Electrical switching device for low-voltage and medium-voltage applications

Abstract

The present disclosure relates to an electrical switching device for low-voltage or medium-voltage applications, which comprises a cabinet, a draw-out switchgear, and a shutter assembly movable along a reference movement plane. The shutter assembly comprises a first shutter panel and a second shutter panel which are at least partially made of a conductive material and are spaced apart from each other. The shutter assembly comprises one or more elongated connecting elements which mechanically connect the first shutter panel and the second shutter panel by means of rigid linkages such that the first shutter panel and the second shutter panel move together along the reference movement plane while maintaining their relative positions. Each connecting element is at least partially made of a conductive material and has an elongated blunt shape including a rounded edge.

Description

Technical Field

[0001] The present invention relates to an electrical switching device for low - voltage or medium - voltage applications.

[0002] More specifically, the present invention relates to an electrical switching device that includes draw - out switchgear and has an improved shutter assembly for isolating the live parts of the switching device. Background Art

[0003] Electrical switching devices are well - known in power transmission and distribution networks.

[0004] Known electrical switching devices generally include a metal cabinet, the interior of which is divided into several compartments or units for accommodating various devices and equipment.

[0005] In many applications, the electrical switching device includes draw - out type switchgear (such as a circuit breaker), that is: switchgear capable of reversibly moving between a first position (insertion position) and a second position (withdrawal position), in the first position, the switchgear is electrically connected to the disconnecting contacts of the switching device, and in the second position, the switchgear is electrically disconnected from the disconnecting contacts.

[0006] The above - mentioned type of electrical switching device generally includes a shutter assembly to isolate the live parts, especially to isolate the disconnecting contacts electrically connected to the line conductors.

[0007] The shutter assembly generally includes one or more shutter panels that can reversibly move between a non - protected position and a protected position corresponding to the movement of the switchgear. In the non - protected position, the disconnecting contacts of the switching device can be electrically coupled to the switchgear, and in the protected position, the shutter panels shield the disconnecting contacts of the switching device and make the disconnecting contacts inaccessible to the switchgear and the operator.

[0008] Even if they generally operate satisfactorily, the currently available electrical switching devices of the above - mentioned type still have some aspects that can be further improved.

[0009] As is well - known, due to the need to ensure an appropriate dielectric distance between the live parts and the rest of the internal components, these systems have relatively large sizes.

[0010] Once it is necessary to compress their overall size for some reason (such as due to the existence of a relatively small installation space), the currently available electrical switching devices will provide poor performance in terms of dielectric insulation.

[0011] Therefore, discharges or arcs often occur, and the discharges or arcs may cause corresponding damage to the internal components of the switching device and may be very dangerous for the operator.

[0012] To mitigate these problems, some prior art electrical switchgear has some internal components (e.g., shutter panels), especially those internal components that are mostly exposed to live parts, which are covered with a special electrical insulating paint.

[0013] Experience has shown that electrical insulating paints can ensure a satisfactory level of dielectric insulation only when the coating of the components is consistent and uniform. Therefore, the spraying process of said components at the industrial level is quite difficult and expensive. Summary of the Invention

[0014] The main object of the present invention is to provide an electrical switchgear, especially an electrical switchgear including draw-out switchgear, which enables the electrical switchgear to overcome or mitigate the above problems of the known art.

[0015] In the context of this object, the object of the present invention is to provide an electrical switchgear in which, even when the internal dielectric distance is relatively small, it can prevent or greatly reduce the formation of discharges or arcs.

[0016] Another object of the present invention is to provide an electrical switchgear that can be easily designed to have an overall compact size while not compromising the dielectric insulation level between the live parts and other internal components of the switchgear.

[0017] Yet another object of the present invention is to provide an electrical switchgear that is easy to manufacture at the industrial level, has a competitive cost, and has an installation similar to the prior art.

[0018] According to the present invention, this object and these objects and other objects are achieved by the electrical switchgear disclosed herein, and the object and these objects and other objects will become apparent from the following description and the drawings.

