JPH05159680A - Current detecting device - Google Patents

Abstract

PURPOSE:To stabilize a power source at the time of short circuit, precisely detect cable information, and improve assembly property by using a current detecting device having two current devices for detecting a current having smaller than a determined standard value and a current larger than the determined standard value, respectively. CONSTITUTION:When the current of a cable is smaller than a standard value, the output signal of a current detecting circuit 1 having a first current transformer 8 is processed in a control circuit 3 to output cable information such as current value and power. When the current is larger than the standard value, the output signal of a current detecting circuit 2 having a second current transformer 9 is compared with a set level, and when it exceeds this level, the detection signal of overcurrent is tripped, and inputted to a circuit 5 to start tripping a device. At the time of short circuit, the output signal of the circuit 2 is directly inputted to the circuit 5. Although the voltage between phases is lowered, the output of the circuit 4 can be stabilized since the output of the current transformer 9 is inputted to the power source circuit 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current detecting device for a circuit breaker.

[0002]

2. Description of the Related Art Conventionally, a current transformer is provided outside a circuit breaker to detect a current value equal to or less than a rated current, but there is a problem that it requires a large installation space and requires a lot of work. For this reason, it has become necessary to incorporate a current transformer into a circuit breaker and process electric circuit information such as a current value, electric energy and power factor in the circuit breaker.

In a circuit breaker, there is an example in which a current transformer and a trip device (release relay) are used as means for detecting an overcurrent in an electric circuit without using a bimetal or a momentary electromagnet. In this example, the current transformer of each phase is built into the circuit breaker, the current in the circuit is converted into a voltage, the signal is sent to the overcurrent detection circuit, and the trip device is driven when the output signal exceeds the set level. By doing so, the electric circuit is cut off.

[0004]

However, the power supply circuit such as the tripping circuit of the tripping device is rectified by inputting the interphase voltage of the electric line. Therefore, when a short-circuit current flows in the electric line,
There is a drawback in that the tripping device may not operate because the interphase voltage decreases and the voltage becomes unstable. In addition, the current transformer has a limit in the current value that can be detected because the current transformer saturates when a large current flows.After the short-circuit current flows, the output signal of the current transformer is limited due to the residual magnetic flux density. However, there is a drawback that the electric path information cannot be accurately detected.

Further, when the current transformer is built in the circuit breaker, there is a drawback that the assemblability is poor. Therefore, an object of the present invention is to provide a current detection device capable of stabilizing a power supply at the time of short circuit, accurately detecting electric circuit information, and improving assemblability.

[0006]

According to another aspect of the present invention, there is provided a current detecting device having a first current transformer for detecting a current up to a predetermined reference value including a rated current value, and A second current detection circuit having a second current transformer that detects a current equal to or greater than a predetermined reference value, and the output signals of the first current detection circuit and the second current detection circuit are input and the current of the circuit is input. A control circuit that outputs electric circuit information such as a value and an overcurrent, a trip circuit that operates by the output signals of the control circuit and the second current detection circuit, and the second current transformer that is connected to the electric circuit. A power supply circuit having an input end connected to the output end of the container and having an output end connected to the control circuit and the trip circuit.

According to a second aspect of the current detecting device of the first aspect, at least one of the first current transformer and the second current transformer has a core gap. According to a third aspect of the present invention, in the second aspect, the current transformer includes a pair of L-shaped cores and one piece of each of the cores inserted from one end side, and the bent portion of the core is pinned. It comprises a pair of coil bobbins to be fixed, and each other piece of the core is connected to the other end side of the coil bibon by a pin to form a gap between the pair of cores.

According to a fourth aspect of the present invention, there is provided the current detection device according to the first aspect, further comprising a leakage current detection circuit having a zero-phase current transformer, wherein an output signal of the leakage current detection circuit is input to the control circuit, and The number 1 of the current transformer and the number 2 of the second current transformer are each one less than the number of poles. According to a fifth aspect of the present invention, in the fourth aspect, the number of poles is three, the R-phase and T-phase electric paths are passed through the first current transformer and the second current transformer, and together with the S-phase. One end of the electric path of each phase is used as a movable contact connection portion and the other end is used as a terminal connection portion through the zero-phase current transformer.

