KR20120058601A - Ground-fault circuit interrupter - Google Patents

Abstract

An earth leakage circuit breaker configured to set the detection sensitivity from a low sensitivity to a high sensitivity by a simple mechanical configuration and forcibly set it to high speed operation is provided. In the ground fault breaker, the projection part 171a demonstrates when the sensitivity-changing setting switch 120 of the restraint setting part 170 is moved to set the sensitivity switching setting part 120 to a high sensitivity (30 Hz). The extension extension switch 172b for switching is extruded and moved, and the demonstration switching setting part 150 is forcibly set to a high speed operation | operation (0 demonstration).

Description

Earth Leakage Circuit Breaker {GROUND-FAULT CIRCUIT INTERRUPTER}

The present invention relates to an earth leakage breaker which performs overcurrent protection and ground current protection in a low voltage distribution system.

The earth leakage breaker has a function to cut off the AC converter when a short circuit occurs, and prevents the occurrence of an AC converter accident. This earth leakage breaker enables switching of the sensitivity current which is the value of the earth leakage current which performs the interruption | operation, and switching of the demonstration time which is a setting value of a demonstration operation time.

Such a ground fault breaker is roughly classified into a ground fault breaker of a Japanese type, and a ground fault breaker of a foreign type (American type). First, a description will be given of a circuit breaker of a Japanese domestic type with reference to the drawings. 7 is a configuration diagram of a conventional domestic type circuit breaker 10. The circuit breaker 10 includes a video current transformer 11, a sensitivity switching setter 12, a filter circuit 13, a ground fault detector 14, a demonstration switching setter 15, and a separate drive unit. (16: tripping driving portion) is provided.

The earth leakage breaker 10 having such a circuit configuration operates as follows.

In the video current transformer 11, a main circuit conductor (not shown) in the iron core 11a penetrates, and a ground fault current caused by a ground fault or the like during a load current flowing through the main circuit conductor or a ground fault current generated by a short circuit (hereinafter, these currents are unbalanced). Current), a secondary output current signal is output from the output winding 11b in proportion to the unbalanced current. This secondary output current signal is input to the sensitivity switching setting unit 12.

In the sensitivity switching setting section 12, the detectable secondary output current signal can be switched in steps from high sensitivity to low sensitivity. Here, the resistors connected to both ends of the output winding 11b are 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 Hz / 300 Hz / 500 Hz, and the switching setting from the normal sensitivity (100 Hz) to the reduction sensitivity (500 Hz) is possible. In addition, the high sensitivity (30 ms) mentioned later cannot be set. The sensitivity switching setting unit 12 outputs the detection operation voltage signal by flowing a secondary output current signal to the resistance value set by the sensitivity switching.

The filter circuit 13 outputs the detection operation voltage signal which removed the noise component which causes a malfunction from the detection operation voltage signal output via the sensitivity switching setting part 12. FIG. The detection operation voltage signal from which the noise component is removed is output to the earth leakage detector 14.

The earth leakage detector 14 outputs a drive voltage signal when the voltage value of the input detection operation voltage signal exceeds a predetermined threshold. The drive voltage signal is output to the setting section 15 for demonstration switching.

The demonstration switching setting section 15 includes a demonstration conversion switch capable of switching setting of a demonstration time (not shown), a plurality of charge resistors that are switched in response to the demonstration time switched by the demonstration conversion switch, and these There is a built-in charging circuit that charges with the charging current determined by the charging resistance. When the demonstration time is switched and set by the demonstration conversion switch in advance, a charging resistor corresponding to the demonstration time is selected and connected to the charging circuit. When the driving voltage signal is input to the demonstration switching setting unit 15, charging to the charging circuit starts. At this time, in the charging period coinciding with the demonstration time, the output from the charging circuit does not become a predetermined voltage. After the demonstration time has elapsed since the charging start to the charging circuit has elapsed, the demonstration switching setting unit 15 terminates charging to the charging circuit, and outputs the driving voltage signal reaching the predetermined voltage to the separate driver 16. .

When the drive voltage signal is input, the separate drive unit 16 drives the open / close mechanism of the main circuit contact (not shown) to open the main circuit.

