JP2009089574A - Ground-fault circuit interrupter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ground-fault circuit interrupter which lowers the voltage applied across the contacts of a test switch and can reduce the isolation resistance between a test coil and the secondary coil of a zero-phase current transformer. <P>SOLUTION: The ground-fault circuit interrupter includes: the zero-phase current transformer inserted in an ac current path; a leakage detecting circuit which generates an output signal, when a leak current flowing through the zero phase current transformer exceeds a given level; a tripping circuit which trips a breaker unit inserted in the ac current path, in response to the output signal from the leak detecting circuit; a rectifying circuit which rectifies the voltage of the ac current path, to supply the rectified voltage to the leak detecting circuit; and a test circuit which supplies a flow of pseudo-leakage current to a test coil which are coiled around the zero-phase current transformer. The test circuit is made up of a serial connection constituted of the test coils, test switches, limiting resistances, and optical insulating means, the serial connection which is connected to the output end of the rectifying circuit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an earth leakage circuit breaker that interrupts an electric circuit when a leakage or ground fault occurs in an AC circuit, and more particularly, to an earth leakage circuit breaker having a test circuit that tests a circuit leakage by causing a pseudo-leakage current to flow through the circuit. Is.

  Various proposals have been made for this type of earth leakage circuit breaker. For example, a zero-phase current transformer is inserted in a three-phase AC circuit, and the two-phase primary conductors of the three-phase AC circuit are connected. Is connected to a test circuit consisting of a series circuit of a test switch, a test resistor, and a test winding of a zero-phase current transformer, and a pseudo-leakage current is caused to flow through the test circuit by operating the test switch. There is one configured to detect the current by a detector and determine the level of the leakage current to interrupt the AC circuit. (For example, see Patent Document 1)

JP 2002-78187 A

  In the above-described conventional earth leakage breaker, the test switch through which the pseudo earth leakage current flows is connected to the AC circuit of the main circuit, and the voltage of the main circuit is applied between the contact points of the test switch. There is a problem that the external shape of the switch becomes large because it is necessary to cope with the circuit voltage. In addition, when the configuration of the power supply of the electronic circuit of the earth leakage breaker is a circuit configuration in which rectification is performed with a voltage close to the main circuit voltage, the main circuit voltage is approximately between the test winding and the secondary winding of the zero-phase current transformer. Therefore, the insulation between the test winding and the secondary winding of the zero-phase current transformer must have a high withstand voltage.

  The present invention has been made to solve the above-described problems, and in a test circuit for an earth leakage circuit breaker, the voltage between the contacts of the test switch can be lowered, and the test switch has a low rated voltage and is small and inexpensive. It is an object of the present invention to provide an earth leakage circuit breaker that can use a switch and that can easily configure a dielectric strength between a test winding and a secondary winding of a zero-phase current transformer with a low withstand voltage.

  An earth leakage breaker according to the present invention is connected to a zero-phase current transformer inserted in an AC circuit and a secondary winding wound around the zero-phase current transformer. A leakage detection circuit that generates an output when the level is exceeded, a tripping circuit that opens the interrupter inserted in the AC circuit by the output of the leakage detection circuit, and a voltage that rectifies the voltage of the AC circuit to rectify the leakage An earth leakage breaker comprising a rectifier circuit to be supplied to a detection circuit and a test circuit for causing a pseudo-leakage current to flow through a test winding wound around the zero-phase current transformer, wherein the test circuit is connected to an output side of the rectifier circuit Further, the test winding, the test switch, the limiting resistor, and the optical insulating means are connected in series.

  As described above, since the test circuit is connected to the output side of the rectifier circuit as described above, an inexpensive switch with a low rated voltage can be used as the test switch, and the test winding of the zero-phase current transformer and Insulation between the secondary windings can be simplified.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of an earth leakage circuit breaker according to Embodiment 1 of the present invention. FIG. 2 is a time chart showing the operation of FIG.
In FIG. 1, the earth leakage breaker 10 has power side terminals R, S, T and load side terminals U, V, W corresponding to the power side terminals R, S, T. Inside, a blocking portion 9 comprising contacts for opening and closing the primary conductors (RU), (SV), and (TW) connecting the power supply side terminal and the load side terminal, and each primary conductor. An overcurrent detection unit (not shown) that detects an overcurrent for each of (RU), (SV), and (T-W) and opens the contact of the blocking unit 9 via a tripping unit (not shown) ing. Note that the contact of the blocking portion 9 is made by manually operating a handle (not shown).

