CN113963997A

CN113963997A - Circuit breaker capable of automatically selecting overload protection mode

Info

Publication number: CN113963997A
Application number: CN202111136662.8A
Authority: CN
Inventors: 沈艳; 许路; 李小利; 何海良
Original assignee: Delixi Electric Co Ltd
Current assignee: Delixi Electric Co Ltd
Priority date: 2021-09-27
Filing date: 2021-09-27
Publication date: 2022-01-21
Anticipated expiration: 2041-09-27
Also published as: CN113963997B

Abstract

The invention relates to the technical field of circuit breakers, and particularly discloses a circuit breaker capable of automatically selecting an overload protection mode, which comprises a base, a middle cover, a selection module and a switch piece, wherein a thermal element assembly for monitoring overload of the circuit breaker is arranged in the base; the switch piece is positioned on the outer surface of the middle cover and connected with the selection module to start the selection module; the thermal element assembly includes an overload trigger; and a switch piece through hole is formed in the middle cover at the corresponding position of the overload trigger piece and the switch piece, and when the circuit breaker is overloaded, the overload trigger piece penetrates through the switch piece through hole to touch the switch piece so as to start the switch piece. A circuit breaker is provided that is attachable to an accessory and is capable of selecting an overload feedback mode.

Description

Circuit breaker capable of automatically selecting overload protection mode

Technical Field

The invention relates to the technical field of circuit breakers, in particular to a circuit breaker capable of automatically selecting an overload protection mode.

Background

When the plastic shell type circuit breaker is used, under the condition of line overload, the circuit breaker can trip through the circuit breaker under the protection effect on a line and electrical elements so as to achieve the aim of line disconnection; however, in some situations, such as fire fighting application, even if the circuit breaker is overloaded, the circuit breaker needs to be kept on continuously, so that whether the circuit breaker is overloaded and needs to be disconnected or not needs to be selected by a customer according to the application situation, and whether the circuit breaker is tripped or not can be freely switched according to requirements or not in some situations.

Most alarm circuit boards of alarm non-tripping products in the current market are all installed inside the products, and due to the structure, except that the circuit boards are easily polluted in the test process, the reliability is reduced, a mode that the products are locked when leaving the factory also exists, the alarm non-tripping mode cannot be changed into the tripping mode, the function is single, and the application range is limited.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides the circuit breaker which is externally provided with an overload signal receiving circuit, can be automatically installed and disassembled, and can automatically select an overload protection mode.

In order to achieve the purpose, the invention adopts the technical scheme that: a circuit breaker capable of automatically selecting overload protection mode comprises a base and a middle cover, wherein at least one end of the base is open, a thermal element assembly used for monitoring overload of the circuit breaker is arranged in the base, the middle cover covers the open end of the base, and the circuit breaker further comprises a circuit breaker,

the selection module is installed on the base or the middle cover, is connected with the warning piece and the shunt release, and is used for starting the warning piece and/or the shunt release;

the switch piece is positioned on the outer surface of the middle cover and is connected with the selection module to start the selection module;

the thermal element assembly includes an overload trigger; the middle cover is provided with a switch piece through hole, when the circuit breaker is overloaded, the overload trigger piece penetrates through the switch piece through hole to touch the switch piece so as to start the switch piece, the selection module comprises a base and an incoming line end and at least two outgoing line ends, the incoming line end is connected with the switch piece so as to receive a starting signal sent by the switch piece, and the two outgoing line ends are respectively connected with the warning piece and the shunt release.

In the technical scheme, the middle cover is fixed on the base through a screw, the middle cover is provided with a switch piece through hole at a position corresponding to the overload trigger piece, the switch piece penetrates through the switch piece through hole to enable the overload trigger piece to be capable of touching or approaching or keeping away from the switch piece, when the circuit breaker is normally electrified, a safety distance or direct contact exists between the overload trigger piece and the switch piece, namely, the switch piece is in an off or on state, when overload current exists in a circuit, the overload trigger piece starts to prop against or approach or keep away from the switch piece, the switch piece is triggered to output a signal, the overload signal is transmitted to the selection module through the signal wire, the selection module is used for starting the warning piece or the shunt release, the warning piece and the shunt release can be used as accessories of the circuit breaker, the switch piece is also a selected component because the switch piece is positioned outside the middle cover, the application range is expanded, and the warning piece and the shunt release can be selected to work or work together through the control piece such as a switch or a chip or a circuit board and the shunt release And the alarm is only given or only released, or the alarm and the release are realized, and various modes are selected, so that the use by a user is convenient.

