EP1876617A1 - Electrical installation switch with pre-arcing chamber, arcing horns and current limiting arc chute - Google Patents

Abstract

Electrical installation device has a contact switch with switch pieces, between which electric arc (6) in an antechamber area is produced during switching off of the device. The arc runs over an arc guide rail into an arc extinguisher. A toggle switch is in upper side of housing. An exhaust opening (13) at a broader side of housing wall discharges the gas escaping from the extinguisher. A baffle prevents re-entering of the gas into the area.

Description

The invention relates to an electrical installation device with at least one switching contact with a fixed and a movable contact piece between which an arc in an arc Vorkammerraum arises when switching off, which arc enters via Lichtbogenleitschienen in a current-limiting arc quenching device, in particular an arc splitter stack, according to the The preamble of claim 1. The invention can be used for example in circuit breakers and motor protection switches.

Miniature circuit breakers and motor protection switches are used in the event of a fault to disconnect electrical lines that are loaded with high current overcurrents from the supply network. For this purpose, usually a fixed and a movable contact piece are provided in an arc Vorkammerraum, which are connected to the respective terminals. The connection terminals are usually located in a connection space, which is separated from the arc prechamber space by a terminal compartment separation.

The components and parts of an installation switching device, such as the rear derailleur, release mechanism, fixed and movable contact piece, arc extinguishing device, connection terminals, etc. are installed inside an insulating housing. This case has Front and rear front sides, a fastening side opposite this, a right and left narrow side and two broad sides.

When opening the switching contact, d. H. when lifting the movable contact piece from the fixed contact piece, there is a switching arc, which is deleted in a quenching device provided for this purpose. The drawn arc commutes from the opened contact pieces on arc guide rails, and then subdivided into an arc splitter stack (Deion quenching chamber). There, a high arc voltage is generated to limit the current, so that the arc goes out.

From the DE 102 42 310 A1 an arc extinguishing arrangement for an electrical switching device is known, which comprises a quenching chamber (in which a switching action between a fixed and a movable contact piece is generated an arc) and a plurality of arc quenching arc splitter stack in which the arc is guided over guide rails.

From the EP 0 251 160 B1 is a quenching device for an electrical switch with located in a Vorkammerraum contact pieces and a quenching stack known, the Vorkammerraum is bounded laterally by Vorkammerplatten. Between the outer sides of the Vorkammerplatten and the inner housing wall so creates a gap that allows a reduction of the excess pressure from the quenching plate stack, without disturbing the development of the arc. The backflowing pressure wave is used to compensate for the negative pressure and for deionization in the contact area. Thus, the backflow gas contributes to the faster quenching of the arc. However, the pre-chamber plates are additional components that increase the effort in the production.

The invention has for its object to provide an electrical installation device with arc Vorkammerraum, arc guide rails and current-limiting arc-extinguishing device, which has a simplified structure with optimal operation.

This object is achieved in conjunction with the features of the preamble according to the invention by the features specified in the characterizing part of claim 1.

According to the invention, the two wide sides of the housing are thus provided with inner recesses in a partial region of the arc prechamber space, so that the partial region delimited by the inner recesses has a reduced width compared with the remaining arc prechamber space.

In the switching device according to the invention, a main channel may be formed, which receives from the arc quenching device with increased pressure escaping gases and continues in the direction from the output to the entrance of the arc quenching device that an acceleration of the gas flow from the origin of the arc results in the direction of the arc quenching device.

According to a preferred embodiment, there is a gap between the edge of the inner recesses and an arc guide rail so that gas can flow through the gap into the subregion of the arc pre-chamber space.

In one advantageous embodiment of the invention, the housing broad sides lowered in the region of the inner recesses can have a three-dimensional structured surface contour, for example a waveform. Such a three-dimensional structures can further optimize the gas flow.

In a preferred embodiment, the partial area of the arc prechamber space according to the invention extends with the inner recess between the switching contact with the contact pieces, the arc quenching device and the arc guide rail facing away from the fixed contact piece.

