JP5310463B2 - Earth leakage breaker - Google Patents

Description

  The present invention relates to a leakage 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 enables switching of the sensitivity current that is the value of the earth leakage current for performing the breaking operation, or switching of the time delay time that is the set value of the time delay operation time.

  Conventional technologies for this type of earth leakage breaker are roughly classified into Japanese type earth leakage breakers and foreign type (European and American type) earth leakage breakers. First, a Japanese earth leakage breaker will be described with reference to the drawings. FIG. 7 is a block diagram of a domestic type earth leakage breaker 10 of the prior art. 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 tripping device 16. .

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 leakage (hereinafter referred to as 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.

  In the sensitivity switching setting unit 12, the secondary output current signal that can be detected by changing the resistance value by switching the resistance connected to both ends of the output winding 11b with a setting switch (not shown) is changed from high sensitivity to low sensitivity. Can be set in stages. 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 is output to the leakage detection unit 14.
The leakage detection unit 14 outputs a drive voltage signal when the voltage value of the detected operation voltage signal exceeds a predetermined threshold value. The drive voltage signal is output to the time delay switching setting unit 15.

  Although not shown in the drawing, the setting unit 15 for time delay switching includes a time delay switching switch that enables switching setting of the time delay time, and a plurality of switches that are switched according to the time delay time set by the time delay switch. A charging resistor and a charging circuit charged with a charging current determined by these charging resistors are built-in. When the time delay time is switched in advance by the time delay changeover switch, the charge resistance corresponding to the time delay is set. It shall be selected and connected to the charging circuit. When the drive voltage signal is input to the time delay switching setting unit 15, charging to the charging circuit starts, and during the charging period that coincides with the time delay time, the output from the charging circuit does not become a predetermined voltage, The drive voltage signal that has finished charging after reaching the predetermined time and has reached a predetermined voltage is output to the tripping device 16.

The tripping device 16 opens a main circuit by driving an opening / closing mechanism portion of a main circuit contact (not shown) when a driving voltage signal is inputted after a set time delay has elapsed.
Such a Japanese earth leakage circuit breaker 100 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), which 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 100 that can be set for a long time cannot be switched and set to high sensitivity (30 mA sensitivity) for the purpose of protecting the human body.

  Next, a foreign type (European and American type) earth leakage breaker will be described. 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 foreign earth leakage breaker 20 of the prior art. 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 tripping device 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.

  In the sensitivity switching setting unit 22, the resistance connected to both ends of the output winding 21b is switched by a setting switch (not shown) so that the resistance value can be changed and set in steps from high sensitivity to low sensitivity. ing. 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 for switching sensitivity. The first circuit is a circuit for switching sensitivity from high sensitivity to low sensitivity. In the second circuit, This is a circuit for high speed operation when set to high sensitivity and time delay operation for others.

  For example, as shown in FIG. 8, the sensitivity switching range is 30 mA / 100 mA / 300 mA / 500 mA, and even higher sensitivity (30 mA) than the domestic type earth leakage circuit breaker 10 shown in FIG. Switching can be set. When the first circuit is switched to high sensitivity (30 mA), the second circuit is further set to forcibly operate at high speed, and a high sensitivity 30 mA forced high speed signal (arrow α in FIG. 8). Is directly output to the time delay switching setting unit 25, bypassing the filter circuit 23 and the leakage detection unit 24. The operation of the time delay switching setting unit 25 in this case will be described later.

  In summary, in the case of high sensitivity (30 mA), a high-sensitivity 30 mA forced high-speed signal (arrow α in FIG. 8) is output to the time delay switching setting unit 25, and other sensitivity (100 mA / 300 mA / 500 mA) The 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 is output to the leakage detector 24.
The leakage detection unit 24 outputs a drive voltage signal when the voltage value of the detected 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, and when the time delay time is set in advance by the time delay changeover switch, the charge resistor corresponding to the time delay time is selected. Connected to the charging circuit. When the drive voltage signal is input to the time delay switching setting unit 25, charging to the charging circuit starts, and during the charging period that coincides with the time delay time, the output from the charging circuit does not become a predetermined voltage. After the extended time has elapsed, the driving voltage signal that has finished charging and has reached a predetermined voltage is output to the tripping device 26. When the high-sensitivity 30 mA forced high-speed signal described above is input, the time delay switching setting unit 25 immediately outputs it as a drive voltage signal to the trip device 26.

The tripping device 26 opens a main circuit by driving an opening / closing mechanism portion of a main circuit contact (not shown) when a driving voltage signal is inputted.
In this way, unlike the domestic type with a single structure, the foreign type (European and American type) can be set to switch to high sensitivity in addition to the setting to switch to low sensitivity or normal sensitivity. When it is performed, it is forcibly operated at high speed even in time-delayed switching, and conforms to the standard (IEC947-2).

