Zero-flashover cover and low-voltage electric appliance

Abstract

The invention relates to the technical field of electrical equipment, and discloses a zero-flashover cover and a low-voltage electric appliance. The zero flashover cover comprises an outer cover and an inner cover, the inner cover is arranged in the outer cover, a first space is defined by the inner cover, a second space is formed between the inner cover and the outer cover, a communicating area is arranged on the inner cover, at least one communicating hole communicating the first space with the second space is formed in the communicating area, and a pressure relief area is arranged on the outer cover. The pressure relief area comprises at least one pressure relief hole communicating the second space with the outside, and the communicating area and the pressure relief area are arranged in a staggered mode. According to the zero-flashover cover, charged particles generated in the breaking process of electrical equipment can be reliably stopped and adsorbed, and interphase breakdown of copper bars of a complete cabinet caused by air exhausted when a low-voltage electrical appliance is broken is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of electrical equipment, and in particular to a zero arcing cover and a low-voltage electrical appliance. Background Art

[0002] Frame type circuit breakers / isolating switches are commonly used low voltage electrical appliances in power systems. Taking isolating switches as an example, Figure 1-Figure 3 A schematic diagram of the decomposition structure of an isolating switch is provided, such as Figure 1-Figure 3 As shown, the isolating switch includes an isolating switch body 10', an arc extinguishing chamber 20' and a zero arcing cover 30', wherein the arc extinguishing chamber 20' is connected to the isolating switch body 10' and is used to quickly extinguish the arc generated when the contacts are disconnected. The zero arcing cover 30' is installed at the outlet of the arc extinguishing chamber 20' and is used to stop the charged particles generated during the disconnection process of the isolating switch, thereby achieving zero arcing of the isolating switch. Since the arc generated during the product disconnection process causes the air to expand due to heat, and the air pressure increases sharply in a short period of time, a pressure relief hole 31' is also provided on the zero arcing cover 30', and the air discharged from the arc extinguishing chamber 20' enters the zero arcing cover 30' and is directly discharged from the pressure relief hole 31'.

[0003] Based on the existing structure, a certain amount of charged particles still remain in the air after it is discharged from the zero arc hood. However, as the power density of the complete cabinet increases, the voltage level of the circuit breaker / disconnector increases, and the structure of the complete cabinet becomes gradually compact, the air with a certain amount of charged particles discharged from the zero arc hood reduces the dielectric properties of the air, and there is a risk of causing phase-to-phase breakdown of the copper busbars of the complete cabinet.

[0004] Therefore, there is an urgent need for a zero arcing cover and a low-voltage electrical appliance to solve the above-mentioned technical problems. Summary of the invention

[0005] One purpose of the present invention is to provide a zero arcing cover that can reliably stop and absorb charged particles generated during the disconnection process of electrical equipment, thereby preventing the air discharged during the disconnection of low-voltage electrical equipment from causing phase-to-phase breakdown of the copper busbars of a complete set of cabinets.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A zero arcing cover comprises an outer cover and an inner cover, wherein the inner cover is arranged inside the outer cover, the inner cover encloses a first space, a second space is formed between the inner cover and the outer cover, a connecting area is arranged on the inner cover, the connecting area has at least one connecting hole connecting the first space and the second space, and a pressure relief area is arranged on the outer cover, the pressure relief area includes at least one pressure relief hole connecting the second space with the outside, and the connecting area and the pressure relief area are staggered.

[0008] As an optional solution, the inner cover includes a labyrinth structure, which is located in the second space and between the connecting area and the pressure relief area. The air entering the second space passes through the labyrinth structure and is discharged from the pressure relief hole.

[0009] As an optional solution, the inner cover includes a first cover body, the first cover body encloses the first space, and the maze structure includes a plurality of partitions arranged at intervals on the outside of the first cover body, and air flow channels are formed between adjacent partitions.

[0010] As an optional solution, a partition is further provided in the second space, at least part of the partition is opposite to the exit of the maze structure, two sides of the partition are connected, and the maze structure and the pressure relief zone are respectively located on two sides of the partition.

[0011] As an optional solution, the inner cover includes a first side wall, the communication area is arranged on the first side wall, the outer cover includes a second side wall, the pressure relief area is arranged on the second side wall, and the first side wall and the second side wall are arranged at an angle.