In a further advantageous embodiment of the invention resulting from the inner recesses two additional side channels between the housing broadside, the edge of the inner recesses and the front housing change.

In this case, in a preferred embodiment, the main channel, which receives and forwards the gases emerging from the arc quenching device, is formed between the housing transformations and one of the arc guide rails. In particular, the main channel is formed in the region of the attachment side of the housing.

In a further preferred embodiment, the main channel is formed between the arc quenching device itself and one of the arc guide rails, again preferably in the region of the attachment side of the housing.

The inventive and advantageous effect of the inner recesses is that the part of the housing broad sides which is lowered in this area has a similar effect on the gas flow in the arc pre-chamber space, as the pre-chamber plates known in the prior art. Namely, their effect is that due to the reduction in the width of the arc prechamber space caused by them, the flow velocity of the gas is increased there, whereby the arc is more rapidly driven into the arc quenching device. To reduce the pressure or to optimize the gas flow, the so-called circulating air principle is usually used. According to this principle, a backflow of the gas takes place from the exit of the arc quenching device into the arc pre-chamber space. In the known embodiment with Vorkammerplatten the circulating air is passed between the housing broadside and the Vorkammerplatten.

Due to the omission of the antechamber plates according to the invention and their replacement by the lowered housing broadside in the region of the inner recess, the pressure equalization and the backflow of the gas from the exit of the arc quenching device to the arc pre-chamber space now take place according to the invention via the main channel.

The inventively provided gap between the arc guide rails and the edge of the inner recess allows a partial inflow of recycled gas through the gap into the arc pre-chamber space, which contributes to an accelerated extinction of the arc.

A further advantageous effects of the gap provided according to the invention lies in the fact that there is no direct contact between the arc guide rail and the edge of the inner recess or the housing broad side and thus no creepage distance can form. This increases the high-voltage strength of an installation device according to the invention.

The advantages achieved by the invention are, in particular, that the proposed measure accelerates the flow of gas from the place of origin of the arc in the direction of arc quenching device at the same time increased high voltage resistance, resulting in an accelerated extinction of the arc results. The switching behavior is improved or the switch-off behavior is stabilized. Accordingly, caused by the arc in the switching device Entry of energy and thus limited thermal effects. Damage to components of the switching device due to impermissibly high thermal load (temperature increase) is prevented. The structure of the switching device is simplified, since additional inserts, such as pre-chamber plates are dispensable. This involves cost savings (parts costs, assembly costs).

In a further advantageous embodiment, the main channel can open into a recirculating air channel, the opening of which then opens into the arc pre-chamber space. In this embodiment, furthermore, the gap, which according to the invention is formed between the edge of the inner recesses and an arc guide rail, can then advantageously be located in the area of the circulating air channel.

With respect to the circulating air channel, a further advantageous embodiment provides that it is bounded on one side by the connection space partition, and on the other side by an arc guide rail, as well as the edge of the inner recess and the gap formed between the two.

An equally advantageous embodiment of the invention in characterized in that the main channel opens into an exhaust duct, the exhaust opening opens into the terminal space, which is opposite to the arc quenching device. The exhaust air opening can also open at a front-side housing wall, so that the exhaust duct directs the gas to the outside of the switching device.

Very advantageous is an embodiment in which a branching both a recirculating air duct and an exhaust duct are connected to the main channel.

Particularly advantageous is an embodiment of an electrical installation device according to the invention, when the housing, at least in the region of the inner recesses, consists of thermoplastic. Thermoplastic material is more exposed to the prevailing temperatures in the vicinity of the arc than other materials used in switchgear housings, for example, stronger than thermoset. The resulting higher pressure is positive for a rapid quenching of the arc, on the other hand, this increased pressure is discharged through the main channel according to the invention. It

Further advantages and advantageous embodiments of the invention are characterized in the subclaims.

