Electrical switchgear for low and medium voltage applications

Abstract

An electrical switchgear for low-voltage or medium-voltage applications includes a cabinet, a withdrawable switching device, and a shield assembly movable along a reference plane of motion. The electrical switchgear includes one or more power connection blocks, each including line contacts, disconnect contacts, and an insulating housing. According to the invention, at least the line contacts and the insulating housing form an integral structure.

Description

TECHNICAL FIELD

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

[0002] More particularly, the present invention relates to an electrical switching device comprising an extractable switching device and having an improved power connection block for electrically connecting with the conductors of an electric line. BACKGROUND

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

[0004] Known electrical switching devices generally comprise a metal cabinet internally divided into several compartments or units which house various devices and equipment.

[0005] In many applications, the electrical switching device comprises a switching device of the extractable type (for example a circuit breaker), i.e. a switching device which can be reversibly moved between a first position (inserted position) in which it is electrically connected with the opening contacts of the switching device and a second position (extracted position) in which it is electrically disconnected from said opening contacts.

[0006] Typically, the electrical switching device of the extractable type also comprises a shutter assembly to isolate the live parts and the power supply parts, in particular the opening contacts electrically connected with the line conductors.

[0007] Even if they operate overall quite satisfactorily, the currently available electrical switching devices of the above type still have some aspects which can be further improved.

[0008] As is known, these systems have a relatively large size due to the need to ensure the proper dielectric distance between the live parts and the remaining internal components.

[0009] Once it is necessary to compress its overall size for some reason (for example, due to the presence of smaller installation spaces), the currently available electrical switching devices are already subjected to a poor performance in terms of dielectric insulation.

[0010] Therefore, discharges or arcs often occur at the live parts. These phenomena can cause relevant damage to the internal components of the switching device and can pose a great danger to the operators. SUMMARY

[0011] The main purpose of the present invention is to provide an electrical switching device, in particular of the type comprising an extractable switching device, which makes it possible to overcome or mitigate the above problems of the known art.

[0012] In the context of this aim, the object of the present application is to provide an electrical switching device in which the formation of discharges or arcs can be prevented or greatly reduced, even if the internal dielectric distance is relatively small.

[0013] Another object of the present application is to provide an electrical switching device which can be easily designed with overall compact dimensions, without compromising the level of dielectric insulation between the live parts and other internal components of the switching device.

[0014] Still another object of the present application is to provide an electrical switching device which is easy to manufacture at an industrial level, at a cost which can compete with similar devices of the prior art.

[0015] According to the present application, this and these objects and others, which will become apparent hereafter, are achieved by means of an electrical switching device according to claim 1 and the relative dependent claims set out below, according to the following description and the attached drawings.

[0016] In a general definition, the electrical switching device according to the present application comprises:

[0017] - a cabinet having a plurality of walls which define an internal volume;

[0018] - one or more first line contacts intended to be electrically connected with a corresponding first conductor of an electric line and one or more second line contacts intended to be electrically connected with a corresponding second conductor of an electric line;

[0019] - one or more first disconnect contacts electrically connected with the first line contacts and one or more second disconnect contacts electrically connected with the second line contacts;

[0020] - an extracted switching device comprising one or more electrodes and one or more third disconnect contacts and one or more fourth disconnect contacts electrically connected to the electrodes, the switching device being reversibly movable between an inserted position, in which the third disconnect contacts are coupled with the first disconnect contacts and the fourth disconnect contacts are coupled with the second disconnect contacts, and an extracted position, in which the third disconnect contacts are uncoupled from the first disconnect contacts and the fourth disconnect contacts are uncoupled from the second disconnect contacts.

[0021] The electrical switching device according to the present application comprises one or more power supply connection blocks, each comprising a line contact, a disconnect contact and an insulating housing which encloses the line contact and the disconnect contact.

[0022] According to the present application, at least the line contact and the insulating housing form a unitary structure.

[0023] Preferably, at least the line contact and the insulating housing are co-molded to form the monolithic structure.

[0024] According to an aspect of the application, the switchgear comprises one or more first power connection blocks, each first power connection block comprising a first line contact, a first disconnect contact and a first insulating housing surrounding the first line contact and the first disconnect contact. At least the first line contact and the first insulating housing form a monolithic structure.

[0025] Preferably, at least the first line contact and the first insulating housing are co-molded to form the monolithic structure.

[0026] Preferably, each first line contact is formed by an elongated conductor having opposite first and second ends. The first end is intended to be coupled with a corresponding first line conductor, while the second end is coupled with a corresponding first disconnect contact.

[0027] Preferably, when the switchgear comprises a plurality of electrical phases, the switchgear according to the application comprises a plurality of first line contacts formed by elongated conductors having different lengths.

[0028] According to an aspect of the application, the insulating housing of a power connection block comprises:

[0029] - a first main section defining a first cavity housing the first disconnect contact, the first main section being intended to receive a third disconnect contact of the switching device when the switching device is in the insertion position;

[0030] - a first bushing section protruding from the first main section and surrounding the first line contact.

[0031] Preferably, the first main section of the first insulating housing comprises a first protrusion comprising one or more first coupling surfaces for mechanical connection with a support of the cabinet.

[0032] Preferably, the first main section of the insulating housing comprises a first flange having one or more second coupling surfaces for mechanical connection with a support of the cabinet.

[0033] Preferably, the first flange further comprises one or more third coupling surfaces for mechanical connection with corresponding coupling surfaces of a first insulating housing of an adjacent first power connection block.