[0012] As an optional solution, a partition is provided in the second space, at least part of the partition is opposite to the pressure relief zone, two sides of the partition are connected, and the communication zone and the pressure relief zone are respectively located on two sides of the partition.

[0013] As an optional solution, the inner cover further includes a third side wall, the third side wall is connected to the first side wall and is arranged at an angle, and the third side wall is at least partially opposite to the partition.

[0014] As an optional solution, a metal baffle is provided in the second space, and a plurality of through holes are provided on the metal baffle. The air is discharged from the pressure relief holes after passing through the metal baffle.

[0015] As an optional solution, the zero arcing cover includes at least two inner covers, and the at least two inner covers divide the outer cover into a corresponding number of independent second spaces, each of the first spaces is correspondingly connected to one of the second spaces, and each of the second spaces is correspondingly provided with the pressure relief zone; or

[0016] The zero arcing cover comprises at least two inner covers, at least two inner covers are arranged in the outer cover and form a second space with the outer cover, and at least two second spaces are communicated with the second space; or

[0017] The zero arcing cover includes at least two outer covers and a corresponding number of inner covers, and each of the outer covers is correspondingly arranged in one of the outer covers.

[0018] Another object of the present invention is to provide a low-voltage electrical appliance which, by adopting the above-mentioned zero arcing cover, can completely eliminate or greatly reduce the concentration of charged particles discharged during the disconnection process, thereby avoiding phase-to-phase breakdown of the copper busbars of nearby equipment cabinets.

[0019] To achieve this object, the present invention adopts the following technical solutions:

[0020] The low-voltage electrical appliance comprises an electrical appliance body and the zero arcing cover, wherein the electrical appliance body is a circuit breaker body or an isolating switch body.

[0021] The beneficial effects of the present invention are:

[0022] The zero arcing cover of the present invention comprises an outer cover and an inner cover. The inner cover is arranged in the outer cover to form two relatively independent first spaces and a second space. The first space and the second space are connected through a connecting hole in a connecting area. When air with charged particles is discharged from the arc extinguishing chamber of the low-voltage electrical appliance, it will first enter the first space. The air will make a detour in the first space and fully contact with the side wall of the first space, so a part of the charged particles can be eliminated. Then the air will enter the second space from the connecting hole. Since the connecting area and the pressure relief area are staggered, the air will also make a detour in the second space and fully contact with the outer wall of the inner cover and the inner wall of the outer cover, so as to further eliminate the charged particles, thereby ensuring that the charged particles in the air finally discharged from the pressure relief hole are completely eliminated or the concentration is extremely small, thereby avoiding the phase breakdown of the copper busbars of the complete cabinet caused by the discharged air.

[0023] The low-voltage electrical apparatus of the present invention, by adopting the above-mentioned zero arcing cover, can completely eliminate or greatly reduce the concentration of charged particles discharged during the disconnection process, thereby avoiding phase-to-phase breakdown of the copper busbars of nearby equipment cabinets. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the exploded structure of the isolating switch provided by the prior art;

[0025] Figure 2 It is a structural schematic diagram of a zero arcing cover provided by the prior art;

[0026] Figure 3 It is a schematic diagram of the flow path of the isolating switch provided by the prior art for exhausting air when breaking the current;

[0027] Figure 4 It is a schematic diagram of the exploded structure of the isolating switch provided in a specific embodiment of the present invention;

[0028] Figure 5 It is a schematic diagram of the exploded structure of the zero arcing cover provided by a specific embodiment of the present invention;

[0029] Figure 6It is a schematic diagram of the flow path of the isolating switch provided in a specific embodiment of the present invention for exhausting air when breaking the current;

[0030] Figure 7 It is a schematic structural diagram of an inner cover provided in a specific embodiment of the present invention.

