WO2011045892A1

WO2011045892A1 - Ground-fault circuit interrupter

Info

Publication number: WO2011045892A1
Application number: PCT/JP2010/005538
Authority: WO
Inventors: 浅野　久伸; 岡本　泰道
Original assignee: 富士電機機器制御株式会社
Priority date: 2009-10-14
Filing date: 2010-09-10
Publication date: 2011-04-21
Also published as: CN102687229A; EP2490244B1; JP5310463B2; EP2490244A1; KR101258393B1; KR20120058601A; JP2011086434A; EP2490244A4; CN102687229B

Abstract

Disclosed is a ground-fault circuit interrupter that has been developed in a manner so as to be forcibly set to high speed operation at the same time that detection sensitivity is set from low sensitivity to high sensitivity by means of a mechanical setup with a simple configuration. In the ground-fault circuit interrupter, when a sensitivity changeover setting unit (120) is set to high sensitivity (30mA) by operating the sensitivity changeover extending slide switch (171b) of a constraint setting unit (170), a projecting part (171a) pushes out a time-delay changeover extending slide switch (172b), and a time-delay changeover setting unit (150) is forcibly set to high speed operation (0ms time delay).

Description

Earth leakage breaker

The present invention relates to a circuit breaker that performs overcurrent protection and ground fault current protection in a low-voltage distribution system.

The earth leakage circuit breaker has a function of interrupting the AC circuit when a leakage occurs, and prevents an AC circuit accident. This earth leakage breaker makes it possible to switch the sensitivity current that is the value of the leakage current that performs the breaking operation, and to switch the time delay that is the set value of the time delay operation time.
Such earth leakage circuit breakers are roughly classified into Japanese type earth leakage circuit breakers and foreign type (European and American type) earth leakage circuit breakers. First, a Japanese earth leakage breaker will be described with reference to the drawings. FIG. 7 is a configuration diagram of a conventional domestic type earth leakage breaker 10. The earth leakage breaker 10 includes a zero-phase current transformer 11, a sensitivity switching setting unit 12, a filter circuit 13, a leakage detection unit 14, a time delay switching setting unit 15, and a trip driving unit 16. Prepare.

The earth leakage breaker 10 having such a circuit configuration operates as follows.
In the zero-phase current transformer 11, a main circuit conductor (not shown) passes through the iron core 11a, and a ground fault current generated due to a ground fault or the like in a load current flowing through the main circuit conductor or a leakage current generated by a ground fault (hereinafter, these currents) Is output from the output winding 11b, a secondary output current signal proportional to the unbalanced current is output. The secondary output current signal is input to the sensitivity switching setting unit 12.

The sensitivity switching setting unit 12 can switch and set the detectable secondary output current signal stepwise from high sensitivity to low sensitivity. Here, the resistance connected to both ends of the output winding 11b is switched by a setting switch (not shown). In this way, the sensitivity is switched by changing the resistance value. The sensitivity switching range can be set to 100 mA / 300 mA / 500 mA, and switching setting from normal sensitivity (100 mA) to low sensitivity (500 mA) is possible. Note that high sensitivity (30 mA) described later cannot be set. The sensitivity switching setting unit 12 outputs a detection operation voltage signal by causing the secondary output current signal to flow through the resistance value set by the sensitivity switching.

The filter circuit 13 outputs a detection operation voltage signal obtained by removing a noise component that causes a malfunction from the detection operation voltage signal output through the sensitivity switching setting unit 12. The detected operation voltage signal from which the noise component has been removed is output to the leakage detection unit 14.
The leakage detector 14 outputs a drive voltage signal when the voltage value of the input detection operation voltage signal exceeds a predetermined threshold value. The drive voltage signal is output to the time delay switching setting unit 15.