  Moreover, as an example of such an earth leakage breaker, for example, Patent Document 1 (invention name: earth leakage breaker) is known. According to Patent Document 1, an earth leakage circuit breaker is disclosed in which a signal is output from a switch when switching to high sensitivity is set, and the switching is forcibly switched to high-speed operation even in time-delayed switching.

  As another example of the earth leakage breaker, the invention disclosed in Patent Document 2 (name of invention: earth leakage breaker) is known. According to Patent Document 2, a ground fault circuit breaker is disclosed in which a signal is output from a decoding circuit when switching to high sensitivity is set, and the switching operation is forcibly switched to high-speed operation even in time delay setting.

  As another example of the earth leakage breaker, an invention disclosed in Patent Document 3 (title of the invention: earth leakage breaker) is known. According to Patent Document 3, an earth leakage circuit breaker that performs both sensitivity current switching and time switching by setting a dial type switch is disclosed.

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) JP 7-141979 A (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. However, there is a demand for an earth leakage circuit breaker that forcibly switches to high-speed operation. The prior art earth leakage circuit breaker 20 shown in FIG. 8 has a sensitivity switching setting unit 22 and a time delay switching setting unit 25. In the pattern wiring connecting the two, a high-sensitivity 30 mA forced high-speed signal, that is, a signal having a small amplitude is easily affected by noise, so that noise countermeasures are necessary and the wiring pattern becomes complicated. there were.

  Also, in order to provide the same function as that of a foreign type (European / US type), it is possible to cope by providing a sensitivity switching setting unit of two circuits and a time delay switching setting unit of one circuit. There was a problem that the earth leakage circuit breaker was enlarged because the setting part for switching was very large. There was a request to secure a compact configuration like the domestic model.

  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, and 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, using a mechanical configuration that is not affected by noise, it is possible to switch the sensitivity from high sensitivity to low sensitivity, and to perform time delay switching from high speed operation to delayed operation. At the same time as the switching setting, regarding the earth leakage breaker forcibly setting the high speed operation in the time delay switching, the sensitivity switching setting unit and the circuit delay switching setting unit which are independent from each other are provided. There has been a demand for switching to high sensitivity and forcibly setting to high speed operation forcibly with time delay switching.

  Accordingly, the present invention has been made in view of the above-described problems, and the object thereof is to set the detection sensitivity from low sensitivity to high sensitivity by a mechanical setting with a simple configuration and at the same time forcibly set to high speed operation. It is in providing the earth-leakage circuit breaker made.

In order to solve the above-mentioned problem, an earth leakage breaker according to claim 1 is
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 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, and is set in advance immediately after inputting the drive voltage signal during high-speed operation or after inputting the drive voltage signal during time-delayed operation. A time delay switching setting unit for outputting a drive voltage signal after the time delay has elapsed;
A tripping device that opens the main circuit by driving the switching mechanism of the main circuit contact when a 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.

Moreover, the earth leakage breaker of the invention described in claim 2 is
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 a part is located on the flow line of the extension slide switch for time delay switching, and the extension slide switch for time delay switching is pushed according to the movement of the extension slide switch for sensitivity switching. A projecting portion for restraining movement by movement or movement of the extension slide switch for time delay switching,
It is characterized by providing.

Moreover, the earth leakage breaker of the invention described in claim 3 is
The earth leakage circuit breaker according to claim 2,
Instead of the sensitivity switching extension slide switch, a sensitivity switching extension slide switch with the protruding portion removed is employed to independently set the sensitivity switching extension setting unit and the time delay switching extension setting unit. It is possible to do it.

  According to the present invention, it is possible to provide a ground fault circuit breaker configured to set the detection sensitivity from a low sensitivity to a high sensitivity by a 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 domestic type earth-leakage circuit breaker of a prior art. It is a block diagram of the foreign-type earth-leakage circuit breaker of a prior art.

  Subsequently, an embodiment 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 device 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. Then, the sensitivity switching setting unit 120 changes the resistance value by switching the resistance connected to both ends of the output winding 110b by the sensitivity switching slide switch 121 interlocked with the constraint setting unit 170, thereby changing the resistance value from high sensitivity to low sensitivity. The sensitivity can be changed and set step by step. Sensitivity switching setting section 120 sends a secondary output current signal to the resistance set for switching, and outputs a detection operation voltage signal. The sensitivity switching setting unit 120 can perform sensitivity switching from high sensitivity to low sensitivity. The sensitivity switching range is 30 mA / 100 mA / 300 mA / 500 mA, so that the sensitivity can be switched stepwise. .

  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 is output to leakage detection unit 140.