Fig.1

einen Schnitt durch ein Schaltgerät gemäß einer ersten Ausführungsform,

Fig. 2

einen Schnitt durch ein Schaltgerät gemäß einer zweiten Ausführungsform,

Fig. 3

einen Schnitt durch ein Schaltgerät gemäß einer dritten Ausführungsform,

Fig. 4

einen Schnitt längs der Schnittlinie AA durch ein mit Inneneinnehmungen versehenes Schaltgerät gemäß der ersten Ausführungsform,

Fig. 5

einen Schnitt durch ein Schaltgerät gemäß einer vierten Ausführungsform,

Fig. 6

einen Schnitt längs der Schnittlinie BB durch ein Schaltgerät gemäß der vierten oder ersten Ausführungsform, sowie

Fig. 7

einen Schnitt durch ein Schaltgerät gemäß einer fünften Ausführungsform.

The invention will be explained below with reference to the embodiments illustrated in the drawings. Show it:

Fig.1

a section through a switching device according to a first embodiment,

Fig. 2

a section through a switching device according to a second embodiment,

Fig. 3

a section through a switching device according to a third embodiment,

Fig. 4

a section along the section line AA through a provided with Inneneinnehmungen switching device according to the first embodiment,

Fig. 5

a section through a switching device according to a fourth embodiment,

Fig. 6

a section along the section line BB by a switching device according to the fourth or first embodiment, as well as

Fig. 7

a section through a switching device according to a fifth embodiment.

In Fig. 1 is a section along the broad side is shown by a switching device according to a first embodiment. To build such a mountable on a top hat rail electrical installation device is expressly to the above-mentioned DE 102 42 310 A1 pointed.

Such a switching device 1 has an approximately cuboid, usually composed of two halves housing of an insulating plastic material, with a front front 101, a rear front 102, a mounting side 103, two broad sides 104 and two end or narrow sides 105 a and 105 b ,

On at least one end face 105 a, 105 b, it has connection means for connection to busbars and / or connection lines (input and output connections). Furthermore, it comprises an electromagnetic release for switching off short-circuit currents, a thermal release switch for overcurrent, a switch lock, a switch knob on the front front side 101 of the housing, at least one switch contact with at least one fixed and at least one movable switch contact piece, arc guide rails for guiding an arc from an arc pre-chamber space in a current-limiting arc extinguishing device, in particular an arc extinguishing package, as well as on the attachment side 103 of the housing mounting means for attachment to a hat profile support rail on. If more than one switching contact is provided, of course, arc quenching packages including arc guide rails are correspondingly multiple.

• je ein Anschlussraum 3, 4 an jeder Stirnseite 105 b, 105 a, mit Anschlussmitteln zur Verbindung mit Stromschienen und/ oder Anschlussleitungen, wobei jeder Anschlussraum 3, 4 durch eine Anschlussraumabtrennung 28 (in der Schnittdarstellung der Figur eins nicht zu sehen) vom weiteren Innenraum des Gerätes abgetrennt ist,
• ein Raum 5 zur Aufnahme des elektromagnetischen Auslösers, des thermischen Auslösers und des Schaltschlosses,
• ein Lichtbogen-Vorkammerraum 7 mit Schaltkontakt, bestehend aus einem beweglichen Kontaktstück 8 und einem festen Kontaktstück 9,
• eine strombegrenzende Löscheinrichtung 12, insbesondere ein Lichtbogenlöschblechpaket,
• eine mit dem festen Kontaktstück 9 elektrisch verbundene Lichtbogenleitschiene 10 sowie eine mit dem beweglichen Kontaktsstück 8 elektrisch verbindbare Lichtbogenleitschiene 11, wobei diese beiden Lichtbogenleitschienen 10,11 dazu dienen, einen zwischen den Kontaktstücken 8, 9 entstandenen Lichtbogen 15 vom Entstehungsort zur Löscheinrichtung 12 zu leiten.