[0031] In the figure:

[0032] 10′, isolating switch body; 20′, arc extinguishing chamber; 30′, zero arcing cover; 31′, pressure relief hole;

[0033] 100, zero arcing cover; 200, isolating switch body; 300, arc extinguishing chamber;

[0034] 10. outer cover; 11. second cover body; 111. pressure relief area; 1111. pressure relief hole; 112. second side wall; 12. partition;

[0035] 20, inner cover; 21, first cover body; 211, communication area; 2111, communication hole; 212, first side wall; 213, third side wall; 22, labyrinth structure; 221, barrier member; 23, connecting plate;

[0036] 30. First Space;

[0037] 40. The second space. DETAILED DESCRIPTION

[0038] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0039] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or 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, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0041] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0042] This embodiment provides a zero arcing cover and a low-voltage electrical appliance, wherein the low-voltage electrical appliance may be a circuit breaker or an isolating switch. The low-voltage electrical appliance comprises an electrical appliance body, an arc extinguishing chamber 300 and a zero arcing cover 100. Taking the low-voltage electrical appliance as an isolating switch as an example, Figure 4 As shown, the electrical appliance body is the isolating switch body 200. In other embodiments, the low-voltage electrical appliance can be a circuit breaker, and the electrical appliance body at this time is the circuit breaker body. In this embodiment, the arc extinguishing chamber 300 is connected to the isolating switch body 200, and the zero arc extinguishing cover 100 is installed at the outlet of the arc extinguishing chamber 300. The isolating switch body 200 will generate arcs and charged particles when breaking the current. The arc extinguishing chamber 300 is used to quickly extinguish the arc, protect the contacts and other components of the isolating switch body 200 from damage by the arc, and also ensure the reliable and safe operation of the power system. Under the action of the arc, the air in the arc extinguishing chamber 300 expands due to heat, and the air pressure increases sharply in a short time, and is discharged after passing through the zero arc extinguishing cover 100. The zero arc extinguishing cover 100 can block and absorb the charged particles in the air, and prevent the discharged air from causing the copper busbars of other electrical equipment in the equipment cabinet to break through.

[0043] like Figure 4-Figure 6As shown, the zero arcing cover 100 includes an outer cover 10 and an inner cover 20, the inner cover 20 is arranged in the outer cover 10, the inner cover 20 is enclosed into a first space 30, a second space 40 is formed between the inner cover 20 and the outer cover 10, a connecting area 211 is arranged on the inner cover 20, and the connecting area 211 has at least one connecting hole 2111 connecting the first space 30 and the second space 40, and a pressure relief area 111 is arranged on the outer cover 10, and the pressure relief area 111 includes at least one pressure relief hole 1111 connecting the second space 40 with the outside, and the connecting area 211 and the pressure relief area 111 are staggered.

[0044] After the isolating switch body 200 interrupts the current, when the air with charged particles is discharged from the arc extinguishing chamber 300, it will first enter the first space 30. The air will make a detour in the first space 30 and fully contact the side wall of the first space 30, so a part of the charged particles can be eliminated. Then the air enters the second space 40 from the connecting hole 2111. Since the connecting area 211 and the pressure relief area 111 are staggered, the air will also make a detour in the second space 40 and fully contact the outer wall of the inner cover 20 and the inner wall of the outer cover 10, so as to further eliminate the charged particles, and ensure that the charged particles in the air finally discharged from the pressure relief hole 1111 are completely eliminated or the concentration is extremely small, thereby avoiding the phase-to-phase breakdown of the copper busbars of the complete cabinet caused by the discharged air.

[0045] In this embodiment, the inner cover 20 and the outer cover 10 are both made of insulating materials, such as plastic. Specifically, the inner cover 20 includes a first cover body 21, which is configured as a box-shaped component with an open bottom, and is surrounded to form a first space 30. The outer cover 10 includes a second cover body 11, which is configured as a box-shaped component with an open bottom, and is used to be fixed on the disconnector body 200. After the inner cover 20 is arranged in the outer cover 30, a second space 40 is formed between the first cover body 21 and the second cover body 11. The cross-sectional size of the second cover body 11 is larger than the cross-sectional size of the first inner cover 20, and the height of the second cover body 11 is larger than the height of the first inner cover 20, so that the entire inner cover 20 can be completely loaded into the second cover body 11, and the second space 40 is formed between the outer wall of the first cover body 21 and the inner wall of the second cover body 11. The opening of the first cover body 21 is opposite to the outlet of the arc extinguishing chamber 300 of the disconnector, and the opening of the second inner cover body 20 (the part not blocked by the inner cover 20) is offset from the outlet of the arc extinguishing chamber 300, thereby ensuring that the air exhausted from the arc extinguishing chamber 300 must pass through the first space 30 and then enter the second space 40 through the connecting hole 2111.

