Fault arc circuit breaker

Abstract

The utility model discloses a fault arc circuit breaker which comprises a shell, a main line conductor, a mutual inductor and a circuit board, a first cavity is formed in the shell, the mutual inductor and the circuit board are both arranged in the first cavity, and at least part of the main line conductor can penetrate through the mutual inductor; wherein the first cavity comprises a mutual inductor containing area, and the mutual inductor is located in the mutual inductor containing area; an avoiding space is formed in the circuit board, and the avoiding space corresponds to the mutual inductor accommodating area; a limiting structure is arranged on the shell and located on one side of the mutual inductor so as to limit the mutual inductor to slide towards the circuit board in the penetrating direction of the main line conductor. The circuit board has the characteristic that the circuit board is more stable.

Description

Technical Field

[0001] This application relates to the field of low-voltage electrical appliances, specifically a fault arc circuit breaker. Background Technology

[0002] An arc fault circuit interrupter (AFDD) is used to detect arc faults in electrical circuits and cut off the power supply in a timely manner when a fault is detected to prevent electrical fires.

[0003] Existing arc fault circuit breakers (AFCs) are very similar in design to residual current circuit breakers (RCCBs), both featuring tripping mechanisms, testing circuits, protection circuits, and other components. The main difference lies in their current transformers: RCCBs use zero-sequence current transformers, while AFCs use high-frequency current transformers. RCCBs employ residual current protection circuits, while AFCs use arc fault protection circuits. RCCBs use residual current testing circuits, which simulate leakage current using mechanical switches. Conversely, AFCs use arc fault testing circuits, which simulate arc fault current using mechanical switches.

[0004] The functionality of test and protection circuits relies heavily on circuit board design. In existing arc fault circuit breakers, the circuit board and instrument transformer are housed together within a single enclosure. These two components are relatively close, and the instrument transformer is installed through the main conductor. While the main conductor provides some radial restraint on the instrument transformer, it is prone to sliding along the conductor's path during transport. This sliding is not ideal; it can easily slide towards the circuit board, scraping components or their solder joints, reducing component lifespan, and in severe cases, causing circuit failure. For example, the arc fault circuit breaker with a double trip unit and its tripping method disclosed in CN111326366A also exhibits a high risk of instrument transformer slippage.

[0005] Therefore, how to improve the design of current transformers and prevent fault arcing circuit breakers caused by current transformers scraping the circuit board is also a question worth considering. Summary of the Invention

[0006] In view of this, the purpose of this application is to overcome the shortcomings of the prior art and to provide a fault arc circuit breaker.

[0007] This application provides: a fault arc circuit breaker, comprising a housing, a main line conductor, an instrument transformer, and a circuit board. A first cavity is provided within the housing, and both the instrument transformer and the circuit board are disposed within the first cavity. At least a portion of the main line conductor passes through the instrument transformer. The first cavity includes an instrument transformer accommodating area, and the instrument transformer is located within this area. A clearance space is provided on the circuit board, corresponding to the instrument transformer accommodating area. A limiting structure is provided on the housing, located on one side of the instrument transformer, to restrict the instrument transformer from sliding towards the circuit board along the direction of the main line conductor.

[0008] In some embodiments of this application, the current transformer includes a body portion and a wiring portion, the wiring portion being located on one side of the body portion, and the limiting structure including a first limiting rib, the width of the first limiting rib being d, 1.5mm≤d≤5mm; the first limiting rib blocks one side of a portion of the body portion to restrict the current transformer from sliding toward the circuit board.

[0009] In some embodiments of this application, the outer shell includes a first half-shell and a second half-shell, and the first cavity is composed of the first half-shell and the second half-shell; the first half-shell includes a partition, and a first limiting rib is located on the partition and extends toward the second half-shell, with the extension dimension being the width dimension of the first limiting rib.

[0010] In some embodiments of this application, the current transformer includes a body portion and a wiring portion, the wiring portion being located on one side of the body portion, and the limiting structure including a second limiting rib; the second limiting rib blocks one side of a portion of the wiring portion or the second limiting rib blocks one side of both a portion of the wiring portion and a portion of the body portion, so as to restrict the current transformer from sliding toward the circuit board.