Within the enclosed by the housing interior are located

• depending on a terminal compartment 3, 4 on each end face 105 b, 105 a, with connection means for connection to busbars and / or connecting cables, each terminal compartment 3, 4 through a terminal compartment partition 28 (not visible in the sectional view of Figure one) from the other interior the device is disconnected,
• a space 5 for receiving the electromagnetic release, the thermal release and the switching mechanism,
• an arc Vorkammerraum 7 with switching contact, consisting of a movable contact piece 8 and a fixed contact piece 9,
• a current-limiting extinguishing device 12, in particular an arc splitter stack,
• an arc guide rail 10 which is electrically connected to the fixed contact piece 9 and an arc guide rail 11 which can be electrically connected to the movable contact piece 8, these two arc guide rails 10, 11 serving to guide an arc 15 formed between the contact pieces 8, 9 from the point of origin to the extinguishing device 12.

The two broad sides 104 of the housing are provided with inner recesses 22, which extend in the region between the switching contact with the contact pieces 8, 9, the arc quenching device 12 and in the remote in the fixed contact piece 9 arc guide rail 11 so that the formed between these inner recesses 22 Prechamber subspace 7a compared to the remaining arc Vorkammerraum 7 has a reduced width and thus a reduced cross-section.

In this way, two additional side channels 26 (see FIG. 6) result between the housing broad sides 104, the edge 24 of the inner recess 22 and the terminal compartment partition 28. These side channels 26 support the abovementioned Gas flow according to the recirculation principle of the arc quenching device back into the arc pre-chamber space or in the outside atmosphere.

FIG. 4 shows a section A-A (section line, see FIG. 1) through a switching device 1 provided with internal recesses 22, FIG. 6 shows a section B-B (sectional line see FIG. 1 or FIG. 5).

In the representation of FIG. 6, the direction of the attachment side 103 is thus directed toward the arc guide rails, the arc quenching device 12 and the prechamber space 7. The connection spaces 3 and 4, separated by the connection space partition 28, are only shown in section. In the arc quenching device 12, the peripheral contour of the arc quenching plates 12 a with their approximately V-shaped, the Vorkammerraum facing incisions, indicated. The dashed line 11a indicates the further course of the arc guide rail 11 parallel to the attachment side 103. The inner recess 22 in the region of the pre-chamber subspace 7a is formed by partially lowering the housing broadside 104. The lowered portion of the housing broadside forms two Vorkammmerraumabdeckplatten 106 which are connected by a circumferential side wall 24 with the remaining part of the housing broadside 104.

Behind the arc guide rail 11 is the limited by the inner recesses 22 pre-chamber part space 7 a. Due to the reduced cross section of this area, the flow velocity of the gas flowing toward the arc quenching device 12 is increased. This measure also leads to an accelerated extinction of the arc.

There is a gap 29 between the arc control center 11 and the side wall 24 of the inner recess 22 through this gap, gas from the recirculating air channel 13, which results between the arc guide rails 11 and the connection space partition 28, flow into the prechamber subspace 7 a. This gas flow is indicated by the arrows E in Figure 6, the gas flow in the recirculating air duct 13 is shown by the arrow top view G.

Below the running in the arc Vorkammerraum 7 portion of the arc guide rail 11, a main channel 19 is formed, which merges into a recirculating air duct 13, which is also below the arc guide respectively between the terminal compartment partition 28 and the arc guide rail 11. To this For example, gases exiting the arc quenching device 12 at elevated pressure may be conveyed into the arc prechamber space 7 where they enter via an orifice 14 near the arc origin, ie, a recirculating air gas flow from the arc quenching device 12 over the arc Main channel 19 and the recirculating air duct 13 back into the arc Vorkammerraum 7, which contributes to a flow optimization and leads to an accelerated transport of the arc in the direction of arc quenching and thus to an accelerated arc extinction.

As already mentioned, on the way to the opening 14 already in the area of the circulating air duct 13, which pass through the gap 29 into the prechamber subspace 7a.