  In addition, the zero-phase current included in the current (for three phases in this example) flowing through the primary conductors (RU), (SV), and (TW) passing through the ring-shaped iron core 2c. It has a zero-phase current transformer 2 for detecting (load-side leakage or ground fault), and the iron core 2c has a secondary winding 2a for taking out the zero-phase current, for testing the leakage breaker function The test winding 2b is wound.

  A test circuit 1 is connected to primary conductors (RU), (SV), and (TW) via a rectifier circuit 3 and a constant voltage circuit 4, and the test circuit 1 is connected to the zero phase. A test winding 2b wound around the current transformer 2, a test switch 11 for turning on and off the pseudo leakage current flowing through the zero-phase current transformer 2, and a current for limiting the pseudo leakage current flowing through the test winding 2b. The limiting element 12 and the optical insulating means 131 are connected in series, and are connected between the constant voltage circuit 4 on the output side of the rectifier circuit 3 and the ground. The light insulating means 131 is composed of a primary side and a secondary side which are insulated from each other, and a light emitting element 131a connected between one of the AC electric circuits and the AC side of the rectifier circuit 3 on the primary side. And a light receiving element 131b that is connected to the current limiting element 12 and controls to generate a ripple in the pseudo leakage current.

  Further, a rectifying element 141 is connected to the light emitting element 131a in an antiparallel relationship with the polarity of the light emitting element 131a. The secondary winding 2a of the zero-phase current transformer 2 is connected to a leakage detection circuit 5 that generates an output when a leakage current flowing through the AC circuit exceeds a predetermined level. Is provided with a tripping circuit 6 that opens the contact of the blocking section 9. The tripping circuit 6 includes an electromagnetic device 61 and switching means 62 that receives the output of the leakage detection circuit 5 and controls the electromagnetic device 61.

Next, the leakage test operation of the leakage breaker according to Embodiment 1 of the present invention configured as described above will be described.
Now, when the contact of the test switch 11 is closed while the contact of the blocking section 9 is closed, the ripple current controlled by the light receiving element 131b according to the half-wave current flowing through the light emitting element 131a of the optical insulating means 131. (Half-wave current) flows in the test winding 2b of the zero-phase current transformer 2 as a pseudo-leakage current.

At this time, since a predetermined pseudo-leakage current limited by the current limiting element 12 is applied to the test winding 2b, a current is generated in the secondary winding 2a by the magnetic flux generated in the annular core 2c. Is detected by the leakage detection unit 5, and when this exceeds a predetermined level, it is determined that leakage has occurred and is output to the trip circuit 6. When the switching means 62 of the tripping circuit 6 receives the output of the leakage detection unit 5 and operates the electromagnetic device 61, the blocking unit 9 performs a blocking operation, and a leakage test is performed.
Since the rectifying element 141 is connected in parallel with the light emitting element 131a on the primary side of the light insulating means 131 in the direction opposite to the polarity of the light emitting element, an alternating current can be continuously supplied to the rectifying circuit 3, so that the above test Power is stably supplied to the leakage detection circuit 5 having the configuration of the circuit 1.

The test circuit 1 is connected to the subsequent stage of the constant voltage circuit 4 that maintains the voltage output from the rectifier circuit 3 at a predetermined voltage, and the voltage applied between the contacts of the test switch 11 can be set to 30 V or less, for example. Is.
Similarly, since the secondary winding 2a and the test winding 2b of the zero-phase current transformer 2 are both connected to the downstream side of the constant voltage circuit 4, the potential difference between the windings can be set to 30 V or less, for example. The insulation between the winding 2a and the test winding 2b can be simplified.