[0011] In some embodiments of this application, the outer shell includes a first half-shell and a second half-shell, and the first cavity is composed of the first half-shell and the second half-shell; the first half-shell includes a partition, and a second limiting rib is located on the partition and extends toward the second half-shell, with the extension dimension being the width dimension D of the second limiting rib, and D is not less than the distance from the center hole of the current transformer to the partition.

[0012] In some embodiments of this application, at least two positioning posts are provided inside the housing, and a matching positioning hole is provided on the circuit board. The circuit board forms a positioning fit with the positioning post through the positioning hole; one of the positioning posts is a second positioning post, and the second limiting rib is integrally formed with the second positioning post.

[0013] In some embodiments of this application, the second limiting rib includes a first surface and a second surface, which are two mutually perpendicular surfaces; the first surface is used to support the circuit board, and the second surface is used to block one side of the wiring portion or to block one side of the wiring portion and part of the body portion.

[0014] In some embodiments of this application, a fault arc test circuit is provided on the circuit board. The fault arc test circuit includes a mechanical switch, which is disposed in a first cavity. At least two positioning posts are provided inside the housing. Adaptive positioning holes are provided on the circuit board, and the circuit board forms a positioning fit with the positioning posts through the positioning holes. One of the positioning posts is a first positioning post, and a portion of the mechanical switch is attached to the first positioning post.

[0015] In some embodiments of this application, the mechanical switch includes a test button, a moving spring, and a stationary conductive element; the moving spring includes a first end, a second end, and a support portion, the first end being electrically connected to the circuit board, the support portion being disposed against a first positioning post, and the second end extending toward the direction of the stationary conductive element; a bearing boss is provided inside the housing, one end of the stationary conductive element being electrically connected to the circuit board, and the other end abutting against the bearing boss; the test button is located above the moving spring, and the second end is normally open with the stationary conductive element, and the normally open state is changed to a closed state under the action of external force.

[0016] In some embodiments of this application, an indicator light is provided on the circuit board, and a light guide post is provided on the housing, with the light guide post corresponding to the indicator light.

[0017] The advantages of this application compared to the prior art are:

[0018] Compared to existing technologies, this new technology adds a limiting structure and a clearance space on the circuit board. This clearance space corresponds to the transformer housing area and refers to areas where the two overlap or coincide, making it less likely for the transformer to come into contact with the circuit board within the transformer housing area. Furthermore, the limiting structure, located on one side of the transformer, restricts the transformer from sliding towards the circuit board along the main conductor's path. This prevents the transformer from scraping the circuit board, improving component lifespan and circuit board stability. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A perspective view of a fault arc circuit breaker according to an embodiment of this application is shown;

[0021] Figure 2 This diagram shows a fault arc circuit breaker according to an embodiment of the present application after the second half-shell is removed;

[0022] Figure 3This application shows a perspective view and a partial enlarged view of the fault arc circuit breaker after the second half-shell is removed, according to an embodiment of the present application.

[0023] Figure 4 This diagram shows a fault arc circuit breaker according to an embodiment of the present application after the second half-shell and circuit board have been removed;

[0024] Figure 5 The illustration shows a perspective view and a partial enlarged view of the fault arc circuit breaker according to an embodiment of this application after removing the second half-shell and the circuit board. Detailed Implementation

[0025] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0026] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing 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, and therefore should not be construed as a limitation of this application.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0028] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0029] In 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. Example

[0030] like Figures 1-5 As shown, an embodiment of this application is a fault arc circuit breaker.

[0031] The fault arc circuit breaker includes a casing, main line conductor 600, current transformer 200, circuit board 300, operating mechanism, moving contact, stationary contact, trip unit 400, tripping mechanism 500, etc.

[0032] The outer shell includes a first half-shell 110, a second half-shell 120, and a third half-shell 130.