The setting unit 15 for time delay switching includes a time delay changeover switch capable of setting the time delay time (not shown) and a plurality of charging resistors that are switched according to the time delay time set by the time delay changeover switch. And a charging circuit charged with a charging current determined by these charging resistors. When the time delay time is switched and set in advance by the time delay changeover switch, the charging resistor corresponding to the time delay time is selected and connected to the charging circuit. When the drive voltage signal is input to the time delay switching setting unit 15, charging of the charging circuit is started. At this time, the output from the charging circuit does not become a predetermined voltage during the charging period that coincides with the time delay. The time delay switching setting unit 15 ends the charging of the charging circuit after the elapse of the time delay from the start of charging of the charging circuit, trips the driving voltage signal that has reached a predetermined voltage, and outputs the driving voltage signal to the driving unit 16. .

When the driving voltage signal is input, the trip driving unit 16 drives a main circuit contact opening / closing mechanism unit (not shown) to open the main circuit.
Such a Japanese earth leakage circuit breaker 10 includes a sensitivity switching setting unit 12 and a time delay switching setting unit 15 so that sensitivity switching and time delay switching can be set independently. . In addition, the JIS standard (JIS C 8371) that is compliant with the domestic model stipulates that at high sensitivity (30 mA sensitivity), it must be non-delayed (high-speed operation type) for the purpose of protecting the human body. . In other words, the earth leakage circuit breaker 10 which can be set for a time delay cannot be switched and set to high sensitivity (30 mA sensitivity) for the purpose of protecting the human body.

Next, foreign-type (European and American) earth leakage circuit breakers will be explained. Foreign type (European and American type) earth leakage circuit breakers use a separate circuit breaker protection unit in combination with a circuit breaker for wiring. Such a foreign type (European and American type) earth leakage breaker will be described with reference to the drawings. FIG. 8 is a configuration diagram of a conventional foreign earth leakage breaker 20. The earth leakage breaker 20 includes a zero-phase current transformer 21, a sensitivity switching setting unit 22, a filter circuit 23, a leakage detection unit 24, a time delay switching setting unit 25, and a trip driving unit 26. .

The earth leakage breaker 20 having such a circuit configuration operates as follows.
In the zero-phase current transformer 21, when an unillustrated main circuit conductor passes through the iron core 21a and an unbalanced current is included in the load current flowing through the main circuit conductor, the output winding 21b is proportional to the unbalanced current. The secondary output current signal is output. The secondary output current signal is input to the sensitivity switching setting unit 22.

The sensitivity switching setting unit 22 switches the resistance connected to both ends of the output winding 21b by a setting switch (not shown). Thus, the sensitivity can be switched and set stepwise from high sensitivity to low sensitivity by changing the resistance value. The sensitivity switching setting unit 22 sends a secondary output current signal to the resistance having the resistance value that has been switched and outputs a detection operation voltage signal. The sensitivity switching setting unit 22 includes first and second circuits that perform sensitivity switching. The first circuit is a circuit for switching sensitivity from high sensitivity to low sensitivity, and the second circuit is a circuit for high speed operation when set to high sensitivity, and a circuit for performing time delay operation other than that. is there.

For example, the sensitivity switching range in the foreign type earth leakage breaker 20 shown in FIG. 8 is 30 mA / 100 mA / 300 mA / 500 mA, and even compared with the domestic type earth leakage breaker 10 shown in FIG. It is possible to switch to a higher sensitivity (30 mA). When the first circuit is switched to high sensitivity (30 mA), the second circuit is further set to forcibly operate at high speed, and the forced high-speed signal (arrow α in FIG. 8) is filtered. The circuit 23 and the leakage detection unit 24 are skipped and output directly to the time delay switching setting unit 25. The operation of the time delay switching setting unit 25 in this case will be described later.

In summary, the sensitivity switching setting unit 22 outputs a forced high-speed signal (arrow α in FIG. 8) to the time delay switching setting unit 25 in the case of high sensitivity (30 mA), and other sensitivity (100 mA / 300 mA). / 500 mA), a detection operation voltage signal is output to the filter circuit 23.
The filter circuit 23 outputs a detection operation voltage signal obtained by removing a noise component that causes a malfunction from the detection operation voltage signal output through the sensitivity switching setting unit 22. The detected operation voltage signal from which the noise component has been removed is output to the leakage detector 24.
The leakage detector 24 outputs a drive voltage signal when the voltage value of the input detection operation voltage signal exceeds a predetermined threshold value. The drive voltage signal is output to the time delay switching setting unit 25.