  FIG. 2 is a time chart showing the operation of FIG. In the figure, 111 is the opening / closing timing of the test switch 11, 133 is a current waveform flowing through the light emitting element 131a of the optical insulating means 131, 201 is a pseudo leakage current waveform flowing through the test winding 2b, and 202 is an output waveform of the secondary winding 2a. , 501 is an output waveform of the leakage detection circuit 5, 621 is an operation waveform of the trigger element 62, and 611 is a current waveform of the tripping device 61.

  A current like a waveform 133 flows in the light emitting element 131a of the optical insulating means 131. When the contact of the test switch 11 is closed at the timing of point A of the waveform 111, the test switch 11 and the light receiving element 131b are opened and closed. A pseudo leakage current having a waveform like the controlled waveform 201 flows in the test winding 2 b of the zero-phase current transformer 2. When an output current such as waveform 202 is generated in the secondary winding 2a of the zero-phase current transformer 2 due to the pseudo-leakage current, and the leakage detection circuit 5 detects a leakage of a predetermined level C or higher, a waveform 501 Output. The switching means 62 composed of, for example, a transistor of the tripping circuit 6 receives the output of the waveform 501 of the leakage detection circuit 5 and operates at the timing as shown by the waveform 621, and current flows through the electromagnetic device 61 as shown by the waveform 611. Then, the interruption operation of the interruption unit 9 is performed, and a leakage test can be performed.

  The current flowing through the test winding 2b is set so that the output of the secondary winding 2a is equal to or higher than the threshold C at which the leakage detection unit 5 set to the leakage detection unit 5 operates the tripping circuit 6. ing. In the above-described embodiment, the example of the circuit breaker corresponding to the three-phase electric circuit has been described. However, the circuit breaker corresponding to the single-phase electric circuit or the three-phase four-wire electric circuit may be connected between the primary conductor of one of the phases and the rectifier circuit. Even when the optical insulating means is connected, the same effect can be obtained.

  As described above, according to the first embodiment of the present invention, since the test circuit is connected to the output side of the rectifier circuit, an inexpensive switch with a low rated voltage can be used as the test switch, and the zero-phase current transformer Since the insulation between the test winding and the secondary winding can be simplified, there is an effect that a small and inexpensive zero-phase current transformer can be used.

Embodiment 2. FIG.
FIG. 3 is a block diagram showing a leakage breaker in Embodiment 2 of the present invention.
In the figure, the feature of the second embodiment is that in the optical insulating means 131, the primary side light emitting element 131a is connected in series with the limiting resistor 151 between one of the primary conductors and the AC side of the rectifier circuit 3. The constant voltage diode 143 is connected in parallel to the series body of the light emitting element 131a and the limiting resistor 151 in the direction opposite to the polarity of the light emitting element. Other than the above, the second embodiment is the same as the first embodiment.

  Now, when a surge voltage is applied between the primary conductors, a surge current flows through the light emitting element 131a of the optical insulating means 131, but the voltage of the limiting resistor 151 rises, and the light emitting element parallels the light emitting element 131a and the limiting resistor 151. Since the voltage applied to the light emitting element 131a and the limiting resistor 151 is limited by the constant voltage diode 143 connected in the direction opposite to the polarity of the current, the surge current flowing through the light emitting element 131a can be limited. At this time, the resistance value of the limiting resistor 151 is desirably as low as possible, for example, 10Ω or less in order to reduce the influence on the power supply of the subsequent circuit. Operations other than those described above are the same as those in the first embodiment.

  As described above, according to the second embodiment of the present invention, as in the first embodiment described above, an inexpensive switch with a low rated voltage can be used as the test switch, and the test winding of the zero-phase current transformer can be used. Since the insulation between the wire and the secondary winding can be simplified, a small and inexpensive zero-phase current transformer can be used, and a small and inexpensive one with a small surge current resistance on the light emitting element side of the optical insulation means There is an effect that can be used.

