JP2007194058A - Circuit breaker - Google Patents

Abstract

There is provided a circuit breaker capable of reducing a temperature difference between phases and suppressing a temperature rise of a phase sandwiched between two phases even in a circuit breaker formed of three or more phases. .
[Solution]
The insulating housing 2 includes a pair of terminals 3 and 4, a fixed contact 9 that is connected to the power supply side terminal 3 and includes a fixed contact 15, and a movable contact 16 that contacts and separates from the fixed contact 15. A movable contact 11 is provided for each phase, and in the power supply side terminal 3 and the load side terminal 4, the power supply side terminal 3 of each phase or the load side terminal 4 of each phase is connected to each other and electrically insulated. It is possible to conduct heat of the power supply side terminal 3 of each phase or the load side terminal 4 of each phase so that there is no temperature difference between the power supply side terminal 3 of each phase or the load side terminal 4 of each phase. Connecting plates 24 and 25 formed of a material having a high thermal conductivity.
[Selection] Figure 1

Description

  The present invention relates to a circuit breaker such as a circuit breaker for wiring and a circuit breaker having a movable contact that opens a contact using an electromagnetic repulsion force when a large current such as a short circuit current flows. The present invention relates to a circuit breaker capable of reducing a temperature rise by dispersing heat generated between phases.

As a conventional circuit breaker, for example, circuit breakers shown in Patent Document 1 and Patent Document 2 are known.
As shown in FIG. 3, the circuit breaker 30 described in Patent Document 1 includes a pair of terminal members 32 and 33 corresponding to an input / output circuit and a terminal member 32 and 33 in a case 31 made of molded insulating material. A fixed contact 34 arranged in series therebetween, a movable contact 35 that contacts and separates from the fixed contact 34, and a relay conductor 36 provided between the terminal member 32 and the fixed contact 34 are provided. Furthermore, a heat conducting member 37 is provided between the terminal member 32 and the fixed contact 34 to thermally bypass the relay conductor 36 without being electrically bypassed. According to such a circuit breaker 30, the Joule heat generated between the contact points of the fixed contact 34 and the movable contact 35 is connected to the external electric wire with good heat dissipation via the heat conducting member 37. Heat conduction to the terminal member 32 can prevent an increase in temperature inside the case 31.

In addition, as shown in FIG. 4, the circuit breaker 40 described in Patent Document 2 includes a front terminal plate 44 for connecting an external wire in a housing 41 formed of a cover 42 and a base 43. And the rear terminal plate 45, the opening / closing mechanism portion 46 for opening and closing the electric circuit, the mover 47 opened and closed by the opening / closing mechanism portion 46, the pair of contacts 48, and the interior connecting the mover 47 and the rear terminal plate 45. A conductor 49, a bimetal 50 that detects an overcurrent and drives the opening / closing mechanism 46, a heater 51 that bends the bimetal 50, and a shielding member 52 that shields heat generated by the heater 51 are provided. Further, the cover 42, the base 43, and the shielding member 52 are formed of a high thermal conductivity, low shrinkage wet unsaturated polyester resin composition. According to such a circuit breaker 40, the heat generated inside the housing 41 is radiated using the surface areas of the shielding member 52, the cover 42, and the base 43 with good thermal conductivity, thereby the circuit breaker. Forty local heat stresses can be eliminated.
Japanese Patent Laid-Open No. 2002-56761 JP-A-5-202277

However, in the circuit breaker 30 described in Patent Document 1, it is possible to individually suppress the temperature rise in each phase. Since the phase sandwiched between the two phases is affected by heat conduction from the adjacent phases, the amount of temperature rise is larger than the phase at both ends, and it is difficult to suppress the temperature rise of the sandwiched phase.
Further, in the circuit breaker 40 described in Patent Document 2, the thermal conductivity of the shielding member 52, the cover 42, and the base 43 is set to be a shielding member formed of a normal low shrinkage wet unsaturated polyester resin composition, The thermal conductivity of the cover and the base can be increased only to about 1.7 times. Similarly to the case of the circuit breaker 30, when the circuit breaker 40 is composed of three or more phases, two phases can be obtained. It is difficult to suppress the temperature rise of the phase sandwiched between the layers.
And in the phase where the temperature rise has occurred, there is a problem that the operating characteristics of the bimetal become unstable and the proper operation of the circuit breaker is hindered.

