Composite insulation high-voltage grounding switch and high-voltage electrical box for vehicle

Abstract

The invention relates to the technical field of high-voltage switch equipment, and provides a composite insulation high-voltage grounding switch and a high-voltage electrical box for a vehicle. The composite insulation high-voltage grounding switch comprises an insulation cylinder, a moving contact, a static contact, a first gas circuit connecting piece and a second gas circuit connecting piece, and the insulation cylinder is provided with a sliding gas channel; the moving contact is arranged in the sliding air passage in a sliding manner; the static contact is arranged at the working position and is used for connecting the vacuum circuit breaker; the first gas circuit connecting piece is arranged at a grounding position and is used for realizing a grounding function when the moving contact is at the grounding position; and the second gas circuit connecting piece is arranged at the working position and is used for realizing the insulating property when the moving contact is located at the working position. The moving contact is slidably arranged in the sliding air channel so as to be switched between the working position and the grounding position, and the electrical gap between the moving contact and the static contact is enlarged as much as possible in a limited space, so that the insulation performance of a product is ensured, and the overall size of the composite insulation high-voltage grounding switch is reduced.

Description

Technical Field

[0001] This invention relates to the field of high-voltage switchgear technology, and in particular to a composite-insulated high-voltage grounding switch and a high-voltage electrical box for vehicles. Background Technology

[0002] Currently, high-voltage electrical boxes used in rail transit vehicles mainly employ the following two insulation methods to achieve insulation isolation between the high-voltage end and ground: 1. Air insulation: Relying on maintaining a sufficient air gap between the high-voltage live parts and the grounding box to ensure insulation strength. This is the most traditional and common method. 2. Composite insulation: Based on air insulation, solid insulating materials are introduced to partially or completely isolate the high-voltage end from the grounding box. This method can effectively reduce the reliance on pure air gaps.

[0003] In existing high-voltage electrical box designs, high-voltage grounding switches are typically considered purely grounding components. Their function is to close during maintenance for reliable grounding and safety; during normal operation, they are in the open position, away from the high-voltage end. Therefore, in current technical solutions, the high-voltage grounding switch itself does not possess any auxiliary insulation function, and isolation between it and the high-voltage end still relies on air gaps or additional insulating components.

[0004] When vehicles are used in high-altitude areas, the reduced atmospheric pressure leads to a decrease in the insulating dielectric strength of the air. This necessitates a significant increase in the electrical clearance between high-voltage equipment and ground to ensure safety, directly resulting in a larger high-voltage electrical box. This increased size creates a sharp conflict with the limited installation space on the vehicle, severely restricting the rational layout of other equipment and constituting a pressing technical challenge that needs to be addressed in high-altitude applications. Summary of the Invention

[0005] This application aims to address at least one of the technical problems existing in the related art. To this end, this application addresses the problem that existing high-voltage electrical boxes for high-altitude environments are too large in size to meet the insulation requirements of low-pressure environments, and provides a composite-insulated high-voltage grounding switch. This switch transforms a simple grounding component into an integrated insulation-grounding component, thereby effectively overcoming the dependence of the box size on electrical clearance without sacrificing insulation performance, and solving the problem of compact space layout.

[0006] This application also proposes a high-voltage electrical box for vehicles.

[0007] According to the first aspect of this application, a composite insulated high-voltage grounding switch includes: An insulating cylinder has an internal cavity for accommodating a vacuum circuit breaker, and the insulating cylinder is provided with a sliding air passage. A movable contact is slidably disposed within the sliding air passage, and the movable contact is configured to switch between two positions: a working position and a contact position. A stationary contact is located in the working position and is used to connect to a vacuum circuit breaker; The first air passage connector is disposed at the contact position and is used to realize the grounding function when the moving contact is in the contact position; The second air passage connector is located at the working position and is used to achieve insulation performance when the moving contact is in the working position.

[0008] According to the composite insulated high-voltage grounding switch of this application, the moving contact is slidably disposed in the sliding air passage to switch between two positions: a working position and a grounding position. When the moving contact is in the working position, the moving contact is connected to the vacuum circuit breaker through the stationary contact and achieves insulation performance through the second air passage connector. When the moving contact is in the grounding position, the moving contact is grounded and insulated through the first air passage connector. The electrical clearance between the moving contact and the stationary contact is maximized within a limited space, thereby ensuring the insulation performance of the product. This is beneficial for reducing the overall size of the composite insulated high-voltage grounding switch and for the arrangement of other equipment in the vehicle.

