwischen diesen brennenden Lichtbogen 3 schematisch im Grundriß;
• Fig.2 die Kontaktstücke 8,9 eines Schaltgerätes und zwei sich an diese anschließende Schienen 1,2 mit einem zwischen diesen brennenden Lichtbogen 3 schematisch im Grundriß;
• Fig.3a-c die Anordnung gemäß Fig.2 jeweils in derselben Darstellung mit einem jeweils unterschiedlich angeordneten Leiter 10 zur Verstärkung des vom Strom in den Schienen 1,2 und dem Lichtbogen 3 erzeugten Magnetfeldes;
• Fig.4a die Anordnung gemäß Fig.3a-b, wobei der dortige Leiter 10 durch eine Leiterschleife 11 ersetzt ist;
• Fig.4b die Anordnung gemäß Fig.4a mit etwas größer ausgeführter Leiterschleife 11;
• Fig.5 die Draufsicht auf ein zweipoliges, als Kombination aus Leitungsschutzschalter und
• Fehlerstromschutzschalter ausgeführtes Schaltgerät;
• Fig.6 die erste Polstrecke 12 des Schaltgerätes gemäß Fig.5 bei abgenommener Seitenschale;
• Fig.7 die zweite Polstrecke 13 des 'Schaltgerätes gemäß Fig.5 bei abgenommener Seitenschale;
• Fig.8 die Darstellung dieses Schaltgerätes in der Darstellung gemäß Fig.6 bei weggelassener Trennwand zwischen den beiden Polstrecken 12,13 und
• Fig.9 die Darstellung dieses Schaltgerätes in der Darstellung gemäß Fig.7 bei weggelassener Trennwand zwischen den beiden Polstrecken 12,13.

The invention will be described in more detail with reference to the accompanying drawings, in which particularly preferred embodiments are shown. Showing:

• Figure 1 shows two live rails 1.2 with a burning between these arc 3 schematically in plan view.
• 2 shows the contact pieces 8.9 of a switching device and two of these subsequent rails 1.2 with a burning between these arc 3 schematically in plan view;
• 3 a - c show the arrangement according to FIG. 2 in each case in the same illustration with a respectively differently arranged conductor 10 for amplifying the magnetic field generated by the current in the rails 1, 2 and the arc 3;
• 4a shows the arrangement of Figure 3a-b, wherein the local conductor 10 is replaced by a conductor loop 11;
• 4b shows the arrangement according to FIG. 4a with a somewhat larger conductor loop 11;
• 5 shows the top view of a two-pole, as a combination of circuit breaker and
• Residual current circuit breaker designed switching device;
• 6 shows the first pole section 12 of the switching device according to Figure 5 with the side shell removed;
• 7 shows the second pole section 13 of the 'switching device according to Figure 5 with the side shell removed;
• 8 shows the illustration of this switching device in the illustration of Figure 6 with omitted partition between the two Polstrecken 12,13 and
• 9 shows the illustration of this switching device in the illustration according to Figure 7 with omitted partition wall between the two Polstrecken 12,13.

The subject invention is based on the following, shown in Figure 1 and known per se principle:

With 1 and 2 in this figure are electrically conductive, current-carrying rails between which an arc 3 burns. The current through the rails 1, 2 and the arc 3 generates an electromagnetic field whose direction is indicated by the symbols 4 and 5. The arc 3 is a current-carrying conductor located within this field, on which this electromagnetic field exerts a force F.

This force F shifts the arc 3 in their direction, ie to the right in the representation according to FIG. Especially with switching devices (see schematic illustration in Figure 2), it is desirable to delete as quickly as possible between two electrically conductive parts, which are formed in a switching device by the fixed and the movable contact piece 8.9 of an interruption contact to the actually disconnect electrical connection between these two contact pieces 8.9.

One way of realizing this rapid deletion is to align the rails 1, 2 approximately V-shaped (see Fig.2), so that the distance between these rails 1,2 widens with increasing distance from the contact pieces 8.9. When caused by the force F running the arc 3 to the right of this is extended and tears off, if it is sufficiently long, from.

Another very frequently used possibility of arc extinguishment is the provision of a spark-quenching chamber 6, as shown in Fig.1. Such a device comprises a plurality of mutually approximately parallel platelets 7, which are aligned approximately normal to the arc 3. If the arc 3 enters such a spark quenching chamber 6, it is subdivided by the platelets 7 into a multiplicity of series-connected partial arcs, which are present between the platelets 7.