[0009]

According to the current detecting device of the present invention, when the electric current of the electric circuit is lower than a predetermined reference value, the output signal of the first electric current detecting circuit is processed by the control circuit and electric current such as electric current value and electric power Output information. When the current in the circuit is larger than the predetermined reference value, the output signal of the second current detection circuit is compared with the set level in the control circuit, and when the output signal exceeds the set level, the overcurrent detection signal is pulled. Input to the release circuit to activate the trip device. When a short circuit occurs, the output signal of the second current detection circuit is directly input to the trip circuit. During this short circuit, the interphase voltage drops, but the output of the second current transformer is input to the power supply circuit, so the output of the power supply circuit is stable.

By thus sharing the detection region with the two current transformers, the current transformer can be easily designed, a high-precision current transformer can be used, and the current transformer can be used as an electronic watt-hour meter. You can also do it. Further, since the output end of the second current transformer is connected to the input end of the power supply circuit, the power supply circuit can be stabilized in the case of a short circuit, and the trip device by the trip circuit can be operated reliably. You can

According to a second aspect of the current detecting device of the first aspect, at least one of the first current transformer and the second current transformer has a gap in the core. In addition to having the effect of item 1, it is possible to reduce the error in the output voltage due to the influence of saturation and residual magnetic flux density even when an overcurrent flows, and to contribute to the stabilization of the power supply during a short circuit.

According to a third aspect of the current detecting device of the present invention, in the second aspect, the current transformer includes a pair of L-shaped cores and one of the cores is inserted from one end side of the current transformer. It consists of a pair of coil bobbins which fix a bending part with a pin, Each other piece of the said core was connected to the other end side of the said coil bibon with a pin, and the gap was formed between the said pair of cores. By setting the pin position so as to have the gap dimension while having the gap size, an accurate gap can be obtained and the assembling property can be improved due to the connection by the pin.

According to a fourth aspect of the current detection device of the first aspect, the leakage current detection circuit having a zero-phase current transformer is provided, and an output signal of the leakage current detection circuit is input to the control circuit. Since the first current transformer and the second current transformer each have one less than the number of poles, the leakage current detection circuit obtains a ground fault detection signal and an earth leakage detection signal in addition to the operation of claim 1. This allows the trip circuit to operate. Although a zero-phase current transformer is added, the size of the first current transformer and the second current transformer of each phase can be reduced and therefore the size of the current transformer is not increased.

According to a fifth aspect of the current detecting apparatus of the present invention, in the fourth aspect, the number of poles is 3, and the R-phase and T-phase electric paths are connected to the first current transformer and the second current transformer. The movable contactor, in addition to the function of claim 4, since one end of the electric path of each phase is used as a connecting portion for the movable contact and the other end is used as a connecting portion for the terminal. Since the current transformer case and the terminal can be integrated into a circuit breaker or the like, the assemblability can be improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. That is, in FIG. 1, the current detection device of the circuit breaker has a first current detection circuit 1, a second current detection circuit 2, a control circuit 3, a power supply circuit 4, and a trip circuit 5. .. As shown in FIG. 5, the circuit breaker has a trip device 6 that operates by the trip circuit 5, and a mechanism portion 50 that operates by the trip device 6 to open the contact portion 7.

The first current detection circuit 1 has a first current transformer 8 for detecting a current up to a predetermined reference value including a rated current value. The predetermined reference value of the embodiment is a current value up to a quasi-overcurrent value slightly higher than the rated current, that is, a current value of 150% of the rated current, and a high-precision current transformer that can detect with high accuracy is used. The second current detection circuit 2 has a second current transformer 9 that detects a current equal to or greater than a predetermined reference value. The embodiment has a function of detecting overcurrent and short circuit current. in this case,
When the second current detection circuit 2 detects a short circuit current, it outputs a short circuit detection signal directly by a known means.

The control circuit 3 inputs the output signals of the first current detection circuit 1 and the second current detection circuit 2 and outputs electric line information such as the electric current value of the electric line and overcurrent. In the embodiment, an A / D conversion circuit 10 for converting an analog signal into a digital signal
And a microcomputer (referred to as a microcomputer) 11 to which the A / D conversion circuit 10 is input. That is, the output signal of the first current detection circuit 1 is sent to the microcomputer 11 through the A / D conversion circuit 10, and electric circuit information such as a current value and electric power is calculated and output by a known program or means. In addition, the output signal of the second current detection circuit 2 is input to determine whether or not there is an overcurrent, and when there is an overcurrent, an overcurrent detection signal is output as circuit information.

The trip circuit 5 operates according to the output signals of the control circuit 3 and the second current detection circuit 2. That is,
The overcurrent detection signal of the control circuit 3 is input to the trip circuit 5, and the second current detection circuit 2 inputs the short circuit current detection signal to the trip circuit 5 to directly drive the trip circuit 5.
The trip device 6 is started by the output signal of the trip circuit 5,
The mechanism unit 50 of FIG. 5 operates to open the contact portion 7 connected to the electric path of FIG.

The power supply circuit 4 has an input end connected to the electric circuit (R phase, T phase) and an output end of the second current transformer 9, and is connected to the control circuit 3 and the trip circuit 5. Has an output end. In the embodiment, the interphase voltage or the like is rectified to generate the first current detection circuit 1 and the A / D conversion circuit 1 of the control circuit 3.
0, power is supplied to the microcomputer 11 and the trip circuit 5. In this case, the inter-phase voltage decreases at the time of short circuit, but since the output of the second current transformer 9 is input to the input terminal of the power supply circuit 4,
The output can be stabilized.

In FIG. 1, reference numeral 12 is a circuit case accommodating the first current detection circuit 1, the second current detection circuit 2, the control circuit 3 and the trip circuit 5. In FIG. 2, 13
Is a current transformer case having an opening 14 on one side surface, a wire through hole 15 is formed in a side plate 48 which is a back wall facing the opening 14, and a concave portion 16 is formed on the outer surface of the bottom portion 47. A terminal guide groove 17 is formed on the inner surface of the. The second current transformer 9 is provided with an electric wire through hole 15 inside the side plate 48.
The first current transformer 8 is arranged so as to be aligned with the front side thereof and is housed therein.

In FIG. 3, a first current transformer 8 and a second current transformer 9 are incorporated in a current transformer case 13, and a braided wire forming a part of an electric path is provided through the current transformer case 13 in an embodiment. To pass through the through-hole 20 of the cover 18 which closes the opening 14 and welds the movable contactor connection portion at one end of the electric wire 19 to the movable contactor 22 of the contact portion 7 to connect the terminal at the other end. The terminal 21 on the fixed side (only a part is shown) is welded to the portion. Thus, the second current transformer 9 is arranged on the movable contact 22 side, and the first current transformer 8 is arranged on the load side terminal 21 side. In addition, 29 and 30 are axes, and 46 is a movable contact.
The fixed terminal 21 is a flat plate bent in a Z shape.
A screw hole 23 is formed in one piece, a through hole 24 is formed in the other piece, and both sides of the one piece are guided by the terminal guide grooves 17 and inserted into the concave portion 16, and the movable contact 22, the current transformer case 13, and the load side. It is integrated with the terminal 21 of.

In FIG. 4, the current transformer case 13 is placed in the breaker body 26, and a screw 25 (only a part of which is shown) is screwed into the screw hole 23 through a hole 27 formed in the bottom of the breaker body 26. By tightening, the current transformer case 13 and the load side terminal 21 can be fixed to the breaker body 26.
Therefore, the structure is simple and the assembly is easy.

In FIG. 5, a current transformer case 13 having a load-side terminal 21, a first current transformer 8 and a second current transformer 9 built therein.
Also, the movable contact 22 of the mechanism portion 50 is integrally inserted into the breaker body 26, the mechanism portion 50 is fixed by fixing means (not shown), and the breaker body 26 is fixed by the screw 25 as described above. To be done. Further, the circuit case 12 and the trip device 6 are incorporated, and the movable contact 2
A fixed contactor (not shown) having a power source side terminal having a fixed contact (not shown) facing the second movable contact 46 is incorporated in the breaker body 26 to assemble the circuit breaker.