Although not shown in the drawing, the setting unit for time delay switching 25 is a time delay switching switch that enables switching setting of the time delay time, and a plurality of charging resistors that are switched in accordance with the time delay time set by the time delay switch. And a charging circuit charged with a charging current determined by these charging resistors. When the time delay time is switched and set in advance by the time delay changeover switch, the charging resistor corresponding to the time delay time is selected and connected to the charging circuit. When the driving voltage signal is input to the time delay switching setting unit 25, charging of the charging circuit is started. At this time, the output from the charging circuit does not become a predetermined voltage during the charging period that coincides with the time delay. The time delay switching setting unit 25 ends the charging of the charging circuit after the elapse of the time delay from the start of charging of the charging circuit, trips the driving voltage signal that has reached a predetermined voltage, and outputs the driving voltage signal to the driving unit 26. . When the forced high-speed signal described above is input, the time delay switching setting unit 25 immediately outputs a drive voltage signal to the trip drive unit 26.

When the drive voltage signal is input, the trip drive unit 26 drives a main circuit contact opening / closing mechanism unit (not shown) to open the main circuit.
In this way, the foreign type (European and American type) earth leakage breaker differs from the domestic type earth leakage breaker in that it can be switched to high sensitivity in addition to switching to low sensitivity or normal sensitivity. . And when performing the switching setting to high sensitivity, the high-speed operation is forcibly performed even in the time-delayed switching. This conforms to the standard (IEC947-2).

Moreover, as an example of such an earth leakage breaker, for example, there is an invention (name of invention: earth leakage breaker) disclosed in Patent Document 1. In this technique, a signal is output from the switch when switching to high sensitivity is set, and the switching is forcibly set to high-speed operation even in time-delayed switching.
Another example of the earth leakage breaker is the invention disclosed in Patent Document 2 (name of invention: earth leakage breaker). This technique is such that a signal is output from the decode circuit at the time of switching setting to high sensitivity, and the switching operation is forcibly switched to high speed operation even at the time delay setting.
Another example of the earth leakage breaker is the invention disclosed in Patent Document 3 (name of invention: earth leakage breaker). This technique performs both sensitivity current switching and time switching by setting a dial type switch.

Japanese Patent Laying-Open No. 2005-327666 (paragraph numbers [0031], [0032], FIGS. 1 and 2) Japanese Patent Laying-Open No. 2005-268097 (paragraph number [0020], FIGS. 1 and 2) Japanese Patent Laid-Open No. 7-141979 (paragraph numbers [0011], [0012], FIG. 2, FIG. 3, FIG. 4)

The domestic earth leakage circuit breaker 10 shown in FIG. 7 has a structure that integrally includes a sensitivity switching setting unit 12 and a time delay switching setting unit 15. It was not intended to switch to operation.
Therefore, as in the foreign earth leakage breaker 20 of FIG. 8, the high speed operation and the time delay operation can be selected and the high sensitivity to the low sensitivity can be set. There was also a request to make an earth leakage circuit breaker that forcibly switches to high speed operation. However, in the foreign earth leakage breaker 20 of FIG. 8, a forced high-speed signal having a small amplitude passes through the pattern wiring connecting the sensitivity switching setting unit 22 and the time delay switching setting unit 25. Since signals with small amplitudes are easily affected by noise, countermeasures against noise are necessary, and the wiring pattern becomes complicated.

In addition, in order to have the same function as an earth leakage breaker of a foreign type (European and American type), it is possible to respond by providing a setting unit for sensitivity switching of two circuits and a setting unit for time delay switching. There was a problem that the earth leakage circuit breaker was enlarged because the setting section for switching the sensitivity of the two circuits was very large. Therefore, it is not possible to ensure a small configuration like a domestic type earth leakage breaker.
The earth leakage circuit breaker disclosed in Patent Document 1 uses a high-speed operation setting based on ON / OFF determination of a push-button type high-speed switch, uses an electric signal, and cannot completely eliminate the influence of noise. .