As a further arrangement of the present invention, the thermal element assembly comprises a bimetal, a connecting plate and a thermal element, the connecting plate and the thermal element are connected together, and one end of the bimetal is connected to the thermal element; the other end is suspended and is provided with the overload trigger.

Among the above-mentioned technical scheme, bimetallic strip, connecting plate and thermal element three are riveted into the thermal element subassembly through the rivet, then assemble the thermal element subassembly on the base, and during the overload, the thermal element generates heat, and circuit temperature rises, and the bimetallic strip of riveting on the thermal element is heated and is buckled or be heated to well lid direction and shorten, makes the switch spare switch on or break off.

As a further arrangement of the invention, the bimetallic strip is arranged in parallel with the middle cover.

Among the above-mentioned technical scheme, make things convenient for overload trigger to pass switch spare through-hole, save the installation space between base and the well lid, rationally distributed

As a further arrangement of the invention, the base is provided with a plurality of groups of the thermal element assemblies, the outer side of the middle cover is fixedly connected with a switch piece circuit board for installing switch pieces, the number of the switch pieces is consistent with that of the thermal element assemblies, and the switch piece circuit board is provided with signal wires connected with the selection module.

Among the above-mentioned technical scheme, more than one thermal element subassembly on the multistage circuit breaker, this just needs a plurality of switching parts, needs parallelly connected between each switching part, therefore the setting of switching part circuit board is favorable to simplifying the overall arrangement, makes each switching part connect in parallel through the switching part circuit board, then passes through signal line output in unison.

As a further arrangement of the present invention, the circuit breaker further includes a surface cover, the surface cover covers the middle cover, and the switch member is disposed between the middle cover and the surface cover.

Among the above-mentioned technical scheme, the face lid can be used to protection switch spare and switch spare circuit board, plays dustproof and waterproof's effect, and the face is covered and is provided with the beading that corresponds with switch spare circuit board, plays the effect of fixed switch spare wire wheel board.

As a further arrangement of the invention, the wire inlet end is connected with the switch piece through a signal wire;

and/or the outlet end is connected with the warning piece and the shunt release through signal lines.

In the above technical solution, except the signal line, the signal line may also be connected through a pin, or wirelessly connected, or integrated together.

As a further arrangement of the invention, the base is mounted on an outer surface of the base;

and/or the selection module further comprises a change-over switch for selectively starting the warning piece or the shunt release, or starting the warning piece and the shunt release simultaneously.

In the above technical scheme, the selection module is provided with the change-over switch, the two outlet terminals are connected in parallel to the change-over switch, and the mode of overload protection, such as alarming, tripping or alarming tripping, is controlled through the change-over switch, and the mode can also be realized through manual wiring.

As a further arrangement of the present invention, the selection module further comprises a selection circuit board; the selective circuit board is electrically connected with the wire inlet end, the wire outlet end and the selector switch, and is used for setting a connecting circuit among the wire cutting switch, the wire inlet end and the wire outlet end.

Among the above-mentioned technical scheme, inlet wire end, outlet wire end and change over switch connect through selecting the line wheel board, simplify the wiring overall arrangement, reduce the volume, are connected with warning piece on one outlet wire end here, are connected with warning piece and shunt release on the other outlet wire end, conveniently switch.

As a further arrangement of the invention, the warning element comprises one or more of a buzzer and an indicator light;

and/or the switch member is a micro switch or a proximity switch or a sensor.

Among the above-mentioned technical scheme, bee calling organ and pilot lamp are with low costs, and long service life, the switch spare plays the effect of signal control and conduction, and the sensor can be pressure sensor or temperature sensor etc..