Such a Japanese circuit-leakage circuit breaker 10 includes a sensitivity switching setter 12 and a demonstration switching setter 15, so that sensitivity switching and demonstration switching can be set independently. In addition, the JIS standard (JIS C 8371) conforming to the domestic model stipulates that, at high sensitivity (30 Hz sensitivity), it must be non- demonstration type (high speed operation type) for the purpose of protecting the human body. . In other words, the earth leakage breaker 10 that can be set for demonstration cannot be set to switch to high sensitivity (30 Hz sensitivity) for the purpose of protecting the human body.

Next, the earth leakage breaker of the foreign type (the Western type) will be described. A foreign type (earthquake type) earth leakage breaker is used by combining an independent earth leakage protection unit having a separate structure with a wiring breaker. Such a foreign type (earthquake type) earth leakage breaker will be described with reference to the drawings. 8 is a configuration diagram of a conventional foreign-type earth leakage breaker 20. The earth leakage breaker 20 includes a video current transformer 21, a sensitivity switching setting unit 22, a filter circuit 23, a ground leakage detecting unit 24, a demonstration switching setting unit 25, and a separate driving unit. (26) is provided.

The earth leakage breaker 20 having such a circuit configuration operates as follows.

In the video current transformer 21, if the main circuit conductor (not shown) in the iron core 21a penetrates and an unbalance current is included in the load current flowing through the main circuit conductor, 2 is proportional to the unbalance current from the output winding 21b. Output the differential output current signal. This secondary output current signal is input to the sensitivity switching setting section 22.

In the sensitivity switching setting section 22, the resistors connected to both ends of the output winding 21b are switched by a setting switch (not shown). In this way, by changing the resistance value, the sensitivity can be switched in steps from high sensitivity to low sensitivity. The sensitivity switching setting unit 22 outputs a detection operation voltage signal by flowing a secondary output current signal to the resistance of the switched value. Moreover, this sensitivity switching setting part 22 is equipped with the 1st, 2nd circuit which performs 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 performing high speed operation when the sensitivity is set to high sensitivity, and for demonstrating the other operation.

For example, the sensitivity switching range in the foreign-type earth leakage breaker 20 shown in FIG. 8 is 30 kV / 100 Pa / 300 Pa / 500 Pa, and the domestic type earth leakage breaker shown in FIG. Compared with 10), it is possible to change the setting to a higher sensitivity (30 Hz). Further, when switching to the high sensitivity (30 Hz) is set in the first circuit, the second circuit is also set to forcibly operate at high speed, and the forced high speed signal (arrow? In FIG. 8) is converted into a filter circuit ( 23) The ground fault detection unit 24 is skipped and output directly to the demonstration switching setting unit 25. In this case, the operation of the demonstration switching setting unit 25 will be described later.

In summary, the sensitivity switching setting section 22 outputs a forced high speed signal (arrow α in FIG. 8) to the demonstration switching setting section 25 in the case of high sensitivity (30 Hz), and the other sensitivity. In the case of (100 Hz / 300 Hz / 500 Hz), the detection operation voltage signal is output to the filter circuit 23.

The filter circuit 23 outputs the detection operation voltage signal from which the noise component causing the malfunction is removed from the detection operation voltage signal output through the sensitivity switching setting unit 22. The detection operation voltage signal from which the noise component is removed is output to the earth leakage detector 24.

The earth leakage detector 24 outputs a drive voltage signal when the voltage value of the input detection operation voltage signal exceeds a predetermined threshold. The drive voltage signal is output to the demonstration switching setting unit 25.

The demonstration switching setting section 25 includes a demonstration conversion switch that enables switching setting of the demonstration time although not shown, a plurality of charge resistors switched in response to the demonstration time switched by the demonstration conversion switch, and these charging resistors. The charging circuit which charges with the charging current determined by this is built. When the demonstration time is switched and set by the demonstration conversion switch in advance, a charging resistor corresponding to the demonstration time is selected and connected to the charging circuit. When the drive voltage signal is input to the demonstration switching setting section 25, charging to the charging circuit starts. At this time, in the charging period coinciding with the demonstration time, the output from the charging circuit does not become a predetermined voltage. After the demonstration time has elapsed from the start of charging to the charging circuit, the demonstration switching setting unit 25 terminates charging to the charging circuit and outputs the driving voltage signal reaching the predetermined voltage to the separate driving unit 26. . In addition, the demonstration switching setting unit 25 immediately outputs the driving voltage signal to the separation driver 26 when the forced high speed signal described above is input.