According to this embodiment, when the electric current of the electric circuit is lower than the predetermined reference value, the control circuit 3 processes the output signal of the first current detecting circuit 1 to obtain electric circuit information such as the electric current value and the electric power. Output. Further, when the current of the electric circuit is larger than a predetermined reference value, the output signal of the second current detection circuit 2 is compared with a set level in the control circuit 3, and when the output signal exceeds the set level, an overcurrent detection signal is detected. Is input to the trip circuit 5 to activate the trip device. When a short circuit occurs, the output signal of the second current detection circuit 2 is directly input to the trip circuit 5. During this short circuit, the inter-phase voltage drops, but the output of the second current transformer 9 is input to the power supply circuit 4, so the output of the power supply circuit 4 is stable.

By thus sharing the detection region with the two current transformers, the current transformer can be easily designed, a high-precision current transformer can be used, and the current transformer can be used as an electronic watt-hour meter. You can also do it. Further, since the output end of the second current transformer 9 is connected to the input end of the power supply circuit 4, the power supply circuit 4 can be stabilized at the time of a short circuit, and the trip device by the trip circuit 5 can be reliably operated. Can be operated.

In this way, the condition of the electric circuit of the circuit breaker can be accurately known. Also, by using a high-precision current transformer, it is possible to detect with high accuracy a current value up to a quasi-overcurrent value that slightly exceeds the rated current. Furthermore, in this embodiment, the load-side terminal 21 is connected to the recess 1 of the current transformer case 13.
6 into the terminal guide groove 17 and the screw hole 23 of the terminal 21
Since the terminal 21 is integrally fixed to the circuit breaker body 26 through the current transformer case 13 by tightening the screw 25 through the hole 27 of the circuit breaker body 26, the assembling property is further improved.

The second embodiment of the present invention is shown in FIGS.
Shown in. That is, in this current detection device, in the first embodiment, the second current transformer 9 has a gap in the core. In the embodiment, a pair of L-shaped cores 33, 35
And a pair of coil bobbins 32 and 38 for inserting the respective pieces of the cores 33 and 35 from one end side and fixing the bent portions 37 of the cores 33 and 35 with the pins 34.
The other pieces of 3, 35 are connected to the other ends of the coil bibons 32, 38 by a pin 28 to form a gap G between the pair of cores 33, 35. Reference numerals 39 and 40 are secondary side coils, 41 and 42 are coil terminals, 43 in FIG. 8 is a pin hole for passing the pin 34 of the coil bibong 32, 35, and 44 is a pin hole of the cores 33, 35.

According to this embodiment, since the second current transformer 9 has the gap G in the cores 33 and 35, the output voltage error due to the effect of saturation and residual magnetic flux density can be reduced even if an overcurrent flows. At the same time, it can contribute to the stabilization of the power supply when a short circuit occurs. Further, since the second current transformer 9 is configured as in the embodiment, by setting the pin position so that the gap dimension can be taken, an accurate gap can be obtained and the assembly by the pin 28 is improved. can do. In this respect, conventionally, the gap G is formed by using a spacer or the like, but there is a drawback that it is not easy to assemble.

Although a gap is provided in the core of the second current transformer 9 in the above embodiment, the first current transformer 8 may be used, or both of them may be used. The third embodiment of the present invention is shown in FIGS. That is, this current detecting device is
In the embodiment of the present invention, the leakage current detection circuit 45 having the zero-phase current transformer 51 is provided, the output signal of the leakage current detection circuit 45 is input to the control circuit 3, and the first current transformer 8 and the second current transformer 8 are provided. Each of the sinks 9 has one less than the number of poles.