As a further arrangement of the invention, a containing groove for installing the selection circuit board is arranged on the base, a slot for inserting and positioning the selection circuit board is arranged on the inner wall of the containing groove, and a cover plate is arranged on the containing groove;

and/or a switch groove for exposing the change-over switch is arranged on the base and is communicated with the accommodating groove;

and/or the change-over switch is a gear shifting switch, a protective cover is covered on the gear shifting switch, a driving rod linked with a shifting rod of the gear shifting switch is arranged on the protective cover, and the driving rod penetrates through the switch slot and is exposed outside to form an operation end;

and/or the switch piece circuit board is connected with the middle cover through a screw, and a dovetail groove for a signal line to pass through is arranged on the middle cover or the base or the connection part of the middle cover and the base;

among the above-mentioned technical scheme, the setting of slot can make things convenient for the selection circuit board fixed, avoids rocking at will, and the width of slot is unanimous with the selection circuit board thickness, realizes zonulae occludens, and the apron is located inserted hole one side of slot, easy to assemble and maintenance, and the side of preferred switch slot is provided with NO TRIP and TRIP's sign, and the person of facilitating the use recognizes change over switch's state, and the selection circuit board is located binding post's below, and it is connected for dismantling with the base, easy to assemble and maintenance. The dovetail groove is arranged to facilitate wiring, the signal line is prevented from being pressed, the overload trigger part is composed of a screw rod and a nut, the screw rod is adjustable, the distance between the bimetallic strip and the switch part can be adjusted, the sensitivity during overload is adjusted, the protective cover has the waterproof and dustproof effects, and the operation end extends out of the switch groove to facilitate shifting.

The invention is further described below with reference to the accompanying drawings.

Drawings

FIG. 1 is an exploded view of the structure of an embodiment of the present invention;

FIG. 2 is an exploded view of a thermal element assembly according to an embodiment of the present invention;

FIG. 3 is an exploded view of the structure of selected modules of an embodiment of the present invention;

FIG. 4 is an exploded view of a cover according to an embodiment of the present invention;

FIG. 5 is a circuit schematic of a select module of an embodiment of the present invention;

FIG. 6 is a schematic diagram of a circuit board of a switching element according to an embodiment of the present invention;

fig. 7 is an exploded view of the structure of an embodiment of the present invention.

The overload protection device comprises a base 1, a middle cover 2, a switch part 21, a switch part through hole 22, a switch part circuit board 23, a positioning hole 231, a signal wire 232, a positioning boss 24, a dovetail groove 25, a mounting groove 26, a shunt release 3, a thermal element assembly 4, a bimetallic strip 41, a connecting plate 42, a thermal element 43, a rivet 44, an overload trigger 411, a screw 4111, a nut 4112, a selection module 5, a base 51, a containing groove 511, a slot 5111, a cover plate 5112, a switch groove 512, a wiring terminal 52, a selection circuit board 53, a change-over switch 53531, a protective cover 5311, a driving rod 5312, an operation end 5312a, a lead 54, a wire inlet end P1, a P2, an alarm non-tripping wire outlet end P3, a P4, an alarm tripping wire outlet end P5, a P6, a face cover 6 and a press rib 61.

Detailed Description

The specific embodiment of the invention is shown in fig. 1-7, a circuit breaker capable of autonomously selecting an overload protection mode comprises a base 1, a middle cover 2, a shunt release 3 and a selection module 5, wherein a thermal element assembly 4 is arranged on the base 1, the selection module 5 comprises a base 51, a connecting terminal 52 arranged on the base 51 and a selection circuit board 53 connected with the connecting terminal 52, the connecting terminal 52 comprises wire inlet ends P1, P2, alarm non-tripping wire outlet ends P3, P4 and alarm tripping wire outlet ends P5, P6, the alarm non-tripping wire outlet ends P3, P4 are connected with a warning piece, the alarm tripping wire outlet ends P5, P6 are connected with the shunt release 3, the selection circuit board 53 is provided with a switch 531 for conducting the wire inlet ends P1, P2 and the alarm non-tripping wire outlet ends P3, P4 and/or the wire inlet ends P1, P2 and the alarm tripping outlet ends P5, P6, the thermal element assembly 4 comprises a bimetallic strip 41, a connecting plate 42 and a thermal element 43, the connecting plate 42 is connected with the thermal element 43, one end of the bimetallic strip 41 is connected with the thermal element 43, the other end of the bimetallic strip is arranged in a suspended manner, an overload trigger 411 is arranged on the end of the bimetallic strip, a switch piece 21 connected with wire inlet ends P1 and P2 is arranged on the outer side of the middle cover 2, and a switch piece through hole 22 for accommodating the switch piece 21 and enabling the switch piece 21 and the overload trigger 411 to be oppositely arranged to enable the overload trigger 411 to drive the switch piece 21 to be conducted is arranged on the middle cover 2.

