JP3361927B2 - Remote test equipment for earth leakage breaker - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote tester for earth leakage circuit breakers, which performs an earth leakage test for earth leakage circuit breakers by remote control.

[0002]

2. Description of the Related Art FIG. 6 is a circuit diagram of a conventional earth leakage breaker with a remote test device. In the figure, 11 is an earth leakage breaker,
C is a zero-phase current transformer, D is a trip electromagnet, S is an opening / closing contact portion, G is a normally open leakage test switch, B1 and B2 are terminals of the leakage test circuit, and 13 is a leakage detection circuit. 14 is an input terminal J1, J via a normally open remote test switch H
2 is an external control power supply for supplying voltage V1 to R2, R1 is a resistor,
C1 is a capacitor, 2 is a rectifier circuit, 3 is a constant current circuit connected to the DC side of the rectifier circuit 2, 16 is a photocoupler for coupling the output side of the constant current circuit 3 and the thyristor circuit 7 side, and its input The output side 16b becomes conductive by passing a current through the side 16a. 7 is the output side 1 of the photocoupler 16
Thyristor circuit connected to 6b, 10 is a rectifier circuit that rectifies and supplies the voltage from the line side to the thyristor circuit 7,
B1 and B2 are earth leakage test circuit terminals connected to the AC side of the rectifier circuit 10. The thyristor circuit 7 serving as an electrical switching circuit includes a thyristor CR1 connected to the output side 16b of the photocoupler 16, a resistor R11 connected between the gate and cathode of the thyristor CR1, a gate of the thyristor CR1 and a rectifier circuit. 10 and a resistor R10 connected through the output side 16b of the photocoupler 16.

In the configuration of FIG. 6, when the operation test of the earth leakage breaker 11 is performed, the remote test switch H is closed so that the AC or DC voltage V1 from the external control power source 14 is input to the input terminal J1 of the remote test apparatus. , J2, in the case of alternating current, it is converted into direct current by the rectifier circuit 2, and in the case of direct current, the constant current circuit 3 is energized as it is.
The voltage converted into DC is supplied to the photocoupler input side 16a via the constant current circuit 3. Photo coupler input side 16
When a current flows through a, the photocoupler output side 16b becomes conductive. The voltage between the leakage test circuit terminals B1 and B2 is converted into direct current by the rectifier circuit 10. Photocoupler output side 1
When 6b becomes conductive, the photocoupler output side 16b, the resistor R1
Through 0, the gate and cathode of thyristor CR1 become conductive, and thyristor CR1 becomes conductive. Thyristor CR
When 1 is conducted, the leakage test circuit terminals B1 and B2 are short-circuited as in the state where the leakage test switch G of the leakage breaker 11 is pressed and closed, and the leakage breaker 11
Operates when there is a short circuit.

[0004]

In the configuration of the conventional remote test device as described above, the terminals B1 and B2 of the earth leakage test circuit in the earth leakage circuit breaker are directly opened / closed by the thyristor CR1. There is a problem that an expensive one is required, an outer shape is large, and an expensive one must be used.

The present invention has been made in order to solve the above problems. A plurality of thyristors for opening and closing terminals of an earth leakage test circuit are connected in series, and a small, low breakdown voltage, inexpensive thyristor is used. You get a remote testing device that you can do.

[0006]

A remote test device for an earth leakage circuit breaker according to the present invention outputs a trip signal for interrupting the line by detecting an imbalance due to a leakage of line current by a zero-phase current transformer. A leakage detection circuit, a plurality of thyristors connected in series are made conductive to create a pseudo-leakage state of the line, an electrical switching means for outputting a trip signal from the leakage detection circuit, and a remote control means for controlling the electrical switching means. A test switch and a photo coupler for electrically insulating and coupling the remote test switch and the electrical switching means and electrically connecting the thyristor by operating the remote test switch are provided.

Further, in the above structure, the voltage from the line side is supplied to each gate of the plurality of thyristors connected in series through the voltage dividing resistor.

Further, in the above structure, a shunt circuit is formed in the voltage dividing resistors for the second and subsequent thyristors by conducting the first thyristor among the plurality of thyristors connected in series.

Further, in the above structure, the shunt circuit is formed of a transistor.

Further, in the above structure, the shunt circuit is formed by a field effect transistor.

Further, in the above structure, a surge absorber is connected in parallel with each voltage dividing resistor.

Further, in the above structure, a surge absorber is connected to the output side of the photocoupler.

[0013]

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1. FIG. 1 is a circuit diagram of an earth leakage breaker with a remote test device. In the figure, R1 is a resistor for limiting inrush current, C1 is a capacitor for preventing malfunction due to capacitance of lead wires connected to the input terminals J1 and J2, 2 is a rectifier circuit,
3 is a constant current circuit connected to the DC side of the rectifier circuit 2, 16
Is the output side of the constant current circuit 3 and the thyristor circuit 7 described later.
It is a photocoupler that couples the output side 16a with the input side 16a by passing a current through the input side 16a.

Reference numeral 7 is a thyristor circuit connected to the output side 16b of the photocoupler 16 and reference numeral 10 is a rectifier circuit for rectifying and supplying the line side voltage to the thyristor circuit 7, B1 and B2.
Is a leakage test circuit terminal connected to the AC side of the rectifier circuit 10. Thyristor circuit 7 that serves as electrical switching means
Is a first-stage thyristor CR2 connected to the output side 16b of the photocoupler 16, a resistor R24 connected between the gate and cathode of the thyristor CR2, and a cathode whose cathode is connected to the anode of the thyristor CR2. Two
The thyristor CR1 at the stage, a resistor R23 connected between the gate and the cathode of the thyristor CR1, a resistor R21 connected between the anode and the gate of the thyristor CR1 on the DC side of the rectifier circuit 10, and a gate of the thyristor CR1. And a resistor R connected between the cathode of thyristor CR2 and thyristor CR2
It consists of 22. The resistors R21 and R22 are voltage dividing resistors that divide the voltage on the line side. Reference numeral 11 is the earth leakage breaker described in FIG. 1, and includes an earth leakage detection circuit 13, a current transformer C, an opening / closing contact portion S, a tripping electromagnet D, and the like.

In the above configuration, the remote test switch H
By closing the switch, the AC or DC voltage V1 from the external control power supply 14 is applied to the input terminal J of the remote tester.
1, applied to J2. When this voltage is AC, it is converted to DC by the rectifier circuit 2, and when it is DC, the constant current circuit 3 is energized as it is. The voltage converted into direct current is made to have a certain constant value by the constant current circuit 3, and the current flows to the photocoupler input side 16a. When a current flows through the photocoupler input side 16a, the photocoupler output side 16b becomes conductive.

The voltage between the leakage test circuit terminals B1 and B2 is converted into direct current by the rectifier circuit 10, and the voltage dividing resistor R
The gate voltage of the thyristors CR1 and CR2 is supplied via 21 and R22. When the photocoupler output side 16b becomes conductive, a current flows between the gate and cathode of the thyristor CR2 via the photocoupler output side 16b and the resistor R21, and the anode and cathode of the thyristor CR2 become conductive. When thyristor CR2 becomes conductive, thyristor CR1
Current flows between the gate and cathode of the thyristor CR1
Conduction between the anode and cathode of, and in the same way as when the leakage test switch G of the leakage breaker 11 is pressed and closed,
The leakage test circuit terminals B1 and B2 are short-circuited, and the leakage breaker 11 operates at the time of leakage.

In the thyristor circuit of the remote test device having the above-mentioned configuration, two thyristors for opening and closing the terminals of the earth leakage test circuit of the earth leakage circuit breaker are connected in series, and a voltage dividing resistor is connected in parallel to each thyristor, and one of them is connected. Since the voltage is not biased to the thyristor, a small and inexpensive thyristor with low withstand voltage can be used.

Embodiment 2. In the circuit shown in FIG. 1 according to the first embodiment, when the photocoupler output side 16b is not conducting, a current of, for example, 1 mA may always flow from the rectifier circuit 10 to the resistors R21 and R22. Therefore, a current of, for example, 1 mA constantly flows through the earth leakage breaker 11 via the earth leakage test circuit terminals B1 and B2, which affects the sensitivity of the earth leakage breaker 11. In the second embodiment, the leakage test circuit terminal B
The current flowing through the earth leakage circuit breaker 11 via B1 and B2 can be reduced, and the influence on the sensitivity of the earth leakage circuit breaker 11 due to the attachment of the remote test device can be reduced.