[0034] Preferably, the first bushing section of the first insulating housing comprises an elongated portion protruding from the first main section and a transversal portion located in a distal position with respect to the first main section. The transversal portion has a free end at which the first line contact is intended to be coupled with a corresponding first line conductor.

[0035] Preferably, the first bushing section of the first insulating housing comprises a second protruding portion comprising one or more fourth coupling surfaces for mechanical connection with the support of the cabinet.

[0036] According to an aspect of the application, each first power connection block comprises one or more first test contacts enclosed in the first insulating housing. Each first test contact is electrically connected with a corresponding first line contact through a corresponding first capacitive circuit.

[0037] Preferably, the first test contacts and the first capacitive circuits are incorporated in a first bushing section of the first insulating housing.

[0038] According to an aspect of the application, the switchgear comprises one or more second power connection blocks, each second power connection block comprising a second line contact, a second disconnect contact and a second insulating housing enclosing the second line contact and the second disconnect contact, at least the second line contact and the second insulating housing forming a monolithic structure.

[0039] Preferably, at least the second line contact and the second insulating housing are co-molded to form the monolithic structure.

[0040] Preferably, each second line contact is formed by an elongated conductor having opposite third and fourth ends. The third end is intended to be coupled with a corresponding second line conductor. The fourth end is coupled with a corresponding second disconnect contact.

[0041] Preferably, the second insulating housing of a second power connection block comprises:

[0042] - a second main section defining a second cavity housing the second disconnect contact, the second cavity being intended to receive a fourth disconnect contact of the switching device when the switching device is in the insertion position;

[0043] - a second bushing section protruding from the second main section and surrounding the second line contact.

[0044] Preferably, the second main section of the second insulating housing comprises a third protruding portion comprising one or more fifth coupling surfaces for mechanical connection with the support of the cabinet.

[0045] Preferably, the second main section of the second insulating enclosure comprises a second flange comprising one or more sixth coupling surfaces mechanically connected with the support of the cabinet.

[0046] Preferably, the second flange comprises one or more seventh coupling surfaces mechanically connected with corresponding coupling surfaces of the second insulating enclosure of an adjacent second power connection block.

[0047] Preferably, the second bushing section of the second insulating enclosure has a free end at which the second line contact is intended to be coupled with a corresponding second line conductor. BRIEF DESCRIPTION OF DRAWINGS

[0048] Further features and advantages of the present application will be derived from the description of a preferred but non-exclusive embodiment of a shutter device in accordance with the present disclosure, a non-limiting example of which is provided in the attached drawings wherein:

[0049] Figures 1-2 A switching device according to the present application in different operating conditions is schematically illustrated;

[0050] Figures 3-11 Different types of first power connection blocks included in a switching device according to the present application are schematically illustrated;

[0051] Figures 12-14 A second power connection block included in a switching device according to the present application is schematically illustrated. DETAILED DESCRIPTION

[0052] With reference to the above-mentioned drawings, the present application relates to an electrical switching device 1 for low or medium voltage applications.

[0053] For the purposes of the present application, the term "low voltage" (LV) relates to working voltages lower than 1 kV AC and 1.5 kV DC, while the term "medium voltage" (MV) relates to working voltages higher than 1 kV up to several tens of kV (for example, 70 kV AC and 100 kV DC).

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

[0055] With reference to the normal installation position, the cabinet 2 comprises a horizontal base wall 21, a horizontal top wall 22 in an opposite position with respect to the horizontal base wall 21, and a plurality of vertical walls 23, 24, 25 arranged perpendicularly with respect to the horizontal base wall 21. Figures 1-2

[0056] ​These vertical walls comprise: a front wall 23 at which an operator can access the internal volume of the cabinet; a rear wall 24 in opposite position with respect to the front wall 23; and a pair of opposite side walls 25 (partly shown in Figures 1-2 Fig. 2) which are perpendicular to the walls 21, 22, 23, 24.

[0057] In general, the cabinet 2 comprises a plurality of compartments 2A, 2B, 2C, 2D adjacent to each other, in order to isolate different internal components of the switchgear.

[0058] Some compartments of the cabinet 2 are intended to be inaccessible to the user during the working life of the switchgear.

[0059] With reference to Figures 1-2 the embodiment shown, these inaccessible compartments comprise, for example: a first compartment 2A to house some live parts of the switchgear 1, i.e. the main electrical connections (for example, busbars, cables, power connection blocks and disconnection contacts) associated with suitable conductors of the electrical lines; and a second compartment 2B to house other live parts of the switchgear 1 and other power switching devices (not shown), for example grounding devices, such as disconnector.

[0060] Conveniently, the above-mentioned inaccessible compartments 2A, 2B are arranged in a distal position with respect to the front wall 23 of the cabinet 2.

[0061] While some compartments of the cabinet 2 are intended to be inaccessible to the user during the working life of the switchgear.

[0062] With reference to Figures 1-2 the embodiment shown, these accessible compartments comprise, for example: a third compartment 2C to house switching devices (for example, draw-out circuit breakers); and a fourth compartment 2D to house auxiliary electrical connections and other auxiliary devices.

[0063] In general, the compartment 2C can be accessed by the operator only when the above-mentioned switching devices are not powered, i.e. when the above-mentioned switching devices are disconnected from the live parts of the switchgear. While the compartment 2D can be accessed even during maintenance operations of the switchgear.

[0064] Conveniently, the above-mentioned accessible compartments 2C, 2D are arranged in a proximal position with respect to the front wall 23 of the cabinet 2.