When the drive voltage signal is input, the separate drive unit 26 drives the open / close mechanism of the main circuit contact (not shown) to open the main circuit.

As described above, unlike the domestic type circuit breaker having a single structure, the circuit breaker of a foreign type (Gumi type) can be set to a high sensitivity switching setting in addition to the setting of switching to a low sensitivity or a normal sensitivity. And when performing switching setting with high sensitivity, it operates forcibly high speed also in demonstration switching. This is based on the standard (IEC947-2).

Moreover, as an example of such an earth leakage breaker, the invention (name of an invention: an earth leakage breaker) disclosed by patent document 1 is mentioned, for example. In this technique, a signal is output from the switch at the time of setting switching to a high sensitivity, and the switching to the high speed operation is forcibly set even in the demonstration switching.

In addition, as another example of an earth leakage breaker, there is an invention (name of the invention: an earth leakage breaker) disclosed in Patent Document 2. In this technique, a signal is output from the decode circuit at the time of setting switching to high sensitivity, and the setting is forcibly switched to high speed operation even in the demonstration setting.

Moreover, as another example of an earth leakage breaker, there exists the invention (name of an invention: an earth leakage breaker) disclosed by patent document 3. As shown in FIG. In this technique, the sensitivity current switching and time switching are performed together by setting the dial switch.

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

The above-described domestic type circuit breaker 10 of FIG. 7 has a structure including a sensitivity switching setter 12 and a demonstration switching setter 15 integrally. It was not set to switch to high speed operation.

Therefore, like the foreign circuit breaker 20 of FIG. 8, the high speed operation and the demonstration operation can be selected, and high sensitivity to low sensitivity can be set. There is a request to use a ground fault breaker for switching. By the way, in the foreign type circuit breaker 20 of FIG. 8, the forced high speed signal with small amplitude passes through the pattern wiring which connected the sensitivity switching setting part 22 and the demonstration switching setting part 25. As shown in FIG. Since signals with small amplitudes are susceptible to noise, noise countermeasures are required and the wiring patterns are complicated.

In addition, in order to have a function similar to a foreign type (circuit type) earth leakage breaker, it is possible to cope by providing a setting circuit for switching the sensitivity of two circuits and a setting for switching the demonstration of one circuit, but the setting for switching the sensitivity of two circuits. Since the parts are very large, there is a problem that the earth leakage breaker is enlarged. Therefore, it is not possible to secure a small configuration like a domestic circuit breaker.

The circuit breaker of Patent Literature 1 uses an electrical signal to set high-speed operation in the on / off determination of a push button type high speed switch, and thus the effect of noise cannot be completely eliminated.

The earth leakage breaker of Patent Literature 2 uses an electrical signal as a setting is performed using a logic decode circuit, so that the influence of noise cannot be completely eliminated.

Although the circuit breaker of patent document 3 can select a high speed operation | movement and a demonstration operation | movement by a mechanical setting, even if it sets high sensitivity, it does not forcibly set the demonstration setting to high speed operation | movement, and there exists a problem from a safety viewpoint.

In summary, there is a request to use a mechanical configuration that is not affected by noise to enable sensitivity switching from high sensitivity to low sensitivity and demonstration switching from high speed operation to demonstration operation. In particular, the circuit breaker is constituted with a configuration for switching the sensitivity of one circuit and a setting for the demonstration switching of one circuit, which are independent of each other. There is a request to make the demonstration available.

Therefore, an object of the present invention is to provide an earth leakage circuit breaker which is configured to set the detection sensitivity from low sensitivity to high sensitivity by forced mechanical setting with a simple configuration and to forcibly set it to high speed operation.