[0009] According to one embodiment of this application, a sealing cap is included for sealing both ends of the sliding air passage. A first air passage connector is connected to the sealing cap at one end, and a second air passage connector is connected to the sealing cap at the other end. The moving contact is configured to switch between a working position and a contact position under the drive of compressed gas.

[0010] According to one embodiment of this application, the moving contact is connected to a metal bellows, which is connected to one of the sealing caps.

[0011] According to one embodiment of this application, a first sealing ring is installed on the sealing cover, the first sealing ring being used to seal the compressed gas within the sliding air passage of the moving contact.

[0012] According to one embodiment of this application, the pressure of the compressed gas is 350 kPa to 400 kPa.

[0013] According to one embodiment of this application, a second sealing ring is included, which is installed on the moving contact to achieve air path sealing of the moving contact within the sliding air passage.

[0014] According to one embodiment of this application, the insulating cylinder is an integrally cast body, and the insulating cylinder further includes an electrode grid, which is disposed on the outside of the insulating cylinder. The electrode grid is used to isolate the working position and the contact position to increase the electrical clearance between the working position and the contact position.

[0015] According to one embodiment of this application, the stationary contact is sealed inside the insulating cylinder; And / or, the first gas connection is a metal gas connection; And / or, the second gas connection is an insulating gas connection.

[0016] According to one embodiment of this application, the sliding air passage includes a first sliding air passage and a second sliding air passage, which are spaced apart along the height direction of the insulating cylinder. Each of the first and second sliding air passages has a slidable moving contact and a stationary contact, one of which is connected to the upper electrode of a vacuum circuit breaker, and the other is connected to the lower electrode of the vacuum circuit breaker. A first end of the first sliding air passage is connected to a first air passage connector, and a second end of the first sliding air passage is connected to a second air passage connector. The first end of the second sliding air passage is connected to the second air passage connector, and the second end of the second sliding air passage is connected to the first air passage connector.

[0017] According to a second aspect embodiment of this application, a high-voltage electrical box for a vehicle includes: The aforementioned composite insulated high-voltage grounding switch; High-voltage equipment is connected to the composite insulated high-voltage grounding switch.

[0018] This invention's high-voltage grounding switch not only realizes the grounding function of the high-voltage circuit, but also integrates solid insulation components, structurally increasing the electrical clearance between the high-voltage end and the grounding end. While ensuring insulation performance, it reduces the product size, achieving the goal of miniaturizing high-voltage electrical boxes for high-altitude areas.

[0019] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is one of the structural schematic diagrams of the composite insulated high-voltage grounding switch provided in the embodiments of this application.

[0022] Figure 2 This is the second schematic diagram of the composite insulated high-voltage grounding switch provided in the embodiments of this application.

[0023] Figure 3 yes Figure 2 A schematic diagram of the A-direction cross-sectional structure of the composite insulated high-voltage grounding switch provided in the embodiment.

[0024] Figure 4 yes Figure 2 A schematic diagram of the composite insulated high-voltage grounding switch in section B provided in the embodiment.

[0025] Figure 5 This is the third schematic diagram of the composite insulated high-voltage grounding switch provided in the embodiments of this application.

[0026] Figure 6 This is the fourth structural schematic diagram of the composite insulated high-voltage grounding switch provided in the embodiments of this application.

[0027] Figure 7 yes Figure 6 A schematic diagram of the C-direction cross-sectional structure of the composite insulated high-voltage grounding switch provided in the embodiment.

[0028] Figure label: 1. Upper flange; 2. Cast body; 2.1. First sliding air passage; 2.2. Second sliding air passage; 2.3. Electrode grid; 3. Lower flange; 4. Lower stationary contact; 5. Upper stationary contact; 6. Insulating cylinder; 7. First air passage connector; 8. Second air passage connector; 9. Second sealing ring; 10. Moving contact; 11. First sealing ring; 12. Sealing cover; 20. Vacuum circuit breaker. Detailed Implementation

[0029] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but should not be used to limit the scope of this application.