The earth leakage circuit breaker disclosed in Patent Document 2 uses a logic decoding circuit for setting and uses an electric signal, and cannot completely eliminate the influence of noise.
The earth leakage breaker disclosed in Patent Document 3 can select a high-speed operation and a time-delayed operation by mechanical setting. However, even if it is set to high sensitivity, the time-delay setting is not forcibly set to high-speed operation. There was a problem from the point of view.

In summary, there has been a demand to enable a sensitivity switching from high sensitivity to low sensitivity and a time delay switching from high speed operation to time delay operation using a mechanical configuration that is not affected by noise. In particular, the earth leakage circuit breaker has a configuration including one independent circuit sensitivity switching setting unit and one circuit time delay switching setting unit, and at the same time the sensitivity switching is set to high sensitivity and at the same time the time delay switching. There was a request to be able to forcibly set to high speed operation.
Accordingly, an object of the present invention is to provide an earth leakage circuit breaker configured to set the detection sensitivity from a low sensitivity to a high sensitivity by mechanical setting with a simple configuration and at the same time to forcibly set to a high speed operation. .

In order to achieve the above object, a first aspect of an earth leakage circuit breaker according to the present invention includes:
A zero-phase current transformer that outputs a secondary output current signal proportional to the unbalanced current contained in the load current of the main circuit conductor penetrating;
Sensitivity switching is performed in a plurality of stages from high sensitivity to low sensitivity, and a sensitivity switching setting unit that outputs a detection operation voltage signal by causing a secondary output current signal to flow through a resistance value set by sensitivity switching;
A filter circuit that outputs a detection operation voltage signal obtained by removing a noise component from the detection operation voltage signal output from the sensitivity switching setting unit;
When the voltage value of the detected operation voltage signal from which the noise component has been removed exceeds a predetermined threshold, a leakage detection unit that outputs a drive voltage signal;
Time delay switching is performed in multiple stages from high-speed operation to time-delayed operation. In high-speed operation, the drive voltage signal is input and then output immediately. In time-delayed operation, the drive voltage signal is input. A setting unit for time delay switching that outputs a drive voltage signal after elapse of a preset time delay time;
A trip driving unit that opens the main circuit by driving the switching mechanism of the main circuit contact when the driving voltage signal is input;
The sensitivity switching of the sensitivity switching setting unit and the time delay switching of the time delay switching setting unit are mechanically linked, and when the time delay switching of the time delay switching setting unit is performed according to the sensitivity switching of the sensitivity switching setting unit. The operation speed that can be set for the sensitivity is determined by constraining the delay switching range. When the sensitivity switching setting unit is set to high sensitivity, the time delay switching setting unit is constrained only to high-speed operation. A constraint setting section to be set;
It is characterized by providing.

In addition, the second aspect is
The constraint setting unit
A sensitivity switching extension setting unit having a sensitivity switching extension slide switch connected to the sensitivity switching slide switch of the sensitivity switching setting unit and moving the sensitivity switching slide switch;
A time delay switching extension setting unit that is connected to the time delay switching slide switch of the time delay switching setting unit and has a time delay switching extension slide switch that moves the time delay switching slide switch;
It is mechanically connected to the extension slide switch for sensitivity switching, and a part of it is located on the flow line of the extension slide switch for time delay switching, and is switched by moving according to the movement of the extension slide switch for sensitivity switching. A projecting portion that restrains the movement of the extension slide switch for time delay switching,
It is characterized by providing.

According to the present invention, it is possible to provide an earth leakage circuit breaker configured to set the detection sensitivity from a low sensitivity to a high sensitivity by mechanical setting with a simple configuration and at the same time forcibly set to a high speed operation.