[0033] The second half-shell 120 is located on one side of the first half-shell 110, and the third half-shell 130 is located on the other side of the first half-shell 110. Here, the first half-shell 110 and the second half-shell 120 are fixed together by snap-fit, and the first half-shell 110 and the third half-shell 130 are fixed together by snap-fit, and then the three are fastened together by rivets. Of course, it is also possible to fasten them together by using only rivets.

[0034] Here, the first half-shell 110 and the third half-shell 130 together form the second space P2, which is used to accommodate the operating mechanism, moving contact, stationary contact and other components (this part can also be called the circuit breaker part). The structure of the moving contact, stationary contact and the second space P2 are common knowledge and will not be described in detail here.

[0035] Here, the first half-shell 110 and the second half-shell 120 together form the first cavity P1, which is used to accommodate the current transformer 200, the circuit board 300, the trip unit 400, and the tripping mechanism 500, etc.

[0036] Here, the circuit board 300 is fixed to the outer casing through a positioning fit. Three positioning posts are formed on the first half-shell 110: a first positioning post 111a, a second positioning post 111b, and a third positioning post, arranged in a triangular pattern. Three matching positioning holes 301 are provided on the circuit board 300, each engaging with one of the three positioning posts. Of course, two or more positioning posts can also be used, as long as at least two are present.

[0037] Here, circuit board 300 includes a fault arc protection circuit, a fault arc test circuit, and a status indication circuit.

[0038] The fault arc protection circuit relies on the current transformer 200 to sample the main line conductor 600. When the sampled current signal meets the set threshold, it will cause the trip unit 400 to be energized, which will cause the trip mechanism 500 to work, causing the operating mechanism to trip and the line where the fault arc circuit breaker is located to be disconnected.

[0039] The fault arc test circuit mainly uses a mechanical switch to generate a simulated fault current, which causes the current signal sampled by the current transformer 200 to exceed a set threshold, causing the operating mechanism to trip (this is the process by which the fault arc protection circuit mentioned above achieves tripping).

[0040] The mechanical switch is attached to the first positioning post 111a. This arrangement allows the first positioning post 111a to serve both as the mounting point for the circuit board 300 and as the mounting point for the mechanical switch, simplifying the internal structure of the circuit breaker and achieving a dual-purpose function.

[0041] The mechanical switch includes a test button 310, a moving spring 320, and a stationary conductive element 330. The moving spring 320, using a conductive spring sheet (or a conductive torsion spring), includes a first end 320a, a second end 320b, and a resting part 320c. The resting part 320c connects the first end 320a and the second end 320b, and is positioned against the first positioning post 111a. The first end 320a is electrically connected to the circuit board 300, for example, by soldering. The second end 320b extends towards the stationary conductive element 330 and is normally open (open when not triggered, hence also called normally open). The stationary conductive element 330 uses a conductive pin, one end of which is soldered to the circuit board 300, and the other end extends towards the first half-shell 110, abutting against the support boss 112 of the first half-shell 110. Here, the support boss 112 is L-shaped. The test button 310 is located above the moving spring 320. When the user presses the test button 310, the second end 320b of the test button 310 contacts the static conductive element 330 under the action of external force (normally open to closed), and the fault arc test circuit is connected. When the external force is released, the test button 310 is reset under the action of the moving spring 320, and the second end 320b returns to its normally open state with the static conductive element 330.

[0042] The status indicator circuit provides feedback on the circuit breaker's operating status via indicator lights. For example, a green light indicates the circuit breaker is closed, while a red light indicates it is in a fault-broken state. A mounting slot is provided on the first half-shell 110, containing a light guide post 350. The light guide post 350 corresponds to the indicator light, effectively guiding the light signal for easy user identification.

[0043] These three circuit configurations are common knowledge in the field and are not the direction of improvement of this application (the direction of improvement of this application is mechanical structure improvement). Therefore, only their functions are introduced here, and their specific circuit configurations are not described in detail.