In order to achieve the above object, a first aspect of the earth leakage breaker according to the present invention,

An image current transformer for outputting a secondary output current signal proportional to an unbalance current included in a load current of a main circuit conductor passing therethrough;

A sensitivity switching setting unit for switching sensitivity from high sensitivity to low sensitivity in multiple stages and outputting a detection operation voltage signal by flowing a secondary output current signal to a resistance value set by the sensitivity switching;

A filter circuit for outputting a detection operation voltage signal from which a noise component is removed from the detection operation voltage signal output from the sensitivity switching setting unit;

An electric leakage detecting unit for outputting a driving voltage signal when the voltage value of the detection operation voltage signal from which the noise component is removed exceeds a predetermined threshold value;

Demonstration switching is performed in multiple stages from the high speed operation to the demonstration operation. In the high speed operation, the driving voltage signal is immediately output after the driving voltage signal is input. A demonstration switching setting unit for outputting a driving voltage signal later;

A separate driver for driving the opening and closing mechanism of the main circuit contact to open the main circuit when a drive voltage signal is input;

Sensitivity switching between the sensitivity switching setting part and the demonstration switching setting part is mechanically interlocked, and in response to the sensitivity switching of the sensitivity switching setting part, the demonstration switching range of the demonstration switching setting part is constrained to set the sensitivity. The speed is determined, and when the sensitivity switching setting part is set to high sensitivity, a restraining setting part is obtained which constrains and sets the demonstration switching setting part only by the high speed operation.

Moreover, a 2nd aspect is

The restraint setting unit,

An extension setting unit for sensitivity switching having a sensitivity switching extension slide switch which is connected to a sensitivity switching slide switch for moving the sensitivity switching unit and which moves the sensitivity switching slide switch;

A demonstration switching extension setting unit having a demonstration switching extension slide switch connected to the demonstration switching slide switch for demonstrating switching setting and moving the demonstration switching slide switch;

A mechanically connected portion of the extension slide switch for sensitivity switching and a part thereof is located on the copper line of the extension slide switch for demonstration switching, and pushes the extension slide switch for demonstration switching by moving in response to the movement of the extension slide switch for sensitivity switching, or And a protrusion for restraining movement of the extension slide switch for demonstration switching.

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

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram of the earth leakage breaker of the form for implementing this invention.
2 is an explanatory diagram of a restraint setting unit of an earth leakage breaker of a form for carrying out the present invention;
3 is an explanatory diagram of an extension setting unit for sensitivity switching and an extension setting unit for demonstration switching;
4 is an explanatory diagram of an extension setting unit for sensitivity switching and an extension setting unit for demonstration switching;
Fig. 5 is an explanatory view of setting restraint by the restraint setting unit, Fig. 5 (a) is an explanatory diagram of positions of the extension slide switch for sensitivity switching and the extension slide switch for demonstration switching, and Fig. 5 (b) is a switch for sensitivity switching; And explanatory drawing of the position of the switch for demonstration switching.
Fig. 6 is an explanatory view of setting restraint by the restraint setting part, Fig. 6A is an explanatory diagram of positions of the extension slide switch for sensitivity switching and the extension slide switch for demonstration switching, and Fig. 6B is a switch for sensitivity switching. And explanatory drawing of the position of the switch for demonstration switching.
7 is a configuration diagram of a conventional domestic type circuit breaker.
8 is a block diagram of a conventional foreign-type earth leakage breaker.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. As shown in FIG. 1, the earth leakage breaker 100 includes a video current transformer 110, a sensitivity switching setting unit 120, a filter circuit 130, an earth leakage detecting unit 140, and a demonstration switching setting. The unit 150, the separation driver 160, and the restraint setting unit 170 are provided. Although the earth leakage breaker 100 of this form overlaps with the prior art, it demonstrates again for convenience of description.

The earth leakage breaker 100 having such a circuit configuration operates as follows.

In the video current transformer 110, if the main circuit conductor (not shown) passes through the iron core 110a, and an unbalanced current is included in the load current flowing through the main circuit conductor, 2 is proportional to the unbalanced current from the output winding 110b. Output the differential output current signal. The secondary output current signal is input to the sensitivity switching setting unit 120.

The sensitivity switching setting part 120 is provided with the sensitivity switch slide switch 121 (refer FIG. 3) which changes sensitivity setting. The sensitivity switch slide switch 121 cooperates with the restraint setting unit 170. The sensitivity switching setting unit 120 changes the resistance value by switching the resistances connected to both ends of the output winding 110b by the sensitivity switching slide switch 121 so that the switching can be set step by step from high sensitivity to low sensitivity. It is. Then, the sensitivity switching setting unit 120 flows a secondary output current signal to the switched set resistance and outputs a detection operation voltage signal. The sensitivity switching range in which the sensitivity switching setting unit 120 can perform the sensitivity switching is set to 30 Hz / 100 Hz / 300 Hz / 500 Hz.

The filter circuit 130 outputs the detection operation voltage signal which removed the noise component which causes a malfunction from the detection operation voltage signal output via the sensitivity switching setting part 120. FIG. The detection operation voltage signal from which the noise component is removed is output to the earth leakage detector 140.

The earth leakage detector 140 outputs a drive voltage signal when the voltage value of the input detection operation voltage signal exceeds a predetermined threshold. This drive voltage signal is output to the demonstration switching setting unit 150.

The demonstration switching setting unit 150 incorporates a demonstration switching slide switch 151 (see Fig. 3), a plurality of charging resistors, and a charging circuit (specifically, a capacitor). The slide switch 151 for demonstration switching enables the switching setting of a demonstration time. The plurality of charging resistors are switched in response to the demonstration time set by the demonstration switching slide switch 151. The charging circuit is charged with a charging current determined by the selected charging resistor. In the demonstration switching setting unit 150, when the demonstration time is switched and set in advance by the demonstration switching slide switch 151, a charging resistor corresponding to the demonstration time is selected and connected to the charging circuit. In the demonstration operation, when the driving voltage signal is input to the demonstration switching setting unit 150, charging to the charging circuit starts. At this time, in the charging period coinciding with the demonstration time, the output from the charging circuit does not become a predetermined voltage. The demonstration switching setting unit 150 terminates charging to the charging circuit after the demonstration time has elapsed since the charging start to the charging circuit, and outputs the driving voltage signal reaching the predetermined voltage to the separate driving unit 160. . In addition, the demonstration switching setting unit 150 also includes a high-speed conduction unit for directly connecting the ground fault detection unit 140 and the separation drive unit 160, and selects the high-speed conduction unit in the high-speed operation described later.

When the drive voltage signal of the demonstration operation or the high speed operation is input, the separate driver 160 drives the opening / closing mechanism of the main circuit contact (not shown) to open the main circuit.

The restraint setting unit 170 mechanically interlocks the sensitivity switching of the sensitivity switching setting unit 120 and the demonstration switching of the demonstration switching setting unit 150 in response to the sensitivity switching of the sensitivity switching setting unit 120. By limiting the demonstration switching range at the time of demonstration switching of the demonstration switching setting unit 150, the settable operating speed for sensitivity is determined. And when the sensitivity switching setting part 120 is set to high sensitivity, the restraint setting part 170 restrains and sets the demonstration switching setting part 150 only by high speed operation | movement. Arrows A and B indicated by the dotted lines in FIG. 1 indicate that the restraint setting unit 170 mechanically restrains the sensitivity switching setting unit 120 and the demonstration switching setting unit 150.

In the earth leakage breaker 100 as described above, the sensitivity can be set step by step at 30 Hz / 100 Hz / 300 Hz / 500 Hz in the sensitivity switching setting section 120, and 0 in the demonstration switching setting section 150. Demonstration can be set in stages of / 200㎳ / 500㎳ / 1000㎳. Then, as a characteristic of the ground fault breaker 100, a restraint setting unit 170 for mechanically interlocking and operating the sensitivity switching setting unit 120 and the demonstration switching setting unit 150 is provided, and in particular, the sensitivity switching setting When the unit 120 is set to a high sensitivity (30 Hz), it is mechanically set to the high-speed operation (0 Hz) in the demonstration switching setting unit 150.

Subsequently, the details of the mechanical structure of the sensitivity switching setting unit 120, the demonstration switching setting unit 150, and the restriction setting unit 170 will be described. As shown in FIG. 2 to FIG. 4, the setting of the sensitivity switching setting unit 120 and the demonstration switching setting unit 150 is restricted by the mechanical linkage structure of the restriction setting unit 170. The sensitivity switching setting unit 120 includes a slide switch 121 for sensitivity switching. The demonstration switching setting unit 150 includes a slide switch 151 for demonstration switching. These sensitivity switching setting unit 120 and demonstration switching setting unit 150 are fixed on the printed circuit board 180 and electrically connected by pattern wiring. The restraint setting unit 170 further includes a sensitivity switching extension setting unit 171 and a demonstration switching extension setting unit 172.

