Switch chamber for an electrical switch

Abstract

The invention relates to a switching chamber for an electrical switch, wherein the switching chamber comprises electrical contacts for switching a current within a switching chamber, wherein at least one outlet is arranged on the switching chamber, and wherein a swirl chamber is arranged on the outlet of the switching chamber.

Description

[0001] The invention relates to a switching chamber for an electrical switch.

[0002] Current-limiting switching devices, especially current-limiting circuit breakers, such as molded-case circuit breakers (MCCBs), are typically used in widely branched power distribution networks. It is common practice to operate a selective grading system with a minimum rated current separation between the switching devices involved. Depending on the connected loads, each branch level can be protected against overloads and short circuits with an appropriately dimensioned switching device.

[0003] For example, a switching device located closest to a load, often referred to as the load-near or downstream switching device, is designed for the lowest rated current. If a short-circuit current flows through both the load-near switching device and a switching device located above the load-near switching device in the power distribution network hierarchy, often referred to as the upstream or remote switching device, only the load-near switching device should trip. In other words, in the event of a fault (short circuit), only the switching device closest to the incident should interrupt the current flow.

[0004] The switching contact pairs of the load-side and remote switching devices create an arc when opened. The opening width of the switching contact pairs and the arc energy are higher in the load-side switching device due to the lower moment of inertia of its moving current path, including the switching contacts. This potentially single-pole opening must be followed by an all-pole disconnection of the load-side switching device. The load-side switching device must not disconnect, so as not to disconnect other loads from the power distribution network. However, the load-side switching device may provide support by briefly lifting its switching contacts, for example, by limiting the current to disconnect the load-side switching device.

[0005] Switchgear that operates in such a staggered manner in power distribution networks behaves selectively. To achieve this selectivity, it is necessary for the switchgear closest to the fault to interrupt the current paths of all switching poles faster than the higher-level switchgear.

[0006] DE 691 10 540 T2 and DE 692 17 441 T2 each disclose electrical switching arrangements in the form of circuit breakers with an insulating housing, which comprise two switching contacts per switching pole that are spring-loaded against each other in the closed position of the circuit breaker. The switching contacts can be separated by the action of electrodynamic recoil forces when the current flowing through the switching contacts exceeds a certain threshold, thus limiting the current.

[0007] The circuit breaker disclosed in the documents comprises an overload and / or short-circuit detection element for actuating a tripping mechanism that automatically trips the circuit breaker in the event of a fault. Furthermore, the circuit breaker disclosed in the documents comprises an actuating element that responds to an overpressure generated in the separation zone of said switching contacts by an arc drawn during electrodynamic recoil of the switching contacts, in order to actuate the tripping mechanism of the circuit breaker.

[0008] Further pressure triggers are also disclosed in the documents DE 10 2009 015 126 A1, DE 10 2011 077 359 A1 and DE 10 2018 211 995 B4.

[0009] The arc created when the switching contact pairs open causes the gas to ionize and a plasma to form. This plasma generates contamination, for example, from the burn-off of the switching contacts. This contamination can build up in the switching chamber of the electrical switch, as well as in the downstream pressure release, and can lead to its malfunction. Contamination of the downstream components caused by the burn-off of contact material during overload or short-circuit shutdown prevents the reliable operation of an electrical switch.

[0010] It is therefore an object of the invention to provide a switching chamber which makes it possible to prevent contamination of the subsequent or downstream assemblies.

[0011] This object is achieved according to the invention by the switching chamber according to claim 1. Alternative embodiments are specified in subclaims 2 to 12.

[0012] The switching chamber for an electrical switch according to claim 1 comprises electrical contacts for switching a current within a switching chamber, wherein at least one outlet is arranged on the switching chamber, wherein a swirl chamber is arranged on the outlet of the switching chamber.

[0013] The advantage here is that the switching chamber with swirl chamber according to the invention allows a filter function to be realized without additional filter elements. This saves components, reduces costs because fewer parts need to be assembled, ensures that contaminants are retained in a defined area, and ensures better function of the downstream contamination-reducing assemblies.

[0014] In one embodiment of the switching chamber according to the invention, the swirl chamber has a gas inlet which is fluidically connected to the outlet of the switching chamber.

[0015] In a further embodiment of the switching chamber according to the invention, the swirl chamber fulfills a filter function through a complex geometry without additional filter elements.