Embodiment 3 FIG.
FIG. 4 is a block diagram showing an earth leakage circuit breaker according to Embodiment 3 of the present invention.
FIG. 5 is a time chart showing the operation of FIG.
The feature of the third embodiment is that the optical insulating means 132 is provided separately from the optical insulating means 131. In the figure, the optical insulating means 132 is in parallel with the light emitting element 132 a connected between the other primary conductor and the AC side of the rectifier circuit 3 and the light receiving element 131 b of the optical insulating means 131 in the same manner as the optical insulating means 131. Rectifying elements 141 and 142 connected in parallel to the light emitting elements 131a and 132a of the optical insulating means 131 and 132 in parallel with the polarities of the light emitting elements, respectively. This is the point. Other than the above, the second embodiment is the same as the first embodiment.

Next, the operation of the ground fault circuit breaker according to Embodiment 3 of the present invention configured as described above will be described with reference to FIG.
In the figure, when the contact of the test switch 11 is closed, the ripple current (half wave current) controlled by the light receiving elements 131b and 132b in accordance with the half wave current flowing through the light emitting elements 131a and 132a of the optical insulating units 131 and 132 is simulated. The leakage current flows to the test winding 2b of the zero-phase current transformer 2, and thereafter the leakage test can be performed by the same operation as in the first embodiment.

  In addition, since the rectifier elements 141 and 142 are connected in parallel with the light emitting elements 131a and 132a of the optical insulating means 131 and 132 in the direction opposite to the polarity of the light emitting elements, an alternating current can be continuously supplied to the rectifying circuit 3. The power supply to the leakage detection circuit 5 having the configuration of the test circuit 1 is stably performed.

FIG. 5 is a time chart showing the operation of FIG.
In the figure, 111 is the opening / closing timing of the test switch 11, 133 is a current waveform flowing through the light emitting element 131a of the optical insulating means 131, 134 is a current waveform flowing through the light emitting element 132a of the optical insulating means 132, and 201 is flowing through the test winding 2b. The pseudo-leakage current waveform, 202 is the output waveform of the secondary winding 2a, 501 is the output waveform of the leakage detection circuit 5, 621 is the operation waveform of the electromagnetic device switching means 62, and 611 is the current waveform of the electromagnetic device 61.

A current like a waveform 133 flows in the light emitting element 131a of the optical insulating means 131 and a waveform 134 flows in the light emitting element 132a of the optical insulating means 132, and the contact of the test switch 11 is closed at the point A of the waveform 111. A pseudo-leakage current having a waveform like waveform 201 controlled by opening / closing of the test switch 11, the light receiving element 131b, and the light receiving element 132b flows in the test winding 2b of the zero-phase current transformer 2.

Then, an output current such as a waveform 202 is generated in the secondary winding 2a of the zero-phase current transformer 2 due to the pseudo leakage current, and when the leakage detection circuit 5 detects a leakage, an output such as a waveform 501 is performed. The switching means 62 of the tripping circuit 6 receives the output of the waveform 501 of the leakage detection circuit 5 and operates at the timing as shown by the waveform 621, the current flows through the electromagnetic device 61 as shown by the waveform 611, so The operation is performed and a leakage test can be performed.
Here, the current flowing through the test winding 2b is set so that the output of the secondary winding 2a is equal to or higher than the threshold C at which the leakage detection unit 5 set to the leakage detection unit 5 operates the tripping circuit 6. Has been.

  As described above, according to the third embodiment of the present invention, since the test switch is configured in the DC circuit, an inexpensive switch having a low rated voltage can be used as the test switch, and the zero-phase current transformer test can be performed. Insulation between the primary winding and the secondary winding can be simplified, so that a small and inexpensive zero-phase current transformer can be used, and two primary conductors among the three-phase primary conductors are optically insulated. Since the light emitting elements 131a and 132a of the means 131 and 132 are connected, the leakage test can be performed in the other phase even if any of the three phases is missing or not connected.