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

In addition, as shown in FIG. 3, the demonstration switching extension setting unit 172 is attached above the demonstration switching setting unit 150. The adhesion state is as shown in FIG. The demonstration switching extension setting unit 172 includes a contact portion 172a, an extension slide switch 172b for demonstration switching, and an intermediate adapter 172c for demonstration switching. Specifically, the demonstration switch extension slide switch 172b is attached to the demonstration switch slide switch 151 via an interlock mechanism in the demonstration adapter intermediate adapter 172c. Then, when the demonstration switching extension slide switch 172b is moved in the direction of arrow a in FIG. 3 (or in the direction of arrow b), the setting unit for demonstration switching is performed through an interlock mechanism in the intermediate adapter 172c for demonstration switching. The slide switch 151 for demonstration switching of 150 also moves in the arrow (a) direction (or the arrow (b) direction) of FIG.

And the protrusion part 171a protrudes and is provided in the extension slide switch 171b for sensitivity switching. The protrusion 171a is mechanically connected to the extension slide switch 171b for sensitivity switching, and a part thereof is located on the same line as the extension slide switch 172b for demonstration switching, and the extension slide switch 171b for sensitivity switching is provided. It moves with movement of the arrow a direction, and abuts against the contact part 172a of the extension slide switch 172b for demonstration switching. Further, if the sensitivity switching extension slide switch 171b is moved in the direction of the arrow a, the protrusion 171a moves the demonstration switching extension slide switch 172b together with the movement of the sensitivity switching extension slide switch 171b. Move it.

The setting of the sensitivity switching setting unit 120 and the demonstration switching setting unit 150 is constrained by the restriction setting unit 170. Specifically, as shown in Fig. 5 (a), when the extension slide switch 171b for sensitivity switching is at the most low-sensitivity side (500 kHz to the bottom of Figs. 5 (a) and 5 (b)), Since the protrusion 171a is also located at the lowermost side, the extension slide switch 172b for switching the demonstration can be moved in the direction of the arrow c without being restrained, and the desired demonstration speed (0 kPa / 200 kPa / 500 kPa) is achieved. / 1000 ms) can be selected.

In the high-speed operation (0 ms), the high-speed conduction unit is selected by the demonstration switching setting unit 150 to directly connect the ground fault detection unit 140 and the separation driver 160. At this time, the demonstration switching setting unit 150 outputs the driving voltage signal to the separation driving unit 160. In this way, it is interrupted by the high speed operation.

In the demonstration operation (200 mW / 500 mW / 1000 mW), the path through the charging resistor and the charging circuit is selected by the setting section 150 for the demonstration switching. Then, the driving voltage signal output from the ground fault detecting unit 140 is applied to the charging resistor to output the charging current, and when the charging current is input to the charging circuit, charging to the charging circuit starts. The demonstration switching setting unit 150 terminates charging the charging circuit after the demonstration time has elapsed since the charging circuit is started, and outputs the driving voltage signal reaching the predetermined voltage to the separate driving unit 160. do. In this way, it is interrupted by the demonstration operation.

On the other hand, as shown in Fig. 6 (a), the extension slide switch 171b for sensitivity switching is moved in the direction of the arrow d, and is the highest sensitivity side (30 'as the upper side of Figs. 6 (a) and 6 (b)). When it is set to, the protrusion 171a also moves in the direction of the arrow d, and the extension slide switch 172b for demonstration switching is brought into contact with the contact portion 172a of the extension slide switch 172b for demonstration switching. Move it. At this time, the extension switching switch 172b for demonstration switching is restrained by the highest demonstration speed (0 ms) and is forcibly set to the highest velocity.

In this case, the high-speed conduction unit is selected inside the demonstration switching setting unit 150. Therefore, the drive voltage signal output from the ground fault detection unit 140 is input to the separation driver 160 as it is. This realizes high speed operation.

In addition, such a setting example is specifically, as shown in Table 1 below. Table 1 shows the correspondence table of the setting positions of the sensitivity switching slide switch 121 and the demonstration switching slide switch 151 (the sensitivity switching extension slide switch 171b and the demonstration switching extension slide switch 172b). It is also a correspondence table).