[0019] Generally speaking, the electrical switchgear according to the present invention includes:

[0020] - A cabinet having a plurality of walls defining an internal volume. The cabinet includes adjacent first and second sections, and the first and second sections are preferably separated by an inner wall, and the inner wall includes an opening defining a passage between the first and second sections.

[0021] - First and second disconnecting contacts intended to be electrically connected to corresponding conductors of an electric wire. The first and second disconnecting contacts are accommodated in the first section of the cabinet;

[0022] - Drawer-type switchgear that can move reversibly along a reference movement direction. The switchgear includes third and fourth disconnecting contacts that can be electrically connected or disconnected from the first and second disconnecting contacts respectively during the corresponding movement of the switchgear. The switchgear is housed in the second section of the cabinet;

[0023] - A shutter assembly that is movable along a reference movement plane perpendicular to the reference movement direction of the switchgear.

[0024] The shutter assembly includes a first shutter panel and a second shutter panel, which are at least partially made of a conductive material and are spaced apart from each other by a separation gap.

[0025] The shutter assembly includes one or more elongated connecting elements that mechanically connect the first and second shutter panels through rigid connectors. In this way, the first and second shutter panels can move together along the reference movement plane while maintaining their relative positions.

[0026] Each connecting element is at least partially made of a conductive material and has an elongated blunt shape including a circular edge.

[0027] Preferably, the shutter assembly includes a pair of connecting elements that are arranged parallel to each other along a direction parallel to the reference movement plane and perpendicular to the bottom wall of the cabinet.

[0028] According to an aspect of the present invention, each connecting element includes opposite first and second ends that are mechanically connected to the first and second shutter panels respectively, and an intermediate portion that defines the separation gap between the first and second shutter panels.

[0029] Preferably, the first and second ends of each connecting element have a circular shape.

[0030] Preferably, the intermediate portion of each connecting element has an elongated circular shape.

[0031] Preferably, the intermediate portion of each connecting element is at least partially covered by an electrically insulating material layer.

[0032] Preferably, the first shutter panel has opposite first and second edges, where the first edge partially defines the separation gap between the first shutter panel and the second shutter panel.

[0033] Preferably, the first edge of the first shutter panel has a circular shape.

[0034] Preferably, the first edge of the first shutter panel is covered by an electrically insulating material layer.

[0035] Preferably, the second shutter panel has opposite third and fourth edges, wherein the third edge partially defines a separation gap between the first shutter panel and the second shutter panel.

[0036] Preferably, the third edge of the second shutter panel has a circular shape.

[0037] Preferably, the third edge of the second shutter panel is covered by an electrically insulating material layer.

[0038] Preferably, the fourth edge of the second shutter panel is covered by an electrically insulating material layer.

[0039] According to one aspect of the invention, the shutter assembly is reversibly movable along the reference movement plane between the following positions:

[0040] - A non-protected position, in which the first shutter panel is not interposed between the first breaking contact and the third breaking contact, and the second shutter panel is not interposed between the second breaking contact and the fourth breaking contact; and

[0041] - A protected position, in which the first shutter panel is interposed between the first breaking contact and the third breaking contact, and the second shutter panel is interposed between the second breaking contact and the fourth breaking contact.

[0042] According to one aspect of the invention, the switchgear is reversibly movable perpendicular to the reference movement plane of the shutter assembly and along the reference movement direction between the following positions:

[0043] - An insertion position, in which the third breaking contact is coupled to the first breaking contact, and the fourth breaking contact is coupled to the second breaking contact; and

[0044] - A withdrawal position, in which the third breaking contact is decoupled from the first breaking contact, and the fourth breaking contact is decoupled from the second breaking contact.

[0045] Preferably, the electrical switching device according to the invention comprises a mechanical device including a plurality of transmission rods that mechanically connect the switchgear to the shutter assembly.

[0046] Conveniently, the movement of the switchgear from the insertion position to the withdrawal position causes the shutter assembly to move from the non-protected position to the protected position.