In FIG. 2, reference numeral 7 is a thyristor circuit connected to the output side 16b of the photocoupler 16. The thyristor circuit 7 serving as an electrical switching means is a photocoupler 1
6, a thyristor CR2 connected to the output side 16b, a resistor R24 connected between the gate and cathode of the thyristor CR2, a thyristor CR1 having a cathode connected to the anode of the thyristor CR2, and a gate of the thyristor CR1. A resistor R23 connected between the cathodes
A resistor R21 connected to the DC side of the rectifier circuit 10 together with the anode of the thyristor CR1, and a resistor R22 connected in series with the cathode of the thyristor CR2.
Resistor R25 connected to the anode of thyristor CR1
And a transistor Q whose base is connected to the connecting portion of the resistors R21 and 22 and whose collector is connected to the resistor R25.
1 and a resistor R26 connected between the base and the emitter of the transistor Q1. The rest of the configuration is similar to that of FIG.

The voltage between the leakage test circuit terminals B1 and B2 is converted into direct current by the rectifier circuit 10, and the voltage dividing resistor R
The gate voltage of the thyristors CR1 and CR2 is supplied via 21 and R22. When the photocoupler output side 16b is not conducting, the resistor R21,
Current always flows through R22, but this current is the leakage breaker 1
The resistances R21 and R22 are set to have high resistance so that the current does not affect the sensitivity of No. 1, for example, a value of 100 μA. When the photocoupler output side 16b becomes conductive, a current flows between the base and the emitter of the transistor Q1 and the collector and emitter of Q1 become conductive. When the transistor Q1 becomes conductive, current flows between the gate and cathode of the thyristor CR2 of the first stage via the photocoupler output side 16b, the collector and emitter of the transistor Q1, and the resistor R25, and between the anode and cathode of this thyristor CR2. Conducts. When the thyristor CR2 becomes conductive, a current flows between the gate and cathode of the second-stage thyristor CR1, and the anode and cathode of this thyristor CR1 become conductive,
The leakage test circuit terminals B1 and B2 are short-circuited, and the leakage breaker 11 operates at the time of leakage.

Therefore, in the first embodiment, the current that constantly flows through the voltage dividing resistor connected in parallel to the thyristor and affects the sensitivity is obtained by connecting the transistor in parallel with the voltage dividing resistor to obtain the voltage dividing resistance value. Can be made larger, so that it can be made smaller. Therefore, the influence on the sensitivity of the earth leakage breaker can be reduced.

Embodiment 3. The transistor Q1 for supplying a current to the gates of the thyristors CR1 and CR2 as shown in FIG. 2 is an N-channel field effect transistor (FET) as in the third embodiment, so that the transistor Q1 is generated. The leakage current generated can be further reduced, and the influence on the sensitivity of the earth leakage breaker 11 can be further reduced.

FIG. 3 is a circuit diagram of an earth leakage breaker with a remote test device according to a third embodiment of the present invention. In FIG. 3, 7 is a thyristor circuit connected to the output side 16b of the photocoupler 16. The thyristor circuit 7 serving as an electrical switching means has a thyristor CR2 connected to the output side 16b of the photocoupler 16, a resistor R24 connected between the gate and cathode of the thyristor CR2, and a cathode at the anode of the thyristor CR2. The connected thyristor CR1, the resistor R23 connected between the gate and the cathode of the thyristor CR1, the resistor R21 connected to the DC side of the rectifier circuit 10 together with the anode of the thyristor CR1, and the thyristor CR2 connected in series. A resistor R22 connected to the cathode, a resistor R25 connected to the anode of the thyristor CR1, a resistor R21 and a resistor R22.
Of the N-channel field effect transistor (FE) whose gate is connected to the connection part of
T) Q10 and a resistor R26 connected between the base and the emitter of the N-channel FET Q10. In addition,
The other structure is similar to that of FIG.

In the above structure, the leakage test circuit terminal B
The voltage between 1 and B2 is converted into a direct current by the rectifier circuit 10, and is divided into thyristor CR via voltage dividing resistors R21 and R22.
1, the gate voltage of CR2 is supplied. When the photocoupler output side 16b is not conducting, a current that does not affect the sensitivity of the earth leakage breaker 11, for example, a current of 100 μA always flows through the resistors R21 and R22 via the rectifier circuit 10. When the photocoupler output side 16b becomes conductive, the resistor R26
A current flows through the gate of the N-channel FET Q10 to generate a potential difference between the gate and the source. When a potential difference is generated between the gate and source of the N-channel FET Q10, conduction is established between the drain and source of the FET Q10. N-channel FET Q1
When 0 is conducted, a current flows between the gate and cathode of the first-stage thyristor CR2 via the photocoupler output side 16b, the N-channel FET Q10, and the resistor R25, and the anode and cathode of this thyristor CR2 are conducted.
When the thyristor CR2 becomes conductive, a current flows between the gate and cathode of the second-stage thyristor CR1 so that the anode and cathode of this thyristor CR1 become conductive, and the leakage test switch G of the earth leakage breaker 11 is pressed to close it. Similarly, the leakage test circuit terminals B1 and B2 are short-circuited, and the leakage breaker 11 operates at the time of leakage.

