CN210092020U - Electric leakage detection tripping accessory and electric leakage circuit breaker of preposed zero-sequence current transformer - Google Patents

Abstract

The utility model discloses a leading zero sequence current transformer's leakage detection dropout annex relates to circuit breaker technical field, including zero sequence current transformer and electric leakage trip gear, zero sequence current transformer is connected with electric leakage trip gear, and zero sequence current transformer arranges circuit breaker unit one end in when cooperation circuit breaker unit uses, and external cable passes behind the zero sequence current transformer and is connected with circuit breaker unit electricity, and whether zero sequence current transformer is used for detecting the electric current that passes through and leaks electricity, and when the electric leakage took place, electric leakage trip gear executed the dropout action. The leakage detection tripping accessory of the preposed zero-sequence current transformer provided by the embodiment is configured on one side of the wiring end of the circuit breaker unit and is generally arranged on one side of the output end of the circuit breaker unit, the combined leakage circuit breaker does not need a cable to penetrate through the zero-sequence current transformer from the inside, after the product is installed, when the leakage circuit breaker is connected into an external cable for use, each external cable penetrates through the zero-sequence current transformer in sequence, and the purpose of detecting leakage current can be achieved.

Description

Electric leakage detection tripping accessory and electric leakage circuit breaker of preposed zero-sequence current transformer

Technical Field

The invention relates to the technical field of circuit breakers, in particular to a leakage detection tripping accessory of a front zero-sequence current transformer and a leakage circuit breaker.

Background

Fig. 1 is a 4P earth leakage circuit breaker using a circular mutual inductor in the prior art, which includes a 4P circuit breaker and a 4P earth leakage detection tripping accessory, wherein a circular zero sequence current mutual inductor 3 (for short, a circular mutual inductor) is arranged in an earth leakage detection tripping accessory 2, and the circuit breaker 1 and the earth leakage detection tripping accessory 2 are connected through a hard copper enameled wire 7. At present, all low-voltage residual current circuit breakers (also called leakage circuit breakers) use a circular zero sequence current transformer 3 to detect leakage, particularly for miniature circuit breakers, because of the limitation of geometric space and the wiring of external cables, the low-voltage residual current circuit breakers can only be designed into the form shown in fig. 1, namely, a group of output ends are additionally arranged on a leakage detection tripping accessory 2, the circular zero sequence current transformer 3 is arranged between an original circuit breaker output end 5 and a leakage detection tripping accessory output end 6, and a group of hard copper enameled wire groups 4 which are formed according to requirements penetrate through the circular zero sequence current transformer 3 to connect the circuit breaker output end 5 and the leakage detection tripping accessory output end 6, thereby occupying a large space, increasing a plurality of material costs and having a complex assembly process.

The residual current circuit breaker using the circular transformer has the following disadvantages:

1. the electric leakage circuit breaker of the existing scheme is a group of general circuit breakers and is additionally provided with an electric leakage detection tripping accessory, and the electric leakage detection tripping accessory is a circular mutual inductor for detecting electric leakage and can only be internally arranged inside the electric leakage detection tripping accessory due to the limitation of geometric space; this requires the additional fabrication of a set of hard copper enameled wire sets (for the insulation of the wires from each other) and the addition of a set of output terminals; one end of the hard copper enameled wire group is respectively connected with each output end of the circuit breaker, and the other end of the hard copper enameled wire group is connected with each output end of the leakage detection tripping accessory after penetrating through the round mutual inductor in a centralized manner; in order to maintain the electrical insulation between the cables, the cables are made of single-stranded preformed hard copper enameled wires, so that the assembly process is very complicated;

2. the existing scheme connects one end of a hard copper enameled wire group penetrating through a round mutual inductor to a matched circuit breaker, the other end of the hard copper enameled wire group is connected to an output wiring frame of a leakage detection tripping accessory, and the wiring frame is arranged on a shell. The wiring frame of each cable occupies a space of 18mm of a module of 1 pole, so that the installation space of the circuit breaker is increased;

3. the temperature rise of the leakage circuit breaker is easily caused by the internal resistance of the single-stranded preformed hard copper enameled wire passing through the circular transformer and the contact resistance connected with the circuit breaker;