[0047] Conveniently, the movement of the switching device from the withdrawn position to the inserted position causes the shutter assembly to move from the protected position to the unprotected position. Description of the Drawings

[0048] Other features and advantages of the present invention will become apparent from the description of the preferred but non-exclusive embodiments of the shutter device according to the present disclosure, for which non-limiting examples are provided in the drawings, in which:

[0049] — Figure 1 Schematically shows a switching device according to the present invention in a possible operating state;

[0050] — Figure 2 Schematically shows a switching device according to the present invention in another possible operating state;

[0051] — Figure 3 —5 schematically shows some views of the components of the shutter assembly in a switching device according to the present invention. Detailed Description

[0052] Referring to the above drawings, the present invention relates to an electrical switching device 1 for low-voltage or medium-voltage applications.

[0053] For the purposes of the present invention, the term "low voltage" (LV) relates to operating voltages below 1 kV AC and 1.5 kV DC, while the term "medium voltage" (MV) relates to operating voltages above 1 kV up to several tens of kV at most, such as operating voltages of 70 kV AC and 100 kV DC.

[0054] The switching device 1 includes a cabinet 2, which includes a plurality of walls 21, 22, 23, 24, 25 defining an internal volume.

[0055] Referring to the normal installation position, the cabinet 2 includes a horizontal base wall 21, a horizontal top wall 22 in a relative position with respect to the base wall 21, and a plurality of vertical walls ( Figure 1 —2) arranged vertically with respect to the base wall 21.

[0056] These vertical walls include: a front wall 23 at which an operator can access the internal volume of the cabinet; a rear wall 24 in a relative position with respect to the front wall 23; and a pair of opposite side walls 25 (partially shown in Figure 1 —2), the pair of side walls 25 being perpendicular to the walls 21, 22, 23, 24.

[0057] Typically, the cabinet 2 includes a first section 2A and a second section 2B adjacent to each other in a distal position and a proximal position, respectively, with respect to the front wall 23.

[0058] The first section 2A of the cabinet 2 houses the live parts of the switching device 1, namely, the main electrical connectors (e.g., busbars, cables, bushings, and disconnecting contacts) and the appropriate conductors of the electric wires.

[0059] In addition, the first section 2A of the cabinet 2 can conveniently house other devices (not shown), such as earthing devices (e.g., disconnectors).

[0060] The first section 2A of the cabinet 2 is conveniently designed to house switchgear (e.g., circuit breakers), auxiliary electrical connectors, and other auxiliary devices.

[0061] Each section 2A, 2B of the cabinet 2 can in turn be divided into different compartments or units to ensure proper isolation of the internal components of the switching device.

[0062] The cabinet 2 conveniently includes an inner wall 27 that separates the first section 2A and the second section 2B.

[0063] The inner wall 27 is arranged perpendicular to the base wall 21 and the side walls 25 of the cabinet 25. Referring to the normal installation position of the cabinet 2, the inner wall 27 extends vertically from the base wall 21 and is parallel to the front wall 23.

[0064] Conveniently, the inner wall 27 includes a plurality of appropriately arranged partition portions 29, each partition portion forming a physical barrier between the sections 2A, 2B of the cabinet 2.

[0065] However, the inner wall 27 includes an opening 28 that forms a passage between the sections 2A, 2B of the cabinet 2 ( Figure 1 ).

[0066] Generally, the cabinet 2 can be arranged according to known types of solutions. Therefore, for the sake of brevity, it will not be described in further detail hereinafter.

[0067] The electrical switching device 1 includes one or more first disconnecting contacts 31 housed in the first section 2A of the cabinet.

[0068] The first disconnecting contact 31 is a fixed electrical contact for electrical connection to the corresponding conductor of the electric wire, which is in turn electrically connected to the power supply.

[0069] For this purpose, each first electrical contact 31 is mechanically and electrically coupled to a corresponding first bushing 310, which is in turn electrically connected to the line conductor.

[0070] Preferably, the first disconnecting contact 31 (which can also be referred to as the "upper fixed disconnecting contact" with reference to the normal installation position of the cabinet) is arranged in a distal position relative to the base wall 21.

[0071] The electrical switching device 1 includes one or more second disconnecting contacts 32 housed in the first section 2A of the cabinet.

[0072] The second breaking contact 32 is a fixed electrical contact for making electrical connection with the corresponding conductor of an electric wire, which is in turn electrically connected to an electrical load.

[0073] To this end, each second electrical contact 32 is mechanically and electrically coupled to a corresponding second sleeve 320, which is in turn electrically connected to a line conductor.

[0074] Preferably, the second breaking contact 32 (which may also be referred to as the "lower fixed breaking contact" with reference to the normal installation position of the cabinet) is conveniently arranged in a proximal position relative to the base wall 21.

[0075] In Figure 1 and Figure 2 the illustrated embodiment, the switching device 1 is of the three-phase type and thus it includes three first breaking contacts 31 and three second breaking contacts 32. However, according to other embodiments of the present invention, the switching device 1 may include a different number of breaking contacts 31, 32.

[0076] Generally, the breaking contacts 31, 32 can be arranged according to known types of solutions. Therefore, in the following, for the sake of brevity, they will not be described in detail.

[0077] The electrical switching device 1 includes a draw-out switchgear 4 housed in the second section 2B of the cabinet 2.

[0078] The switchgear 4 preferably includes a switch unit 41 mounted on appropriate rails 42, which are capable of sliding along an appropriate sliding plane parallel to the base wall 21 of the cabinet 2.

[0079] The switchgear 4 can thus be reversibly moved along a first reference direction D, which is conveniently parallel to the base wall 21 and perpendicular to the front wall 23 and the inner wall 27 of the cabinet 2 ( Figure 1 ).

[0080] The switchgear 4 includes one or more third breaking contacts 43, each of which is electrically connected to a corresponding electrode of the switch unit 41.

[0081] When the switchgear moves correspondingly, the third breaking contacts 43 can be electrically coupled to or disconnected from the first breaking contacts 31 of the switching device.

[0082] Preferably, the third breaking contacts 43 (which may also be referred to as the "upper movable breaking contacts" with reference to the normal installation position of the cabinet) are in a distal position relative to the base wall 21.

[0083] The switchgear 4 includes one or more fourth breaking contacts 44, each of which is electrically connected to a corresponding electrode of the switch unit 41.

[0084] When the switching device moves correspondingly, the fourth breaking contact 44 can be electrically connected to or disconnected from the second breaking contact 32 of the switching device.

[0085] Preferably, the fourth breaking contact 44 (which can also be referred to as the "lower movable breaking contact" with reference to the normal installation position of the cabinet 2) is in a proximal position relative to the base wall 21.

[0086] As described above, when the switching device moves appropriately, the breaking contacts 43, 44 of the switching device can be connected to or disconnected from the breaking contacts 31, 32 of the switching device.

[0087] In particular, the switching device 4 can move reversibly along the reference movement direction D between the following positions:

[0088] - Insertion position A1 ( Figure 1 ), in which the third breaking contact 43 is connected to the first breaking contact 31, and the fourth breaking contact 44 is connected to the second breaking contact 32; and

[0089] - Withdrawal position A2 ( Figure 2 ), in which the third breaking contact 43 is disconnected from the first breaking contact 31, and the fourth breaking contact 44 is disconnected from the second breaking contact 32.

[0090] When the switching device is in the insertion position A1, for each electrical phase, current can flow along the conduction path including the first breaking contact 31, the third breaking contact 43, the electrode of the switching unit 41, the fourth breaking contact 44, and the second breaking contact 32.

[0091] When the switching device is in the withdrawal position A2, the breaking contacts 43, 44 are separated from the breaking contacts 31, 32, and no current can flow along the electrodes of the switching device. Therefore, the electrical continuity between the first and second breaking contacts 31, 32 of the switching device is interrupted.

[0092] In order to connect to or disconnect from the breaking contacts 31 and 32, the breaking contacts 43, 44 conveniently pass through the opening 28 in the inner wall 27 of the cabinet.

[0093] In Figure 1 and Figure 2 In the illustrated embodiment, the switching device 4 is of the three-phase type, so it includes three third breaking contacts 43 and three fourth breaking contacts 44. However, according to other embodiments of the present invention, the switching device 4 can include different numbers of breaking contacts 43, 44.

[0094] Preferably, the switching device 4 is a circuit breaker.