It is a block diagram of the earth-leakage circuit breaker of the form for implementing this invention. It is explanatory drawing of the restraint setting part of the earth-leakage circuit breaker of the form for implementing this invention. It is explanatory drawing of the extension setting part for sensitivity switching, and the extension setting part for time delay switching. It is explanatory drawing of the extension setting part for sensitivity switching, and the extension setting part for time delay switching. FIGS. 5A and 5B are explanatory diagrams of setting constraints by the constraint setting unit, in which FIG. 5A is an explanatory diagram of positions of a sensitivity switching extension slide switch and a time delay switching extension slide switch, and FIG. It is explanatory drawing of the position of the switch for extension switching. 6A and 6B are explanatory diagrams of setting constraints by the constraint setting unit, in which FIG. 6A is an explanatory diagram of positions of an extension slide switch for sensitivity switching and an extension slide switch for time delay switching, and FIG. It is explanatory drawing of the position of the switch for extension switching. It is a block diagram of the conventional domestic type earth leakage circuit breaker. It is a block diagram of the conventional foreign type earth leakage circuit breaker.

Embodiments of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the leakage breaker 100 includes a zero-phase current transformer 110, a sensitivity switching setting unit 120, a filter circuit 130, a leakage detection unit 140, a time delay switching setting unit 150, A removal driving unit 160 and a constraint setting unit 170 are provided. Although the earth leakage breaker 100 of this form has a point which overlaps with a prior art, it demonstrates again for convenience of explanation.
The earth leakage breaker 100 having such a circuit configuration operates as follows.
In the zero-phase current transformer 110, if a main circuit conductor (not shown) is passed through the iron core 110a and an unbalanced current is included in the load current flowing through the main circuit conductor, the output winding 110b is proportional to the unbalanced current. The secondary output current signal is output. The secondary output current signal is input to the sensitivity switching setting unit 120.

The sensitivity switching setting unit 120 includes a sensitivity switching slide switch 121 (see FIG. 3) for performing sensitivity switching setting. The sensitivity switching slide switch 121 is linked to the constraint setting unit 170. The sensitivity switching setting unit 120 can change the resistance value by switching the resistance connected to both ends of the output winding 110b by the sensitivity switching slide switch 121, and can perform the switching setting stepwise from high sensitivity to low sensitivity. Has been made. Then, the sensitivity switching setting unit 120 outputs a detection operation voltage signal by causing the secondary output current signal to flow through the resistance set for switching. The sensitivity switching range in which the sensitivity switching setting unit 120 can perform sensitivity switching is set to 30 mA / 100 mA / 300 mA / 500 mA.

The filter circuit 130 outputs a detection operation voltage signal obtained by removing a noise component that causes a malfunction from the detection operation voltage signal output through the sensitivity switching setting unit 120. The detected operation voltage signal from which the noise component has been removed is output to leakage detection unit 140.
The leakage detection unit 140 outputs a drive voltage signal when the voltage value of the input detection operation voltage signal exceeds a predetermined threshold value. This drive voltage signal is output to the time delay switching setting unit 150.

The time delay switching setting unit 150 includes a time delay switching slide switch 151 (see FIG. 3), a plurality of charging resistors, and a charging circuit (specifically, a capacitor). The time delay switching slide switch 151 is capable of setting the time delay switching. The plurality of charging resistors are switched in accordance with the time delay time set by the time delay switching slide switch 151. The charging circuit is charged with a charging current determined by the selected charging resistor. In the time delay switching setting unit 150, when the time delay time is switched and set in advance by the time delay switching slide switch 151, the charging resistor corresponding to the time delay time is selected and connected to the charging circuit. When a drive voltage signal is input to the time delay switching setting unit 150 during the time delay operation, charging of the charging circuit is started. At this time, the output from the charging circuit does not become the predetermined voltage in the charging period that coincides with the time delay. The time delay switching setting unit 150 ends the charging to the charging circuit after the elapse of the time delay from the start of charging the charging circuit, trips the driving voltage signal that has reached a predetermined voltage, and outputs the driving voltage signal to the driving unit 160. . In addition, the time delay switching setting unit 150 also includes a high-speed conduction unit that directly connects the leakage detection unit 140 and the trip driving unit 160, and selects the high-speed conduction unit during high-speed operation to be described later.