  The present invention has been made to solve the above-described problems of the prior art, and the object of the present invention is to reduce the temperature difference between each phase in two or more phases even in a circuit breaker formed of three or more phases. An object of the present invention is to provide a circuit breaker that can suppress an increase in temperature of a sandwiched phase and can ensure proper operation.

A circuit breaker according to claim 1 of the present invention includes a pair of power supply side terminals and a load side terminal connected to a plurality of external electric wires in the insulating casing, and the power supply side terminals and the load side terminals. A fixed contact that is connected to one of the fixed contacts, a movable contact that includes a movable contact that contacts and separates from the fixed contact, the other of the movable contact, the power supply side terminal, and the load side terminal. In a circuit breaker having an internal conductor for connecting each phase,
In either one or both of the power supply side terminal and the load side terminal, the power supply side terminals of the respective phases or the load side terminals of the respective phases are connected to each other, and are electrically insulative and have a power supply of each phase. A connection formed of a material having thermal conductivity capable of conducting heat of the power supply side terminal of each phase or the load side terminal of each phase in a state where there is no temperature difference between the side terminals or the load side terminals of each phase. A circuit breaker comprising a plate.

According to a second aspect of the present invention, a circuit breaker according to a second aspect of the present invention includes a pair of power supply side terminals and load side terminals connected to a plurality of external electric wires in the insulating casing, the power supply side terminals and the load. A stationary contact that is connected to one of the side terminals and includes a stationary contact; a movable contact that includes a movable contact that contacts and separates from the stationary contact; and the movable contact, the power supply side terminal, and the load side terminal In the circuit breaker having an internal conductor connecting the other for each phase,
Heat conduction that connects the stationary contacts of the respective phases to each other, is electrically insulative, and can conduct the heat of the stationary contacts in a state where there is no temperature difference between the stationary contacts of each phase A connection plate formed of a material having a rate is provided.

A circuit breaker according to claim 3 of the present invention includes a pair of power supply side terminals and load side terminals connected to a plurality of external electric wires, the power supply side terminals and the load in an insulating casing. A stationary contact that is connected to one of the side terminals and includes a stationary contact; a movable contact that includes a movable contact that contacts and separates from the stationary contact; and the movable contact, the power supply side terminal, and the load side terminal In the circuit breaker having an internal conductor connecting the other for each phase,
The fixed contacts of each phase are connected to each other, have electrical conductivity, and have a thermal conductivity capable of conducting heat of the fixed contacts in a state where there is no temperature difference between the fixed contacts of each phase. A connection plate made of a material is provided.

According to a fourth aspect of the present invention, there is provided a circuit breaker according to a fourth aspect of the present invention, wherein a pair of power supply side terminals and load side terminals connected to a plurality of phases of external electric wires, the power supply side terminals and the load in an insulating casing. A stationary contact that is connected to one of the side terminals and includes a stationary contact; a movable contact that includes a movable contact that contacts and separates from the stationary contact; and the movable contact, the power supply side terminal, and the load side terminal In the circuit breaker having an internal conductor connecting the other for each phase,
The internal conductors of the respective phases are connected to each other, are electrically insulating, and have a thermal conductivity capable of conducting the heat of the internal conductors in a state where there is no temperature difference between the internal conductors of the respective phases. A connection plate made of a material is provided.

According to a fifth aspect of the present invention, a circuit breaker according to claim 5 includes a pair of power-side terminals and load-side terminals connected to a plurality of external electric wires in the insulating housing, the power-side terminals and the load. A stationary contact that is connected to one of the side terminals and includes a stationary contact; a movable contact that includes a movable contact that contacts and separates from the stationary contact; and the movable contact, the power supply side terminal, and the load side terminal In a circuit breaker having an internal conductor for connecting the other and a bimetal forcibly opening the movable contact from the fixed contact via an open / close mechanism for each phase,
The bimetals of the respective phases are connected to each other, and are formed of a material having a thermal conductivity capable of conducting heat of the bimetal in a state of being electrically insulative and eliminating the temperature difference between the bimetals of the respective phases. It is characterized by comprising a connected plate.

  A circuit breaker according to a sixth aspect of the present invention is the circuit breaker according to any one of the first to fifth aspects, wherein the material is silica, alumina, boron nitride, magnesia, aluminum nitride, and the like. It is characterized in that it is a material in which any one of silicon nitride or any combination thereof is combined.