[0065] Advantageously, each compartment 2A, 2B, 2C, 2D of the cabinet 2 can in turn be divided into different compartments or units, in order to ensure a proper isolation of the internal components of the switchgear.

[0066] Preferably, the cabinet 2 conveniently comprises an internal wall 27 which separates the inaccessible compartments 2A, 2B from the accessible compartment 2C.

[0067] The inner wall 27 is arranged perpendicularly with respect to the base wall 21 and the side walls 25 of the cabinet 2. With reference 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.

[0068] Conveniently, the inner wall 27 comprises a plurality of suitably arranged partition portions, each of which forms a physical barrier. However, the inner wall 27 comprises one or more openings which form suitable passages between the inaccessible compartments 2A, 2B and the accessible compartment 2C of the cabinet 2. Figures 1-2 ).

[0069] In general, the cabinet 2 can be arranged according to known types of solutions. Therefore, for the sake of brevity, it will not be further described in detail hereinafter.

[0070] The electrical switching device 1 comprises one or more first fixed line contacts 70, which are intended to be electrically connected with a corresponding first conductor (not shown) of an electric line, which is preferably electrically connected to an electric source.

[0071] The electrical switching device 1 comprises one or more second fixed line contacts 80, which are intended to be electrically connected with a corresponding second conductor (not shown) of an electric line, which is preferably electrically connected to one or more electric loads.

[0072] The electrical switching device 1 comprises one or more first fixed opening contacts 71 electrically connected with the first line contacts 70 and one or more second fixed opening contacts 81 electrically connected with the second line contacts 80.

[0073] The electrical switching device 1 comprises one or more first power supply connection blocks 7, which are preferably housed in the compartment 2A of the cabinet.

[0074] The first power supply connection blocks 7 conveniently comprise the corresponding first line contacts 70 and the corresponding first opening contacts 71, thereby providing an electrical connection with the corresponding first conductor of an electric line.

[0075] The electrical switching device 1 comprises one or more second power supply connection blocks 8, which are preferably housed in the compartment 2B of the cabinet.

[0076] The second power supply connection blocks 8 conveniently comprise the corresponding second line contacts 80 and the corresponding second opening contacts 81, thereby providing an electrical connection with the corresponding second conductor of an electric line.

[0077] With reference to the normal installation position of the cabinet, the first power connection block 7 is preferably arranged in an upper position, i.e. in a distal position with respect to the base wall 21, while the second power connection block 8 is preferably arranged in a lower position, i.e. in a proximal position with respect to the base wall 21.

[0078] In Figures 1-2 In the illustrated embodiment, the switchgear 1 is of the three-phase type. In this case, it conveniently comprises three first power connection blocks 7 and three second power connection blocks 8.

[0079] However, according to other embodiments of the application, the switchgear 1 can comprise a different number of electrical phases, and therefore a different number of power connection blocks, i.e. one first power connection block 7 and one second power connection block 8 for each electrical phase.

[0080] The electrical switchgear 1 comprises an extracted switching device 4 housed in the compartment 2C of the cabinet 2.

[0081] The switching device 4 preferably comprises a switching unit 41 mounted on suitable guide means 42 which can slide along suitable sliding planes parallel to the base wall 21 of the cabinet 2.

[0082] The switching device 4 is reversibly movable along a 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. Figures 1-2 ).

[0083] The switching device 4 comprises one or more third disconnecting contacts 43, each of which is electrically connected to a corresponding electrode of the switching unit 41.

[0084] The third disconnecting contacts 43 can be electrically coupled to or decoupled from the first disconnecting contacts 71 of the switchgear upon corresponding movement of the switching device.

[0085] The switching device 4 comprises one or more fourth disconnecting contacts 44, each of which is electrically connected to a corresponding electrode of the switching unit 41.

[0086] The fourth disconnecting contacts 44 can be electrically coupled to or decoupled from the second disconnecting contacts 81 of the switchgear upon corresponding movement of the switching device.

[0087] With reference to the normal installation position of the cabinet, the third disconnecting contacts 43 are preferably arranged in an upper position, i.e. in a distal position with respect to the base wall 21, while the fourth disconnecting contacts 44 are preferably arranged in a lower position, i.e. in a proximal position with respect to the base wall 21.

[0088] As described above, the third disconnect contact 43 and the fourth disconnect contact 44 of the switching device can be connected to or disconnected from the disconnect contacts 71 and 81 of the power connection blocks 7 and 8 when the switching device is properly moved.

[0089] In particular, the switching device 4 is reversibly movable between the following positions along the reference motion direction D:

[0090] -Insert position A1( Figure 1 In the insertion position A1, the third disconnecting contact 43 is connected to the first disconnecting contact 71, and the fourth disconnecting contact 44 is connected to the second disconnecting contact 81; and

[0091] -Extract position A2( Figure 1 In the withdrawn position, the third disconnecting contact 43 is disconnected from the first disconnecting contact 71, and the fourth disconnecting contact 44 is disconnected from the second disconnecting contact 81.

[0092] When the switching device is in the insertion position A1, for each electrical phase, the current can flow along the conductive path including the first line contact 70, the first disconnect contact 71, the third disconnect contact 43, the electrode of the switching unit 41, the fourth disconnect contact 44, the second disconnect contact 81, and the second line contact 80.

[0093] When the switching device is in the withdrawn position A2, the disconnecting contacts 43 and 44 are separated from the disconnecting contacts 71 and 81, and no current can flow along the electrodes of the switching device. Therefore, the electrical continuity between the first line contact 70 and the second line contact 80 of the switching device (and thus between the first conductor and the second conductor of the wire) is interrupted.

[0094] In order to connect or disconnect with disconnect contacts 71 and 81, disconnect contacts 43 and 44 conveniently pass through appropriate openings in the inner wall 27 of the cabinet.

[0095] exist Figure 2 In the embodiment shown, the switching device 4 is a three-phase type, and therefore it includes three third disconnect contacts 43 and three fourth disconnect contacts 44.

[0096] However, according to other embodiments of the invention, the switching device 4 may include different numbers of disconnecting contacts 43, 44 (i.e., a third disconnecting contact 43 and a fourth disconnecting contact 44 for each electrical phase).

[0097] Preferably, the switching device 4 is a circuit breaker.

[0098] However, according to some embodiments of the invention, it can be of a different type, such as a contactor.

[0099] Generally speaking, the switching device 4 can be arranged according to known types of solutions.

[0100] Therefore, for the sake of brevity, it will not be described in further detail below.

[0101] Preferably, the switchgear 1 includes a shield assembly 5.

[0102] The basic function of the baffle assembly 5 is to provide a physical barrier between the disconnecting contacts 71, 81 of the power connection blocks 7, 8 and the disconnecting contacts 43, 44 of the switching device at the openings in the inner wall 27, especially when the switching device is in the withdrawn position A2.

[0103] The cover assembly 5 is operably associated with the inner wall in such a way that it can move along a reference motion plane defined by the inner wall 27 of the cabinet 2.

[0104] Preferably, the baffle assembly 5 includes one or more baffle panels 51, 52, which are formed of conductive material plates arranged along the inner wall 27.

[0105] exist Figures 1-2 The image shows a blind assembly 5 comprising two different blind panels 51 and 52, which are securely connected to each other in an integrally movable manner by a suitable rod.

[0106] However, other solutions are also feasible depending on the requirements. For example, the mask assembly 5 may include multiple mask panels that move independently of each other, or it may include a single mask panel.

[0107] Conveniently, the baffle assembly 5 can be reversibly moved along the reference motion plane between the following positions:

[0108] - In unprotected position A3, at the aforementioned opening in the inner wall 27, one or more shielding panels 51, 52 are not inserted between the first disconnecting contact 71 and the third disconnecting contact 43, or between the second disconnecting contact 81 and the second disconnecting contact 44. Figures 1-2 );and

[0109] - Protective position A4, in which one or more shielding panels 51, 52 are inserted between the first disconnecting contact 71 and the third disconnecting contact 43 and between the second disconnecting contact 81 and the fourth disconnecting contact 44 at the aforementioned opening in the inner wall 27. Figure 1 ).

[0110] Preferably, the electrical switching device 1 includes an actuation mechanism (not shown) that includes a plurality of drive rods that mechanically connect the switching device 4 (in particular the movable guide device 42) to the shield assembly 5.

[0111] The actuation mechanism is essentially guided to actuate the shield assembly 5 in coordination with the movement of the switching device 4.

[0112] Generally, the baffle assembly 5 and the aforementioned actuation mechanism can be arranged according to known types of solutions. Therefore, for the sake of brevity, they will not be described in further detail below.

[0113] According to an important aspect of the invention, one or more power connection blocks 7, 8 are arranged in a manner that ensures proper dielectric insulation of the live parts of the switching equipment while simultaneously reducing the size compared to the corresponding solution in the prior art.

[0114] Specifically, one or more power connection blocks 7, 8 include line contacts 70, 80, disconnect contacts 71, 81, and insulating housings 72, 82 made of electrically insulating material, the insulating housings 72, 82 surrounding the line contacts and the disconnect contacts.

[0115] According to the present invention, at least the line contacts 70, 80 and the insulating housings 72, 82 form a monolithic structure.

[0116] For clarity, the term "integral structure" is defined as a structure made from a single piece, meaning that no specific connecting devices are used to connect different parts or materials.

[0117] Preferably, at least the line contacts 70, 80 and the insulating housings 72, 82 are co-molded to form the integral structure.

[0118] The co-molding process used to obtain the above overall structure can be of a known type, and for the sake of brevity, it will not be described in detail here.

[0119] The solution provided by the present invention allows for the prevention of the use of screws or other mechanical connecting devices to assemble the line contacts 70, 80 with the corresponding insulating housings 72, 82, as is common in available solutions in the prior art.

[0120] Therefore, the insulating housings 72 and 82 of the power connection blocks 7 and 8 have a single-piece structure made of electrically insulating material, which does not exhibit break lines or break points.

[0121] As is easily understood, this feature greatly improves the electrical insulation performance of power connection blocks 7 and 8.

[0122] Therefore, power connection blocks 7 and 8 can ensure a satisfactory dielectric insulation level for the corresponding fixed line contacts and fixed disconnect contacts, while providing electrical continuity between the line conductors and these fixed disconnect contacts of the switching equipment.

[0123] The above-mentioned improvements to the solution proposed in this invention allow for the design of switching devices with a compact overall size without compromising the dielectric insulation level between live parts and other internal components.

[0124] According to a preferred embodiment of the present invention ( Figure 2 ):

[0125] Each first power connection block 7 includes a first line contact 70, a first disconnect contact 71, and a first insulating housing 72 made of an electrically insulating material, the first insulating housing 72 surrounding the first line contact and the first disconnect contact. Conveniently, at least the first line contact 70 and the first insulating housing 72 of each first power connection block 7 are co-molded to form an integral structure.

[0126] Each second power connection block 8 includes a second line contact 80, a second disconnect contact 81, and a second insulating housing 82 made of an electrically insulating material, the second insulating housing 82 surrounding the second line contact and the second disconnect contact. Conveniently, at least the second line contact 80 and the first insulating housing 82 of each second power connection block 8 are co-molded to form an integral structure.