The shunt release is an accessory for remotely controlling the opening brake. When the power supply voltage is equal to any voltage between 70% and 110% of the rated control power supply voltage, the circuit breaker can be reliably disconnected. The shunt release is a short-time working system, the energizing time of the coil generally cannot exceed 1S, otherwise the coil can be blown. In order to prevent the coil from being burnt out, the plastic shell circuit breaker is characterized in that a microswitch is connected in series with the shunt release, when the shunt release is attracted by the armature, the microswitch is switched from a closed state to an open state, and a control circuit of a power supply of the shunt release is cut off. Even if the button is manually pressed, the shunt coil is not electrified any more all the time, so that the burning loss of the coil is avoided. When the breaker is buckled and closed again, the micro switch returns to the closed position again. The shunt release is mainly used for remotely opening the switch to control the open loop. The action principle is as follows: when the tripper (coil) of the pressure tripper works normally, voltage exists, and the voltage enables a locking hook of the tripper to overcome the spring force, so that the circuit breaker can be normally closed. When the voltage drops to its set value, the latch hook of the trip unit will reset and the circuit breaker will trip to break the circuit.

The bimetallic strip 41, the connecting plate 42 and the thermal element 43 are riveted into the thermal element assembly 4 through the rivet 44, then the thermal element assembly 4 is assembled on the base 1, the middle cover 2 is fixed on the base 1 through the screw, the switch piece through hole 22 is arranged at the position of the middle cover 2 corresponding to the overload trigger piece 411, the switch piece 21 penetrates through the switch piece through hole 22, so that the overload trigger piece 411 can touch the switch piece 21, when the circuit breaker is normally electrified, a safety distance is reserved between the overload trigger piece 411 of the bimetallic strip 41 and the switch piece 21, when overload current exists in a circuit, the thermal element 43 generates heat, the temperature of the circuit rises, the bimetallic strip 41 riveted on the thermal element 43 is heated and warps towards the middle cover 2, the overload trigger piece 411 starts to abut against the switch piece 21, the switch piece 21 is triggered, and an overload signal is transmitted to the selection module 5 through the signal line 232. In this embodiment, the bimetal 41 is arranged in parallel with the middle cover 2 to optimize the circuit breaker structure.

The selection module 5 is provided with a change-over switch 531, the alarm non-tripping outlet terminals P3 and P4 and the alarm tripping outlet terminals P5 and P6 are connected in parallel to the change-over switch 531, the alarm non-tripping or alarm tripping is controlled by the change-over switch 531, when the alarm is switched to the alarm non-tripping state, the alarm non-tripping outlet terminals P3 and P4 and the inlet terminals P1 and P2 are conducted through the change-over switch 531, and when the alarm tripping outlet terminals P5 and P6 and the inlet terminals P1 and P2 are conducted through the change-over switch 531; in other implementations, the diverter switch switches the circuit breaker to, when the circuit breaker is overloaded, activate the alert and shunt release.

The outer side of the middle cover 2 is fixedly connected with a switch piece circuit board 23, at least one switch piece 21 is arranged on the switch piece circuit board 23, and a signal wire 232 connected with the wire inlet ends P1 and P2 is arranged on the switch piece circuit board 23. The number of the thermal element assemblies 4 is more than one, so that the number of the switch pieces 21 is more than one, the switch pieces 21 are connected in parallel through the switch piece circuit board 23, then the signal line 232 is led out from the switch piece circuit board 23, the circuit is simple, the layout is convenient, the middle cover 2 can be provided with the mounting groove 26 matched with the switch piece circuit board 23, the switch piece circuit board 23 is fixedly connected with the middle cover 2 through screws, and the installation is convenient and the structure is simple.