[0030] In the description of the embodiments of this application, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections, wherein a fixed connection can include an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0032] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0033] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0034] Please refer to the composite insulated high-voltage grounding switch proposed in the embodiments of this application. Figure 1 and Figure 2 The composite insulated high-voltage grounding switch includes: an insulating cylinder 6, a moving contact 10, and a stationary contact (refer to...). Figure 4 The upper stationary contact 5, or refer to Figure 3The lower stationary contact 4), the first air path connector 7, and the second air path connector 8 are included. The insulating cylinder 6 has an internal receiving cavity for accommodating the vacuum circuit breaker 20. The insulating cylinder 6 has a sliding air passage. The moving contact 10 is slidably disposed in the sliding air passage and is configured to switch between two positions: a working position and a grounding position. The stationary contact is disposed in the working position and is used to connect the vacuum circuit breaker 20. The first air path connector 7 is disposed in the grounding position and is used to achieve the grounding function when the moving contact 10 is in the grounding position. The second air path connector 8 is disposed in the working position and is used to achieve the insulation performance when the moving contact 10 is in the working position.

[0035] According to the composite insulated high-voltage grounding switch of this application, the moving contact is slidably disposed in the sliding air passage to switch between two positions: working position and grounding position. When the moving contact is in the working position, the moving contact is connected to the vacuum circuit breaker 20 through the stationary contact and achieves insulation performance through the second air passage connector. When the moving contact is in the grounding position, the moving contact is grounded and insulated through the first air passage connector. The electrical clearance between the moving contact and the stationary contact is maximized within a limited space, thereby ensuring the insulation performance of the product (especially the insulation performance in high-altitude and low-pressure environments). This helps to reduce the overall size of the composite insulated high-voltage grounding switch, solves the core problem of miniaturization of high-voltage electrical boxes in high-altitude areas, and facilitates the layout of other equipment in the vehicle.

[0036] It should be noted that the operating logic of this switch corresponds to the vehicle's operating status. When the locomotive and rolling stock are in operation, the vacuum circuit breaker 20 is energized, and the moving contact must be in the working position to ensure the normal operation of the vacuum circuit breaker 20. When the locomotive and rolling stock are undergoing maintenance, the vacuum circuit breaker 20 is de-energized. To ensure the safety of maintenance work, the moving contact must be in the grounding position to ground the vacuum circuit breaker 20 to the vehicle's high-voltage circuit.

[0037] In one key embodiment, the position switching of the moving contact 10 is achieved by compressed gas drive. Specifically, when compressed gas is introduced into the beginning or end of the sliding gas passage, the gas pressure pushes the moving contact 10 to slide within the gas passage, thereby accurately and reliably completing the switching action between the working position and the contact position. This driving method is not only simple and reliable, but its working medium (compressed gas) itself is also key to achieving improved insulation performance.

[0038] According to one embodiment of this application, refer to Figure 3 and Figure 4 The composite insulated high-voltage grounding switch includes a sealing cover 12, which is used to seal both ends of the sliding air passage. A first air passage connector 7 is connected to the sealing cover 12 at one end, and a second air passage connector 8 is connected to the sealing cover 12 at the other end. The moving contact 10 is configured to switch between two positions, a working position and a grounding position, under the drive of compressed gas.

[0039] Understandably, compressed gas can be filled into the sliding air passage, which not only provides the driving force for the movement of the moving contact, but also solves the problem of reduced insulation performance caused by the decrease in air pressure at high altitudes.

[0040] To ensure the airtightness of the air passage and maintain stable internal air pressure to preserve insulation strength, this invention employs multiple sealing measures. First, a first sealing ring 11 is installed on the sealing cover 12 to achieve a static seal at the end of the sliding air passage. Second, a second sealing ring 9 (preferably a lip-shaped sealing ring) is installed on the moving contact 10 to achieve a dynamic seal between the moving contact and the air passage wall during sliding.

[0041] According to one embodiment of this application, the moving contact 10 is connected to a metal bellows, which is connected to one of the sealing caps 12.

[0042] According to one embodiment of this application, a first sealing ring 11 is installed on the sealing cover 12. The first sealing ring 11 is used to seal the compressed gas within the sliding air passage of the moving contact. It is understood that the sealing cover 12 is used to seal the beginning and end of the sliding air passage, and the first sealing ring 11 is installed on the sealing cover 12 to achieve the function of sealing the compressed gas within the air passage.

[0043] According to one embodiment of this application, the pressure of the compressed gas is 350 kPa to 400 kPa.

[0044] According to one embodiment of this application, the composite insulated high-voltage grounding switch includes a second sealing ring 9, and the moving contact 10 is equipped with the second sealing ring 9 to achieve air sealing of the moving contact 10 in the sliding air passage.

[0045] In one embodiment, the second sealing ring 9 is a lip seal. The lip seal 9 is installed on the moving contact 10 to achieve the air passage sealing function at the front and rear ends of the moving contact.