For example, in the case where the sensitivity is set to 500 mW with the slide switch 121 for sensitivity switching, all kinds of settings such as 0 m, 200 mW, 500 mW, 1000 mV with the demonstration time are set with the slide switch 151 for demonstrating conversion. can do. In the case where the sensitivity sensitivity is set to 100 ms in the slide switch 121, the demonstration time is 0 sec and 200 ms in the setting time of the slide switch 151 for demonstration switching. That is, the demonstration switching slide switch 151 can be moved by the amount of the movement of the sensitivity switching slide switch 121. When the sensitivity switch 30 is set to a high sensitivity of 30 ms, only the high-speed operation with a demonstration time of 0 ms is possible with the slide switch 151 for demonstration switching.

In the above, the earth leakage breaker 100 of embodiment of this invention was demonstrated. By adopting such a configuration, the sensitivity switching setting unit 120 becomes a switch by one circuit, and the size and cost can be reduced even when compared to the sensitivity switching setting unit of the switch by two circuits as in the prior art. To realize. In addition, since the setting is made only by the machine, the pattern connecting the sensitivity switching setting section 120 and the demonstration switching setting section 150 is eliminated, and the wiring pattern is reduced and simplified.

In addition, since all the circuits pass through the filter circuit 130 and the ground fault detecting unit 140, the wiring pattern can also be omitted in this respect.

According to this embodiment of the present invention, when the detection sensitivity is set from low sensitivity to high sensitivity, an earth leakage breaker forcibly set to high speed operation by mechanical operation can be provided.

(Possibility of industrial use)

The present invention is particularly applicable as an earth leakage breaker that realizes an overcurrent protection function and a ground current protection function in a low voltage distribution system.

100: leakage circuit breaker 110: video current transformer
110a: iron core 110b: output winding
120: sensitivity switching setting section 121: sensitivity switch slide switch
130: filter circuit 140: ground fault detection unit
150: demonstration switching setting unit 151: demonstration switching slide switch
160: separate drive unit 170: restraint setting unit
171: sensitivity setting extension setting unit 171a: protrusion
171b: Extension Slide Switch for Sensitivity Switching
171c: intermediate adapter for sensitivity switching 172: extension setting unit for demonstration switching
172a: abutment
172b: extension slide switch for demonstration switching
172c: demonstration adapter intermediate adapter 180: printed board
A, B: mechanical restraint

Claims (2)

An image current transformer for outputting a secondary output current signal proportional to an unbalance current included in a load current of a main circuit conductor passing therethrough;
A sensitivity switching setting unit for switching sensitivity from high sensitivity to low sensitivity in multiple stages and outputting a detection operation voltage signal by flowing a secondary output current signal to a resistance value set by the sensitivity switching;
A filter circuit for outputting a detection operation voltage signal from which a noise component is removed from the detection operation voltage signal output from the sensitivity switching setting unit;
An electric leakage detecting unit for outputting a driving voltage signal when the voltage value of the detection operation voltage signal from which the noise component is removed exceeds a predetermined threshold value;
Demonstration switching is performed in multiple stages from the high speed operation to the demonstration operation. In the high speed operation, the driving voltage signal is immediately output after the driving voltage signal is input. In the demonstration operation, the preset driving time is elapsed after the driving voltage signal is input. A demonstration switching setting unit for outputting a driving voltage signal later;
A separate driver for driving the opening and closing mechanism of the main circuit contact to open the main circuit when a drive voltage signal is input;
Sensitivity switching between the sensitivity switching setting part and the demonstration switching part switching part is mechanically interlocked, and in response to the sensitivity switching of the sensitivity switching setting part, the demonstration switching range of the demonstration switching part is constrained to set the sensitivity. And a speed limiter configured to determine the speed, and to restrain and set the demonstration switching setting part only by high-speed operation when the sensitivity switching setting part is set to high sensitivity. The method of claim 1,
The restraint setting unit,
An extension setting unit for sensitivity switching having a sensitivity switching extension slide switch which is connected to a sensitivity switching slide switch for moving the sensitivity switching unit and which moves the sensitivity switching slide switch;
A demonstration switching extension setting unit having a demonstration switching extension slide switch connected to the demonstration switching slide switch for demonstrating switching setting and moving the demonstration switching slide switch;
A mechanically connected portion of the extension slide switch for sensitivity switching and a part thereof is located on the copper line of the extension slide switch for demonstration switching, and pushes the extension slide switch for demonstration switching by moving in response to the movement of the extension slide switch for sensitivity switching, or An earth leakage circuit breaker, comprising: obtaining a protrusion for restraining movement of an extension slide switch for demonstration switching.

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