[0127] For simplicity, the most relevant aspects of the invention will now be described with reference to these preferred embodiments.

[0128] According to one aspect of the invention, the first line contact 70 of the first power connection block 7 is formed of a conductor having an elongated shape having opposing first end 701 and second end 702.

[0129] The first end 701 of the first line contact 70 is intended to be connected to the corresponding first line conductor (e.g., threaded connection), while the second end 702 is intended to be connected to the corresponding first disconnect contact 71 (e.g., threaded connection or integrally formed).

[0130] Preferably, when the first power connection block 7 is installed in its natural operating position, the first line contact 70 has a vertically elongated portion 70A extending toward the top wall 22 in a direction substantially perpendicular to the base wall 21 of the cabinet 2, and a transverse portion 70B extending in a direction substantially parallel to the base wall 21 of the cabinet 2 and oriented toward the front wall 23.

[0131] Preferably, the lateral portion 70B of the first line contact 70 includes a first end 701 intended to be connected to the corresponding first line conductor, while the vertical portion 70A of the second line contact 70 includes a second end 702 connected to the corresponding first disconnect contact 71.

[0132] Preferably, the first line contact 70 has an inverted L-shaped shape with rounded edges, wherein the longer leg is formed by the vertical portion 70A and the shorter leg is formed by the horizontal portion 70B.

[0133] Preferably, when the electrical switching equipment includes multiple electrical phases, the first line contact 70 is formed of conductors with elongated shapes of different lengths.

[0134] In particular, the vertical portion 70A of the first line contact 71 has a different length, which means that the second end 701 of the first line contact 71 is at a different height relative to the base wall 21.

[0135] This solution allows for space savings in compartment 2A of cabinet 2 and simplifies the electrical connection to the first conductor of the wires.

[0136] Preferably (as shown in the accompanying drawings), the first disconnect contact 71 of the first power connection block 7 is formed by a conductive bushing, which is connected (e.g., threaded) to the second end 702 of the corresponding first line contact 70 when a one-piece structure formed by the first line contact 70 and the first insulating housing 72 is realized.

[0137] According to an alternative embodiment, the first disconnect contact 71 can be integrally implemented with the first line contact 70. In this case, the first disconnect contact becomes part of the co-molded integral structure of the corresponding first power connection block 7.

[0138] According to one aspect of the present invention, the first insulating housing 72 of the first power connection block 7 includes a first main section 720 and a first bushing section 723.

[0139] The main section 720 of the first insulating housing 72 is designed to include a first chamber 721, which houses the terminal portion (including the second end 702) of the first line contact 70 and the first disconnect contact 71.

[0140] When the switching device is in the insertion position A1, the first chamber 721 receives the third disconnect contact 43 of the switching device 4.

[0141] Preferably, the first chamber 721 has an elongated shape that extends along a first axis S1 parallel to the direction of movement D of the switching device and has opposing ends 7211 and 7212.

[0142] Specifically, the first chamber 721 includes a first blind end 7211 and a first open end 7212, wherein the terminal portion of the first line contact 70 (including the second end 702) and the first disconnect contact 71 are accommodated at the first blind end 7211, and the first open end 7212 allows the third disconnect contact 43 of the switching device 4 to pass through.

[0143] Preferably, the first main section 720 of the first insulating housing 72 includes a first protrusion 724 for mechanically connecting the first power connection block 7 to the fixed support.

[0144] Preferably, the first protrusion 724 includes one or more first engagement surfaces 7241 for mechanical connection with the support of the cabinet 2.

[0145] Preferably, the first protrusion 724 includes a free end having a first connecting surface 7241 at which the first protrusion is mechanically connected (e.g., by thread) to an internal support wall or component of the cabinet 2.

[0146] Preferably, the first protrusion 724 is formed from a solid elongated portion of the first insulating housing 72, which conveniently has a cylindrical shape and is provided with external insulating fins on the outside.

[0147] Preferably, the first protrusion 724 is located at the first blind end 7211 of the first chamber 721 and protrudes from the opposite side of the first main section 720 relative to the first bushing section 723 of the first insulating housing 72.

[0148] Preferably, when the first power connection block 7 is installed in its working position, the first protrusion 724 extends toward the base wall 21 of the cabinet 2 in a direction substantially perpendicular to the base wall 21 of the cabinet 2.

[0149] Preferably, the first main section 720 of the first insulating housing 72 includes a first flange 725 for mechanically connecting the first power connection block 7 to the fixed support.

[0150] Preferably, the first flange 725 includes one or more second engagement surfaces 7251, 7252 for mechanical connection with the support of the cabinet 2.

[0151] Preferably, the first flange 725 includes one or more third coupling surfaces 7253, 7254 for mechanically connecting to a corresponding coupling surface of the first insulating housing 72 of another first power connection block 7.

[0152] Preferably, the first flange 725 is located at the first opening end 7212 of the first chamber 721.

[0153] Preferably, the first flange 725 is formed by a shaped protrusion (e.g., rectangular or square) of the first insulating housing 72, which is oriented perpendicularly to the extension axis S1 of the first chamber 721.

[0154] Preferably, on the side located at the distal position relative to the first blind end 7211 of the first chamber 721, the first flange 725 includes a flat edge portion 7252 at which the first flange can be mechanically connected (e.g., threaded connection) to the internal support wall of the cabinet 2.