[0016] In a further embodiment of the switching chamber according to the invention, the swirl chamber with complex geometry has the shape of a semi-ellipsoid or a cone.

[0017] In a further embodiment of the switching chamber according to the invention, the geometry of the swirl chamber is divided into a swirl zone and lateral settling zones. The lateral settling zones serve to absorb contaminants.

[0018] In a further embodiment, the gas inlet into the swirl chamber is arranged off-center to the swirl chamber.

[0019] In a further embodiment of the switching chamber according to the invention, the outlet from the swirl chamber is arranged at the end of the swirl zone with the smallest radius.

[0020] In a further embodiment, the outlet from the swirl chamber leads directly or indirectly to a pressure trigger for detecting the triggering of the electrical switch via the pressure increase.

[0021] In a further embodiment of the switching chamber according to the invention, the swirl chamber is part of the switching chamber. The swirl chamber can be formed in the housing wall of the switching chamber. Alternatively, the swirl chamber is a separate component mounted on the switching chamber.

[0022] The above-described properties, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the description of the embodiments which are explained in more detail in connection with the figures.

[0023] Showing: Fig. 1 electrical switch with switching chamber and electrical contacts; Fig. 2A and Fig. 2B previous solution for reducing contamination at the outlet of the switching chamber; Fig. 3A and Fig. 3B previous solution for reducing contamination at the outlet of the switching chamber; Fig. 4A and Fig. 4B switching chamber according to the invention with swirl chamber in different representations; Fig. 5A and Fig. 5B different sectional planes through the switching chamber according to the invention with swirl chamber; and Fig. 6A and Fig. 6B further different sectional planes through the switching chamber according to the invention.

[0024] Fig. 1 shows an electrical switch 1000 with a switching chamber 100. The switching chamber 100 comprises electrical contacts 1010; 1020 or 1010'; 1020' for switching a current within an opening distance 1500; 1500'. In the illustration of Fig. 1 shows a double breaker with two contact pairs 1010; 1020 and 1010'; 1020' as well as two opening gaps 1500; 1500'. Likewise, the switching chamber 100 can comprise at least one pair of electrical contacts 1010; 1020 and at least one opening gap 1500.

[0025] The switching chamber 100 has an outlet 1510 so that a pressure increase from the switching chamber 100 can be fluidically transmitted through this outlet 1510 to a pressure trigger.

[0026] In Fig. 2A and Fig. 2B shows a section of a switching chamber 100, wherein an additional component 999 is provided, which provides flow guidance so that contamination cannot reach the downstream assembly directly.

[0027] Fig. 3A and Fig. 3B also show parts of the switching chamber 100 and the additional component 999. In Fig. Figure 3B shows the flow path along the additional component 999. The labyrinthine flow of the gases is intended to create deposits of contaminants. This principle needs to be improved.

[0028] In Fig. 4A shows the switching chamber 100 of an electrical switch 1000 according to the invention. At the outlet 1510 of the switching chamber 100 ( Fig. 1 and Fig. 5A), a swirl chamber 150 is arranged for this purpose. The swirl chamber 150 has a gas inlet 158, which is fluidly connected to the outlet 1510 of the switching chamber 100.

[0029] The swirl chamber 150 fulfills a filter function through its complex geometry without additional filter elements. For this purpose, the swirl chamber 150 with its complex geometry has the shape of a semi-ellipsoid or a cone.

[0030] The geometry of the swirling chamber 150 is divided into a swirling zone 151 and lateral settling zones 152. These lateral settling zones 152 serve to absorb contaminants.

[0031] Fig. 4B shows another view of the switching chamber 100 according to the invention. The gas flows from the switching chamber 100 through the gas inlet 158 ​​into the swirl chamber 150. The swirl chamber 150 has a swirl zone 151 and lateral settling zones 152. The gas inlet 158 ​​into the swirl chamber 150 is arranged off-center relative to the swirl chamber 150.

[0032] The outlet 159 from the swirl chamber 150 is arranged at the end of the swirl zone 151 with the smallest radius.

[0033] In the Fig. 5A and Fig. 5B shows the switching chamber 100 according to the invention in different sectional views. Fig. 5A shows the switching chamber 100 with the opening section 1500 and its outlet 1510 into the swirl chamber 150.

[0034] The further sectional view of the Fig. 5B shows the gas inlet 158 ​​into the swirl chamber 150, as well as the swirl zone 151 and the lateral settling zones 152. The outlet 159 from the swirl chamber 150 is arranged at the end of the swirl zone 151 with the smallest radius.