[0095] However, according to some embodiments of the present invention, it can be of a different type, for example, a contactor.

[0096] Generally, the switching device 4 can be arranged according to known types of solutions. Therefore, for the sake of brevity, it will not be described in further detail hereinafter.

[0097] According to the present invention, the switching device 1 includes a shutter assembly 5.

[0098] The basic function of the shutter assembly 5 is to provide a physical barrier at the opening 28 of the inner wall 27, between the break contacts 31, 32 of the switching device and the break contacts of the switching equipment, especially when the switching equipment is in the withdrawn position A2.

[0099] The shutter assembly 5 is operatively associated with the inner wall 27 of the cabinet 2 in a manner that it can move along a reference movement plane P defined by the inner wall.

[0100] Conveniently, the reference movement plane P is perpendicular to the reference movement direction D of the switching equipment 4, and thus is a vertical plane perpendicular to the base wall 21 (referring to the normal installation position of the cabinet 2).

[0101] Therefore, the shutter assembly 5 can move along a second reference movement direction V, which is parallel to the reference movement plane P and perpendicular to the base wall 21 of the cabinet (so the normal installation position of the cabinet 2 is vertical).

[0102] According to an important aspect of the present invention, the shutter assembly 5 is arranged to have a reduced size relative to the corresponding solutions of the prior art.

[0103] According to the present invention, the shutter assembly 5 includes a first shutter panel 51 and a second shutter panel 52, and the first shutter panel 51 and the second shutter panel 52 are at least partially made of a conductive material, such as aluminum.

[0104] Preferably, each shutter panel 51, 52 is formed by a plate of conductive material arranged along the reference movement plane P.

[0105] In the embodiment shown in the cited drawings, conveniently, the shutter panels 51, 52 have a rectangular shape. However, according to other embodiments of the present invention, they can have different shapes, such as square or polygonal.

[0106] According to the present invention, the first shutter panel 51 and the second shutter panel 52 are arranged along the same reference movement plane P (parallel to each other), and they are spaced apart from each other by a separation gap 55.

[0107] Preferably, the first shutter panel 51 is arranged at a distal position relative to the base wall 21, i.e., at an upper position along the reference movement plane P (referring to the normal installation position of the cabinet).

[0108] Preferably, the first shutter panel 51 includes opposite first and second edges 511, 512, and the opposite first and second edges 511, 512 extend along a direction parallel to the reference movement plane P and parallel to the base wall 21 of the cabinet 2, i.e., horizontally along the reference movement plane P (referring to the normal installation position of the cabinet).

[0109] Preferably, the first edge 511 of the first shutter panel 51 (upward) defines a separation gap 55 between the first shutter panel 51 and the second shutter panel 52.

[0110] Preferably, the second edge 512 of the first shutter panel 51 extends parallel to the first edge 511 in a distal position relative to the separation gap 55 and the base wall 21.

[0111] Preferably, the second shutter panel 52 is arranged at a proximal position relative to the base wall 21, i.e., at a lower position along the reference movement plane P (referring to the normal installation position of the cabinet 2).

[0112] Preferably, the second shutter panel 52 includes opposite third and fourth edges 523, 524, and the opposite third and fourth edges 523, 524 extend along a direction parallel to the reference movement plane P and parallel to the base wall 21 of the cabinet 2, i.e., horizontally along the reference movement plane P (referring to the normal installation position of the cabinet 2).

[0113] Preferably, the third edge 523 of the second shutter panel 52 (downward) partially defines the separation gap 55 between the first shutter panel 51 and the second shutter panel 52.

[0114] Preferably, the fourth edge 524 of the second shutter panel 52 extends parallel to the third edge 523 in a distal position relative to the separation gap 55 and a proximal position relative to the base wall 21.

[0115] According to the present invention, the shutter assembly 5 includes one or more elongated connecting elements 53, which mechanically connect the first and second shutter panels 51, 52 through rigid connectors.

[0116] In this way, the first and second shutter panels 51, 52 can move together (as an integral part) along the reference movement plane P, and they can maintain their relative positions unchanged during their movement.