Embodiment 4 FIG.
FIG. 6 is a block diagram showing an earth leakage circuit breaker according to Embodiment 4 of the present invention, and FIG. 7 is a time chart showing the operation of FIG.
In the fourth embodiment, the above-described second and third embodiments are combined to have both characteristics. That is, first, two primary sides of the optical insulating means are provided, and one of each is connected in parallel with the series body of the light emitting element 131a and the limiting resistor 151, and the constant voltage diode 143 is connected in the direction opposite to the polarity of the light emitting element 131a. The other is composed of a constant voltage diode 144 connected in parallel to a series body of a light emitting element 132a and a limiting resistor 152 in a direction opposite to the polarity of the light emitting element 132a. In addition, limiting resistors 8a to 8c are newly inserted in the circuits from the primary conductors (RU), (SV), and (TW) to the rectifier circuit 3, respectively.

  On the other hand, the test circuit 1 in which the secondary side of the optical insulating means is inserted includes a current limiting element 12 for limiting the test current to the constant voltage circuit 4 via the test winding 2b of the zero-phase current transformer 2, and a series circuit therewith. And a series circuit of a test switch 11 and a current limiting element 16 between the constant voltage circuit 4 and the input terminal of the switching element 17. And a parallel circuit of two light receiving elements 131b and 132b on the secondary side of the optical insulating means are connected in series.

  In addition, it has a leakage detection circuit 5 connected to the secondary winding 2a of the zero-phase current transformer 2, and a tripping circuit 6 that receives the output of the leakage detection circuit 5 and opens the contact of the breaking unit 9. However, the tripping circuit 6 is connected to the electromagnetic device 61, the electromagnetic device driving switching means 62 that receives the output of the leakage detection circuit 5 and controls the electromagnetic device 61, and the input terminal of the switching element 17. A pseudo-leakage current control means 73 that receives the output of the detection circuit 5 and turns off the switching element 17 and is inserted on the input side of the leakage detection circuit 5 and contributes to voltage stabilization of the leakage detection circuit 5 when the test circuit 1 is operated. And a rectifying element 71 for preventing current from flowing from the smoothing capacitor 72 to the test circuit 1 side.

Next, the operation of the ground fault circuit breaker according to Embodiment 4 of the present invention configured as described above will be described.
Now, when the contact of the test switch 11 is closed in a state where the contact of the blocking unit 9 is closed, the light receiving elements 131b and 132b according to the half-wave currents flowing through the light emitting elements 131a and 132a of the optical insulating means 131 and 132. The ripple current (half-wave current) controlled through the pseudo-leakage current switching element 17 flows through the test winding 2b of the zero-phase current transformer 2 as a pseudo-leakage current.

  At this time, since a predetermined pseudo-leakage current limited by the current limiting element 12 is applied to the test winding 2b, a current is generated in the secondary winding 2a by the magnetic flux generated in the annular core 2c. Is detected by the leakage detection unit 5, and if a current of a predetermined level or more flows, it is determined that leakage has occurred and is output to the trip circuit 6. When the switching means 62 of the tripping circuit 6 receives the output of the leakage detection unit 5 and operates the electromagnetic device 61, the blocking unit 9 performs a blocking operation, and a leakage test is performed.

  Due to the leakage test, the leakage detection circuit 5 operates the electromagnetic device 61 as described above, and at the same time, the pseudo leakage current control means 73 is turned on and the pseudo leakage current switching element 17 that controls the test current is turned off. During the operation, pseudo-leakage current is prevented from flowing. Therefore, a stable test operation is possible even when the operating current is limited by the configuration of the limiting resistors 8a to 8c and the constant voltage circuit 4. Even when the main circuit voltage is low and most of the current output from the constant voltage circuit 4 is consumed by the pseudo leakage current due to the operation of the test circuit 1, the voltage of the leakage detection circuit 5 is the smoothing capacitor 72 and the rectifying element. Stabilization is compensated by the action of 71.

  Moreover, since the constant voltage diodes 143 and 144 are connected in parallel with the light emitting elements 131a and 132a of the optical insulating means 131 and 132 in the opposite direction to the polarity of the light emitting elements as in the third embodiment, the alternating current is continuously supplied. Thus, the power can be supplied to the rectifier circuit 3 in a stable manner, and the power supply to the leakage detection circuit 5 having the configuration of the test circuit 1 can be stably performed.