The trip driving unit 160 opens a main circuit by driving an opening / closing mechanism unit (not shown) of a main circuit contact when a driving voltage signal for time delay operation or high speed operation is input.
The constraint setting unit 170 mechanically links the sensitivity switching of the sensitivity switching setting unit 120 and the time delay switching of the time delay switching setting unit 150, and performs time delay switching according to the sensitivity switching of the sensitivity switching setting unit 120. The operation speed that can be set for the sensitivity is determined by constraining the time delay switching range at the time of time delay switching of the setting unit 150. When the sensitivity switching setting unit 120 is set to high sensitivity, the constraint setting unit 170 sets the time delay switching setting unit 150 by constraining only to high-speed operation. 1 indicate that the constraint setting unit 170 mechanically constrains the sensitivity switching setting unit 120 and the time delay switching setting unit 150.

In such an earth leakage breaker 100, the sensitivity setting unit 120 can set the sensitivity in steps of 30 mA / 100 mA / 300 mA / 500 mA, and the time delay switching setting unit 150 can set the sensitivity to 0 ms / 200 ms / 500 ms / A time delay can be set in steps of 1000 ms. As a characteristic of the earth leakage breaker 100, there is provided a constraint setting unit 170 that operates the sensitivity switching setting unit 120 and the time delay switching setting unit 150 in a mechanically interlocked manner. When the sensitivity (30 mA) is set, the time delay switching setting unit 150 is mechanically set to high speed operation (0 ms).

Next, details of the mechanical structure of the sensitivity switching setting unit 120, the time delay switching setting unit 150, and the constraint setting unit 170 will be described. As shown in FIGS. 2 to 4, the settings of the sensitivity switching setting unit 120 and the time delay switching setting unit 150 are restricted by the mechanical interlocking structure of the constraint setting unit 170. The sensitivity switching setting unit 120 includes a sensitivity switching slide switch 121. The time delay switching setting unit 150 includes a time delay switching slide switch 151. The sensitivity switching setting unit 120 and the time delay switching setting unit 150 are fixed on the printed circuit board 180 and are electrically connected by pattern wiring. The constraint setting unit 170 further includes a sensitivity switching extension setting unit 171 and a time delay switching extension setting unit 172.

As shown in FIG. 3, a sensitivity switching extension setting unit 171 is attached above the sensitivity switching setting unit 120. The attached state is as shown in FIG. The sensitivity switching extension setting unit 171 includes a projecting portion 171a, a sensitivity switching extension slide switch 171b, and a sensitivity switching intermediate adapter 171c. Specifically, a sensitivity switching extension slide switch 171b is attached to the sensitivity switching slide switch 121 via an interlocking mechanism in the sensitivity switching intermediate adapter 171c. When the sensitivity switching extension slide switch 171b is moved in the direction of arrow a in FIG. 3 (or in the direction of arrow b), the sensitivity switching slide of the sensitivity switching setting unit 120 is moved via the interlocking mechanism in the sensitivity switching intermediate adapter 171c. The switch 121 also moves in the same arrow a direction (or arrow b direction).

Further, as shown in FIG. 3, a time delay switching extension setting portion 172 is attached above the time delay switching setting portion 150. The attached state is as shown in FIG. The time delay switching extension setting unit 172 includes a contact portion 172a, a time delay switching extension slide switch 172b, and a time delay switching intermediate adapter 172c. Specifically, the time delay switching extension slide switch 172b is attached to the time delay switching slide switch 151 via an interlocking mechanism in the time delay switching intermediate adapter 172c. When the extension slide switch 172b for time delay switching is moved in the direction of arrow a in FIG. 3 (or in the direction of arrow b), the time of the time delay switching setting unit 150 is set via the interlocking mechanism in the time delay switching intermediate adapter 172c. The extension switching slide switch 151 also moves in the direction of arrow a (or arrow b) in FIG.