A positioning structure is arranged between the middle cover 2 and the switch piece circuit board 23. The arrangement of the positioning structure can facilitate the installation of the circuit board 23 of the switch part, the positioning is firstly carried out through the positioning structure before screwing the screw, the subsequent screw connection is facilitated, and the installation efficiency is improved.

The above-described positioning structure includes the positioning boss 24 and the positioning hole 231 provided between the middle cap 2 and the switch element wiring board 23. The two preferable positioning bosses 24 correspond to two ends of the switch piece circuit board 23, the two positioning bosses 24 are arranged in a staggered mode, the positioning bosses 24 of the middle cover 2 penetrate through the positioning holes 231 of the switch piece circuit board 23, tapping screws penetrate through the switch piece circuit board 23 and tapping screw holes in the middle cover 2 to fix the switch piece circuit board 23, the mounting grooves 26 also have a positioning effect on the switch piece circuit board 23, and the two positioning bosses can be used as auxiliary parts or as one of the auxiliary parts, so that the structure is simple, and the installation is convenient.

The switch piece circuit board 23 is connected with the middle cover 2 through screws, a dovetail groove 25 for the signal line 232 to pass through is arranged on the peripheral side edge of the middle cover 2, and the overload trigger piece 411 comprises a screw rod 4111 and a nut 4112. The dovetail groove 25 is arranged to facilitate wiring and prevent the signal line 232 from being pressed, the overload trigger 411 is composed of a screw 4111 and a nut 4112, the screw 4111 is adjustable, the distance between the bimetallic strip 41 and the switch member 21 can be adjusted, and the sensitivity during overload is adjusted.

The upper cover of the middle cover 2 is provided with a surface cover 6, and the surface cover 6 is provided with a pressing rib 61 corresponding to the switch piece circuit board 23. The signal line 232 is led out from the dovetail groove 25 of the middle cover 2, and then the switch part circuit board 23 is reinforced by the pressing rib 61 on the surface cover 6 for further fixing, so that the switch part circuit board 23 is prevented from shaking.

The base 51 is fixed on the base 1 or the middle cover 2, the base 51 is provided with a containing groove 511 for mounting the option circuit board 53, the base 51 is provided with a switch groove 512 for exposing the switch 531, and the switch groove 512 is communicated with the containing groove 511. The side of the switch slot 512 is preferably provided with an NO trip and a trip identifier, so that a user can conveniently recognize the state of the switch 531, and the selection circuit board 53 is positioned below the wiring terminal 52 and detachably connected with the base 51, so that the installation and the maintenance are convenient.

The switch 531 is a shift switch, a protective cover 5311 covers the shift switch, a driving rod 5312 linked with a shift lever of the shift switch is disposed on the protective cover 5311, and the driving rod 5312 penetrates through the switch slot 512 and is exposed to the outside to form an operating end 5312 a. The protection cover 5311 has waterproof and dustproof functions, and the operation end 5312a extends out of the switch slot 512 to facilitate shifting.

The wire inlet ends P1 and P2, the alarm tripping wire outlet ends P3 and P4, the alarm tripping wire outlet ends P5 and P6, and the selection circuit board 53 are all connected by a wire 54, the inner wall of the accommodating groove 511 is provided with a slot 5111 for the selection circuit board 53 to be inserted and positioned, and the accommodating groove 511 is provided with a cover plate 5112. The slot 5111 is convenient for fixing the selective circuit board 53, random shaking is avoided, the width of the slot 5111 is consistent with the thickness of the selective circuit board 53, tight connection is achieved, and the cover plate 5112 is located on one side of the insertion hole of the slot 5111, so that the installation and maintenance are convenient.

The warning part comprises one or more of a buzzer and an indicator light, and the switch part 21 is a micro switch or a proximity switch or a sensor. The buzzer and the indicator light have low cost and long service life, the switch piece 21 plays the role of signal control and conduction, and the sensor can be a pressure sensor or a temperature sensor and the like.