4. in the existing scheme, single-stranded preformed hard copper enameled wires penetrating through a circular transformer are used, all single-stranded preformed hard copper enameled wire welding connection pieces penetrating through the circular transformer are arranged, and a connection frame is assembled on a plastic bottom box, so that a large amount of copper materials and plastic materials are consumed;

5. the comprehensive cost is high: the threading process of the single-stranded preformed hard copper enameled wire is complex, and the manufacturing time is long; the difficulty in welding and assembling the single-stranded preformed hard copper enameled wire and the wiring frame is high; a large number of prefabricated single-stranded hard copper enameled wires are used, the processing process is long, and a large number of copper materials are consumed; a plastic bottom box is required to be manufactured for placing the circular mutual inductor and arranging the wiring frame of all the single-stranded preformed hard copper enameled wires, so that a large amount of plastic materials are consumed; the overall material and assembly costs of the residual current circuit breaker are high.

Disclosure of Invention

The invention aims to provide a leakage detection tripping accessory of a preposed zero-sequence current transformer, which aims to solve the problems that the existing leakage circuit breaker needs to manufacture a hard copper enameled wire which penetrates through a round transformer to connect the output end of the circuit breaker with the output end of the leakage detection tripping accessory, the occupied space is large, the material cost is increased, and the assembly process is complicated.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a zero sequence current transformer's electric leakage detection dropout annex, includes zero sequence current transformer and electric leakage trip gear, and zero sequence current transformer is connected with electric leakage trip gear, and zero sequence current transformer arranges circuit breaker unit one end in when cooperation circuit breaker unit uses, and external cable passes the electric connection of zero sequence current transformer back with circuit breaker unit, and zero sequence current transformer is used for detecting whether electric leakage of current that passes through, and when electric leakage takes place, electric leakage trip gear carries out the tripping action.

Furthermore, the zero sequence current transformer is arranged outside the electric leakage tripping device, and when the zero sequence current transformer is matched with the circuit breaker unit for use, the electric leakage tripping device is arranged on one side of the circuit breaker unit and is mechanically linked with the circuit breaker unit.

Further, zero sequence current transformer includes the iron core, is equipped with two and above transverse arrangement and insulated through wires hole of each other in the iron core hole, and the winding has mutual inductor coil on the iron core, the both ends of mutual inductor coil all are connected with the outer lead wire of mutual inductor coil, mutual inductor coil passes through the outer lead wire of mutual inductor coil and is connected with the electronic circuit board electricity in the electric leakage trip gear, and when the electric leakage takes place, electronic circuit board signals messenger electric leakage trip gear execution tripping operation.

Furthermore, a test loop coil is wound on the iron core, two ends of the test loop coil are connected with test loop coil outer leads, and the test loop coil outer leads are electrically connected with the electronic circuit board.

Furthermore, the zero sequence current transformer further comprises a protection box, the shape of the protection box is matched with that of the iron core, the iron core is arranged in the protection box, and the transformer coil and the test loop coil are wound on the protection box to form an iron core winding.

Furthermore, the zero sequence current transformer further comprises a housing, the iron core winding is arranged in the housing, two or more threading columns with inner holes communicated with two ends are arranged on the housing, and the threading columns are arranged in the inner holes of the iron core winding in a penetrating manner.

Furthermore, epoxy resin glue is filled and sealed in the inner space of the shell, and the epoxy resin glue is used for fixing and sealing the element and the electric connection joint which are arranged in the shell.

Further, the iron core is in a flat runway shape.

Furthermore, the threading hole is provided with a power taking piece, the power taking piece is connected with a power taking lead, and the power taking lead is electrically connected with the electronic circuit board.

As a preferred scheme, the electric leakage tripping device is provided with a zero line switch fracture, one of the threading holes on the zero sequence current transformer corresponds to the wiring frame of the zero line switch fracture, the other threading holes are provided with electricity taking pieces, the electricity taking pieces are connected with electricity taking leads, and the electricity taking leads are electrically connected with an electronic circuit board.