In the embodiment, the output signal of the leakage current detecting device 45 is input to the A / D conversion circuit 10 of the control circuit 3.
The other configuration of FIG. 9 is similar to that of FIG. The first current transformer 8 detects up to 150% of the rated current with high accuracy, inputs the output signal to the first current detection circuit 2, sends it to the microcomputer 11 through the A / D conversion circuit 10, and outputs the R phase signal. And circuit information such as T-phase current value and electric power are calculated. Further, regarding the electric circuit information such as the current value of the S phase, the output signal of the zero-phase current transformer 51 is input to the leakage current detection circuit 45 and is sent from the A / D conversion circuit 10 to the microcomputer 11, and the first current transformer 8 It is obtained by calculation together with the output signal of When an overcurrent flows, in the R phase and the T phase, the output signal of the second current transformer 9 is input to the second current detection circuit 2 and sent to the microcomputer 11 via the A / D conversion circuit 10. However, the S phase is a zero phase current transformer 51.
Is output to the leakage current detection circuit 45, sent from the A / D conversion circuit 10 to the microcomputer 11, and is calculated and determined together with the output signal of the second current transformer 9, and the trip circuit 5
The tripping device 6 is activated through to cut off the electric circuit. When a short-circuit current further flows, the output signal of the second current transformer 9 is directly sent from the second current detection circuit 2 to the trip circuit 5 to activate the trip device 6. If a leakage current flows,
The output signal of the zero-phase current transformer 51 is input to the leakage current detection circuit 45, sent to the microcomputer 11 through the A / D conversion circuit 10 for determination, and the trip device 6 is activated through the trip circuit 5. Others are the same as the operation of FIG.

In FIG. 10, the first current transformer 8, the second current transformer 9 and the zero-phase current transformer 51 are installed in the current transformer case 13. In this case, the width of the central portion of the current transformer case 13 is about half the thickness, and the electric wire through hole 15 ′ in the central portion is formed large to pass the three electric wires 19. The zero-phase current transformer 51 is built in the center of the current transformer case 13, and the second current transformer 9 and the first current transformer 8 are mounted on the both sides of the zero current transformer 51 in this order in the current transformer case 13. Reference numeral 52 is a groove for guiding the electric wire 19.

In FIG. 11 to FIG. 13, the R-phase and T-phase electric wires 19 are folded back through the first current transformer 8 and the second current transformer 9, and the S-phase electric wires 19 and zero-phase current are changed. The movable contactor connection portion at one end of each phase electric wire 19 is welded to the movable contactor 22, and the terminal connection portion at the other end is welded to the load side terminal 21 through the container 51. That is, R, T
Regarding the electric wire 19 of the phase, one end thereof is welded to the end of the movable contact 22, the first electric current transformer 8 and the second electric current transformer 9 are folded back, and the other is passed through the zero-phase electric current transformer 51. The end is the terminal 21 on the load side.
Weld to. For the S phase, the movable contact 22 has an electric wire 1
One end of 9 is welded and passed through the zero-phase current transformer 51, and the other end is welded to the terminal 21 on the load side. The connection structure of the load side terminal 21 connected to the electric wire 19 is similar to that of the first embodiment.

According to this embodiment, the zero-phase current detection circuit 4
From 5, it is possible to obtain ground fault and leakage detection signals, which enables the trip circuit 5 to operate. That is, as in the first embodiment, the electric current information of the R and T phase electric lines, the electric line information such as electric power can be accurately known by the first current transformer 8, and the situation of the S phase electric line can be zero. The signal of the phase current detection circuit 45 and the signal of the first current detection circuit 1 can be used for accurate detection, and an overcurrent or short circuit can be detected by the output signal of the second current transformer 9, and a ground fault or an electric leakage can be detected. It can be detected by the zero-phase current transformer 51. Further, although the zero-phase current transformer 51 is added, the size of the first current transformer 8 and the second current transformer 9 of each phase can be reduced, and therefore the size is not increased.

Further, the R-phase and T-phase electric lines 19 are passed through the first current transformer 8 and the second current transformer 9 and are passed through the zero-phase current transformer 51 together with the S-phase, and one end of each phase electric line is passed. Since the connecting portion for the movable contact is used and the other end is used for the terminal, the movable contact 2
2, the current transformer case 13, and the load-side terminal 21 can be integrated into a circuit breaker or the like, so that the assemblability can be improved.

Although the above-mentioned embodiment had a three-pole structure,
It can also be applied to a multi-pole structure having two or more poles. In addition, the first current detection circuit 1 and the second current detection circuit 2
And may be shared by the first current transformer 8 and the second current transformer 9.