• • Eine erste Gasströmung nach dem Umluftprinzip von der Lichtbogenlöscheinrichtung 12 über den Hauptkanal 19, die Verzweigung 16, den Umluftkanal 13 und die Öffnung 14 zurück in den Lichtbogen-Vorkammerraum 7.
• • Eine zweite Gasströmung von der Lichtbogenlöscheinrichtung 12 über den Hauptkanal 19, die Verzweigung 16, den Abluftkanal 17 und die Abluftöffnung 18, wobei eine relativ hohe Druckdifferenz zwischen dem Gasdruck in der Lichtbogenlöscheinrichtung 12 einerseits und dem Druck der Außenatmosphäre andererseits dazu herangezogen wird, eine Beschleunigung der Gasströmung (und damit der Lichtbogen-Bewegung) vom Ort der Lichtbogen-Entstehung zur Lichtbogenlöscheinrichtung zu erzielen.

FIG. 2 shows a section through a switching device 20 according to a second embodiment. In contrast to the first embodiment, the main channel 19 at the end of a branch 16, through which except the recirculating air duct 13 via an exhaust port 18 in the arc quenching device 12 opposite (and by means of the arc Vorkammerraums 7 separated therefrom) terminal space 3 opening exhaust duct 17 is realized , Alternatively, the exhaust port 18 is located on the narrow sides 105b of the connection space 3. The proposed measure results in two gas flows:

• • A first gas flow according to the circulating air principle of the arc quenching device 12 via the main channel 19, the branch 16, the recirculating air duct 13 and the opening 14 back into the arc Vorkammerraum. 7
• • A second gas flow from the arc quenching device 12 via the main channel 19, the branch 16, the exhaust duct 17 and the exhaust port 18, wherein a relatively high pressure difference between the gas pressure in the arc quenching device 12 on the one hand and the pressure of the outside atmosphere on the other hand is used to accelerate the gas flow (and thus the arc movement) from the place of arc generation to the arc quenching device to achieve.

FIG. 3 shows a section through a switching device 21 according to a third embodiment. In contrast to the first embodiment, the main channel 19 does not open into a recirculating air duct 13, but only into the exhaust duct 17, which via the exhaust port 18 opens into the terminal compartment 3. The proposed measure is a relatively high pressure difference between the gas pressure in the arc quenching device 12 on the one hand and the pressure of the outside atmosphere on the other hand used to accelerate the gas flow (and thus the arc). Movement) from the location of the arc generation to the arc quenching device 12 to achieve.

• • über Abluftkanal 17 zur Abluftöffnung 18 oder
• • über Umluftkanal 13 zur Öffnung 14 oder
• • über Verzweigung 16 in Abluftkanal 17 + Abluftöffnung 18 und Umluftkanal 13 + Öffnung 14.

FIG. 5 shows a section through a switching device 27 according to a fifth embodiment. In this embodiment, the arc guide rail 11 is adjacent to the bottom housing wall (front side), so that a main channel 25 between arc quenching device 12 and guide rail 11 is formed. The result is a gas flow from the main channel 25 in two side channels 26 between the housing wall of the broad side 23, edge 24 of the inner recess 22 and the bottom housing wall. This gas flow continues

• • via exhaust duct 17 to the exhaust port 18 or
• • via recirculating air duct 13 to the opening 14 or
• • via branching 16 in exhaust air duct 17 + exhaust air opening 18 and recirculating air duct 13 + opening 14.

It is assumed above that the main channel 19 and the recirculating air channel 13 are formed by a defined distance between the arc guide rail and the housing wall. Alternatively, the arc guide rail 11 itself may be partially formed in the form of a channel.

Figure 7 shows in the switching device 30, a variant of the embodiment, as shown in Figures 1,5 and 6. The difference from the embodiment according to FIG. 6 is that the antechamber space cover plate 106, which results from the lowered part of the housing broad side in the region of the inner recess 22, has a wave-shaped or zigzag-shaped three-dimensional surface contour. As a result, the gas flow is again positively influenced.

LIST OF REFERENCE NUMBERS

1

switchgear

2

Mounting means for mounting on a day rail

3

connection space

4

connection space

5

Room for electromagnetic release, thermal release and the switch lock

6

toggle switch

7

Arc chamber area

7a

Antechamber subspace

8th

Movable contact piece

9

solid contact piece

10

Arc guide rail, connected with a fixed contact piece

11

Arc guide rails, facing away from the fixed contact piece

12

Current limiting arc quenching device, arc splitter package

13

return air duct

14

opening

15

Electric arc

16

branch

17

exhaust duct

18

exhaust vent

19

main channel

20

switchgear

21

switchgear

22

Inneneinnehmung

24

Edge of the inner recess

25

main channel

26

side channel

27

switchgear

28

Connection compartment partition

29

gap

101

Front front

102

Rear front

103

mounting side

104

broadside

105a

narrow side

105b

narrow side

106

Vorkammerraumabdeckplatte

Claims (14)

Electrical installation device, in particular circuit breaker or motor protection switch, with a housing, with at least one switching contact with a fixed and a movable contact piece (8, 9), between which an arc (15) in an arc prechamber space (7) is formed during an elimination, which Arc via arc guide rails (10, 11) enters a current-limiting arc quenching device (12), in particular arc splitter stack, characterized in that in a partial region (7a) of the arc pre-chamber space, the two broad sides of the housing with internal recesses (22) are provided so the partial region (7a) delimited by the inner recesses has a reduced width in relation to the remaining arc prechamber space (7). Electrical installation device according to claim 1, characterized in that a main channel (19, 25) is formed, which receives from the arc quenching device (12) with increased pressure escaping gases and in the direction from the output to the input of the arc quenching device (12) continues such that a Acceleration of the gas flow from the origin of an arc (15) in the direction of arc quenching (12) results Electrical installation device according to claim 2, characterized in that between the edge (24) of the inner recess (22) and an arc guide rail (11) there is a gap (29), so that through the gap (29) through gas in the portion (7a ) of the arc pre-chamber space can flow. Installation device according to claim 3, characterized in that the partial region (7a) of the Lichtvorkammerraums extending between the switching contact with the contact pieces (8, 9), the arc quenching device (12) and the solid contact piece facing away from the arc guide rail (11). Installation device according to one of the preceding claims, characterized in that by the Inneneinnehmung (22), two additional side channels (26) between the housing wall of the broad side (23), edge (24) of the Inneinnehmung (22) and frontal housing wall result. Installation device according to one of the preceding claims, characterized in that the main channel (19) between the housing wall and an arc guide rail (11) is formed. Installation device according to one of the preceding claims, characterized in that the main channel (25) between the arc quenching device (12) and an arc guide rail (11) is formed. Installation device according to one of the preceding claims, characterized in that the main channel (19, 25) opens into a recirculating air channel (13), the opening (14) in the arc pre-chamber space (7) opens. Installation device according to claim 8, characterized in that the gap formed between the edge (24) of the inner recess (22) and an arc guide rail (11) is in the region of the circulating air channel (13). Installation device according to claim 9, characterized in that the recirculating air duct is bounded on one side by the terminal compartment separation, and on the other side by an arc guide rail (11), the edge (24) of the inner recess (22) and the gap. Installation device according to one of the preceding claims, characterized in that the main channel (19, 25) in an exhaust duct (17) opens, the exhaust port (18) opens in the arc quenching opposite terminal space (3) respectively at the frontal housing wall. Installation device according to one of the preceding claims, characterized in that via a branch (16) both a recirculation duct (13) and an exhaust duct (17) on the main channel (19, 25) are connected. Installation device according to one of the preceding claims, characterized in that in the region of the inner recesses (22) lowered housing broad sides have a three-dimensionally structured surface contour. Installation device according to one of the preceding claims, characterized in that the housing consists of thermoplastic at least in the region of the inner recesses (22).

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