Compared with the prior art, the leakage detection tripping accessory provided by the invention has the following advantages:

1. when the zero sequence current transformer is placed outside the electric leakage tripping device, the zero sequence current transformer is configured at the front end of the threading direction of the input end or the output end of the circuit breaker unit, all external cables parallelly penetrate through the inside of the zero sequence current transformer and can be directly connected with the wiring frame of the circuit breaker unit, a hard copper enameled wire does not need to be prefabricated, and the production process is simplified. The normal conductive connecting pieces of all the conductive main loops penetrate through the zero sequence current transformer in parallel, and the conductive cable does not need to be reshaped, so that the method is simple and convenient. Because the zero sequence current transformer is arranged outside the electric leakage tripping device, the width of the electric leakage tripping device is limited to one modulus, when the electric leakage detection tripping accessory of the preposed zero sequence current transformer is matched with circuit breaker units with different numbers for use, the combined electric leakage circuit breaker only increases one modulus by 18mm compared with the total width of each circuit breaker unit, the comprehensive cost is low, the structure is simple, the assembly process is simple, and materials are saved.

2. The zero sequence current transformer of the leakage detection tripping accessory is different from the traditional core wire penetrating mode of a round transformer, the zero sequence current transformer of the leakage detection tripping accessory is provided with a plurality of mutually insulated and transversely arranged threading holes, the whole zero sequence current transformer is in a flat runway shape according to the corresponding inner hole size of the design of circuit breaker units with different pole numbers, the flat runway shape zero sequence current transformer is externally arranged at the front end of the threading direction of the output end or the input end of the circuit breaker unit, and the external cable of the circuit breaker unit is skillfully and directly penetrated through the zero sequence current transformer to realize the wiring of the circuit breaker unit by utilizing the advantage of the large transverse size of a flat runway shape iron core so as to collect and detect leakage current.

3. The leakage detection tripping accessory of the preposed zero-sequence current transformer provided by the invention is divided into two types, one type does not have a zero line (N line) switch fracture, and the leakage detection tripping accessory does not need to arrange a wiring frame of a cable on a shell; a zero line wiring frame is arranged on the electric leakage detection tripping accessory of another break with the zero line switch, and the electric leakage circuit breaker can save 1-pole circuit breaker units by using the electric leakage detection tripping accessory.

The invention also aims to provide an electric leakage circuit breaker, which is formed by assembling and combining an electric leakage detection tripping accessory of a preposed zero-sequence current transformer and at least one circuit breaker unit, wherein the zero-sequence current transformer is configured at the front end of the input end or the threading direction of the output end of the circuit breaker unit, and when the electric leakage circuit breaker is connected with external cables, all the external cables penetrate through the zero-sequence current transformer and then are directly connected with a wiring frame of the circuit breaker unit for wiring, so that the aim of detecting the electric leakage current is fulfilled.

Compared with the prior art, the residual current circuit breaker provided by the invention has the following advantages:

1. when the leakage detection tripping accessory (hereinafter referred to as leakage detection tripping accessory) of the preposed zero-sequence current transformer provided by the invention is matched with the circuit breaker unit for use, the leakage detection tripping accessory is detachably connected with the circuit breaker unit, the zero-sequence current transformer of the leakage detection tripping accessory is preposed at the front end of the wiring direction of the input end or the output end of the circuit breaker unit, and the leakage tripping device is arranged at one side of the circuit breaker unit. The combined residual current circuit breaker does not need a cable to penetrate through a mutual inductor from the inside, and when the combined residual current circuit breaker is connected to an external cable for use after a product is installed, the external cable of all poles of a circuit breaker unit penetrates through a zero sequence current mutual inductor, so that the purpose of detecting the residual current can be achieved. All the conductive cables of the main loop parallelly penetrate through the zero sequence current transformer, and the conductive cables do not need to be reshaped, so that the method is simple and convenient.

2. Because the zero sequence current transformer is arranged outside the electric leakage tripping device, the width of the electric leakage tripping device can be limited within a modulus, when the electric leakage detection tripping accessory of the preposed zero sequence current transformer is matched with circuit breaker units with different numbers for use, the combined electric leakage circuit breaker is only increased by 18mm of modulus compared with the total width of each circuit breaker unit, the comprehensive cost is low, the structure is simple, the assembly process is simple, and materials are saved.