[0046] In some embodiments, the zero arcing cover 100 includes at least two inner covers 20, at least two inner covers 20 are arranged in the outer cover 10, and at least two inner covers 20 divide the outer cover 10 into a corresponding number of independent second spaces 40, each first space 30 is correspondingly connected to a second space 40, and each second space 40 is correspondingly provided with a pressure relief zone 111. In other words, the zero arcing cover 100 as a whole includes multiple groups of first spaces 30 and second spaces 40, and the charged particles generated by the contact disconnection of each pole of the low-voltage electrical appliance are correspondingly eliminated through a group of first spaces 30 and second spaces 40. In this embodiment, Figure 4-Figure 6 As shown, the isolating switch is a DC isolating switch, which includes two poles. Correspondingly, the zero arc cover 100 includes two inner covers 20. After the two inner covers 20 are installed in the outer cover 10, two independent second spaces 40 are formed. The first space 30 formed by each inner cover 20 is correspondingly connected to a second space 40. The two groups of first spaces 30 and second spaces 40 respectively shield and absorb the charged particles generated by the contact disconnection of the two poles of the DC isolating switch. In other embodiments, a corresponding number of inner covers 20 can also be set according to the number of poles of the low-voltage electrical appliance. In this embodiment, as Figure 6 and Figure 7 As shown, the inner cover 20 further includes a connecting plate 23, which is connected to the outer side of the first cover body 21. After the inner cover 20 is installed in the outer cover 10, the connecting plate 23 abuts against the inner wall of the outer cover 10, so that at least two independent second spaces 40 can be formed in the outer cover 10. In this embodiment, both inner covers 20 are provided with the connecting plate 23, and the two connecting plates 23 are arranged in close contact. In other embodiments, only one of the inner covers 20 may be provided with the connecting plate 23.

[0047] In some embodiments, the zero arcing cover 100 includes at least two inner covers 20, at least two inner covers 20 are arranged in the outer cover 10, only one second space 40 is formed in the outer cover 10, and each second space 40 is connected to the second space 40. In this embodiment, the number of the inner covers 20 can be set according to the number of poles of the low-voltage electrical appliance, and the air with charged particles generated by the disconnection of each pole contact enters a first space 30, and the air in each first space 30 enters the second space 40 and is discharged.

[0048] In some embodiments, the zero arcing cover 100 includes at least two outer covers 10 and a corresponding number of inner covers 20, and each outer cover 10 is correspondingly arranged in an outer cover 10. In this embodiment, the number of inner covers 20 and outer covers 10 can be set according to the number of poles of the low-voltage electrical appliance, and the air with charged particles generated by the disconnection of each pole contact enters a first space 30 and a second space 40 to eliminate the charged particles.

[0049] In some embodiments, the zero arcing cover 100 includes only an inner cover 20 and an outer cover 10, and the charged particles generated by the disconnection of the contacts of each pole of the two-pole or multi-pole low-voltage electrical appliance are eliminated by sharing the inner cover 20 and the outer cover 10.

[0050] In this embodiment, Figure 5 and Figure 6 As shown, the first cover body 21 includes a first side wall 212, the communication area 211 is arranged on the first side wall 212, the second cover body 11 includes a second side wall 112, the pressure relief area 111 is arranged on the second side wall 112, and the first side wall 212 is arranged at an angle to the second side wall 112. Such an arrangement allows the air discharged from the communication hole 2111 to make at least one turn before being discharged from the pressure relief hole 1111, thereby increasing the flow path of the air in the second space 40, which is conducive to the side wall of the second space 40 to fully stop and absorb the charged particles in the air.

[0051] In this embodiment, Figure 6 As shown, the first side wall 212 and the second side wall 112 are arranged vertically, and the first side wall 212 is the top plate of the first cover body 21, and the second side wall 112 is the side plate of the second cover body 11. The communication area 211 on the first side wall 212 is located at one end of the first side wall 212 away from the second side wall 112, so that the flow range and time of air in the second space 40 can be increased as much as possible, and the effect of stopping and adsorbing charged particles can be improved. The inner cover 20 also includes a third side wall 213, which is connected to the first side wall 212 and is opposite to and spaced from the second side wall 112. In this way, after the air enters the second space 40, it can not only flow above the first side wall 212, but also flow between the second side wall 112 and the third side wall 213, further improving the effect of removing charged particles. In this embodiment, the outer cover 10 includes two second side walls 112, which are arranged opposite to each other, and each second side wall 112 is provided with a pressure relief area 111. Optionally, the two second side walls 112 are respectively located on the left and right sides of the low-voltage electrical appliance.