[0155] Preferably, on this side, the first flange 725 includes one or more protruding ribs 7251, which are designed to insert into suitable openings in the aforementioned internal support wall of the cabinet 2.

[0156] Preferably, the first flange 725 includes opposing first and second side edges, which are oriented perpendicularly to the base wall 21 of the cabinet 2 when the first power connection block 7 is installed in its working position.

[0157] At the first lateral edge, the first flange 725 includes a connecting groove 7253, while at the second lateral edge, the first flange 725 includes a connecting rib 7254.

[0158] When the electrical switchgear includes multiple electrical phases, the connecting groove 7253 and / or connecting rib 7254 can be connected to the corresponding connecting rib 7254 and / or connecting groove 7253 of the first flange 725 of the adjacent first power connection block 7.

[0159] This solution further improves the stability of the first power connection block 7, allows for a reduction in the lateral space required to accommodate the first power connection block 7, and further improves the electrical insulation performance of the first power connection block 7, because the first insulating housings 72 of adjacent first power connection blocks 7 can be mechanically combined to form a single insulating structure.

[0160] The first bushing section 723 of the first insulating housing 72 is designed to protrude from the first main section 720 and surround the first line contact 70 throughout its entire holding length.

[0161] Preferably, the first bushing section 723 includes a free end at which the first line contact 70 is intended to connect with a corresponding first line conductor.

[0162] Preferably, the first bushing section 723 includes a vertical portion 7231 that protrudes from the first main section 720 at a first blind end 7211 of the first chamber 720 on the side opposite to the first protrusion 724 of the first main section 720.

[0163] When the first power connection block 7 is installed in its working position, the vertical portion 7231 of the first bushing section 723 extends along the second axis S perpendicular to the base wall 21 of the cabinet 2 and is oriented toward the top wall 22.

[0164] The vertical portion 7231 of the first bushing section 723 preferably has a cylindrical shape and is provided with external insulating fins.

[0165] Preferably, the first bushing section 723 of the first insulating housing 72 includes a transverse portion 7232 that is located distally relative to the first main section 720 and extends along a direction substantially parallel to the base wall 21 of the cabinet 2 and toward the front wall 23.

[0166] Conveniently, the transverse portion 7232 includes the free end of the first bushing section.

[0167] The transverse portion 7232 preferably has a cylindrical shape and is provided with external insulating fins.

[0168] Preferably, the first bushing section 723 of the first insulating housing 72 includes a second protrusion 7235, which is used to mechanically connect the first power connection block 7 to the fixed support.

[0169] Preferably, the second protrusion 7235 includes one or more fourth coupling surfaces 7236 for mechanical connection with the support of the cabinet 2.

[0170] Preferably, the second protrusion 7235 includes a free end having a fourth connecting surface 7236 at which the fourth connecting surface 7236 is mechanically connected (e.g., threaded connection) to an internal support wall or component of the cabinet 2.

[0171] Preferably, the second protrusion 7235 is formed from a solid elongated portion of the first bushing section 723, which conveniently has a cylindrical shape and is provided with external insulating fins on the outside.

[0172] Preferably, the second protrusion 7235 is aligned with the transverse portion 7232 of the first bushing section 723 on the opposite side of the first bushing section 723 and oriented in the opposite direction.

[0173] Preferably, the first bushing section 723 has a "T" shape, wherein the longer leg is formed by the vertical portion 7231, while the shorter leg is formed by the horizontal portion 7232 and the protrusion 7235.

[0174] According to one aspect of the invention, the first power connection block 7 includes one or more first test contacts 79 for allowing measurement of the voltage of the first line contact 70.

[0175] The first test contact 79 is electrically connected to the corresponding first line contact 70 through the corresponding first capacitor circuit 791 (which may be of a known type).

[0176] Preferably, the first test contact 79 and the first capacitor circuit 791 are combined in the first bushing section 723 of the first insulating housing 72 in such a way that they are completely surrounded by an electrical insulating material, particularly at the fixed portion 7235 of the first bushing section 723.

[0177] According to one aspect of the invention, the second line contact 80 of the second power connection block 8 is formed of a conductor having an elongated shape having opposing first end 801 and second end 802.

[0178] The first end 801 of the second line contact 80 is intended to be connected to the corresponding second line conductor (e.g., threaded connection), while the second end 802 is intended to be connected to the corresponding second disconnect contact 81 (e.g., threaded connection or integrally formed).

[0179] Preferably, when the second power connection block 8 is installed in its natural operating position, the second line contact 80 extends toward the base wall 21 of the cabinet 2 in a direction substantially perpendicular to the base wall 21 of the cabinet 2.

[0180] Preferably, the second line contact 80 has a cylindrical shape with rounded edges.

[0181] Preferably (as shown in the accompanying drawings), the second disconnect contact 81 of the second power connection block 8 is formed by a conductive bushing, which is connected (e.g., threaded) to the second end 802 of the corresponding second line contact 80 when a one-piece structure formed by the second line contact 80 and the second insulating housing 82 is realized.

[0182] According to an alternative embodiment, the second disconnect contact 81 can be integrally implemented with the second line contact 80. In this case, it will be part of the co-molded integral structure of the corresponding second power connection block 8.

[0183] According to one aspect of the invention, the second insulating housing 82 of the second power connection block 8 includes a second main section 820 and a second bushing section 823. The second main section 820 of the second insulating housing 82 is designed to include a second chamber 821, which accommodates the terminal portion (including the second end 802) of the second line contact 80 and the second disconnect contact 81.

[0184] When the switching device is in the insertion position A1, the second chamber 821 receives the fourth disconnect contact 44 of the switching device 4.