  A circuit breaker according to claim 7 of the present invention is the circuit breaker according to any one of claims 1 to 5, wherein the material is a resin material having heat resistance or flame resistance. Material mixed with glass filler and mixed with any one powder or particle of silica, alumina, boron nitride, magnesia, aluminum nitride, silicon nitride and calcium carbonate, or any combination of powder or particles It is characterized by being.

  Here, the resin material having heat resistance or flame retardancy includes phenol resin, poly-imide, poly-ether-imide, poly-amide-imide, poly-ether-ether-ketone, poly-phenyrin sulfide, poly-polyimide. A material obtained by combining any one or any of ether / sulfone, poly-amide, fluororesin (PTFE, PFA, FEP) and liquid crystal polymer (LCP).

  According to these configurations, each connection plate is formed of a material having electrical insulation and high thermal conductivity, so that even when the circuit breaker is formed in three or more phases, Due to the heat conduction through the connecting plate, the temperature difference in each phase is suppressed to a small level. Therefore, it is possible to ensure proper operation of the circuit breaker.

  According to the circuit breaker according to any one of claims 1 to 7, the power supply side terminal, the load side terminal, the fixed contact, the fixed contact, the internal conductor or the bimetal provided in each phase are connected to each other. Electrically insulative and capable of conducting the heat of these conductors in a state where there is no temperature difference between the power supply side terminal, load side terminal, fixed contact, fixed contact, internal conductor or bimetal of each phase Even when the circuit breaker is formed in three or more phases, the temperature difference between the phases can be kept small by the heat conduction of the connection plate even when the circuit breaker is formed in three or more phases by the configuration including the connection plate formed of a material having thermal conductivity. There is an effect that it is possible to suppress the temperature rise of the phase sandwiched between the two phases. Further, through the connection plate, there is an effect that the amount of heat released to the housing is increased, and the temperature rise of the conductor itself that has generated heat due to Joule heat can be suppressed. Therefore, there is an effect that it is possible to ensure proper operation of the circuit breaker.

Hereinafter, a circuit breaker according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a vertical cross-sectional view of a main part of a central phase portion in a three-phase circuit breaker according to an embodiment of the present invention.
As shown in FIG. 1, the circuit breaker 1 includes three pairs of power source side terminals 3 and load side terminals 4 connected to a three-phase external power source in an insulating container (housing) 2 and three sets of circuit breakers. The part 5 and three sets of tripping mechanisms 6 are provided.
The insulating container 2 includes a case 7 and a cover 8 that is detachably attached to the case 7. Further, the inside of the insulating container 2 is partitioned into a three-phase space by a phase interval wall (not shown). Although only the central pole portion is shown in FIG. 1, in each space of the three-phase space of the insulating container 2, the terminals 3 and 4, the blocking portion 5, and the removing mechanism 6 are accommodated one by one.

  Each power supply side terminal 3 is formed of a flat conductor and is connected to an external electric wire on the power supply side. The power supply side terminals 3 installed in each space of the three-phase space are provided so as to be in contact with the lower surface thereof, and are connected to each other by a plate-like power supply side terminal connection plate 24 communicating with the three-phase space. Yes. Each load side terminal 4 is formed of a flat conductor and is connected to an external electric wire on the load side. The load-side terminals 4 installed in each space of the three-phase space are provided so as to be in contact with the lower surface thereof, and are connected to each other by a flat load-side terminal connection plate 25 that communicates with the three-phase space. Yes. Here, the power supply side terminal connection plate 24 and the load side terminal connection plate 25 are incorporated in the case 7 so that the surfaces thereof are in contact with the case 7.

Each blocking section 5 has a fixed contact 9 fixed to the case 7 and an elongated plate-shaped movable contact 11 that is driven to open and close by an opening / closing mechanism 10. The blocking section 5 includes an arc extinguishing chamber. 12 is installed.
The fixed contact 9 is formed of a flat conductor, the power supply side terminal 3 is integrally formed at one end, and the fixed contact 15 is provided on the upper surface of the other end. The fixed contacts 9 installed in each space of the three-phase space are provided so as to be in contact with the lower surface of the other end, and are connected to each other by a flat fixed contact connecting plate 26 that communicates with the three-phase space. Has been. Further, the fixed contacts 15 provided in each space of the three-phase space are connected to each other by a flat plate-like fixed contact connecting plate 27 that is provided so as to be in contact with the lower surface thereof and communicates with the three-phase space. .