[0117] This solution allows reducing the overall size of the cabinet 2, especially in the direction perpendicular to the front wall 23.

[0118] Preferably, the shutter assembly 5 includes a pair of connecting elements 53 which are arranged parallel to each other along a direction parallel to the reference movement plane P and perpendicular to the base wall 21 of the cabinet 2.

[0119] According to another important aspect of the present invention, each connecting element 53 is at least partially made of a conductive material (such as Al or Cu) and has an elongated blunt shape including a circular edge.

[0120] Due to this arrangement, during the operation of the electrical switching device, the intensity of the electric field present at the opening 28 of the inner wall 27 is reduced because the connecting element 53 smoothes the electric field lines and increases the mutual distance between these electric field lines.

[0121] In addition, the arrangement of the conductive connecting elements 53 connected to both shutter panels 51, 52 ensures the electrical continuity between the shutter panels, which allows these components to be grounded through the wall of the cabinet 2 without the need to use dedicated grounding leads or wiring.

[0122] Preferably, each connecting element 53 is formed by a shaped strip of conductive material and includes opposite first end 531 and second end 532 and an intermediate portion 533.

[0123] The first end 531 and the second end 532 of each connecting element 53 are mechanically connected to the first shutter panel 51 and the second shutter panel 52 respectively.

[0124] The intermediate portion 533 of each connecting element 53 thus conveniently defines a separation gap 55 between the first shutter panel 51 and the second shutter panel 52.

[0125] Preferably, the first end 531 and the second end 532 of each connecting element 53 formed by the shaped strip have a circular shape.

[0126] Preferably, the first end 531 and the second end 532 include coupling surfaces 531A, 532A which are respectively coupled to the shutter panels 51, 52.

[0127] Preferably, at each coupling surface 531A, 532A, appropriate holes 531B, 532B for inserting corresponding coupling screws are conveniently arranged.

[0128] Preferably, each coupling surface 531A, 532A is flat so as to rest completely on the corresponding coupling surfaces (not shown) of the shutter panels 51, 52. In this way, when they are mechanically coupled to the shutter panels 51, 52, the formed first end and second end 531, 532 protrude from these shutter panels in a circular shape.

[0129] Preferably, the middle part 533 of each connecting element 53 has an elongated circular shape, such as a cylindrical shape.

[0130] Preferably, the middle part 533 of each connecting element 53 is covered by an electrically insulating material layer 534.

[0131] This solution is very advantageous because it significantly improves the dielectric insulation of the connecting element 53, especially in the area where it is more directly exposed to the energized parts of the switching device through the opening 28 in the inner wall 27.

[0132] Preferably, the electrically insulating material layer 534 is co-molded with the corresponding connecting element 53. However, other solutions can also be adopted to cover the middle part 533 with the corresponding electrically insulating material layer.

[0133] According to another aspect of the present invention, the shutter panels 51, 52 are also arranged in such a way as to reduce the electric field strength present at the opening 28 in the inner wall 27 during the operation of the electrical switching device.

[0134] Preferably, the first shutter panel 51 has a first edge 511, which defines a separation gap 55 between the shutter panels and is provided with a circular shape.

[0135] Preferably, the second shutter panel 52 has a third edge 523, which defines the separation gap 55 between the shutter panels at the lower side and is provided with a circular shape.

[0136] Preferably, the first edge 511 of the first shutter panel 51 is covered by an electrically insulating material layer 511A.

[0137] Preferably, the third edge 523 of the second shutter panel 52 is covered by an electrically insulating material layer 523A.

[0138] Preferably, the fourth edge 524 of the second shutter panel 52 is covered by an electrically insulating material layer 524A, and the fourth edge 524 is located at a position opposite to the third edge 523.

[0139] All these arrangements significantly improve the dielectric insulation performance of the shutter panels 51 and 52, especially in the area where they are more directly exposed to the energized parts of the switching device through the opening 28 in the inner wall 27.

[0140] Preferably, the electrically insulating material layers 511A, 523A, 524A can be formed by profiles of electrically insulating material, and the profiles of electrically insulating material are mechanically coupled to the corresponding edges 511, 523, 524 of the first and second shutter panels 51, 52 by suitable connecting screws.