[0185] Preferably, the second chamber 821 has an elongated shape that extends along a fourth axis S4 parallel to the direction of movement D of the switching device and has opposing ends 8211 and 8212.

[0186] Specifically, the second chamber 821 includes a second blind end 8211 and a first open end 8212, wherein the terminal portion (including the second end 802) of the second line contact 80 and the first disconnect contact 81 are accommodated at the second blind end 8211, and the first open end 8212 allows the fourth disconnect contact 44 of the switching device 4 to pass through.

[0187] Preferably, the second main section 820 of the second insulating housing 82 includes a third protrusion 824 for mechanically connecting the first power connection block 8 to the fixed support.

[0188] Preferably, the third protrusion 824 includes one or more fifth coupling surfaces 8241 for mechanical connection with the support of the cabinet 2.

[0189] Preferably, the third protrusion 824 includes a free end having a connecting surface 8241 at which the third protrusion is mechanically connected (e.g., by thread) to an internal support wall or component of the cabinet 2.

[0190] Preferably, the third protrusion 824 is formed from a solid elongated portion of the second insulating housing 82, which conveniently has a cylindrical shape and is provided with external insulating fins on the outside.

[0191] Preferably, the third protrusion 824 is located at the second blind end 8211 of the second chamber 821 and protrudes from the opposite side of the second main section 820 relative to the second bushing section 823 of the second insulating housing 82.

[0192] Preferably, when the second power connection block 8 is installed in its working position, the third protrusion 824 extends toward the top wall 22 along a direction substantially perpendicular to the base wall 21 of the cabinet 2.

[0193] Preferably, the second main section 820 of the second insulating housing 82 includes a second flange 825 for mechanically connecting the second power connection block 8 to the fixed support.

[0194] Preferably, the second flange 825 includes one or more sixth coupling surfaces 8251, 8252 for mechanical connection with the support of the cabinet 2.

[0195] Preferably, the second flange 825 includes one or more seventh coupling surfaces 8253, 8254 for mechanical connection with a corresponding coupling surface of the second insulating housing 82 of another second power connection block 8.

[0196] Preferably, the second flange 825 is positioned at the opening end 8212 of the second chamber 821.

[0197] Preferably, the second flange 825 is formed by a shaped protrusion (e.g., rectangular or square) of the second insulating housing 82, which is oriented perpendicularly to the extending axis S4 of the second chamber 821.

[0198] Preferably, on the side located at the distal position relative to the blind end 8212 of the second chamber 821, the second flange 825 includes a flat edge portion 8252 at which the second flange can be mechanically connected (e.g., threaded connection) to the internal support wall of the cabinet 2.

[0199] Preferably, on this side, the second flange 825 includes one or more protruding ribs 8251, which are designed to be inserted into suitable openings in the aforementioned internal support wall of the cabinet 2.

[0200] Preferably, when the second power connection block 8 is installed in its working position, the second flange 825 includes opposing third and fourth lateral edges, which are oriented perpendicularly to the base wall 21 of the cabinet 2.

[0201] At the third lateral edge, the second flange 825 includes a connecting groove 8253, while at the fourth lateral edge, the second flange includes a connecting rib 8254.

[0202] When the electrical switchgear includes multiple electrical phases, the connecting groove 8253 and / or connecting rib 8254 can be connected to the corresponding connecting rib 8254 and / or connecting groove 8253 of the second flange 825 of the adjacent second power connection block 8.

[0203] This solution offers advantages similar to those described for the flange of the first power connection block 7.

[0204] The second bushing section 823 of the second insulating housing 82 is designed to protrude from the second main section 820 and surround the second line contact 80 over the entire holding length of the second line contact 80.

[0205] Preferably, the second bushing section 823 includes a free end at which the second line contact 80 is intended to connect with a corresponding second line conductor.

[0206] The second bushing section 823 preferably has a cylindrical shape and is provided with external insulating fins.

[0207] According to some embodiments of the present invention (not shown), the second power connection block 8 may include one or more second test contacts to allow measurement of the voltage of the second line contact 80.

[0208] The second test contact is electrically connected to the corresponding second line contact 80 via the corresponding second capacitor circuit 891 (which may be of a known type).

[0209] Preferably, the second test contact and the associated second capacitor circuit are integrated into the third protrusion 824 of the second insulating housing 82 in such a manner that they are completely surrounded by an electrically insulating material.

[0210] Obviously, Figures 1-2 Figures 1-2 This is a preferred embodiment of the present invention, wherein each first power connection block 7 and each second power connection block 8 includes an integral structure formed by at least co-molded line contacts 70, 80 and insulating housings 72, 82.

[0211] According to some embodiments of the present invention (not shown), only some power connection blocks 7, 8 (e.g. only the first power connection block 7 or only the second power connection block 8) may include a co-molded integral structure according to the claimed invention.

[0212] In practice, it has been found that the electrical switchgear according to the present invention offers relevant advantages over corresponding solutions of the prior art.

[0213] Due to the arrangement of the power connection blocks 7 and 8 with improved insulation properties, the formation of discharge or arc can be prevented or greatly reduced even if the internal dielectric distance is relatively small.

[0214] This allows for the removal of the switching equipment in a very safe manner and greatly enhances the level of safety for operators who may have access to compartment 2C of cabinet 2 (e.g., during maintenance operations).

[0215] Furthermore, this electrical switchgear can be easily designed with a compact overall size without compromising the dielectric insulation level between live parts and other internal components.