  The leakage detection unit 140 outputs a drive voltage signal when the voltage value of the detected 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 responds to the time delay switching slide switch 151 (see FIG. 3) that enables setting of the time delay switching, and the time delay time set by the time delay switching slide switch 151. And a charging circuit (specifically, a capacitor) charged with a charging current determined by the selected charging resistor. When the time delay time is switched and set in advance by the time delay switching slide switch 151, the time delay switching setting unit 150 selects a charging resistor corresponding to the time delay time and is connected to the charging circuit. When a drive voltage signal is input to such a time delay switching setting unit 150 during the time delay operation, charging to the charging circuit starts, and the output from the charging circuit is a predetermined voltage during the charging period that coincides with the time delay time. In other words, the driving voltage signal that has reached the predetermined voltage after the completion of the charging time is output to the tripping device 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 tripping device 160, which is selected during high-speed operation as described later.

  The tripping device 160 opens a main circuit by driving an opening / closing mechanism portion (not shown) of a main circuit contact when a driving voltage signal of either a time delay operation or a 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 newly 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, and in particular, the sensitivity switching setting unit 120. When high 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 setting of the sensitivity switching setting unit 120 and the time delay switching setting unit 150 is 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 electrically connected to the 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 switch of the sensitivity switching setting unit 120 is moved via the interlocking mechanism of the sensitivity switching intermediate adapter 171c. 121 also moves in the same arrow a direction (or arrow b direction).

  As shown in FIG. 3, a time delay switching extension setting unit 172 is attached above the time delay switching setting unit 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 time-delay switching extension slide switch 172b is moved in the direction of arrow a in FIG. 3 (or in the direction of arrow b), the time-delay switching setting unit 150 performs time delay through the interlocking mechanism of the time-delay switching intermediate adapter 172c. The switching slide switch 151 also moves in the direction of arrow a (or arrow b) in FIG.

  The sensitivity switching extension slide switch 171b is provided with a protruding portion 171a. 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. Further, when moving in the direction of the arrow a, the extension switching switch 172b for time delay switching is moved together with the extension slide switch 171b for sensitivity switching.

  By such a constraint setting unit 170, the sensitivity switching setting unit 120 and the time delay switching setting unit 150 are set. 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 installation portion 171a is also located on the lower side, the extension slide switch 172b for time delay switching is not restrained and can move in the direction of the 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 detection unit 140 and the trip device 160 are directly connected to trip the drive voltage signal. To 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 and is output from the leakage detection unit 140. The drive voltage signal is applied to the charging resistor and the charging current is output. When this charging current is input to the charging circuit, charging to the charging circuit starts. The drive voltage signal thus output is output to the trip device 160. In this way, the interruption by the time delay operation is performed.

  However, 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, contacts the abutting portion 172a of the time-delay switching extension slide switch 172b, and the time-delay switching extension slide switch 172b also moves to change the time delay. The extension slide switch 172b is forcibly set to the maximum speed by being constrained by the maximum time delay speed (0 ms).

  In this case, the high-speed conduction unit is selected in the time delay switching setting unit 150, and the drive voltage signal output from the leakage detection unit 140 is input to the trip device 160 as it is. Thereby, high-speed operation is realized.

  In addition, although it is such a setting example, it becomes as shown in the following Table 1 specifically. This table is 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. ).

  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 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 the present invention as described above, 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.

  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.

100: Earth leakage breaker 110: Zero phase current transformer 110a: Iron core 110b: Output winding 120: Sensitivity switching setting unit 121: Sensitivity switching slide switch 130: Filter circuit 140: Earth leakage detection unit 150: Time delay switching setting Unit 151: time delay switching slide switch 160: tripping device 170: restraint setting unit 171: sensitivity switching extension setting unit 171 a: protruding portion 171 b: sensitivity switching extension slide switch 171 c: sensitivity switching intermediate adapter 172: hour Extension switching extension setting portion 172a: Abutment portion 172b: Time delay switching extension slide switch 172c: Time delay switching intermediate adapter 180: Printed circuit board A, B: Mechanical restraint

Claims (3)

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 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, and is set in advance immediately after inputting the drive voltage signal during high-speed operation or after inputting the drive voltage signal during time-delayed operation. A time delay switching setting unit for outputting a drive voltage signal after the time delay has elapsed;
A tripping device that opens the main circuit by driving the switching mechanism of the main circuit contact when a 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 a part is located on the flow line of the extension slide switch for time delay switching, and the extension slide switch for time delay switching is pushed according to the movement of the extension slide switch for sensitivity switching. A projecting portion for restraining movement by movement or movement of the extension slide switch for time delay switching,
An earth leakage circuit breaker comprising: The earth leakage circuit breaker according to claim 2,
Instead of the sensitivity switching extension slide switch, a sensitivity switching extension slide switch with the protruding portion removed is employed to independently set the sensitivity switching extension setting unit and the time delay switching extension setting unit. An earth leakage circuit breaker characterized by being made possible.

Images