[0052] like Figure 6 and Figure 7As shown, the inner cover 20 also includes a labyrinth structure 22, which is located in the second space 40 and between the connecting area 211 and the pressure relief area 111. The air entering the second space 40 passes through the labyrinth structure 22 and is discharged from the pressure relief hole 1111. When the airflow flows through the labyrinth structure 22, it not only continuously changes the flow direction, but also forms a vortex or a return flow, so that it can more fully contact the side wall of the labyrinth structure 22, thereby greatly improving the effect of removing charged particles. In this embodiment, the labyrinth structure 22 is arranged on the first side wall 212 and is located on the side of the connecting area 211 close to the pressure relief area 111. In addition, the upper end of the labyrinth structure 22 abuts against the top plate of the second cover body 11, so as to ensure that the air must first pass through the labyrinth structure 22 and then be discharged from the pressure relief area 111. In other embodiments, the labyrinth structure 22 can also be arranged on the third side wall 213, or a part is arranged on the first side wall 212, and a part is arranged on the second side wall 112.

[0053] like Figure 7 As shown, the maze structure 22 includes a plurality of spacers 221 arranged at intervals on the outside of the first cover body 21, and an air flow channel for air to pass through is formed between adjacent spacers 221. With such an arrangement, when the air flows out of one air flow channel, it may flow to different air flow channels, thereby increasing the circuitous path and time of the air in the second space 40, so as to fully contact the spacers 221 and improve the effect of removing charged particles. In this embodiment, the plurality of spacers 221 are columnar and evenly distributed. In other embodiments, the plurality of spacers 221 can also be arranged to be unevenly distributed. Optionally, the cross-section of the spacer 221 can be in various shapes such as a triangle, a hypotenuse, a grid, a line, a Tesla valve, etc., as long as it can increase the contact between the air and the material, it is not limited here.

[0054] like Figure 6 As shown, a partition 12 is also provided in the second space 40, at least part of the partition 12 is opposite to the outlet of the labyrinth structure 22, the two sides of the partition 12 are connected, and the labyrinth structure 22 and the pressure relief zone 111 are respectively located on both sides of the partition 12. Therefore, after the air passes through the labyrinth structure 22, it needs to further bypass the partition 12 to reach the pressure relief zone 111, thereby further increasing the flow path of the air in the second space 40 and improving the zero arcing cover 100 The effect of eliminating charged particles in the air. In this embodiment, the partition 12 is connected to the top plate of the second cover body 11, and the lower end is higher than the lower end of the first cover body 21. Air can pass from below the partition 12. In this embodiment, the partition 12 is arranged between the third side wall 213 and the second side wall 112, so the partition 12 is also opposite to the pressure relief area 111. Such a configuration ensures that the airflow will not be discharged directly from the pressure relief hole 1111 after bypassing the front side of the partition 12, but needs to further move along the back side of the partition 12 to reach the pressure relief hole 1111, thereby further increasing the air discharge path.

[0055] In summary, combined Figure 6 As shown, the flow path of air in the zero arcing cover 100 is roughly as follows: the air enters the first space 30 from the opening on the lower side of the first cover body 21, reaches the connecting area 211 after the first space 30 is fully in contact with the inner wall of the first cover body 21, and enters the second space 40 upward from the connecting hole 2111; then the air is stopped by the top plate of the second cover body 11 and changes to horizontal movement and passes through the labyrinth structure 22; then the air passes through the stopper of the partition 12 and flows downward between the partition 12 and the second side wall 112; then the air flows horizontally around the partition 12 and then turns back, and finally is discharged from the pressure relief hole 1111.

[0056] Optionally, in this embodiment, the partition 12 is integrally formed with the second cover body 11. In other embodiments, the partition 12 can also be fixed to the second cover body 11 by bonding, fastener connection, etc.