For an arc to persist, it must be driven by a specified minimum voltage (= sustain voltage). A voltage necessary to maintain a series connection of a plurality of partial arcs is higher than the voltage required to maintain a single arc having the same total length. If the voltage between the rails 1, 2 is lower than the sum of the sustaining voltages of the partial arcs, the arc 3 in the spark-quenching chamber 6 can be extinguished and the electrical connection between the rails 1, 2 can be interrupted. The in-motion of the arc into the spark-quenching chamber 6 is achieved by the above-discussed physical fact of the generation of a force F on the arc 3 caused by the magnetic field of current flow in the rails 1,2.

In the common switching devices, the two discussed possibilities of arc extinction are combined, so the rails 1.2 aligned diverging from each other and provided in the region of the contact pieces 8,9 remote ends of these rails 1,2 a spark quenching chamber 6, as in Fig.2 is entered with dotted lines.

In order to accelerate the path movement of the arc 3 of the contact pieces 8.9 in the direction of the more spaced apart ends of the rails 1.2 and / or the in-movement of the arc 3 in the spark quenching chamber 6 and thus an even faster arc extinction To achieve the magnetic field moving the arc 3 can be amplified in a conventional manner.

For this purpose, a current-carrying conductor 10 is provided which extends in sections approximately parallel to the area A ₁ circumscribed by the contact pieces 8, 9 and the rails ₁ , ₂ (see FIGS. 3 a, b, c). The current flow in this conductor 10 generates a magnetic field represented by the symbols 4 ', 5', which corresponds to the magnetic field prevailing within the area A ₁ superimposed. If the current flow direction in the conductor 10 is selected in the manner shown in FIG. 3a, b, c, the magnetic field in the area A _{1 is} amplified.

The exact course of the conductor 10 is to be chosen so as to give the discussed effect of magnetic field amplification. This conductor 10 can therefore be arranged anywhere in the area outside the area A ₁ (see Fig. 3a, b, c). The closer it is to the surface A ₁ , the greater, of course, the magnetic field in this area A ₁ reinforcing effect, which is why it is preferably located in the region of the boundary, for example at a short distance lying exactly over one of the rails 1.2.

4a, instead of a single, substantially straight conductor 10, a conductor loop 11 is used, which is arranged so that the surface A ₂ spanned by it is approximately parallel to the contact pieces 8, 9 and the rails 1, 2 circumscribed area A ₁ and this area A ₁ at least partially covered. The conductor loop 11 is therefore coplanar over the surface A ₁ . In the region of the overlap of the surfaces A ₁ and A ₂ , the magnetic field driving the arc 3 in the direction of the spark-quenching chamber 6 is amplified. Outside of this coverage area, the magnetic field generated by the conductor loop 11 attenuates the magnetic field generated by rails 1, 2 and arc, which in turn leads to a lower running speed of the arc 3 in this area. In the arrangement according to FIG. ₄ , this region lying outside the coverage area of the areas A ₁ and A ₂ is already in the spark-quenching chamber 6, that is to say in an area in which the arc 3 is already shortly before its extinction and therefore no longer further must be moved.

Of course, the most favorable design variant of the conductor loop 11, taking into account the information just given, is to make it cover the entire surface A ₁ (see FIG. 4 b).

The number of turns of the conductor loop 11 can be selected arbitrarily high, but since only small forces are required for further movement of an arc 3, it is sufficient, as shown in Fig.4a, b, to provide a single winding.

The invention uses the provision of a discussed conductor 10 and a discussed conductor loop 11 to increase the running speed of an arc 3 and is to apply this principle in a multi-pole switching device. An example of such a multi-pole switching device is shown in FIGS. 5 to 9, to which reference is made below:

This multi-pole switching device is bipolar and designed as a combination of circuit breaker and residual current device. Each pole section 12, 13 has at least one input terminal 14, 14 'and one output terminal 15, 15'. The input terminal 14,14 'of each Polstrecke 12,13 is electrically connected to the output terminal 15,15' of this Polstrecke 12,13 by a connecting line.

In the pole section 12 illustrated in FIG. 6 with the side shell removed, the input terminal 14 is connected via the bimetallic strip 16 and via a flexible conductor cable 17 to the contact bridge 18, which carries the movable contact piece 9. in the switched state is this movable contact piece 9 on the fixed contact piece 8, which is fixed to the contact piece carrier 19. This carrier 19 is connected to the first end of the coil 20, whose second end is connected via a further conductor 21 to the output terminal 15.

The coil 20 has an armature slidably mounted in its longitudinal direction, which from the magnetic field of the coil 20 - if this has a sufficient strength due to a short-circuit current is pressed against the contact bridge 18 so that the switching mechanism 26 is triggered and pivots the contact bridge 18 of this becomes. Ultimately, the movable contact piece 9 is lifted from the stationary contact piece 8 by these operations. The coil 20 with the movable armature forms the short-circuit current detector of the circuit breaker part of the present switching device.

