Connecting device of circuit breaker and cable

Abstract

The utility model discloses a connecting device for a circuit breaker and a cable, and relates to the technical field of cable connection, the connecting device comprises a wiring terminal, a sealing tube and an insulating tube, the wiring terminal is a sleeve structure, one end of the wiring terminal is provided with a mounting hole, the mounting hole is matched with a connecting screw on the circuit breaker, and the insulating tube is arranged in the sealing tube. The other end of the wiring terminal extends into the sealing pipe and is connected with the sealing pipe in a crimping or threaded connection mode, the length of the sealing pipe is smaller than that of the insulating pipe, the insulating pipe extends into the sealing pipe and is connected with the sealing pipe in a thermal shrinkage mode, the cable extends into the insulating pipe, and the inner core is in contact with the inner wall of the wiring terminal. According to the utility model, a large-current cable head can be conveniently connected to the molded case circuit breaker, and a protection effect can be provided for a connection position.

Description

Technical Field

[0001] This utility model relates to the field of cable connection technology, and in particular to a connection device for circuit breakers and cables. Background Technology

[0002] In electrical systems, cables are crucial components for transmitting electrical energy, and their specifications and types vary widely. Currently, in practical applications, there are situations where high-current cable heads are difficult to connect to low-current molded case circuit breakers. This is because cable heads are typically directly connected to the connecting screws on the circuit breaker's connection plate. However, high-current cable heads have larger diameters and thicker inner cores, making it difficult to directly bend the inner core and wrap it around the connecting screw. This situation affects the normal connection of the circuit, and the lack of a protective structure at the connection point between the inner core and the circuit breaker leads to poor connection stability. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a connection device for a circuit breaker and a cable, which facilitates the connection of high-current cable heads to the molded case circuit breaker and also provides protection at the connection point.

[0004] According to an embodiment of the present invention, a circuit breaker and cable connection device is used to connect a circuit breaker and a cable, wherein the cable includes an inner core and an insulation layer, the insulation layer is sleeved on the outer periphery of the inner core, and the connection device includes a terminal block, a sealing tube, and an insulation tube.

[0005] The terminal block is a sleeve structure. One end of the terminal block has a mounting hole that mates with a connecting screw on the circuit breaker. The other end of the terminal block extends into the sealing tube and is connected to the sealing tube by crimping or threading. The length of the sealing tube is less than the length of the insulating tube. The insulating tube extends into the sealing tube and is connected to the sealing tube by heat shrinking. The cable extends into the insulating tube, and its inner core contacts the inner wall of the terminal block. The insulating tube and the insulating layer are connected by heat shrinking.

[0006] The circuit breaker and cable connection device according to the present utility model embodiment has at least the following beneficial effects: by setting up structures such as terminals, sealing tubes and insulating tubes, the connection device can be understood as being fixedly connected to the end of the cable. The cable can be directly connected to the connection screw of the circuit breaker through the mounting hole of the terminal, thereby realizing the connection of high current cable into the miniature circuit breaker. The operation is convenient and the connection is stable. The sealing tube and insulating tube can ensure that the cable and the connection device are connected firmly, which can improve the connection stability and play an insulating and sealing protection role, which is conducive to improving the working stability of the circuit breaker.

[0007] According to some embodiments of the present invention, the cable further includes a semi-conductive layer, the connecting device further includes a stress cone, the semi-conductive layer is located between the inner core and the insulating tube, and the stress cone is sleeved on the outer periphery of the semi-conductive layer and fits against the outer wall of the semi-conductive layer.

[0008] According to some embodiments of the present invention, the connecting device further includes a sheath tube, which is located on the outer periphery of the insulating layer and on the side of the stress cone away from the sealing tube. One end of the sheath tube extends into the insulating tube and abuts against the stress cone. The sheath tube is made of polypropylene.

[0009] According to some embodiments of this utility model, the stress cone is made of ethylene-vinyl acetate material.

[0010] According to some embodiments of the present invention, a rain cover is provided around the outer periphery of the insulating tube, the outer diameter of the rain cover gradually increases from top to bottom, and the rain cover is connected to the insulating tube by heat shrinking.

[0011] According to some embodiments of the present invention, the rain cover is provided with multiple parts.

[0012] According to some embodiments of the present invention, the cable further includes a copper shielding layer located on the outer periphery of the insulation layer. The connecting device further includes a heat-shrinkable finger sleeve, which is sleeved on the outer periphery of the copper shielding layer and covers the outer periphery of the cable. A portion of the heat-shrinkable finger sleeve extends into the insulation tube. The heat-shrinkable finger sleeve and the insulation tube are connected by heat shrinking. The gap between the heat-shrinkable finger sleeve and the copper shielding layer is filled with epoxy resin medium. The heat-shrinkable finger sleeve is connected to the outer wall of the cable by heat shrinking.

[0013] According to some embodiments of this utility model, the sealing tube is made of polyolefin material.

[0014] According to some embodiments of this utility model, the insulating tube is made of polyethylene.

[0015] Additional aspects and advantages of this invention 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 the invention. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0017] Figure 1 This is a cross-sectional view of a circuit breaker and cable connection device according to some embodiments of the present invention;

[0018] Figure 2This is a cross-sectional view of a circuit breaker and cable connection device according to some embodiments of the present invention;

[0019] Figure 3 This is a schematic diagram of the connection device between the circuit breaker and the cable according to some embodiments of the present invention;

[0020] Figure 4 This is a cross-sectional view of a cable according to some embodiments of the present invention.

[0021] Figure label:

[0022] Circuit breaker 100, connecting screw 101;

[0023] Cable 200, inner core 201, semiconductive layer 202, insulation layer 203, copper shielding layer 204;

[0024] Connection device 300, terminal block 301, mounting hole 302, sealing tube 303, insulating tube 304, stress cone 305, rain cover 306, sheath tube 307, heat shrink finger sleeve 308, epoxy resin medium 309. Detailed Implementation

[0025] The embodiments of this utility model 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 utility model, and should not be construed as limiting this utility model.

[0026] Reference Figure 1 and Figure 2 As shown in the illustration, a connection device 300 is provided in this embodiment of the present invention, specifically used to connect a circuit breaker 100 and a cable 200. The cable 200 is a high-current cable with a relatively large diameter, suitable for photovoltaic project inverter output lines that use low-voltage grid connection. Currently, due to the low voltage access level and long cable transmission distance, existing cable joints are incompatible with the molded case circuit breakers in the grid-connected cabinet.

[0027] It's important to explain that in electrical systems, cables, as crucial components for transmitting electrical energy, come in a wide variety of specifications and types. However, in practical applications, it's common to encounter situations where cable heads are too large to be directly connected to molded case circuit breakers (MCCBs). This may be due to a large cable cross-sectional area, or a mismatch between the cable head's shape and size and the circuit breaker's connecting screws. For example, high-current cable heads have larger diameters and thicker inner cores, making it difficult to directly bend the inner core and wrap it around the connecting screw. This situation affects the normal circuit connection, and the lack of a protective structure at the connection point between the inner core and the circuit breaker leads to poor connection stability. This situation not only affects the normal circuit connection but may also pose safety hazards.

[0028] Currently, when encountering problems such as small circuit breaker spacing and inability to install large cables, the only option is to return the circuit breaker to the factory for modification, requiring project customization of the circuit breaker and switchgear. This leads to an increase in project installation time and cost, as well as electrical performance and safety risks, and difficulties in maintenance and repair.

[0029] Reference Figure 3 As shown, cable 200 includes a cable, which includes an inner core 201 and an insulation layer 203, with the insulation layer 203 surrounding the inner core 201. Multiple cables can be used. Figure 3 There are three cables in the middle. Figure 2 The image only shows one cable connected to circuit breaker 100. (Refer to...) Figure 1 and Figure 2 As shown, the connecting device 300 includes a terminal block 301, a sealing tube 303, and an insulating tube 304. The terminal block 301 is a copper lug with a sleeve structure. One end of the terminal block 301 has a mounting hole 302, which mates with a connecting screw 101 on the circuit breaker 100. The other end of the terminal block 301 extends into the sealing tube 303 and is connected to the sealing tube 303 by crimping or threading. The length of the sealing tube 303 is less than the length of the insulating tube 304. The insulating tube 304 extends into the sealing tube 303 and is connected to the sealing tube 303 by heat shrinking. The cable 200 extends into the insulating tube 304, and its inner core 201 contacts the inner wall of the terminal block 301. The insulating tube 304 is connected to the insulating layer 203 by heat shrinking.

[0030] In this embodiment, by setting up structures such as terminal block 301, sealing tube 303, and insulating tube 304, the connecting device 300 can be understood as being fixedly connected to the end of the cable 200. The cable 200 can be directly connected to the connecting screw 101 of the circuit breaker 100 through the mounting hole 302 of the terminal block 301. After tightening the connecting screw 101, the terminal block 301 will be locked, thereby realizing the connection of high current cable into the miniature circuit breaker 100. The operation is convenient and the connection is stable. The sealing tube 303 and insulating tube 304 can ensure that the cable 200 and the connecting device 300 are connected firmly, which can improve the connection stability and play an insulating and sealing protection role, ensuring a firm connection and good conductivity, which is beneficial to providing the working stability of the circuit breaker 100.

[0031] In this embodiment, the molded case circuit breaker and the cable 200 are directly connected by the connecting device 300, which has the advantages of simplifying the installation process, improving flexibility, enhancing safety, and facilitating maintenance and repair. It can also omit the installation steps of the wiring terminal 301, thereby simplifying the installation process, helping to reduce installation time and cost, and improving installation efficiency.

[0032] The connection device 300 in this embodiment is easy to disassemble and replace, which makes it easier to check and repair circuit problems during maintenance and repair. This helps to reduce the difficulty and time of maintenance and repair, and improve the reliability and service life of the equipment.

[0033] During the installation of the connector 300 onto the cable 200, one end of the terminal block 301 is inserted into the sealing tube 303, and the sealing tube 303 and the terminal block 301 are crimped together using crimping pliers or connected together using screws to ensure a tight connection between the sealing tube 303 and the terminal block 301. Then, the insulating tube 304 is inserted into the sealing tube 303, and the connection point between the insulating tube 304 and the sealing tube 303 is heated using a hot air gun to shrink it and make it fit tightly against the outer circumference of the insulating tube 304.

[0034] Reference Figure 2 and Figure 3 As shown, according to some embodiments of the present invention, the cable 200 further includes a semi-conductive layer 202, and the connecting device 300 further includes a stress cone 305. The semi-conductive layer 202 is located between the inner core 201 and the insulating tube 304, and the stress cone 305 is sleeved on the outer periphery of the semi-conductive layer 202 and fits against the outer wall of the semi-conductive layer 202. The stress cone 305 includes a conical section, the outer diameter of which gradually decreases from top to bottom. The conical section is positioned corresponding to the cut end of the cable 200, and the stress cone 305 is made of ethylene-vinyl acetate material.

[0035] It should be noted that at the termination or joint of cable 200, the cutting of the metal sheath and outer shielding layer will cause electric field concentration at these breaks, resulting in a sharp increase in electric field strength. The stress cone 305, through its special geometry, gradually expands the insulation diameter of cable 200 into a cone shape, thereby controlling the axial stress of cable 200 and gradually reducing the electric field strength. This effectively reduces the electric field strength at the edge of the metal sheath. The stress cone 305 can change the geometry of the electric field concentration point, making the electric field distribution more uniform and avoiding problems such as insulation breakdown caused by excessive electric field concentration, thus improving the reliability and safety of cable 200 operation. The stress cone 305 utilizes the principle of gradually reducing capacitance to gradually increase the thickness of the original insulation layer 203 of cable 200, causing the electric field strength on the insulation surface to gradually decrease, thereby controlling the axial stress within the allowable range.

[0036] During the installation of the stress cone 305, the installation range of the stress cone 305 is first measured and the temporary protection on the shorter stripped side is removed. Positioning marks are made with PVC tape, and the insulation surface of the cable 200 is cleaned again. Silicone grease is then evenly applied to the insulation surface of the cable 200. A special tool is used to install the stress cone 305 into the middle connection position of the cable 200. In this step, the outer wall of the stress cone 305 will fit tightly with the inner wall of the semi-conductive layer 202, forming a mechanical connection. The stress cone 305 can produce a certain deformation, which makes the insulating tube 304 and the semi-conductive layer 202 clamp together. During the service life, the internal interface of the cable will not separate due to thermal expansion and contraction caused by changes in ambient temperature or operating current, thus preventing internal creepage breakdown. This effectively solves the stress concentration problem at the cable end.

[0037] Reference Figure 2 As shown, according to some embodiments of this utility model, a plurality of rainproof covers 306 are fitted around the outer periphery of the insulating tube 304. The outer diameter of the rainproof covers 306 gradually increases from top to bottom, and the rainproof covers 306 are connected to the insulating tube 304 by heat shrinking. The rainproof cover 306 can be understood as a single-hole rain skirt made of silicone rubber. The rainproof cover 306 serves to block rain, preventing rainwater from entering the connection position of the connecting device 300. The rainproof cover 306 can also guide rainwater to drip downwards quickly, preventing rainwater from accumulating.

[0038] During the installation of the rain cover 306, the rain cover 306 is placed over the outside of the insulating tube 304, ensuring that the neck of the rain cover 306 fits tightly against the insulating tube 304. A hot air gun is used to heat the neck of the rain cover 306, causing it to shrink and fit tightly against the insulating tube 304. The heating should be even and moderate to avoid overheating, which could damage or deform the rain cover 306. After the heating and shrinking are complete, carefully check whether the connection between the rain cover 306 and the insulating tube 304 is firm and tight, ensuring that there is no looseness, gaps or cracks.

[0039] Reference Figure 2 As shown, according to some embodiments of the present invention, the connecting device 300 further includes a sheath tube 307, which is sleeved around the outer periphery of the cable 100 to provide protection. The sheath tube 307 is located on the outer periphery of the insulation layer 203 and on the side of the stress cone 305 away from the sealing tube 303. One end of the sheath tube 307 extends into the insulation tube 304 and abuts against the stress cone 305, thereby limiting the stress cone 305. The sheath tube 307 can be made of polypropylene.

[0040] During the installation of the sheath 307, the sheath 307 is placed over the cable 200 under the rain cover 306, ensuring that the starting end of the sheath 307 is tightly fitted to the end of the stress cone 305. The sheath 307 is heated with a hot air gun to shrink and fit tightly onto the cable 200. Heating should be uniform and moderate to avoid overheating that could damage or deform the sheath 307. At the same time, it is important to ensure that the sheath 307 completely covers the end of the stress cone 305 to form an effective seal.

[0041] Reference Figure 2 As shown, according to some embodiments of this utility model, the cable 200 further includes a copper shielding layer 204, which is located on the outer periphery of the insulation layer 203. The connecting device 300 further includes a heat-shrinkable finger sleeve 308, which is sleeved on the outer periphery of the copper shielding layer 204 and covers the outer periphery of the cable 200. A portion of the heat-shrinkable finger sleeve 308 extends into the insulation tube 304, and the heat-shrinkable finger sleeve 308 is connected to the insulation tube 304 by heat shrinking. The gap between the heat-shrinkable finger sleeve 308 and the copper shielding layer 204 is filled with epoxy resin medium 309, and the heat-shrinkable finger sleeve 308 is connected to the outer wall of the cable 200 by heat shrinking. By providing the heat-shrinkable finger sleeve 308, the copper shielding layer 204 can be protected.

[0042] During the installation of the heat shrink finger sleeve 308, firstly, one end of the copper braided grounding material of the cable 200 is welded to the copper shielding layer 204. Then, a constant force spring is used to fix the welded copper braided material to the cable 200. Next, self-adhesive tape is used to tightly wrap the copper braided material, the constant force spring, and the copper shielding layer 204 together to ensure a firm connection. Then, the heat gun is adjusted to an appropriate temperature to heat the heat shrink finger sleeve 308. After the heat shrink finger sleeve 308 is fully shrunk and tightly attached to the cable 200, the surface of the heat shrink finger sleeve 308 is gently pressed with pliers to further fix its position and eliminate any potential gaps. Finally, epoxy resin filler and the corresponding curing agent are mixed in proportion and injected into the gap between the heat shrink finger sleeve 308 and the cable 200 using a syringe. This ensures that the epoxy resin filler can completely fill the cable 200 joint. The epoxy resin filler will cover the surface of the copper shielding layer 204, forming a sealing effect.

[0043] According to some embodiments of this utility model, the sealing tube can be made of polyolefin material, and the insulating tube can be made of polyethylene material.

[0044] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationships based on the directional or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 this utility model.

[0045] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0046] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0047] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A device for connecting a circuit breaker to a cable, characterized in that The application is applied to connect a circuit breaker with a cable, the cable comprises a core and an insulation layer, the insulation layer is sleeved on the outer periphery of the core, the connecting device comprises a terminal, a sealing tube and an insulation tube; The terminal is a sleeve structure, one end of the terminal is provided with a mounting hole, the mounting hole is matched with a connecting screw on the circuit breaker, the other end of the terminal is inserted into the sealing tube and connected with the sealing tube through crimping or threaded connection, the length of the sealing tube is less than the length of the insulation tube, the insulation tube is inserted into the sealing tube and connected with the sealing tube through heat shrinkage, the cable is inserted into the insulation tube, and the core is in contact with the inner wall of the terminal, and the insulation tube is connected with the insulation layer through heat shrinkage.

2. The connection device according to claim 1, characterized in that The cable further comprises a semi-conductive layer, the connecting device further comprises a stress cone, the semi-conductive layer is located between the core and the insulation tube, and the stress cone is sleeved on the outer periphery of the semi-conductive layer and is attached to the outer wall of the semi-conductive layer.

3. The connection device according to claim 2, characterized in that The connecting device further comprises a sheath tube, the sheath tube is located on the outer periphery of the insulation layer, the sheath tube is located on the side of the stress cone away from the sealing tube, one end of the sheath tube is inserted into the insulation tube and abuts against the stress cone, and the sheath tube is made of polypropylene.

4. The connection device of claim 2, wherein The stress cone is made of ethylene-vinyl acetate.

5. The connection device of claim 1, wherein The outer periphery of the insulation tube is sleeved with a rain cover, the outer diameter of the rain cover gradually increases from top to bottom, and the rain cover is connected with the insulation tube through heat shrinkage.

6. The connection device according to claim 5, characterized in that The rain cover is provided with a plurality of 7. The connection device of claim 1, wherein The cable further comprises a copper shielding layer, the copper shielding layer is located on the outer periphery of the insulation layer, the connecting device further comprises a heat shrinkable finger sleeve, the heat shrinkable finger sleeve is sleeved on the outer periphery of the copper shielding layer and covers the outer periphery of the cable, part of the heat shrinkable finger sleeve is inserted into the insulation tube, the heat shrinkable finger sleeve is connected with the insulation tube through heat shrinkage, the gap between the heat shrinkable finger sleeve and the copper shielding layer is filled with epoxy resin medium, and the heat shrinkable finger sleeve is connected with the outer wall of the cable through heat shrinkage.

8. The connection device of claim 1, wherein The sealing tube is made of polyolefin.

9. The connection device of claim 1, wherein, The insulation tube is made of polyethylene.

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