  The movable contact 11 has a movable contact 16 that contacts and separates from the fixed contact 15 at one end, and the other end is connected to the load side terminal 4 via an internal conductor 23. The other end of the movable contact 11 is supported by an insulating holder 17. Here, the holders 17 of the respective phases are integrally connected to each other with the same rotation axis, and the movable contact 11 supported by the holder 17 is driven to open / close by the opening / closing mechanism 10 via the holder 17. Thus, it is provided so as to be rotatable with respect to the case 7.

The inner conductor 23 is a lead wire. The internal conductors 23 installed in each space of the three-phase space are provided so as to come into contact with the lead wires, and are connected to each other by a flat-plate-like internal conductor connection plate 28 that communicates with the three-phase space. Here, the inner conductor connecting plate 28 is incorporated in the case 7 so that the surface thereof is in contact with the case 7.
The arc extinguishing chamber 12 has a configuration in which a plurality of grids 20 made of a magnetic material are stacked and supported at appropriate intervals on a pair of left and right side walls (support side walls) 19 of an insulating support. The movable contact 11 has a U shape provided with a notch through which the movable contact 11 passes when driven.

An arc gas discharge port (not shown) is provided in front of the shut-off unit 5, and the arc gas discharge port is closed by an insulating protective plate 21 that prevents foreign matter from entering.
The arc gas generated at the time of interruption includes metal melts generated from the respective contacts 15, 16, the stationary contact 9 and the movable contact 11, the grid 20, etc., but the partition wall moves the arc gas to the switching mechanism 10. The shielding prevents the metal melt contained in the arc gas from scattering and adhering to the opening / closing mechanism 10 and its peripheral part.

Each tripping mechanism 6 has a heater 13 having one end connected to the load-side terminal 4 and a bimetal 14 that is bent by the heat of the heater 13. The bimetal 14 installed in each space of the three-phase space is provided so as to be in contact with the lower end thereof, and is connected to each other by a flat bimetal connection plate 29 that communicates with the three-phase space.
In the circuit breaker 1, when an overload current flows through the heater 13, the heater 13 generates heat and a large amount of heat is transmitted from the heater 13 to the bimetal 14, so that the bimetal 14 is greatly curved. Then, when the opening / closing mechanism 10 is operated by the bending of the bimetal 14, the movable contact 16 of the movable contact 11 is forcibly opened from the fixed contact 15 of the fixed contact 9.
The circuit breaker 1 having the above-described configuration is characterized by the power source side terminal connecting plate 24, the load side terminal connecting plate 25, the fixed contact connecting plate 26, the fixed contact connecting plate 27, the internal conductor connecting plate 28, and the like. The configuration includes the bimetal connection plate 29 and the material of these connection plates 24, 25, 26, 27, 28, and 29.

  That is, in the circuit breaker 1, the power supply side terminal connection plate 24 is electrically insulative and the heat of the power supply side terminals 3 of each phase is eliminated so that there is no temperature difference between the power supply side terminals 3 of each phase. It is formed with the material which has the thermal conductivity which can conduct. Further, the load side terminal connecting plate 25 is electrically insulative and can conduct heat of the load side terminals 4 of these phases in a state where there is no temperature difference between the load side terminals 4 of the respective phases. It is made of a material having thermal conductivity. The fixed contact connecting plate 26 is electrically insulative and has a thermal conductivity capable of conducting the heat of the fixed contact 9 in a state where there is no temperature difference between the fixed contact 9 of each phase. It is formed with the material which has. Further, the fixed contact connecting plate 27 is made of a material having a thermal conductivity capable of conducting the heat of the fixed contact 15 in a state in which the temperature difference between the fixed contacts 15 of each phase is eliminated. Is formed. Further, the inner conductor connecting plate 28 is made of a material having a thermal conductivity capable of conducting the heat of the inner conductor 23 in a state that is electrically insulative and eliminates the temperature difference between the inner conductors 23 of each phase. Is formed. Further, the bimetal connecting plate 29 is formed of a material having a thermal conductivity capable of conducting the heat of the bimetal 14 so as to be electrically insulative and eliminate the temperature difference between the bimetals 14 of the respective phases. Yes. Hereinafter, these materials are collectively referred to as insulating high thermal conductivity materials.