  In addition, when a surge voltage is applied between the primary conductors, a surge current flows through the light emitting element 131a of the optical insulating means 131, but the voltage of the limiting resistor 151 rises and reverses to the series of the light emitting element 131a and the limiting resistor 151. Since the constant voltage diode 143 connected in parallel limits the voltage applied to the light emitting element 131a and the limiting resistor 151, the surge current flowing through the light emitting element 131a is limited. The combination of the light emitting element 132a, the limiting resistor 152, and the constant voltage diode 144 of the optical insulating means 132 operates in the same manner as described above, and the surge current flowing through the light emitting element 132a is limited.

Since the light-emitting elements 131a and 132a of the optical insulating means 131 and 132 are connected to two primary conductors of the three-phase primary conductors, testing is possible regardless of which of the three phases is missing or not connected. As a result, a more stable test circuit can be realized.
At this time, the resistance values of the limiting resistors 151 and 152 are desirably as low as possible, for example, 10Ω or less in order to reduce the influence on the power supply of the subsequent circuit.

  In the time chart of FIG. 7, 111 is the opening / closing timing of the test switch 11, 133 is a current waveform flowing through the light emitting element 131a of the optical insulating means 131, 134 is a current waveform flowing through the light emitting element 132a of the optical insulating means 132, 201 is a test winding. Quasi-leakage current waveform flowing in the line 2b, 202 is an output waveform of the secondary winding 2a, 501 is an output waveform of the leakage detection circuit 5, 621 is an operation waveform of the electromagnetic device switching means 62, 611 is a current waveform of the electromagnetic device 61, Reference numeral 731 denotes an operation waveform of the pseudo leakage current control means 73.

  A current like a waveform 133 flows in the light emitting element 131a of the optical insulating means 131 and a waveform 134 flows in the light emitting element 132a of the optical insulating means 132, and the contact of the test switch 11 is closed at the point A of the waveform 111. The pseudo-leakage current having the waveform 201, which is controlled by opening / closing the test switch 11, the light receiving element 131b, and the light receiving element 132b, flows in the test winding 2b of the zero-phase current transformer 2. Then, an output current such as a waveform 202 is generated in the secondary winding 2a of the zero-phase current transformer 2 due to the pseudo leakage current, and when the leakage detection circuit 5 detects a leakage, an output such as a waveform 501 is performed.

  The pseudo leakage current control means 73 of the tripping circuit 6 receives the output of the waveform 501 of the leakage detection circuit 5 and operates at the timing as shown by the waveform 731 to turn off the pseudo leakage current switching element. The pseudo leakage current does not flow at the position. At the same time, the electromagnetic device switching means 62 of the trip circuit 6 receives the output of the waveform 501 of the leakage detection circuit 5 and operates at the timing as shown by the waveform 621, and a current flows through the trip device 61 as shown by the waveform 611. Then, the interruption operation of the interruption unit 9 is performed, and a leakage test can be performed. Here, the current flowing through the test winding 2b is set so that the output of the secondary winding 2a is equal to or higher than the threshold C at which the leakage detection unit 5 set to the leakage detection unit 5 operates the tripping circuit 6. Has been.

  As described above, according to the fourth embodiment of the present invention, since the test switch is configured in the DC circuit, an inexpensive switch with a low rated voltage can be used as the test switch, and the zero-phase current transformer test can be performed. Since the insulation between the primary winding and the secondary winding can be simplified, a small and inexpensive zero-phase current transformer can be used. Further, there is an effect that a small and inexpensive device having a small surge current resistance can be used on the light emitting element side of the optical insulating means, and that an inexpensive power supply circuit having a small output current and a simple configuration can be used.

  In each of the above embodiments, the example of the circuit breaker corresponding to the three-phase electric circuit has been described. However, even in the circuit breaker corresponding to the three-phase four-wire electric circuit, between the primary conductor and the rectifier circuit of any three phases. Of course, the same effect can be obtained even when the optical insulating means is connected.