The bimetal strip 16 is heated by the current flowing through it and thereby bends so that its connected to the conductor cable 17 end is pivoted to the right. If too high a continuous current, this bending of the bimetallic strip 16 to such an extent that pivots over the bracket 22, the contact bridge 18 and the movable contact piece 9 is lifted from the fixed contact piece 8. The bimetallic strip 16 thus forms the overcurrent detector of the circuit breaker part of the present switching device.

In the connecting line between the input terminal 14 and the output terminal 15 of this Polstrecke 12 are thus two the current through this connecting line detecting measuring devices and a switching contact (fixed and movable contact piece 8.9) on which said two current-measuring devices act, i. open it.

Furthermore, electrically conductive rails 1, 2 are provided, which adjoin the contact pieces 8, 9 and serve to conduct arcing arcs between the contact pieces 8, 9 away from them. In the space between these rails 1,2 a plurality of spaced apart mutually parallel electrically conductive plate 7 is provided, which forms a spark-quenching chamber 6 with already discussed above operating principle.

In the second Polstrecke 13, which is shown with removed side shell in Figure 7, the connecting line between the input terminal 14 'and the output terminal 15' is formed by a continuous conductor cable 23. This conductor cable 23 and the previously mentioned, the coil 20 of the first pole section 12 with its output terminal 15 connecting conductor 21 are guided by the toroidal core 24 of a summation current transformer. The secondary winding of this summation current transformer is connected to an electronic unit (indicated by the outline 25 of the printed circuit board carrying this electronics), which electronics evaluate the signal supplied by the summation current transformer. The electronics are further connected to the switching mechanism acting on the movable contact piece 9, so that they can cause the opening of the interruption contact 8.9 of the first pole section 12 when an unacceptably high difference between the currents in the conductor cables 21 and 23 is detected. The second Polstrecke 13 thus included the components of a residual current detection circuit formed of a summation current transformer and a secondary winding of its connected evaluation circuit. This evaluation circuit can of course be realized in another form, for example by a permanent magnet release.

As clearly shown in Fig. 7, the conductor line 23 forming the connection line between the input terminal 14 'and the output terminal 15' is in the form of a conductor loop having a turn. This conductor loop is arranged so that the surface A ₂ spanned by it lies approximately parallel to the area A ₁ circumscribed by the contact pieces 8, 9 and the rails _{1, 2} , and covers this area A _{1 in} regions.

This regional overlapping can be seen in particular from FIGS. 8 and 9, in which all housing parts of the switching device, in particular also the partition wall lying between the two pole sections 12, 13, have been omitted. The area in which the areas A ₁ and A ₂ overlap is here in the area of the contact pieces 8, 9 and in the area of the immediately adjacent sections of the rails _{1, 2} .

The first Polstrecke 12 is provided for connection of the phase conductor L of a two-pole voltage supply network, the second Polstrecke 13 for connecting the neutral conductor N of this voltage supply network. Arises at the opening of the switching contact an arc between its contact pieces 8.9 and subsequently between the adjoining these components rails 1.2, so this arc ensures that initially also in the neutral conductor N and thus in the conductor cable 23 current flows , This current flow therefore leads to the initially discussed amplification of that magnetic field which is circumscribed by the contact pieces 8, 9 and the rails 1, 2 in the presence of an arc between the contact pieces 8, 9 and the rails 1, 2 in the rails 1 , 2 and the arc flowing current is caused.

The invention is by no means limited to the particularly preferred embodiment shown in FIGS. Its underlying principle is, in a multipole switching device designed in any way the above discussed with reference to Fig.1-4b principle of increasing the arc speed with the help of an already existing connection line Polaus, adjacent to a one switching contact with subsequent Arc extinguishing device comprising Polstrecke is to realize.

It follows first that the connecting line does not have to have the shape of a conductor loop with only one turn, it could also be provided several turns. However, it is also sufficient in the sense of FIG. 3a-c to provide only a portion of the conductor loop provided in FIGS. The remaining sections of the conductor cable 23 can be laid arbitrarily. In this context, it should be noted that it is common - in contrast to the embodiment shown in Figures 6-9, the input terminal 14 'of the neutral pole section 13 at the lower edge of the device, ie adjacent to the input terminal 14 of the phase conductor Polstrecke 12 to arrange. It is sufficient to effect the magnetic field amplification in question, to lay the conductor cable 23 in the form of in Fig.9 with 23 'designated upper branch or designated by 23 "lower branch of the conductor loop.