[0141] However, other solutions can also be adopted to cover the edges 511, 523, 524 of the first and second shutter panels 51, 52 with corresponding electrically insulating material layers.

[0142] As described above, the shutter assembly 5 (including the first and second shutter panels 51, 52 mechanically connected as an integral part by one or more connecting elements 53) can move along the reference movement plane P defined by the inner wall 27 and along the second reference movement direction V.

[0143] Conveniently, the shutter assembly 5 can move reversibly along the reference movement plane P between the following positions:

[0144] - The non-protection position A3, in which at the opening 28 of the inner wall 27 ( Figure 1 ), the first shutter panel 51 is not inserted between the first breaking contact 31 and the third breaking contact 43, and the second shutter panel 52 is not inserted between the second breaking contact 32 and the fourth breaking contact 44; and

[0145] - The protection position A4, in which at the opening 28 of the inner wall 27 ( Figure 2 ), the first shutter panel 51 is inserted between the first breaking contact 31 and the third breaking contact 43, and the second shutter panel 52 is inserted between the second breaking contact 32 and the fourth breaking contact 44.

[0146] Preferably, the electrical switch device 1 includes an actuating mechanism 6, which includes a plurality of transmission rods that mechanically connect the switching device 4 (in particular the movable wheel carrier 42) to the shutter assembly 5 ( Figure 3 ).

[0147] The actuating mechanism 6 is substantially oriented to actuate the shutter assembly 5 in coordination with the movement of the switching device 4.

[0148] In particular, the actuating mechanism 6 is designed such that:

[0149] - The movement of the switching device 4 from the insertion position A1 to the extraction position A2 causes the shutter assembly 5 to move from the non-protection position A3 to the protection position A4;

[0150] - The movement of the switching device 4 from the extraction position A2 to the insertion position A1 causes the shutter assembly 5 to move from the protection position A4 to the non-protection position A3.

[0151] Generally, the actuating mechanism 6 can be arranged according to known types of solutions. Therefore, for the sake of brevity, it will not be further described in detail hereinafter.

[0152] In practice, it has been found that the electrical switch device according to the present invention provides relevant advantages over corresponding solutions of the prior art.

[0153] Due to the presence of an arrangement that can reduce the electric field strength and improve the dielectric insulation properties at the opening 28 of the inner wall 27, even if the internal dielectric distance is relatively small, the formation of discharges or arcs can be prevented or greatly reduced.

[0154] This allows the withdrawal operation of the switching device to be carried out in a very safe manner and greatly improves the safety level for an operator who may be close to the part 2B of the cabinet 2 (for example, during maintenance operations).

[0155] Furthermore, the electrical switching device can be easily designed to have an overall compact size while not compromising the dielectric insulation level between the live parts and other internal components.

[0156] The electrical switching device according to the invention can be easily implemented at an industrial level. Thus, it can be easily manufactured at a competitive cost using similar equipment of the prior art.