It is a block diagram which shows the structure of the earth-leakage circuit breaker in Embodiment 1 of this invention. It is a time chart of FIG. It is a block diagram which shows the structure of the earth-leakage circuit breaker in Embodiment 2 of this invention. It is a block diagram which shows the structure of the earth-leakage circuit breaker in Embodiment 3 of this invention. It is a time chart of FIG. It is a block diagram which shows the structure of the earth-leakage circuit breaker in Embodiment 4 of this invention. It is a time chart of FIG.

Explanation of symbols

1 test circuit, 2 zero-phase current transformer, 2a secondary winding,
2b test winding, 2c iron core, 3 rectifier circuit,
4 Constant voltage circuit, 5 Earth leakage detection circuit, 6 Trip circuit,
8a limiting resistor, 8b limiting resistor, 8c limiting resistor,
9 circuit breaker, 10 earth leakage circuit breaker, 11 test switch,
12 current limiting elements, 16 current limiting elements,
17 pseudo leakage current switching element, 61 electromagnetic device,
62 electromagnetic device driving switching means, 71 rectifying element,
72 smoothing capacitor, 73 pseudo leakage current control means,
131 optical insulating means, 131a light emitting element, 131b light receiving element,
141 rectifier element, 142 rectifier element, 143 constant voltage diode, 144 constant voltage diode, 151 limiting resistor, 152 limiting resistor.

Claims (8)

  A zero-phase current transformer inserted in the AC circuit and a secondary winding wound around this zero-phase current transformer are connected to generate an output when the leakage current flowing through the AC circuit exceeds a predetermined level. A leakage detection circuit, a tripping circuit that opens the interrupter inserted in the AC circuit by the output of the leakage detection circuit, a rectification circuit that rectifies the voltage of the AC circuit and supplies the voltage to the leakage detection circuit, An earth leakage circuit breaker having a test circuit for supplying a pseudo-leakage current to a test winding wound around the zero-phase current transformer, wherein the test circuit is connected to the test winding and a test switch on an output side of the rectifier circuit. An earth leakage circuit breaker comprising: a series connection body of a limiting resistor and optical insulating means.   The optical insulating means comprises a light emitting element whose primary side is inserted between the AC circuit and the rectifier circuit, and a light receiving element whose secondary side controls a pseudo-leakage current flowing in the test circuit. The earth leakage circuit breaker according to claim 1.   The earth leakage breaker according to claim 2, wherein a rectifying element is connected in antiparallel to the light emitting element of the optical insulating means.   2. A limiting resistor is connected in series to the light emitting element of the optical insulating means, and a constant voltage diode having a direction opposite to the polarity of the light emitting element is connected to a series circuit of the light emitting element and the limiting resistor. The earth leakage breaker described.   A plurality of the optical insulating means are arranged, and the primary side of each optical insulating means is connected between at least two phases of the AC circuit and the rectifier circuit, and the secondary side of each optical insulating means is tested as described above. The earth leakage circuit breaker according to claim 1, wherein the circuit breakers are connected in parallel in the circuit.   The earth leakage circuit breaker according to claim 1, further comprising pseudo earth leakage current control means for controlling a pseudo earth leakage current generated by the test circuit based on an output of the earth leakage detection circuit.   2. The leakage breaker according to claim 1, wherein the leakage breaker is supplied from the output side of the rectifier circuit to the test circuit and the leakage detection circuit via a constant voltage circuit.   The trip circuit includes an electromagnetic device, switching means for driving the electromagnetic device that receives the output of the leakage detection circuit and controls the electromagnetic device, and the output of the leakage detection circuit connected to the input terminal of the switching element. A pseudo-leakage current control means for turning off the switching element, a smoothing capacitor that is inserted on the input side of the leakage detection circuit and contributes to voltage stabilization of the leakage detection circuit during operation of the test circuit, and from the smoothing capacitor to the test circuit side 2. The earth leakage circuit breaker according to claim 1, wherein the circuit breaker is constituted by a rectifying element that prevents current from flowing out.

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