Both ends of the signal line 232 drawn out from the middle cover 2 are connected to the line inlet ends P1 and P2 of the selection module 5, respectively. The assembly steps are as follows: the shift switch is first passed through the switch slot 512, then the two ends of the selection circuit board 53 are aligned with the slots 5111, and the protective cover 5311 is pressed on the shift switch. Finally, the cover plate 5112 is fixed to the base 511 by self-tapping screws. The realization function is as follows: firstly, the signal line 232 is respectively connected to the inlet terminals P1 and P2, once the product overload alarm signal is transmitted to the selection circuit board 53 through the interface, the alarm non-tripping outlet terminals P3 and P4 can be connected to a circuit with an alarm signal such as a buzzer or an indicator light, and the alarm tripping outlet terminals P5 and P6 are connected to the shunt release. The implementation mode is as follows: when the shift switch is shifted to NO TRIP, the alarm tripping outlet wire ends P3 and P4 are conducted with the inlet wire ends P1 and P2 and connected with an external alarm line, when an overload condition occurs in the line, an overload alarm function is realized, and the alarm tripping outlet wire ends P5 and P6 are disconnected with the inlet wire ends P1 and P2 at the moment, and NO output exists. When the gear shifting switch is shifted to the TRIP, the alarm tripping outlet terminals P3 and P4 are disconnected from the inlet terminals P1 and P2, the alarm tripping outlet terminals P5 and P6 are connected with the inlet terminals P1 and P2, the shunt release 3 receives a signal to execute tripping action, the circuit breaker is disconnected, and the overload tripping function is realized. The assembly is simple, the reliability is higher, the switching piece circuit board 23 is equivalent to an accessory and can be independently installed, the switching piece circuit board 23 is positioned between the middle cover 2 and the face cover 6, the influence of the test of the product is small, and the possibility of failure is lower.

In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

The present invention is not limited to the above embodiments, and those skilled in the art can implement the present invention in other embodiments according to the disclosure of the present invention, or make simple changes or modifications on the design structure and idea of the present invention, and fall into the protection scope of the present invention.

Claims

1. The utility model provides a circuit breaker of overload protection mode can independently select, includes base and well lid, the at least one end opening of base, and be provided with in the base and be used for monitoring circuit breaker overloaded thermal element subassembly, well lid closes the open end of base, its characterized in that: also comprises the following steps of (1) preparing,

2. The circuit breaker of claim 1, wherein: the thermal element assembly comprises a bimetallic strip, a connecting plate and a thermal element, wherein the connecting plate and the thermal element are connected together, and one end of the bimetallic strip is connected to the thermal element; the other end is suspended and is provided with the overload trigger.

3. The circuit breaker of claim 2, wherein: the bimetallic strip and the middle cover are arranged in parallel.

4. The circuit breaker of claim 1 or 2 or 3, wherein: the base is provided with a plurality of groups of thermal element assemblies, the outer side of the middle cover is fixedly connected with a switch piece circuit board used for installing switch pieces, the number of the switch pieces is consistent with that of the thermal element assemblies, and the switch piece circuit board is provided with signal wires connected with the selection module.

5. The circuit breaker of claim 1 or 2 or 3, wherein: the circuit breaker further comprises a surface cover, the surface cover covers the middle cover, and the switch piece is arranged between the middle cover and the surface cover.

6. The autonomously selectable overload protection mode circuit breaker according to claim 4, wherein: the wire inlet end is connected with the switch piece through a signal wire;

7. The circuit breaker of claim 1 or 2 or 3 or 6, wherein: the base is mounted on the outer surface of the base;

8. The autonomously selectable overload protection mode circuit breaker according to claim 7, further comprising: the selection module also comprises a selection circuit board; the selective circuit board is electrically connected with the wire inlet end, the wire outlet end and the selector switch, and is used for setting a connecting circuit among the wire cutting switch, the wire inlet end and the wire outlet end.

9. The circuit breaker of claim 1 or 2 or 3 or 6 or 8, wherein: the warning piece comprises one or more of a buzzer and an indicator light;

and/or the switch member is a micro switch or a proximity switch or a sensor.

10. The autonomously selectable overload protection mode circuit breaker of claim 9, wherein: the base is provided with a containing groove for installing the selective circuit board, the inner wall of the containing groove is provided with a slot for inserting and positioning the selective circuit board, and the containing groove is provided with a cover plate;

and/or the switch piece circuit board is connected with the middle cover through screws, and a dovetail groove for a signal wire to pass through is arranged on the middle cover or the base or the joint of the middle cover and the base.