[0036]

According to the current detecting device of the first aspect of the present invention, by sharing the detection region with the two current transformers, the current transformer can be easily designed and a high precision current transformer can be used. Not only can it be used, but it can also be used as an electronic watt-hour meter. Further, since the output end of the second current transformer is connected to the input end of the power supply circuit, the power supply circuit can be stabilized in the case of a short circuit, and the trip device by the trip circuit can be operated reliably. There is an effect that can be.

According to a second aspect of the current detecting device of the first aspect, at least one of the first current transformer and the second current transformer has a gap in the core. In addition to having the effect of item 1, it is possible to reduce the error in the output voltage due to the influence of saturation and residual magnetic flux density even when an overcurrent flows, and to contribute to the stabilization of the power supply during a short circuit.

According to a third aspect of the present invention, in the second aspect, the current transformer includes a pair of L-shaped cores, and one piece of each of the cores is inserted from one end side of the current transformer. It consists of a pair of coil bobbins that fix the bent portion with a pin, and each other piece of the core is connected to the other end of the coil bibon with a pin to form a gap between the pair of cores. By setting the pin position so as to have the gap dimension while having the gap size, an accurate gap can be obtained and the assembling property can be improved due to the connection by the pin.

According to a fourth aspect of the current detection device of the first aspect, the leakage current detection circuit having a zero-phase current transformer is provided, and an output signal of the leakage current detection circuit is input to the control circuit. Since each of the first current transformer and the second current transformer has one less than the number of poles, it has the effect of claim 1 and also obtains a ground fault and earth leakage detection signal by the earth leakage current detection circuit. This allows the trip circuit to operate. Although a zero-phase current transformer is added, the size of the first current transformer and the second current transformer of each phase can be reduced and therefore the size of the current transformer is not increased.

According to the current detecting device of claim 5, in claim 4, the number of poles is 3, and the R-phase and T-phase electric paths are connected to the first current transformer and the second current transformer. The movable contactor, in addition to the function of claim 4, since one end of the electric path of each phase is used as a connecting portion for the movable contact and the other end is used as a connecting portion for the terminal. Since the current transformer case and the terminal can be integrated into a circuit breaker or the like, the assemblability can be improved.

[Brief description of drawings]

FIG. 1 is a block circuit diagram of a first embodiment of the present invention.

FIG. 2 is an exploded perspective view illustrating storage of a current transformer.

FIG. 3 is a perspective view showing a connection of current transformers.

FIG. 4 is a perspective view illustrating fixing of a current transformer case.

FIG. 5 is an exploded perspective view of a circuit breaker.

FIG. 6 is a perspective view of a current transformer according to a second embodiment.

FIG. 7 is a sectional view thereof.

FIG. 8 is a partially exploded perspective view thereof.

FIG. 9 is a block circuit diagram of a third embodiment.

FIG. 10 is an exploded perspective view illustrating storage of a current transformer.

FIG. 11 is a perspective view showing a connection of current transformers.

FIG. 12 is a sectional view of a current transformer.

FIG. 13 is a perspective view showing the wiring of an electric circuit on the primary side of a current transformer.

FIG. 14 is an exploded perspective view of a circuit breaker.

[Explanation of symbols]

 1 1st electric current detection circuit 2 2nd electric current detection circuit 3 control circuit 4 power supply circuit 5 trip circuit 8 1st current transformer 9 2nd current transformer

[Procedure amendment]

[Submission date] April 8, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 2

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 5

[Correction method] Change

[Correction content]

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

According to a second aspect of the present invention, in the first aspect, the second current transformer has a core gap. According to a third aspect of the present invention, in the second aspect, the current transformer includes a pair of L-shaped cores and one piece of each of the cores inserted from one end side, and the bent portion of the core is pinned. It is characterized by comprising a pair of coil bobbins to be fixed, and connecting each other piece of the core to the other end side of the coil bobbin by a pin to form a gap between the pair of cores.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