Fourth Embodiment As shown in FIG. 1, when two thyristors with low withstand voltage are connected in series, when a high voltage exceeding the withstand voltage limit of the thyristor occurs due to surge or the like,
The thyristor may be damaged. The fourth embodiment is an embodiment for coping with this.

FIG. 4 is a circuit diagram of a remote tester for an earth leakage breaker according to the fourth embodiment. In the illustrated thyristor circuit 7, AB1 is a surge absorber connected in parallel to the resistor R21, and AB2 is a surge absorber connected in parallel to the resistor R22. Other configurations are the same as those in FIG. 3, and thus description thereof will be omitted. The surge absorbers AB1 and AB2 can protect the thyristors CR1 and CR2 from a high voltage due to a surge generated between the leakage test circuit terminals B1 and B2. The surge absorbers AB1 and AB2 in the thyristor circuit 7 are connected to resistors R21 and R2, respectively.
2 may be connected in parallel, the other structure may be the structure of the thyristor circuit 7 as shown in FIGS.

Embodiment 5. In the fifth embodiment shown in FIG. 5, a resistor R27 and a surge absorber AB3 are connected to the output side 16b of the photocoupler 16 connected to the gate of the thyristor CR2 of the thyristor circuit 7 for the purpose of voltage protection due to a surge or the like. Other configurations are the same as those in FIG. 4, and thus description thereof will be omitted. In the circuit configuration as shown in FIG. 5, the resistor R27 and the surge absorber AB3 can suppress the voltage applied to the photocoupler output side 16b when a surge occurs to be lower than the voltage applied to the surge absorber AB2. Therefore, the thyristor CR2 is used as the photocoupler 16.
Withstand voltage lower than that of can be used.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a remote tester for an earth leakage breaker according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a remote test device for an earth leakage breaker according to a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing a remote tester for an earth leakage breaker according to a third embodiment of the present invention.

FIG. 4 is a circuit diagram showing a remote tester for an earth leakage breaker according to a fourth embodiment of the present invention.

FIG. 5 is a circuit diagram showing a remote tester for an earth leakage breaker according to a fifth embodiment of the present invention.

FIG. 6 is a circuit diagram showing a conventional remote tester for an earth leakage breaker.

[Explanation of symbols]

B1, B2 earth leakage test circuit terminal, H remote test switch, R21, R22, R23, R24, R25, R2
6 resistance, Q1 transistor, Q10 field effect transistor, AB1, AB2, AB3 surge absorber, CR1, CR2 thyristor, 2 rectifier circuit, 3
Constant current circuit, 7 thyristor circuit, 10 rectifier circuit, 11
Earth leakage breaker, 13 earth leakage detection circuit, 14 control power supply, 16 photo coupler.

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Claims (7)

(57) [Claims] 1. A leakage detection circuit for detecting an imbalance due to a leakage of a line current by a zero-phase current transformer and outputting a trip signal for cutting off the line, and connecting a plurality of thyristors connected in series to each other. Electrical switching means for creating a pseudo leakage state of the line and outputting a trip signal from the leakage detection circuit, a remote test switch for controlling the electrical switching means, and an electrical connection between the remote test switch and the electrical switching means. A remote test device for an earth leakage breaker, which is provided with a photocoupler electrically insulated and coupled to electrically connect the thyristor by operating the remote test switch. 2. A plurality of thyristors connected in series comprises:
2. The remote test device for an earth leakage breaker according to claim 1, wherein the voltage from the line side is supplied to each gate via a voltage dividing resistor. 3. A shunt circuit is formed in the voltage dividing resistors for the second and subsequent thyristors by conducting the first thyristor among a plurality of thyristors connected in series. Item 2. A remote test device for an earth leakage breaker according to item 2. 4. The remote test device of the earth leakage breaker according to claim 3, wherein the shunt circuit is formed by a transistor. 5. The remote test device for an earth leakage breaker according to claim 3, wherein the shunt circuit is formed by a field effect transistor. 6. A remote test device for an earth leakage circuit breaker according to claim 2, further comprising a surge absorber connected in parallel with each voltage dividing resistor. 7. A remote test device for an earth leakage breaker according to claim 1, further comprising a surge absorber connected to an output side of the photocoupler.