[0057] In this embodiment, the zero arcing cover 100 also includes a metal baffle (not shown in the figure), which is arranged in the second space 40. The metal baffle is provided with a plurality of through holes, and the air is discharged from the pressure relief hole 1111 after passing through the metal baffle. On the one hand, compared with the inner cover 20 and the outer cover 10 of the insulating material, the metal baffle can absorb the charged particles more efficiently, thereby ensuring that the charged particles in the air finally discharged from the pressure relief hole 1111 are completely eliminated or the content is extremely low; on the other hand, the metal baffle is arranged in the second space 40, thereby ensuring that it is far enough away from the arc extinguishing chamber 300, so as to avoid arc breakdown. Optionally, the metal baffle can be arranged in the maze structure 22, or near the partition 12, or near the pressure relief zone 111, which is not specifically limited here. Optionally, the metal baffle can be fixed by plugging, fastener connection, etc. Optionally, the metal baffle can be made of stainless steel or other metal materials, which is not limited here.

[0058] Obviously, the above embodiments of the present invention are only examples for clearly explaining the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation and application scope, and the content of this specification should not be understood as limiting the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. Zero flashover cover, characterized in that: The invention comprises an outer cover (10) and an inner cover (20), wherein the inner cover (20) is arranged inside the outer cover (10), the inner cover (20) encloses a first space (30), a second space (40) is formed between the inner cover (20) and the outer cover (10), a connecting area (211) is arranged on the inner cover (20), the connecting area (211) has at least one connecting hole (2111) connecting the first space (30) and the second space (40), and the outer cover (10) is provided with a pressure relief area (111), the pressure relief area (111) includes at least one pressure relief hole (1111) connecting the second space (40) with the outside, and the connecting area (211) and the pressure relief area (111) are staggered.

2. The zero arcing cover according to claim 1, characterized in that: The inner cover (20) comprises a labyrinth structure (22), wherein the labyrinth structure (22) is located in the second space (40) and between the connecting area (211) and the pressure relief area (111), and air entering the second space (40) passes through the labyrinth structure (22) and is discharged from the pressure relief hole (1111).

3. The zero arcing cover according to claim 2, characterized in that: The inner cover (20) comprises a first cover body (21), the first cover body (21) enclosing the first space (30), and the labyrinth structure (22) comprises a plurality of partitions (221) arranged at intervals on the outside of the first cover body (21), and air flow channels are formed between adjacent partitions (221).

4. The zero arcing cover according to claim 2, characterized in that: A partition (12) is also provided in the second space (40), at least a portion of the partition (12) is opposite to the outlet of the labyrinth structure (22), two sides of the partition (12) are connected, and the labyrinth structure (22) and the pressure relief area (111) are respectively located on two sides of the partition (12).

5. The zero arcing cover according to claim 1, characterized in that: The inner cover (20) comprises a first side wall (212), the communication area (211) is arranged on the first side wall (212), the outer cover (10) comprises a second side wall (112), the pressure relief area (111) is arranged on the second side wall (112), and the first side wall (212) and the second side wall (112) are arranged at an angle.

6. The zero arcing cover according to claim 5, characterized in that: A partition (12) is provided in the second space (40), at least a portion of the partition (12) is opposite to the pressure relief area (111), two sides of the partition (12) are connected, and the communication area (211) and the pressure relief area (111) are respectively located on two sides of the partition (12).

7. The zero arcing cover according to claim 6, characterized in that: The inner cover (20) further comprises a third side wall (213), the third side wall (213) being connected to the first side wall (212) and arranged at an angle, and the third side wall (213) is at least partially opposite to the partition plate (12).

8. The zero arcing cover according to claim 1, characterized in that: A metal baffle is provided in the second space (40), and a plurality of through holes are provided on the metal baffle. Air passes through the metal baffle and is discharged from the pressure relief hole (1111).

9. The zero arcing cover according to any one of claims 1 to 8, characterized in that: The zero arcing cover comprises at least two inner covers (20), the at least two inner covers (20) divide the outer cover (10) into a corresponding number of independent second spaces (40), each of the first spaces (30) is correspondingly connected to one of the second spaces (40), and each of the second spaces (40) is correspondingly provided with the pressure relief zone (111); or The zero arcing cover comprises at least two inner covers (20), at least two inner covers (20) are arranged in the outer cover (10), and form a second space (40) with the outer cover (10), and at least two second spaces (40) are communicated with the second space (40); or The zero arcing cover comprises at least two outer covers (10) and a corresponding number of inner covers (20), and each of the outer covers (10) is correspondingly arranged inside one of the outer covers (10).

10. Low voltage electrical apparatus, characterized in that: It comprises an electrical appliance body and the zero arcing cover as claimed in any one of claims 1 to 9, wherein the electrical appliance body is a circuit breaker body or an isolating switch body (200).

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