3. The number of the inner holes of the zero sequence current transformer corresponds to the number of poles of the breaker unit, and the fact that each external cable of the breaker unit sequentially penetrates through the threading holes of the zero sequence current transformer is guaranteed. The external cables do not influence each other in each threading hole, and the insulating effect is good, and the electric leakage circuit breaker is difficult for rising temperature.

Drawings

Fig. 1 is a partial sectional view of a conventional 4P earth leakage breaker using a circular transformer;

fig. 2 is a schematic perspective view of a zero-sequence current transformer of the leakage detection tripping accessory of a pre-zero-sequence current transformer without a break of a zero-line switch according to embodiment 1 of the present invention;

FIG. 3 is a top view of FIG. 2;

FIG. 4 is an exploded view of FIG. 2;

fig. 5 is a schematic perspective view of the leakage detection tripping accessory of the pre-zero-order current transformer without the break of the zero-line switch according to embodiment 1 of the present invention;

fig. 6 is a schematic perspective view of a zero-sequence current transformer of the leakage detection tripping accessory of the pre-zero-sequence current transformer with a break of the zero-line switch according to embodiment 1 of the present invention;

FIG. 7 is a top view of FIG. 6;

FIG. 8 is an exploded view of FIG. 6;

fig. 9 is a schematic perspective view of a leakage detection tripping accessory of a front zero-order current transformer with a break of a zero-line switch according to embodiment 1 of the present invention;

fig. 10 is a front view of the earth leakage breaker of embodiment 2, specifically, a front view of a 3P + N type earth leakage breaker;

fig. 11 is a front view of a conventional 3P + N type earth leakage breaker;

fig. 12 is a front view of the earth leakage breaker of embodiment 2, specifically, a front view of a 3P-type earth leakage breaker;

fig. 13 is a front view of a conventional 3P-type earth leakage breaker;

fig. 14 is a schematic view of a portion of the internal structure of the electrical leakage trip device;

fig. 15 is a left side view of fig. 14.

Detailed Description

The invention will now be further described with reference to the accompanying drawings and detailed description.

Example 1: in the prior art, a circular zero sequence transformer is adopted as a tripping accessory for leakage detection, a single strand of external cable needs to be specially made into single-stranded hard copper enameled wires, each single-stranded hard copper enameled wire is intensively made into a group of hard copper enameled wires, and then the whole group of hard copper enameled wires penetrate through a central hole of the circular zero sequence transformer.

Referring to fig. 2 to 9, 14 and 15, the embodiment provides a leakage detection tripping accessory for a front zero-sequence current transformer, which includes a zero-sequence current transformer 10 and a leakage tripping device 20, when the zero-sequence current transformer 10 is used in cooperation with a circuit breaker unit, the zero-sequence current transformer 10 is disposed at one end of the circuit breaker unit, an external cable passes through the zero-sequence current transformer 10 and is electrically connected to the circuit breaker unit, the zero-sequence current transformer 10 is used for detecting whether a current passing through the zero-sequence current transformer leaks electricity, and when the current leaks electricity, the leakage tripping device 20 executes a tripping action.

The leakage detection tripping accessory (hereinafter referred to as leakage detection tripping accessory) of the pre-zero-sequence current transformer provided by this embodiment forms a leakage breaker when being matched with the breaker unit 30 for use, the leakage detection tripping accessory is detachably connected with the breaker unit 30, the zero-sequence current transformer 10 is placed outside the leakage tripping device, and specifically, the zero-sequence current transformer 10 is configured at the front end of the input end or the threading direction of the output end of the breaker unit 30. Unlike the traditional central hole threading manner of the circular zero sequence current transformer 40, in the leakage detection tripping accessory of the pre-zero sequence current transformer provided by the embodiment, all external cables parallelly pass through the inner hole of the zero sequence current transformer 10.