[0044] The first cavity P1 contains a transformer housing area P10, where the transformer 200 is housed. The transformer 200 is mounted on the main line conductor 600 to induce current in the circuit flowing through it. The transformer 200 serves as the sampling element for the fault arc protection circuit. The transformer 200 used here is a high-frequency current transformer, such as a Rogowski Coil transformer. However, it is not limited to this specific current transformer; any transformer capable of fault arc detection is acceptable. The transformer 200 includes a body 210 (which can also be described as a magnetic ring and winding section) and a wiring section 220 (the part where the winding leads connect to the circuit board 300). The wiring section 220 is used for electrical connection to the circuit board 300, allowing the signal sampled by the transformer 200 to be transmitted to the circuit board 300. For the wiring section 220, it can be connected to the circuit board 300 by wires or by connectors.

[0045] The circuit board 300 is also fixed in the first cavity P1. Here, the circuit board 300 has a clearance space 340, which corresponds to the transformer housing area P10. This means that the clearance space 340 and the transformer housing area P10 are either identical or partially overlapping. Due to the design of the clearance space 340, the transformer 200 is less likely to come into contact with the circuit board 300 during installation.

[0046] A limiting structure is provided on the outer casing. This limiting structure blocks one side of the current transformer 200, preventing the current transformer 200 from sliding towards the circuit board 300 along the direction in which the main conductor 600 passes. This prevents the current transformer 200 from scratching the circuit board 300. Here, since the current transformer 200 itself is passed through by the main conductor 600, the radial movement of the current transformer 200 is generally limited by the main conductor 600, so the movement is relatively slight, and this movement is unlikely to scratch the circuit board 300.

[0047] There are two specific limiting structures, and both methods do not necessarily need to be present simultaneously; having one of them is sufficient. Of course, using both methods will result in a better limiting effect.

[0048] In the first approach, the limiting structure includes a first limiting rib 113, the width of which is d, and d is 2mm. In this approach, the first limiting rib 113 blocks one side of a portion of the main body 210, thereby limiting the current transformer 200 by obstructing the main body 210 and preventing the current transformer 200 from sliding towards the circuit board 300. With this design, because a portion of the main body 210 is closer to the partition 115 of the first housing than the wiring portion 220, a small protrusion of the rib can achieve a good limiting effect. Such a limiting rib also does not easily occupy too much of the first cavity P1. Of course, the value of d can also be 1.5mm, 3mm, 3.5mm, etc., as long as it meets the condition 1.5mm ≤ d ≤ 5mm.

[0049] The first rib is actually a rib that extends from the partition 115 toward the second half-shell 120. The width of the first limiting rib 113 is actually the extension dimension of the first limiting rib 113.

[0050] As a second method, the limiting structure includes a second limiting rib 114, which blocks one side of a portion of the wiring section 220 and a portion of the body section 210 to prevent the current transformer 200 from sliding towards the circuit board 300. The wiring section 220 is a certain distance from the partition 115, so the second limiting rib 114 can also provide a good limiting effect. Of course, in addition to this, the second limiting rib 114 can also block only one side of the wiring section 220.

[0051] The second limiting rib 114 is also a rib extending from the partition 115 toward the second half-shell 120, except that its extension dimension is D (that is, the width dimension of the second limiting rib 114). In this embodiment, D is greater than the distance from the center hole of the current transformer 200 to the partition 115. Of course, D can also be equal to the distance from the center hole of the current transformer 200 to the partition 115, as long as it is not less than the distance from the center hole of the current transformer 200 to the partition 115.

[0052] The second limiting rib 114 can be an independent rib or a rib attached to the positioning post of the mounting circuit board 300. To simplify the structure and ensure the structural strength of the injection molding, the second limiting rib 114 is integrally molded with the second positioning post 111b.

[0053] The second limiting rib 114 is actually shorter than the second positioning post 111b. Therefore, the second limiting rib 114 includes a first surface 114a and a second surface 114b, which are two mutually perpendicular surfaces. The second surface 114b is used to block the current transformer 200, while the first surface 114a can be used to support the circuit board 300 (abut against the circuit board 300). This allows a single limiting rib to have a dual function, simplifying the structural design and improving the stability of the circuit board 300.