[0216] The electrical switching device according to the invention can be easily implemented at an industrial level. Therefore, the electrical switching device can be easily manufactured at a cost that is competitive with similar devices in the prior art.

Claims

1. An electrical switching device (1) for low or medium voltage applications, comprising: - a cabinet (2) having a plurality of walls (21, 22, 23, 24, 25) defining an internal volume; - one or more first line contacts (70) intended to be electrically connected with a corresponding first conductor of an electrical line and one or more second line contacts (80) intended to be electrically connected with a corresponding second conductor of an electrical line; - one or more first disconnect contacts (71) electrically connected with the first line contacts (70) and one or more second disconnect contacts (81) electrically connected with the second line contacts (80); - an extracted switching device (4) comprising one or more third disconnect contacts (43) and one or more fourth disconnect contacts (44), the switching device being reversibly movable between an inserted position (Al) in which the third disconnect contacts (43) are coupled with the first disconnect contacts (71) and the fourth disconnect contacts (44) are coupled with the second disconnect contacts (81), and an extracted position (A2) in which the third disconnect contacts (43) are uncoupled from the first disconnect contacts (71) and the fourth disconnect contacts (44) are uncoupled from the second disconnect contacts (81); characterized in that it comprises one or more first power connection blocks (7) comprising first line contacts (70), first disconnect contacts (71) and a first insulating housing (72) surrounding the first line contacts and the first disconnect contacts, at least the first line contacts (70) and the first insulating housing (72) being co-molded to form a monolithic structure; the first insulating housing (72) comprising: - a first main section (720) defining a first chamber (721) housing the first disconnect contacts (71), the first chamber (721) being intended to receive the third disconnect contacts (43) of the switching device when the switching device is in the inserted position (Al); and - a first bushing section (723) protruding from the first main section (720) and surrounding the first line contacts (70); the first main section (720) comprising a first protrusion (724) comprising one or more first coupling surfaces (7241) for mechanical connection with a support of the cabinet; the first chamber (721) comprising a first blind end (7211) and a first open end (7212); and the first protrusion (724) being located at the first blind end (7211) of the first chamber (721) and protruding from an opposite side of the first main section (720) with respect to the first bushing section (723) of the first insulating housing (72); The first main section (720) comprises a first flange (725) having one or more second coupling surfaces (7251, 7252) for mechanical connection with the support of the cabinet; The first flange (725) comprises one or more third coupling surfaces (7253, 7254) for mechanical connection with corresponding coupling surfaces of the first insulating housing (72) of an adjacent first power connection block (7).

2. The electrical switching apparatus of claim 1 wherein, The first line contact (70) is formed by an elongated conductor having opposite first and second ends (701, 702), the first end being intended to be coupled with a corresponding first line conductor, the second end being coupled with a corresponding first disconnect contact (71).

3. The electrical switching device according to either of Claims 1 or 2, wherein, The electrical switching device comprises a plurality of first line contacts (70) formed by elongated conductors having different lengths.

4. The electrical switching device according to claims 1 or 2, wherein, The first bushing section (723) comprises an elongated portion (7231) protruding from the first main section (720) and a transverse portion (7232) located in a distal position with respect to the first main section (720), the transverse portion having a free end (7234) at which the first line contact (70) is intended to be coupled with a corresponding first line conductor.

5. The electrical switching device according to Claims 1 or 2, wherein, The first bushing section (723) comprises a second protrusion (7235) comprising one or more fourth coupling surfaces (7236) for mechanical connection with the support of the cabinet.

6. The electrical switching device of claim 1 or 2, wherein, The first power connection block (7) comprises one or more first test contacts (79) electrically connected with a corresponding first line contact (70) through a corresponding first capacitive circuit (791).

7. The electrical switching device of Claim 6 wherein, The first test contact (79) and the first capacitive circuit (791) are incorporated in the first bushing section (723).

8. The electrical switching device of claim 1 or 2, wherein, The electrical switching device comprises one or more second power connection blocks (8) comprising a second line contact (80), a second disconnect contact (81) and a second insulating housing (82) surrounding the second line contact and the second disconnect contact, at least the second line contact (80) and the second insulating housing (82) forming a monolithic structure.

9. The electrical switching device of Claim 8 wherein, The second line contact (80) is formed by an elongated conductor having opposite third and fourth ends (801, 802), the third end being intended to be coupled with a corresponding second line conductor, the fourth end being coupled with a corresponding second disconnect contact (81).

10. The electrical switching device of Claim 8 wherein, The second insulating housing (82) comprises: - a second main section (820) defining a second cavity (821) housing the second disconnect contact (81), the second cavity being intended to receive a fourth disconnect contact (44) of the switching device when the switching device is in the insertion position (A1); - a second bushing section (823) protruding from the second main section (820) and surrounding the second line contact (80).

11. The electrical switching device of Claim 10 wherein, Said second main section (820) comprises a third protrusion (824) comprising one or more fifth coupling surfaces (8241) to be coupled with the support of the cabinet.

12. The electrical switching device according to claims 10 or 11, characterized in that Said second main section (820) comprises a second flange (825) comprising one or more sixth coupling surfaces (8251, 8252) to be coupled with the support of the cabinet.

13. The electrical switching device of Claim 12 wherein, Said second flange (825) comprises one or more seventh coupling surfaces (8253, 8254) to be coupled with corresponding coupling surfaces of a second insulating housing (82) of an adjacent second power connection block (8).

14. The electrical switching device according to any of claims 10 or 11, wherein, Said second bushing section (823) has a free end (8231) at which the second line contact (80) is intended to be coupled with a corresponding second line conductor.

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