According to a fourth aspect of the present invention, there is provided the current detection device according to the first aspect, further comprising a leakage current detection circuit having a zero-phase current transformer, wherein an output signal of the leakage current detection circuit is input to the control circuit, and Each of the first current transformer and the second current transformer has one less than the number of poles. Claim 5
The current detecting device according to claim 4, wherein the number of poles is three.
In this case , the R-phase and T-phase electric paths are passed through the first current transformer and the second current transformer, and together with the S phase are passed through the zero-phase current transformer, and one end of each phase electric path is connected for the movable contact. Part, and the other end is a terminal connection part.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

According to the current detection device of claim 2, in claim 1, since the second current transformer has a gap in the core, it has the function of claim 1 and saturates even when an overcurrent flows. It is possible to reduce the error of the output voltage due to the influence of the residual magnetic flux density, and to contribute to the stabilization of the power supply during a short circuit.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

According to a fifth aspect of the present invention, in the fourth aspect, when the number of poles is 3 , the R-phase and T-phase electric paths are passed through the first current transformer and the second current transformer. In addition to the action of claim 4, the movable contactor is connected to the zero-phase current transformer together with the S phase, and one end of the electric path of each phase is used as a movable contactor connection portion and the other end is used as a terminal connection portion. Since the current transformer case and the terminal can be integrated into a circuit breaker or the like, the assemblability can be improved.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

FIG. 9 to the third embodiment of the invention of this 1
4 shows. That is, this current detection device is provided with the leakage current detection circuit 45 having the zero-phase current transformer 51 in the first embodiment, inputs the output signal of the leakage current detection circuit 45 to the control circuit 3, and Each of the current transformer 8 and the second current transformer 9 is less than the number of poles by one.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0037

[Correction method] Change

[Correction content]

According to the current detecting device of the second aspect, in the first aspect, since the second current transformer has a gap in the core, it has the effect of the first aspect and is saturated even when an overcurrent flows. It is possible to reduce the error of the output voltage due to the influence of the residual magnetic flux density, and to contribute to the stabilization of the power supply during a short circuit.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Item name to be corrected] 0040

[Correction method] Change

[Correction content]

According to the current detecting device of the fifth aspect, in the fourth aspect, when the number of poles is 3 , the R-phase and T-phase electric paths are passed through the first current transformer and the second current transformer. In addition to the effect of claim 4, the movable contactor is connected to the zero-phase current transformer together with the S phase, and one end of the electric path of each phase is used as the movable contactor connection portion and the other end is used as the terminal connection portion. Since the current transformer case and the terminal can be integrated into a circuit breaker or the like, the assemblability can be improved.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takehiko Okada 1048, Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Works, Ltd.

Claims (5)

[Claims] 1. A first current detection circuit having a first current transformer that detects a current up to a predetermined reference value including a rated current value, and a second current detection circuit that detects a current equal to or higher than the predetermined reference value. A second current detection circuit having a current transformer, and a control circuit for inputting the output signals of the first current detection circuit and the second current detection circuit and outputting electric path information such as electric current value and overcurrent of the electric path. And a trip circuit that operates according to the output signals of the control circuit and the second current detection circuit, and an input end that is connected to the electric circuit and is connected to the output end of the second current transformer. A current detection device comprising: a control circuit; and a power supply circuit having an output terminal connected to the trip circuit. 2. The current detection device according to claim 1, wherein at least one of the first current transformer and the second current transformer has a gap in a core. 3. The current detection device according to claim 2,
The current transformer comprises a pair of L-shaped cores and a pair of coil bobbins that insert one piece of each of the cores from one end side and fix a bent portion of the core with a pin, and each of the other pieces of the core. Is connected to the other end side of the coil bibon by a pin to form a gap between the pair of cores. 4. A leakage current detection circuit having a zero-phase current transformer is provided, and an output signal of the leakage current detection circuit is input to the control circuit, and the first current transformer and the second current transformer are provided.
The number of each current transformer is less than the number of poles by one.
The described current detection device. 5. The current detecting device according to claim 4,
The number of poles is three, the R-phase and T-phase electric paths are passed through the first current transformer and the second current transformer, and together with the S-phase are passed through the zero-phase current transformer, A current detecting device, wherein one end is a connecting portion for a movable contact and the other end is a connecting portion for a terminal.