[0035] Fig. 6A and Fig. 6B show further sectional views through the switching chamber 100 according to the invention. In Fig. 6A shows the gas inlet 158, which is arranged off-center to the swirl chamber 150. Likewise, Fig. 6A shows the switching chamber 100 according to the invention with swirl chamber 150 and swirl zone 151 and lateral calming zones 152.

[0036] In Fig. 6B again shows the swirl chamber 150 with its outlet 159. At the outlet 159 from the swirl chamber 150, a pressure trigger can be arranged directly or indirectly to detect a triggering of the electrical switch 1000 via the pressure increase.

[0037] According to the representations of the Fig. 4A, Fig. 4B, Fig. 5A, Fig. 5B, Fig. 6A and Fig. 6B, the swirl chamber 150 may be part of the switching chamber 100. For example, the swirl chamber 150 may be formed in the housing wall of the switching chamber 100.

[0038] Alternatively, the swirl chamber 150 may be a separate component mounted on the switching chamber 100.

[0039] During overload and / or short-circuit shutdown, exhaust gases are generated, the exhaust gas flow of which causes contamination within the switching chamber 100. Due to the swirl chamber 150 according to the invention between the switching chamber 100 and the downstream assembly, the contamination remains in the swirl chamber 150. For example, the contamination can be deposited in the lateral settling zones 152, thereby preventing it from escaping from the swirl chamber 150 through the outlet 159.

[0040] The switching chamber 100 according to the invention fulfills a filter function through a complex geometry in a single component without additional filter elements. The complex geometry has, for example, the shape of a semi-ellipsoid or a cone. This geometry is divided into a swirl zone 151 and lateral settling zones 152. The settling zones 152 serve to absorb contaminants. The gas inlet 158 ​​into the swirl chamber 150 should be designed off-center within the swirl chamber 150. The outlet 159 from the swirl chamber 150 is at the end of the swirl zone 151 with the smallest radius.

[0041] The advantages here are the saving of components, the saving of costs due to the saving of parts and assembly costs, the retention of contamination in a defined area and a better function of the subsequent contamination-reduced assemblies. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 691 10 540 T2

[0006] DE 692 17 441 T2

[0006] DE 10 2009 015 126 A1

[0008] DE 10 2011 077 359 A1

[0008] DE 10 2018 211 995 B4

[0008]

Claims

[1] Switching chamber (100) for an electrical switch (1000), wherein the switching chamber (100) comprises electrical contacts (1010; 1020) for switching a current within an opening distance (1500), wherein at least one outlet (1510) is arranged on the switching chamber (100), characterized by that a swirl chamber (150) is arranged at the outlet (1510) of the switching chamber (100). [2] Switching chamber (100) according to claim 1, wherein the swirl chamber (150) has a gas inlet (158) which is fluidically connected to the outlet (1510) of the switching chamber (100). [3] Switching chamber (100) according to claim 1 or 2, wherein the swirl chamber (150) fulfills a filter function through a complex geometry without additional filter elements. [4] Switching chamber (100) according to claim 1, 2 or 3, wherein the swirl chamber (150) with complex geometry has the shape of a semi-ellipsoid or a cone. [5] Switching chamber (100) according to one of the preceding claims, wherein the geometry of the swirl chamber (150) is divided into a swirl zone (151) and lateral calming zones (152). [6] Switching chamber (100) according to claim 5, wherein the calming zones (152) serve to absorb contamination. [7] Switching chamber (100) according to one of the preceding claims, wherein the gas inlet (158) into the swirl chamber (150) is arranged off-center to the swirl chamber (150). [8] Switching chamber (100) according to one of the preceding claims, wherein the outlet (159) from the swirl chamber (150) is arranged at the end of the swirl zone (151) with the smallest radius. [9] Switching chamber (100) according to one of the preceding claims, wherein the outlet (159) from the swirl chamber (150) leads directly or indirectly to a pressure trigger for detecting a triggering of the electrical switch (1000) via the pressure increase. [10] Switching chamber (100) according to one of the preceding claims, wherein the swirl chamber (150) is part of the switching chamber (100). [11] Switching chamber (100) according to claim 10, wherein the swirl chamber (150) is formed in the housing wall of the switching chamber (100). [12] Switching chamber (100) according to one of claims 1 to 9, wherein the swirl chamber (150) is a separate component mounted on the switching chamber (100).

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