The insulating high thermal conductivity material is preferably a material having a thermal conductivity of 1 [W / m · K] or more, more preferably 3 [W / m · K] or more. For example, silica, alumina, nitriding A material in which any one or a combination of boron, magnesia, aluminum nitride, and silicon nitride is considered.
Moreover, as an insulating high thermal conductivity material, after mixing a glass filler with a heat-resistant or flame-resistant resin material, any of silica, alumina, boron nitride, magnesia, aluminum nitride, silicon nitride and calcium carbonate is added to this. A material mixed with a single powder or particle, or a combination of any powder or particle (hereinafter referred to as silica or the like) may be used. In addition, heat-resistant or flame-retardant resin materials include phenol resin, poly-imide, poly-ether-imide, poly-amide-imide, poly-ether-ether-ketone, poly-phenyline-sulfide, poly-polyimide. It refers to a material combining any one or any of ether / sulfone, poly-amide, fluororesin (PTFE, PFA, FEP) and liquid crystal polymer (LCP). The mixing ratio of the heat-resistant or flame-resistant resin material, the glass feeler, and the powder or particles of silica or the like is 20 to 50% by weight of the heat-resistant or flame-resistant resin material, and the glass feeler 10 It is preferable that it is -30 weight%, and powders or particles, such as a silica, 40-70 weight%.

According to the circuit breaker 1 in this embodiment, the thermal conductivity of each connection plate 24, 25, 26, 27, 28, 29 is 1 to 100 [W / m · K], which is a conventional phenol resin. It becomes possible to form about 1.4 to 140 times the thermal conductivity 0.7 [W / m · K] of the case made of the material.
In addition, the connection form of each connection plate 24, 25, 26, 27, 28, 29 and each conductor 3, 4, 9, 14, 15, 23 is mechanical / physical, such as screw fastening, bonding, adhesion, contact, etc. Any form may be used as long as they are connected to each other.

  In the circuit breaker 1, insulation is provided by Joule heat generated in a conductor (hereinafter referred to as a conductor) such as a power source side terminal 3, a load side terminal 4, a fixed contact 9, a movable contact 11, an internal conductor 23, and a heater 13. A temperature rise occurs in each space of the three-phase space of the container 2. In this case, since each connection plate 24, 25, 26, 27, 28, 29 formed of a material having electrical insulation and high thermal conductivity is provided, the three phases of the insulating container 2 are provided. Even when a temperature difference occurs in each space, it is possible to efficiently conduct heat from a high temperature space to a low temperature space, and it is possible to reduce the temperature difference between each phase of the three-phase space It becomes.

Further, each connection plate 24, 25, 26, 27, 28, 29 is inserted between the conductor and the case 7, and the contact area between each connection plate 24, 25, 26, 27, 28, 29 and the case 7 is increased. By enlarging, Joule heat generated in the conductor can be efficiently radiated to the case 7 through the connection plates 24, 25, 26, 27, 28, 29, and the temperature of the conductor itself generated by Joule heat is increased. It is possible to suppress the rise.
Therefore, according to the circuit breaker 1, it becomes possible to reduce the temperature difference between the respective phases of the three-phase space and to suppress the temperature rise of the phase sandwiched between the two phases. It becomes possible to ensure operation.

As mentioned above, although embodiment of this invention was described, in this embodiment, a various change is possible. For example, the circuit breaker 1 is formed in three phases, but is not limited to such a configuration, and can be formed by appropriately increasing or decreasing the number of phases.
Each connection plate 24, 25, 26, 27, 28, 29 may be at least one, or a plurality may be used in appropriate combination.

It is a longitudinal cross-sectional view of the principal part of the center phase part in the three-phase circuit breaker which concerns on embodiment of this invention. It is a longitudinal cross-sectional view of the principal part of the circuit breaker described in patent document 1. It is a longitudinal cross-sectional view of the principal part of the circuit breaker described in patent document 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circuit breaker 2 Insulation container 3 Power supply side terminal 4 Load side terminal 5 Breaking part 6 Tripping mechanism 7 Case 8 Cover 9 Fixed contact 10 Opening / closing mechanism 11 Movable contact 12 Arc-extinguishing chamber 13 Heater 14 Bimetal 15 Fixed contact 16 Movable Contact 17 Holder 19 Side wall 20 Grid 21 Guard plate 23 Internal conductor 24 Power supply side terminal connection plate 25 Load side terminal connection plate 26 Fixed contact connection plate 27 Fixed contact connection plate 28 Internal conductor connection plate 29 Bimetal connection plate 30 Circuit breaker 31 Case 32 Terminal member 33 Terminal member 34 Fixed contact 35 Movable contact 36 Relay conductor 37 Heat conducting member 40 Circuit breaker 41 Case 42 Cover 43 Base 44 Front terminal plate 45 Rear terminal plate 46 Opening / closing mechanism 47 Mover 48 Contact 49 Inner conductor 50 Bimetal 51 Heater 52蔽部 material