Furthermore, the application of the subject invention is not limited to switching devices in which circuit breaker and residual current device function are combined. Rather, it is possible to realize the inventive principle in a multi-pole, only one of the two circuit breaker functions having switching device (three- or four-pole circuit breaker or four-pole residual current circuit breaker, each for a three-phase system).

Here, of course, a switching contact with arc extinguishing device not only in one of the Polstrecken, but at least in all phase conductor Polstrecken, usually in the neutral conductor Polstrecke be provided. This does not hinder the application of the subject invention, also here the connecting line of one of the Polstrecken in one of the ways discussed above is guided so that the current flow in this connection line that magnetic field is increased, which is one between the rails 1.2 of an adjacent Polstrecke pending Arc moves.

In this connection, it should be noted with regard to the two-pole RCCB switch illustrated in FIGS. 6 to 9 that the neutral conductor N can be made interruptible here, too. in its pole section 13, a switching contact according to the design of the first pole section 12 may be installed.

In all possible embodiments, however, it must be considered that the desired magnetic field amplification only results if the current in the section of the connecting line used for this purpose has the correct flow direction. To ensure that the switching device according to the invention is connected in the necessary manner with the voltage supply network or with the forwarding to the consumers, is on the housing of the switching device in the range of each terminal 14,15; 14 ', 15' printed, .which line to the respective terminal 14, 15; 14 ', 15' is to be connected.

Claims (6)

1. A multipole switching device in which every pole section (12, 13) comprises at least one input terminal (14, 14') and one output terminal (15, 15') which are mutually electrically connected via a connecting lead and at least one measuring device is provided for detecting the current flowing in said connecting lead, with at least one pole section (12) being provided in whose connecting lead is switched a switching contact with a fixed (8) and a movable contact point (9), with electrically conductive rails (1, 2) being adjacent to the contact points (8, 9), which rails guide away from said contact points (8, 9) any arcs (3) arising between said contact points (8, 9), characterized in that the connecting lead between at least one pole section (13) which is situated adjacent to the pole section (12) having the switching contact (8, 9) is guided at least in sections in such a way that the magnetic field generated in operation by the current flowing in the same amplifies the magnetic field which is produced in the surface area (A₁) as defined by the contact points (8, 9) and the rails (1, 2) by the current flowing in the rails (1, 2) and in the arc (3) in the case of the presence of an arc (3) between the contact points (8, 9) and the rails (1, 2).
2. A multipole switching device as claimed in claim 1, characterized in that the connecting lead extends at least in sections slightly parallel to the surface area (A₁) as defined by the contact points (8, 9) and the rails (1, 2) in the region of the edge of said surface area.
3. A multipole switching device as claimed in claim 1, characterized in that the connecting lead is designed in the form of a conductor loop and is arranged in such a way that the surface area (A₂) as defined by the same is situated approximately parallel to the surface area (A₁) as defined by the contact points (8, 9) and the rails (1, 2) and covers said surface area (A₁) at least in sections.
4. A multipole switching device as claimed in claim 3, characterized in that the surface area (A₂) as defined by the conductor loop covers the surface area (A₁) as defined by the contact points (8, 9) and the rails (1, 2) at least in the region of the contact points (8, 9) and in the region of the sections of the rails (1, 2) which are directly adjacent to the same.
5. A multipole switching device as claimed in claim 3, characterized in that the conductor loop comprises one winding.
6. A multipole switching device as claimed in claim 1 with two pole sections (12, 13) configured as a combination of a miniature circuit-breaker and residual-current-operated circuit-breaker, with the first pole section (12), which is provided for connecting the phase conductor (L) of a single-phase voltage supply network, comprising the measuring devices of a miniature circuit-breaker (overcurrent detector and fault current detector) as well as a switching contact triggered by said measuring devices via a switching mechanism (26) and electrically conductive rails (1, 2) which are adjacent to the fixed (8) or movable contact point (9) of said switching contact (8, 9), and the second pole section (13) provided for connecting the neutral conductor (N) of a single-phase voltage supply network comprises the components of a fault-current recognition circuit (summation current transformer and evaluation circuit connected to its secondary winding), with the connecting leads both of said neutral-conductor pole section (13) as well as the phase-conductor pole section (12) being guided through the annular core (24) of the summation current transformer and the evaluation circuit acting upon the switching mechanism (26) arranged in the phase-conductor pole section (12), characterized in that the connecting lead of the neutral-conductor pole section (13) is formed by a stranded conductor and is arranged in such a way that the surface area (A₂) as defined by the same is situated approximately parallel to the surface area (A₁) as defined by the contact points (8, 9) and the rails (1, 2) and covers said surface area (A₁) at least in the region of the contact points (8, 9) and in the region of the sections of the rails (1, 2) which are directly adjacent to said contact points.