Referring to fig. 10 and 12, the zero sequence current transformer is disposed outside the leakage tripping device, and when the zero sequence current transformer is used in cooperation with the breaker unit, the leakage tripping device is disposed on one side of the breaker unit and mechanically linked with the breaker unit. As shown in fig. 5 and 9, the zero sequence current transformer and the leakage trip device are substantially L-shaped. The width of the electric leakage tripping device can be set to be the width of one circuit breaker unit, and compared with the traditional electric leakage detection tripping accessory, the electric leakage tripping device greatly reduces the whole volume.

Referring to fig. 2 to 4 and fig. 6 to 8, the zero sequence current transformer 10 includes an iron core 101 (not shown), two or more transversely arranged and mutually insulated threading holes 102 are formed in an inner hole of the iron core 101, a transformer coil 104 is wound on the iron core 101, both ends of the transformer coil 104 are connected to transformer coil outer leads, the transformer coil 104 is electrically connected to an electronic circuit board in the leakage tripping device through the transformer coil outer leads, and when leakage occurs, the electronic circuit board sends a signal to enable the leakage tripping device to perform a tripping operation.

In this embodiment, the iron core 101 is wound with a test loop coil 105, both ends of the test loop coil 105 are connected with test loop coil outer leads, and the test loop coil outer leads are connected with an electronic circuit board.

As a further improvement, the zero sequence current transformer 10 further includes a protection box 106, the shape of the protection box 106 is adapted to the shape of the iron core 101, the iron core 101 is placed in the protection box 106, and the transformer coil 104 and the test loop coil 105 are wound on the protection box 106 to form an iron core winding.

The zero sequence current transformer 10 provided by this embodiment has the threading holes 102 corresponding to the wiring frame of the circuit breaker unit 30, the zero sequence current transformer 10 is arranged at the front end of the threading direction of the input end or the output end of the circuit breaker unit 30, the single-stranded external cable can be connected with the circuit breaker unit 30 by sequentially and directly passing through the corresponding threading holes 102, the hard copper enameled wire and the hard copper enameled wire group do not need to be manufactured, and the production process is greatly simplified. External cables of all main loops penetrate through inner holes of the zero sequence current transformer 10 in parallel, the conductive cables do not need to be reshaped, the operation is simple and convenient, and the conductive cables of all loops do not need to be concentrated in the center of the inner holes of the zero sequence current transformer 10.

Preferably, the iron core 101 in this embodiment is in the shape of a flat racetrack, and has an elongated inner hole, in which a plurality of threading holes 102 are transversely arranged. By utilizing the advantage of large transverse size of the flat runway-shaped iron core 101, all external cables of the breaker unit 30 are skillfully and directly passed through the zero sequence current transformer 10 to realize wiring of the breaker unit 30, so as to collect and detect leakage current. The wiring frame of the input end or the output end of the breaker unit 30 is opposite to the threading holes 102 of the zero sequence current transformer 10, and the number of the threading holes 102 is the same as that of the matched breaker units 30.

The leakage detection tripping accessory provided by this embodiment is divided into two types, one type does not have a zero line (N-line) switch break, as shown in fig. 2 to 4, the leakage detection tripping accessory does not need to set a cable connection frame on a housing 109, the threading holes 102 of the zero sequence current transformer 10 are all configured with power taking pieces 107, the power taking pieces 107 are connected with power taking leads 103, and the power taking leads 103 are electrically connected with the leakage tripping device 20; another zero-line switch break, as shown in fig. 6 to 8, a zero-line connection frame is arranged on the leakage detection tripping accessory, specifically, the zero-line switch break is arranged on the leakage tripping device 20, one of the threading holes 102 of the zero-sequence current transformer 10 is concentrically opposite to the connection frame of the zero-line switch break, the other threading holes 102 are provided with a power taking piece 107, the power taking piece 107 is connected with a power taking lead 103, the power taking lead 103 is electrically connected with the leakage tripping device 20, and the leakage circuit breaker can save the 1-pole breaker unit 30 by using the leakage detection tripping accessory.

In this embodiment, the zero sequence current transformer 10 further includes a housing 109, the core winding is disposed in the housing 109, two or more threading posts 108 having inner holes with two through ends are disposed on the housing 109, and the threading posts 108 are disposed in the inner holes of the core winding. Epoxy glue is filled and sealed in the inner space of the shell 109, the epoxy glue is used for fixing and sealing an element arranged in the inner part of the shell 109, one end of the electricity taking piece 107 is fixed on the shell 109 and positioned outside the threading hole 102, and the other end of the electricity taking piece protrudes relative to the epoxy glue. When the electrical leakage detection tripping accessory is assembled with the circuit breaker units 30, the wiring frame of each circuit breaker unit 30 corresponds to one threading hole 102, and the electricity taking piece 107 is connected with the wiring frame of the circuit breaker unit 30.

The assembly process of the electrical leakage detection tripping accessory provided by the embodiment is as follows: the iron core 101 is arranged in a protection box 106, then a mutual inductor coil 104 and a test loop coil 105 are wound on the protection box 106, the two ends of the mutual inductor coil 104 are respectively welded with the outer leads of the mutual inductor coil, and the two ends of the test loop coil 105 are welded with the outer leads of the test loop coil. The iron core winding with the mutual inductor coil 104 and the test loop coil 105 wound thereon is arranged in a casing 109, the electricity taking leads 103 with different lengths are welded on the electricity taking sheets 107 respectively according to needs, and the electricity taking sheets 107 are arranged outside the corresponding threading holes 102 in sequence according to the lengths of the electricity taking leads 103. And finally, encapsulating epoxy resin glue in the inner space of the shell 109, wherein the epoxy resin glue is used for fixing and sealing the transformer coil 104, the test loop coil 105, the power taking sheet 107 and various external leads.

As shown in fig. 14 and 15, the electrical leakage trip unit 20 basically includes an accessory base 230 and a trip mechanism disposed within the accessory base 230, an electromagnetic trip coil assembly 210 and an electronics board assembly 220. The tripping mechanism mainly comprises a push rod 201, a lock catch rod 203, a rotating shaft 202 and a tripping shaft 204 linked with the lock catch rod 203, wherein the tripping shaft 204 outputs tripping mechanical energy outwards to push the matched circuit breaker to act; the electromagnetic trip coil assembly 210 mainly comprises an electromagnetic coil, a movable iron core 211, a reset spring 212 and a mandril 213; the electronic circuit board assembly 220 (i.e., PCBA) mainly comprises a rectifying step-down circuit, a signal comparison circuit, an anti-jamming circuit, an integrated circuit element 221, a thyristor 222, a test resistor 223, and the like. Various electric connection interfaces are arranged on the electronic circuit board assembly 220, 2 leads of the zero sequence current transformer are respectively connected to the ZCT1 and the ZCT2 of the electronic circuit board assembly 220, 2 leads of the Test loop Coil are connected to the Test1 and the Test2 of the electronic circuit board assembly 220, power taking sheet leads are respectively connected to the L (live wire) and the N (neutral wire), and 2 leads of the electromagnetic trip Coil are respectively connected to the Coil1 and the Coil2 of the electronic circuit board assembly. The principle of the zero line current transformer is that when the leakage detected by the zero line current transformer reaches a rated action value, an integrated circuit outputs a trigger signal to trigger the silicon controlled rectifier 222 to be conducted, after an electromagnetic coil connected with the silicon controlled rectifier 222 in series is electrified, the movable iron core 211 moves rightwards, the push rod 201 of the tripping mechanism is pulled to enable the locking rod 203 to rotate anticlockwise around the rotating shaft 202, the tripping shaft 204 linked with the locking rod 203 rotates, and a circuit breaker matched with an accessory is pushed to act.

Example 2: referring to fig. 10 and 12, the present embodiment provides a leakage circuit breaker, which is formed by assembling a leakage detection tripping accessory (hereinafter referred to as a leakage detection tripping accessory) of a front zero-sequence current transformer provided in embodiment 1 and at least one breaker unit 30, wherein the zero-sequence current transformer 10 is configured at a front end of an input end or an output end of the breaker unit 30 in a threading direction, when the leakage circuit breaker is connected to an external cable, all the external cables directly connect with a connection frame of the leakage circuit breaker after passing through the zero-sequence current transformer, so as to achieve a purpose of detecting a leakage current.

The circuit breaker units 30 are arranged side by side, the wiring frames of the input ends or the output ends of the circuit breaker units 30 are concentrically opposite to the threading holes 102 of the zero sequence current transformer 10, and the electric leakage tripping device 20 is installed on one side of the circuit breaker units 30.

In this embodiment, the size of the transverse dimension of the inner hole of the zero sequence current transformer 10 corresponds to the size of the wiring terminal of the circuit breaker unit 30, for the leakage detection tripping accessory without a break of a zero line (N line) switch, the number of the threading holes 102 in the zero sequence current transformer 10 is the same as the number of poles of the circuit breaker unit 30, and the threading holes 102 correspond to the wiring frames of the input end or the output end of the circuit breaker unit 30 one by one; for the leakage detection tripping accessory with the zero line switch break, one of the threading holes 102 on the zero sequence current transformer 10 corresponds to the wiring frame of the zero line switch break, and the other threading holes 102 correspond to the wiring frames of the input end or the output end of the circuit breaker unit 30 one by one. When the external cable is connected for use, the single cables of each pole of the breaker unit 30 penetrate through the threading holes 102 of the zero sequence current transformer 10 one by one and then are connected to the breaker unit 30, so that the purpose of detecting leakage current is achieved. The external cables do not influence each other in each threading hole 102, the insulation effect is good, and the electric leakage circuit breaker is not easy to heat up.

Fig. 10 shows the 3P + N type residual current circuit breaker according to the present embodiment, wherein the leakage detection tripping accessory has a break of the null line switch, fig. 11 shows the conventional 3P + N type residual current circuit breaker, and the residual current circuit breaker in fig. 10 saves the 1-pole circuit breaker unit 30 compared with the residual current circuit breaker in fig. 11. The zero sequence current transformer 10 in fig. 10 is installed on the terminal side of the circuit breaker unit 30, the width of the leakage detection tripping accessory is only one module H, and the width of the whole leakage circuit breaker is 4 modules 4H. The existing circular zero sequence current transformer 40 in fig. 11 is installed in the leakage detection tripping accessory, the width of the leakage detection tripping accessory is the same as the total width of the circuit breaker unit 30, and is four modules 4H, and the width of the whole leakage circuit breaker is 8 modules 8H. Fig. 10 is a 4-modulus 4H reduction from fig. 11.

Fig. 12 shows the 3P-type residual current circuit breaker in this embodiment, wherein the leakage detection tripping accessory does not have the break of the neutral switch, and the overall width of the residual current circuit breaker is four modules 4H. Fig. 13 shows a conventional 3P type residual current circuit breaker, in which the width of the leakage detection trip accessory is 3 modules 3H, which is the same as the total width of the breaker unit 30, and the entire width of the 3P type residual current circuit breaker is 6 modules 6H. Fig. 12 is a 2 modulus reduction 2H from fig. 13.

The electric leakage detection tripping accessory provided by the embodiment is compared with the existing electric leakage detection tripping accessory using the circular mutual inductor, and indexes in the aspects of product structure, product size, assembly mode, comprehensive cost and the like are shown in table 1.

Table 1 electric leakage detection tripping accessory of preposition zero sequence current mutual inductor and each index comparison table of electric leakage detection tripping accessory with round zero sequence current mutual inductor

In summary, the electrical leakage tripping device 20 of the electrical leakage detecting tripping accessory provided in this embodiment has a width dimension of only one module of 18mm, so that the electrical leakage breaker formed by combining the electrical leakage detecting tripping accessory and the breaker unit 30 is only wider than the breaker unit 30 by one module, and compared with the prior art, the electrical leakage tripping device greatly saves the use and installation space and the material cost. In addition, the external cable directly passes through the front zero sequence current transformer 10 and then is communicated with the circuit breaker unit 30, a hard copper enameled wire is not needed, the production process is greatly simplified, and the production cost is saved. The parameters obtained from actual production show that the overall cost of the leakage detection tripping accessory provided by the invention is reduced by about 30% on average compared with the existing leakage detection tripping accessory with the circular ring-shaped iron core 101 structure.