Claims (7)

A pair of power supply side terminals and load side terminals connected to a plurality of external electric wires in an insulating casing, and a fixed contact connected to one of the power supply side terminals and the load side terminals, and having a fixed contact A movable contact provided with a movable contact contacting and separating from the fixed contact, and an internal conductor connecting the movable contact and the other of the power supply side terminal and the load side terminal for each phase. In the circuit breaker
In either one or both of the power supply side terminal and the load side terminal, the power supply side terminals of the respective phases or the load side terminals of the respective phases are connected to each other, and are electrically insulative and have a power supply of each phase. A connection formed of a material having thermal conductivity capable of conducting heat of the power supply side terminal of each phase or the load side terminal of each phase in a state where there is no temperature difference between the side terminals or the load side terminals of each phase. A circuit breaker comprising a plate. A pair of power supply side terminals and load side terminals connected to a plurality of external electric wires in an insulating casing, and a fixed contact connected to one of the power supply side terminals and the load side terminals, and having a fixed contact A movable contact provided with a movable contact contacting and separating from the fixed contact, and an internal conductor connecting the movable contact and the other of the power supply side terminal and the load side terminal for each phase. In the circuit breaker
Heat conduction that connects the stationary contacts of the respective phases to each other, is electrically insulative, and can conduct the heat of the stationary contacts in a state where there is no temperature difference between the stationary contacts of each phase A circuit breaker comprising a connection plate formed of a material having a rate. A pair of power supply side terminals and load side terminals connected to a plurality of external electric wires in an insulating casing, and a fixed contact connected to one of the power supply side terminals and the load side terminals, and having a fixed contact A movable contact provided with a movable contact contacting and separating from the fixed contact, and an internal conductor connecting the movable contact and the other of the power supply side terminal and the load side terminal for each phase. In the circuit breaker
The fixed contacts of each phase are connected to each other, have electrical conductivity, and have a thermal conductivity capable of conducting heat of the fixed contacts in a state where there is no temperature difference between the fixed contacts of each phase. A circuit breaker comprising a connection plate made of a material. A pair of power supply side terminals and load side terminals connected to a plurality of external electric wires in an insulating casing, and a fixed contact connected to one of the power supply side terminals and the load side terminals, and having a fixed contact A movable contact provided with a movable contact contacting and separating from the fixed contact, and an internal conductor connecting the movable contact and the other of the power supply side terminal and the load side terminal for each phase. In the circuit breaker
The internal conductors of the respective phases are connected to each other, are electrically insulating, and have a thermal conductivity capable of conducting the heat of the internal conductors in a state where there is no temperature difference between the internal conductors of the respective phases. A circuit breaker comprising a connection plate made of a material. A pair of power supply side terminals and load side terminals connected to a plurality of external electric wires in an insulating casing, and a fixed contact connected to one of the power supply side terminals and the load side terminals, and having a fixed contact A movable contact provided with a movable contact that contacts and separates from the fixed contact, an internal conductor that connects the movable contact to the other of the power supply side terminal and the load side terminal, and the movable via an opening / closing mechanism. In a circuit breaker having a bimetal that forcibly opens a contact from the fixed contact for each phase,
The bimetals of the respective phases are connected to each other, and are formed of a material having a thermal conductivity capable of conducting heat of the bimetal in a state of being electrically insulative and eliminating the temperature difference between the bimetals of the respective phases. A circuit breaker comprising a connected plate.   6. The material according to any one of claims 1 to 5, wherein the material is any one of silica, alumina, boron nitride, magnesia, aluminum nitride, and silicon nitride, or a combination thereof. Circuit breaker.   The material is a powder or particles of any one of silica, alumina, boron nitride, magnesia, aluminum nitride, silicon nitride and calcium carbonate after mixing a glass filler with a heat resistant or flame resistant resin material. The circuit breaker according to any one of claims 1 to 5, wherein the circuit breaker is a material mixed with any combination of powders or particles.

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