Claims

1. An electrical switching device (1) for low-voltage or medium-voltage applications, characterized in that, the electrical switching device comprises: a cabinet (2) having a plurality of walls (21, 22, 23, 24, 25) defining an internal volume, the cabinet comprising an adjacent first section (2A) and a second section (2B); a first breaking contact (31) and a second breaking contact (32) capable of being electrically connected to corresponding conductors of an electric wire, the first breaking contact and the second breaking contact being received in the first section (2A) of the cabinet; a draw-out type switching device (4) capable of reversibly moving along a reference movement direction (D), the switching device comprising a third breaking contact (43) and a fourth breaking contact (44), and when the switching device performs a corresponding movement, the third breaking contact and the fourth breaking contact can be electrically coupled or decoupled from the first breaking contact (31) and the second breaking contact (32) respectively, the switching device being received in the second section (2B) of the cabinet; a shutter assembly (5) capable of moving along a reference movement plane (P) perpendicular to the reference movement direction (D) of the switching device, wherein the shutter assembly (5) comprises a first shutter panel (51) and a second shutter panel (52), the first shutter panel and the second shutter panel being at least partially made of a conductive material and spaced apart from each other, and wherein the shutter assembly (5) comprises one or more elongated connecting elements (53), the connecting elements mechanically connecting the first shutter panel and the second shutter panel by means of a rigid link such that the first shutter panel and the second shutter panel move together along the reference movement plane (P) while maintaining their relative positions, wherein each connecting element (53) is at least partially made of a conductive material and has an elongated blunt shape with a rounded edge, wherein each connecting element (53) comprises: opposite first ends (531) and second ends (532) mechanically connected to the first shutter panel (51) and the second shutter panel (52) respectively; and an intermediate portion (533), the intermediate portion defining a separation gap (55) between the first shutter panel (51) and the second shutter panel (52), the intermediate portion of each connecting element having an elongated circular shape, wherein the first ends (531) and the second ends (532) of each connecting element (53) have a circular shape, and the first ends and the second ends of each connecting element comprise flat coupling surfaces (531A, 532A) for coupling to corresponding coupling surfaces of the first shutter panel (51) and the second shutter panel (52), and wherein the intermediate portion (533) of each connecting element (53) is at least partially covered by a first electrically insulating material layer (534) co-molded with the connecting element (53).

2. The electrical switching device according to claim 1, characterized in that, The shutter assembly (5) includes a pair of connecting elements (53), and the pair of connecting elements are arranged parallel to each other in a direction parallel to the reference movement plane (P) and perpendicular to the base wall (21) of the cabinet.

3. The electrical switching device according to claim 1, characterized in that the first shutter panel (51) has opposite first and second edges (511, 512), wherein the first edge (511) partially defines a separation gap (55) between the first shutter panel (51) and the second shutter panel (52), wherein the first edge (511) has a circular shape.

4. The electrical switching device according to claim 3, characterized in that the first edge (511) of the first shutter panel (51) is covered by a second electrically insulating material layer (511A).

5. The electrical switching device according to claim 1, characterized in that the second shutter panel (52) has opposite third and fourth edges (523, 524), wherein the third edge (523) partially defines a separation gap (55) between the first shutter panel (51) and the second shutter panel (52), wherein the third edge (523) has a circular shape.

6. The electrical switching device according to claim 5, characterized in that the third edge (523) of the second shutter panel (52) is covered by a third electrically insulating material layer (523A).

7. The electrical switching device according to claim 5 or 6, characterized in that the fourth edge (524) of the second shutter panel (52) is covered by a fourth electrically insulating material layer (524A).

8. The electrical switching device according to claim 1, characterized in that the shutter assembly (5) is capable of reversibly moving along the reference movement plane (P) between a non-protected position (A3) and a protected position (A4). In the non-protected position, the first shutter panel (51) is not inserted between the first breaking contact (31) and the third breaking contact (43), and the second shutter panel (52) is not inserted between the second breaking contact (32) and the fourth breaking contact (44). In the protected position, the first shutter panel (51) is inserted between the first breaking contact (31) and the third breaking contact (43), and the second shutter panel (52) is inserted between the second breaking contact (32) and the fourth breaking contact (44).

9. The electrical switching device according to claim 8, characterized in that The switching device (4) is reversibly movable between an insertion position (A1) and a withdrawal position (A2) along the reference movement direction (D). In the insertion position, the third breaking contact (43) is coupled to the first breaking contact (31), and the fourth breaking contact (44) is coupled to the second breaking contact (32). In the withdrawal position, the third breaking contact (43) is decoupled from the first breaking contact (31), and the fourth breaking contact (44) is decoupled from the second breaking contact (32).

10. The electrical switching device according to claim 9, characterized in that the electrical switching device comprises an actuating mechanism (6), the actuating mechanism comprising a plurality of transmission rods mechanically connecting the switching device (4) to the shutter assembly (5), wherein movement of the switching device from the insertion position (A1) to the withdrawal position (A2) causes the shutter assembly (5) to move from the non-protected position (A3) to the protected position (A4); and wherein movement of the switching device from the withdrawal position (A2) to the insertion position (A1) causes the shutter assembly (5) to move from the protected position (A4) to the non-protected position (A3).

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