The above description is only for the purpose of illustrating the embodiments of the present invention, and any modifications and variations made by those skilled in the art may be made without departing from the scope of the present invention.

Claims (11)

1. The utility model provides a leading zero sequence current transformer's leakage detection dropout annex which characterized in that: the zero sequence current transformer is connected with the electric leakage tripping device, the zero sequence current transformer is arranged at one end of the circuit breaker unit when the zero sequence current transformer is matched with the circuit breaker unit for use, an external cable penetrates through the zero sequence current transformer and then is electrically connected with the circuit breaker unit, the zero sequence current transformer is used for detecting whether the passing current leaks electricity, and when the electric leakage occurs, the electric leakage tripping device executes tripping action.

2. A leakage detection trip accessory for a front-end zero-sequence current transformer, according to claim 1, wherein: the zero sequence current transformer is arranged outside the electric leakage tripping device, and when the zero sequence current transformer is matched with the breaker unit for use, the electric leakage tripping device is arranged on one side of the breaker unit and is mechanically linked with the breaker unit.

3. A leakage detection trip accessory for a front-end zero-sequence current transformer, according to claim 1, wherein: the zero sequence current transformer comprises an iron core, wherein two or more transverse-arranged and mutually-insulated threading holes are formed in an inner hole of the iron core, a transformer coil is wound on the iron core, outer leads of the transformer coil are connected to two ends of the transformer coil, the transformer coil is electrically connected with an electronic circuit board in the electric leakage tripping device through the outer leads of the transformer coil, and when electric leakage occurs, the electronic circuit board sends a signal to enable the electric leakage tripping device to execute tripping action.

4. A leakage detection trip accessory for a front-end zero-sequence current transformer, according to claim 3, wherein: the iron core is wound with a test loop coil, two ends of the test loop coil are connected with test loop coil outer leads, and the test loop coil outer leads are electrically connected with the electronic circuit board.

5. The leakage detection trip accessory of the pre-zero sequence current transformer of claim 4, wherein: the zero sequence current transformer further comprises a protection box, the shape of the protection box is matched with that of the iron core, the iron core is arranged in the protection box, and the transformer coil and the test loop coil are wound on the protection box to form an iron core winding.

6. A leakage detection trip accessory for a front-end zero-sequence current transformer, according to claim 5, wherein: the zero sequence current transformer further comprises a shell, the iron core winding is arranged in the shell, two or more threading columns with inner holes communicated with two ends are arranged on the shell, and the threading columns penetrate through the inner holes of the iron core winding.

7. A leakage detection trip accessory for a front-end zero-sequence current transformer, according to claim 6, wherein: epoxy resin glue is filled and sealed in the inner space of the shell, and the epoxy resin glue is used for fixing and sealing elements and electric connection joints arranged in the shell.

8. A leakage detection trip accessory for a front-end zero-sequence current transformer, according to claim 3, wherein: the iron core is in a flat runway shape.

9. A leakage detection trip accessory for a front-end zero-sequence current transformer according to any of claims 3 to 8, wherein: the threading hole is provided with a power taking piece, the power taking piece is connected with a power taking lead, and the power taking lead is electrically connected with the electronic circuit board.

10. A leakage detection trip accessory for a front-end zero-sequence current transformer according to any of claims 3 to 8, wherein: the electric leakage tripping device is provided with a zero line switch fracture, one of the threading holes in the zero sequence current transformer corresponds to the wiring frame of the zero line switch fracture, and the other threading holes are provided with electricity taking pieces which are connected with electricity taking leads which are electrically connected with an electronic circuit board.

11. An earth leakage circuit breaker, characterized in that: the leakage detecting trip accessory of the pre-zero-sequence current transformer of any one of claims 1 to 10, and at least one circuit breaker unit are assembled, wherein the zero-sequence current transformer is disposed at the front end of the input end or the output end of the circuit breaker unit in the threading direction, and when the leakage circuit breaker is connected to an external cable, all the external cables are directly connected with the wiring frame of the circuit breaker unit after passing through the zero-sequence current transformer, so as to achieve the purpose of detecting leakage current.

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