Further, the extension switch 171b for sensitivity switching is provided with a protruding portion 171a protruding. The projecting portion 171a is mechanically connected to the sensitivity switching extension slide switch 171b, and a part thereof is positioned on the flow line of the time delay switching extension slide switch 172b, and the arrow a of the sensitivity switching extension slide switch 171b. It moves along with the movement of the direction and comes into contact with the contact portion 172a of the extension slide switch 172b for time delay switching. When the sensitivity switching extension slide switch 171b is further moved in the direction of arrow a, the projecting portion 171a moves the time extension switching extension slide switch 172b as the sensitivity switching extension slide switch 171b is moved.

The setting of the sensitivity switching setting unit 120 and the time delay switching setting unit 150 is constrained by such a constraint setting unit 170. Specifically, as shown in FIG. 5A, when the sensitivity switching extended slide switch 171b is on the lowest sensitivity side (500 mA below FIGS. 5A and 5B), Since the setting portion 171a is also at the lowermost side, the extension slide switch 172b for time delay switching is not restrained and can move in the direction of arrow c, and a desired time delay speed (0 ms / 200 ms / 500 ms / 1000 ms) can be selected. .

During high-speed operation (0 ms), the high-speed conduction unit is selected by the time delay switching setting unit 150 and the leakage detecting unit 140 and the trip driving unit 160 are directly connected. At this time, the time delay switching setting unit 150 trips the drive voltage signal and outputs it to the drive unit 160. In this way, shut-off is performed by high-speed operation.
Further, during the time delay operation (200 ms / 500 ms / 1000 ms), a path that passes through the charging resistor and the charging circuit is selected by the time delay switching setting unit 150. Then, the drive voltage signal output from the leakage detection unit 140 is applied to the charging resistor to output a charging current. When this charging current is input to the charging circuit, charging of the charging circuit is started. The time delay switching setting unit 150 terminates the charging of the charging circuit after a time delay has elapsed since the charging of the charging circuit is started, trips the driving voltage signal that has reached a predetermined voltage, and outputs the driving voltage signal to the driving unit 160. Output. In this way, the interruption by the time delay operation is performed.

On the other hand, as shown in FIG. 6A, the sensitivity switching extended slide switch 171b is moved in the direction of the arrow d and set to the highest sensitivity side (upper side of FIGS. 6A and 6B and 30 mA). In this case, the projecting portion 171a also moves in the direction of the arrow d, and contacts the contact portion 172a of the time delay switching extension slide switch 172b to move the time delay switching extension slide switch 172b. At this time, the extension slide switch 172b for time delay switching is constrained to the maximum time delay speed (0 ms) and is forcibly set to the maximum speed.

In this case, the high-speed conduction unit is selected inside the time delay switching setting unit 150. Therefore, the drive voltage signal output from the leakage detection unit 140 is input to the trip drive unit 160 as it is. Thereby, high-speed operation is realized.
Such a setting example is specifically shown in Table 1 below. In Table 1, a correspondence table of setting positions of the sensitivity switching slide switch 121 and the time delay switching slide switch 151 (also a correspondence table of setting positions of the sensitivity switching extension slide switch 171b and the time delay switching extension slide switch 172b). Is).

For example, when the sensitivity switching slide switch 121 is set to a low sensitivity of 500 mA, the time delay switching slide switch 151 can set all kinds of time delay times of 0 ms, 200 ms, 500 ms, and 1000 ms. When the sensitivity switching slide switch 121 is set to the normal sensitivity of 100 mA, the time delay switching slide switch 151 is set to two types of time delay times of 0 ms and 200 ms. That is, the time delay switching slide switch 151 can be moved by the amount of movement of the sensitivity switching slide switch 121. When the sensitivity switching slide switch 121 sets the high sensitivity to 30 mA, the time delay switching slide switch 151 can perform only a high-speed operation with a time delay of 0 ms.