[0054] Of course, the above example illustrates a structure where the arc fault protection module and the circuit breaker are integrated. In addition, a split structure can also be used (for example, an arc fault protection module consisting only of the first half-shell 110, the second half-shell 120, and the circuit board 300 and other components inside them, which can be spliced ​​with a circuit breaker to achieve the arc fault protection function).

[0055] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example 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.

[0056] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A fault arc circuit breaker, comprising a housing, a main line conductor, a current transformer, and a circuit board, wherein a first cavity is provided inside the housing, and the current transformer and the circuit board are both disposed within the first cavity, and at least a portion of the main line conductor passes through the current transformer; characterized in that: The first cavity includes a transformer housing area, in which the transformer is located; a clearance space is provided on the circuit board, which corresponds to the transformer housing area; a limiting structure is provided on the housing, located on one side of the transformer, to restrict the transformer from sliding along the main conductor path towards the circuit board.

2. The fault arc circuit breaker according to claim 1, characterized in that: The current transformer includes a body and a wiring part. The wiring part is located on one side of the body. The limiting structure includes a first limiting rib with a width dimension d, which is 1.5mm≤d≤5mm. The first limiting rib blocks one side of part of the body to restrict the current transformer from sliding toward the circuit board.

3. The fault arc circuit breaker according to claim 2, characterized in that: The outer shell includes a first half-shell and a second half-shell, and the first cavity is composed of the first half-shell and the second half-shell. The first half-shell includes a partition, and a first limiting rib is located on the partition and extends toward the second half-shell, with the extension dimension being the width dimension of the first limiting rib.

4. The fault arc circuit breaker according to claim 1, characterized in that: The current transformer includes a body and a wiring section. The wiring section is located on one side of the body. The limiting structure includes a second limiting rib. The second limiting rib blocks one side of a portion of the wiring section or blocks one side of both a portion of the wiring section and a portion of the body to restrict the current transformer from sliding toward the circuit board.

5. A fault arc circuit breaker according to claim 4, characterized in that: The outer shell includes a first half-shell and a second half-shell. The first cavity is composed of the first half-shell and the second half-shell. The first half-shell includes a partition. A second limiting rib is located on the partition and extends toward the second half-shell. The extension dimension is the width dimension D of the second limiting rib, and D is not less than the distance from the center hole of the current transformer to the partition.

6. A fault arc circuit breaker according to claim 4, characterized in that: The outer casing has at least two positioning posts, and the circuit board has matching positioning holes. The circuit board forms a positioning fit with the positioning posts through the positioning holes; one of the positioning posts is the second positioning post, and the second limiting rib is integrally formed with the second positioning post.

7. A fault arc circuit breaker according to claim 6, characterized in that: The second limiting rib includes a first surface and a second surface, which are two mutually perpendicular surfaces; the first surface is used to support the circuit board, and the second surface is used to block one side of the wiring part or to block one side of the wiring part and part of the body part.

8. A fault arc circuit breaker according to claim 1, characterized in that: The circuit board is equipped with a fault arc test circuit, which includes a mechanical switch and is located in the first cavity. At least two positioning posts are provided inside the housing, and the circuit board is provided with matching positioning holes. The circuit board forms a positioning fit with the positioning posts through the positioning holes. One of the positioning posts is the first positioning post, and the part of the mechanical switch is attached to the first positioning post.

9. A fault arc circuit breaker according to claim 8, characterized in that: The mechanical switch includes a test button, a moving spring, and a stationary conductive component. The moving spring includes a first end, a second end, and a support portion. The first end is electrically connected to the circuit board, the support portion is set against the first positioning post, and the second end extends towards the location of the stationary conductive component. A support boss is provided inside the housing. One end of the stationary conductive component is electrically connected to the circuit board, and the other end abuts against the support boss. The test button is located above the moving spring, and its second end is normally open with the stationary conductive component. When the test button is subjected to external force, the normally open state is changed to a closed state.

10. A fault arc circuit breaker according to claim 1, characterized in that: Indicator lights are installed on the circuit board, and light guides are installed on the outer casing, with the light guides corresponding to the indicator lights.

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