[0046] In one embodiment, a second sealing ring 9 is installed on the moving contact 10 to achieve a gas path sealing function. A metal bellows is connected to the rear end of the moving contact 10, and the metal bellows is connected to either the first gas path connector 7 or the second gas path connector 8 at the rear end. A metal gas path connector is used at the contact position and fixed thereto, while an insulating gas path connector is used at the working position. When the composite insulated high-voltage grounding switch needs to achieve the grounding function, air is introduced through the air inlet at the contact position. The gas pushes the moving contact 10, which slides along the sliding air passage to the working position and contacts the stationary contact, thus achieving the grounding function. Of course, the air inlet can be located at other positions besides the contact position, such as at the first end or the second end of the sliding air passage.

[0047] When the high-voltage grounding switch needs to return to the working position, air is introduced from the air inlet of the working position, and the moving contact 10 slides back to the grounding position along the sliding air passage to achieve separation and insulation between the high-voltage end and the grounding end. Since the moving contact sliding air passage is filled with compressed gas of 350kPa to 400kPa, the insulation performance of the compressed gas is much higher than that of ordinary air, thus increasing the insulation performance between the moving and stationary contacts.

[0048] The sealing cover 12 and the sealing ring 11 seal the sliding air passage. The sealing cover 12 is threaded and is used to connect the first air passage connector 7 or the second air passage connector 8, and is also used to connect the metal bellows.

[0049] According to one embodiment of this application, refer to Figure 5 The insulating cylinder is a cast body integrally cast. The insulating cylinder also includes an electrode grid 2.3. The electrode grid 2.3 is located on the outside of the insulating cylinder. The electrode grid 2.3 is used to isolate the working position and the contact position to increase the electrical clearance between the working position and the contact position.

[0050] Understandably, the insulating cylinder is a casting made of insulating material through integral casting, and the insulating material can be epoxy resin. This process allows the complex sliding air channels, receiving cavities, and external electrode grids 2.3 inside the insulating cylinder to be molded into a single unit, resulting in high structural strength and stable and reliable insulation performance.

[0051] In one embodiment, refer to Figure 6 and Figure 7 The insulating cylinder 6 includes an upper flange 1, a casting body 2, and a lower flange 3. The casting body has an integrally formed sliding air passage and a receiving cavity inside, and an integrally formed electrode grid on the outside. The insulating cylinder 6 is fixedly mounted on the fixed base plate via the lower flange 3.

[0052] According to one embodiment of this application, the stationary contact is sealed inside the insulating cylinder.

[0053] According to one embodiment of this application, the first gas passage connector 7 is a metal gas passage connector; According to one embodiment of this application, the second gas connection 8 is an insulating gas connection.

[0054] According to one embodiment of this application, the sliding air passage includes a first sliding air passage 2.1 and a second sliding air passage 2.2. The first sliding air passage 2.1 and the second sliding air passage 2.2 are spaced apart along the height direction of the insulating cylinder 6. Each of the first sliding air passage 2.1 and the second sliding air passage 2.2 is provided with a slidable moving contact 10 and a stationary contact. One stationary contact is connected to the upper electrode of the vacuum circuit breaker 20, and the other stationary contact is connected to the lower electrode of the vacuum circuit breaker 20. The first end of the first sliding air passage 2.1 is connected to a first air passage connector 7, and the second end of the first sliding air passage 2.1 is connected to a second air passage connector 8. The first end of the second sliding air passage 2.2 is connected to the second air passage connector 8, and the second end of the second sliding air passage 2.2 is connected to the first air passage connector 7.

[0055] Understandably, by installing the first and second air passage connectors on the first and second sliding air passages in opposite configurations, this application spatially offsets the working and contact positions of the first and second sliding air passages. This "misaligned" layout ensures that any electrical breakdown that may occur between the first and second sliding air passages no longer follows a short, vertical line, but must instead bypass a large portion of the circumference of the insulating cylinder, thereby significantly increasing the effective electrical clearance and achieving extremely high insulation performance within a compact structure.

[0056] It is understood that there are two moving contacts, one of which is slidably disposed within the first sliding air passage 2.1, and the other is slidably disposed within the second sliding air passage 2.2. The first end of the first sliding air passage 2.1 has a working position, and the second end of the second sliding air passage 2.2 has a working position. There are also two stationary contacts, one of which (upper stationary contact 5) is connected to the upper electrode of the vacuum circuit breaker 20, and the other stationary contact (lower stationary contact 4) is connected to the lower electrode of the vacuum circuit breaker 20. The head is disposed in the first sliding air passage 2.1, and the other stationary contact head is disposed in the second sliding air passage 2.2; there are two first air passage connectors 7, one of which is connected to the second end of the first sliding air passage 2.1, and the other of which is connected to the first end of the second sliding air passage 2.2; there are two second air passage connectors 8, one of which is connected to the first end of the first sliding air passage 2.1, and the other of which is connected to the second end of the second sliding air passage 2.2.

[0057] According to a second aspect embodiment of this application, a high-voltage electrical box for a vehicle includes: The aforementioned composite insulated high-voltage grounding switch; High-voltage equipment, connected to a composite insulated high-voltage grounding switch.

[0058] This invention's high-voltage grounding switch not only realizes the grounding function of the high-voltage circuit, but also integrates solid insulation components, structurally increasing the electrical clearance between the high-voltage end and the grounding end. While ensuring insulation performance, it reduces the product size, achieving the goal of miniaturizing high-voltage electrical boxes for high-altitude areas.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite insulated high-voltage grounding switch, characterized in that, include: The insulating cylinder (6) has an internal cavity for accommodating a vacuum circuit breaker, and the insulating cylinder (6) has a sliding air passage. A movable contact (10) is slidably disposed within the sliding air passage, the movable contact (10) being configured to switch between two positions: a working position and a contact position; A stationary contact is located in the working position and is used to connect to a vacuum circuit breaker; The first gas path connector (7) is provided at the contact position and is used to realize the grounding function when the moving contact (10) is in the contact position; The second air passage connector (8) is provided at the working position and is used to achieve insulation performance when the moving contact (10) is in the working position.

2. The composite insulated high-voltage grounding switch according to claim 1, characterized in that, Includes a sealing cap (12) for sealing both ends of the sliding air passage, a first air passage connector (7) connected to the sealing cap (12) at one end, a second air passage connector (8) connected to the sealing cap (12) at the other end, and a moving contact (10) configured to switch between a working position and a contact position under the drive of compressed gas.

3. The composite insulated high-voltage grounding switch according to claim 2, characterized in that, The moving contact (10) is connected to a metal bellows, which is connected to one of the sealing caps (12).

4. The composite insulated high-voltage grounding switch according to claim 2, characterized in that, A first sealing ring (11) is installed on the sealing cover (12), and the first sealing ring (11) is used to seal the compressed gas in the sliding air passage of the moving contact.

5. The composite insulated high-voltage grounding switch according to claim 2, characterized in that, The pressure of the compressed gas is 350 kPa to 400 kPa.

6. The composite insulated high-voltage grounding switch according to claim 1, characterized in that, Includes a second sealing ring (9), which is installed on the moving contact (10) to achieve air passage sealing of the moving contact (10) in the sliding air passage.

7. The composite insulated high-voltage grounding switch according to claim 1, characterized in that, The insulating cylinder is an integrally cast casting body. The insulating cylinder also includes an electrode grid (2.3). The electrode grid (2.3) is located on the outside of the insulating cylinder. The electrode grid (2.3) is used to isolate the working position and the contact position to increase the electrical clearance between the working position and the contact position.

8. The composite insulated high-voltage grounding switch according to claim 1, characterized in that, The stationary contact is sealed inside the insulating cylinder; And / or, the first gas connection (7) is a metal gas connection; And / or, the second gas connection (8) is an insulating gas connection.

9. The composite insulated high-voltage grounding switch according to any one of claims 1 to 8, characterized in that, The sliding air passage includes a first sliding air passage (2.1) and a second sliding air passage (2.2). The first sliding air passage (2.1) and the second sliding air passage (2.2) are spaced apart along the height direction of the insulating cylinder (6). Each of the first sliding air passage (2.1) and the second sliding air passage (2.2) is provided with a slidable moving contact (10). Each of the first sliding air passage (2.1) and the second sliding air passage (2.2) is provided with a stationary contact. One of the stationary contacts is connected to the upper electrode of the vacuum circuit breaker, and the other stationary contact is connected to the lower electrode of the vacuum circuit breaker. The first end of the first sliding air passage (2.1) is connected to the first air passage connector (7), and the second end of the first sliding air passage (2.1) is connected to the second air passage connector (8). The first end of the second sliding air passage (2.2) is connected to the second air passage connector (8), and the second end of the second sliding air passage (2.2) is connected to the first air passage connector (7).

10. A high-voltage electrical box for a vehicle, characterized in that, include: The composite insulated high-voltage grounding switch according to any one of claims 1 to 9; High-voltage equipment is connected to the composite insulated high-voltage grounding switch.

Images