The earth leakage breaker 100 according to the embodiment of the present invention has been described above. By adopting such a configuration, the sensitivity switching setting unit 120 becomes a single-circuit switch, and is smaller and less expensive than the sensitivity switching setting unit of the two-circuit switch as in the prior art. Realize. Further, since the setting is made only by the machine, there is no pattern connecting the sensitivity switching setting unit 120 and the time delay switching setting unit 150, and the wiring pattern is reduced and simplified.
Furthermore, since all the circuits pass through the filter circuit 130 and the leakage detection unit 140, the wiring pattern can be omitted also in this respect.
According to such an embodiment of the present invention, when the detection sensitivity is set from low sensitivity to high sensitivity, it is possible to provide an earth leakage circuit breaker that is forcibly set to high speed operation by mechanical operation.

Industrial applicability

The present invention can be applied as an earth leakage circuit breaker that realizes an overcurrent protection function and a ground fault current protection function particularly in a low voltage distribution system.

DESCRIPTION OF SYMBOLS 100 ... Earth leakage circuit breaker, 110 ... Zero phase current transformer, 110a ... Iron core, 110b ... Output winding, 120 ... Sensitivity switching setting part, 121 ... Sensitivity switching slide switch, 130 ... Filter circuit, 140 ... Earth leakage detection part , 150 ... time delay switching setting section, 151 ... time delay switching slide switch, 160 ... tripping drive section, 170 ... constraint setting section, 171 ... sensitivity switching extension setting section, 171a ... projecting section, 171b ... sensitivity Extension slide switch for switching, 171c... Intermediate adapter for switching sensitivity, 172... Extension setting portion for time delay switching, 172a... Abutting portion, 172b. ... PCB, A, B ... Mechanical restraint

Claims

A zero-phase current transformer that outputs a secondary output current signal proportional to the unbalanced current contained in the load current of the main circuit conductor penetrating;
Sensitivity switching is performed in a plurality of stages from high sensitivity to low sensitivity, and a sensitivity switching setting unit that outputs a detection operation voltage signal by causing a secondary output current signal to flow through a resistance value set by sensitivity switching;
A filter circuit that outputs a detection operation voltage signal obtained by removing a noise component from the detection operation voltage signal output from the sensitivity switching setting unit;
When the voltage value of the detected operation voltage signal from which the noise component has been removed exceeds a predetermined threshold, a leakage detection unit that outputs a drive voltage signal;
Time delay switching is performed in multiple stages from high-speed operation to time-delayed operation. In high-speed operation, the drive voltage signal is input and then output immediately. In time-delayed operation, the drive voltage signal is input. A setting unit for time delay switching that outputs a drive voltage signal after elapse of a preset time delay time;
A trip driving unit that opens the main circuit by driving the switching mechanism of the main circuit contact when the driving voltage signal is input;
The sensitivity switching of the sensitivity switching setting unit and the time delay switching of the time delay switching setting unit are mechanically linked, and when the time delay switching of the time delay switching setting unit is performed according to the sensitivity switching of the sensitivity switching setting unit. The operation speed that can be set for the sensitivity is determined by constraining the delay switching range. When the sensitivity switching setting unit is set to high sensitivity, the time delay switching setting unit is constrained only to high-speed operation. A constraint setting section to be set;
An earth leakage circuit breaker comprising:
The earth leakage breaker according to claim 1, wherein
The constraint setting unit
A sensitivity switching extension setting unit having a sensitivity switching extension slide switch connected to the sensitivity switching slide switch of the sensitivity switching setting unit and moving the sensitivity switching slide switch;
A time delay switching extension setting unit that is connected to the time delay switching slide switch of the time delay switching setting unit and has a time delay switching extension slide switch that moves the time delay switching slide switch;
It is mechanically connected to the extension slide switch for sensitivity switching, and part of it is located on the flow line of the extension slide switch for time delay switching, and is switched according to the movement of the extension slide switch for sensitivity switching. A projecting portion that restrains the movement of the extension slide switch for time delay switching,
An earth leakage circuit breaker comprising: