JPH10248156A - Circuit breaker with leak alarm - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a constant voltage circuit for relay drive, which supplies the driving power supply of a leak alarm relay. SOLUTION: A leakage current flows to main circuit conductors 1a to 1c, and a secondary voltage is generated in a residual current transformer 5. Then, an on-control signal is outputted from an operation control circuit 7, a transistor 32 is turned on, and a leak alarm relay 31 is electrified. At this time, a voltage- dividing signal Sa by voltage-dividing resistances 27a, 27b is inputted to a power- supply monitoring circuit 34, and a signal Sb which turns on a transistor 35 is outputted at a point of time delayed by 50ms from a point of time when the voltage-dividing signal is inputted. As a result, a transistor 28 at a constant- voltage circuit 22 for relay drive is turned off, and a power supply to the leak alarm relay 31 is cut off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker with a leakage alarm having a function of outputting a leakage alarm signal when a ground fault current flows in a main circuit.

[0002]

The conventional structure of this type of circuit breaker with a leakage alarm, for example, a circuit breaker for wiring, will be described with reference to FIG. The three-phase main circuit 1 includes three conductors 1a, 1
b and 1c, one end of which is connected to the power supply terminals 3a to 3c via the contacts 2a to 2c, and the other end of which is connected to the load terminals 4a to 4c. The contacts 2a to 2c are configured to be opened when an overcurrent flows, for example, in response to energization of an actuator (not shown).

[0003] A zero-phase current transformer 5 is provided in the main circuit 1, and the zero-phase current transformer 5 is adapted to the magnitude of leakage current (ground fault current) flowing through the main circuit conductors 1a to 1c. An operation control circuit 7 serving as a first control circuit generates a secondary voltage (detection voltage) and passes the secondary voltage via a current-voltage conversion resistor 6.
It is configured to give to. This operation control circuit 7
Is configured to amplify the secondary voltage and to supply an amplified signal (ON control signal) to the gate of the thyristor 8. A series circuit formed by connecting the thyristor 8 and the leakage alarm relay 9 in series is connected between the output terminals of the first constant voltage circuit 13. The leak alarm relay 9 has a leak alarm contact 10.

The first constant voltage circuit 13 receives a rectified output from the rectifier circuit 11 connected to the main circuit conductors 1a and 1c via resistors 12a and 12b, and outputs, for example, 24
It is configured to output a constant voltage of V. An output terminal of the first constant voltage circuit 13 is connected to a second constant voltage circuit 14, and the second constant voltage circuit 14
For example, it is configured to output a constant voltage of 5 to 10 V and supply it to the operation control circuit 7.

In the case of the above configuration, when a ground fault or a ground fault occurs on the load side, a zero-phase current (ground fault current) flows through the main circuit 1, and a secondary voltage is output from the zero-phase current transformer 5. And
This secondary voltage is amplified by the operation control circuit 7 and the thyristor 8
To the gate. As a result, the thyristor 8 is turned on, the leakage alarm relay 9 is energized, and the leakage alarm contact 10
Are configured to perform, for example, an ON operation.

In the above configuration, when the leakage is detected and the thyristor 8 is turned on once, while the main circuit 1 is energized,
The leakage alarm relay 9 is configured to be continuously energized.
Further, an AC voltage of about 100 to 400 V flows through the main circuit 1, and the first constant voltage circuit 13 outputs a constant voltage of about 24 V from an output obtained by rectifying such a high AC voltage. The current consumption of the leakage alarm relay 9 is relatively large. For this reason, the power transistor built in the first constant voltage circuit 13 has to consume considerably large power.

Therefore, it is necessary to use a large-capacity power transistor as described above and to provide a large-sized radiating fin or the like in order to smoothly radiate heat generated from the power transistor.

However, when a large-capacity transistor, a large fin, and the like are provided in the first constant voltage circuit 13, the first constant voltage circuit 13 cannot be accommodated in the case of the circuit breaker, and an external unit is added. I had to.

On the other hand, it is conceivable to use a switching power supply circuit with a small loss as the first constant voltage circuit 13. However, such a configuration complicates and enlarges the configuration of the power supply circuit. An external unit was required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to reduce the size of a relay driving constant voltage circuit for supplying a driving voltage to a leakage alarm relay.
An object of the present invention is to provide a circuit breaker with a leakage alarm that can make an external unit unnecessary.

[0011]

According to a first aspect of the present invention, there is provided a circuit breaker with an earth leakage alarm, comprising: a main circuit provided with a switching contact;
A leak detector that detects a ground fault current flowing in the main circuit and outputs a leak detection signal when a leak or a ground fault occurs on the load side, a leak alarm relay having a leak alarm contact, and a current flowing in the main circuit. A relay drive constant voltage circuit having a rectifier circuit for rectifying an alternating current, a transistor, receiving an output from the rectifier circuit and supplying a drive constant voltage to the earth leakage alarm relay, A switching element that cuts off electricity, a first control circuit that controls on / off of the switching element based on a leakage detection signal from the leakage detector, and an on control for turning on the switching element from the first control circuit A second control circuit that turns off the transistor of the constant voltage circuit for driving the relay at a point in time that is delayed by a set time from the point of input of the signal. It is constituted by a latch type relay having a function of latching the operation state of the earth leakage alarm contact when operated by being energized for a time, and the set time of the second control circuit is longer than a predetermined time of the earth leakage alarm relay. There is a characteristic in the setting.

According to this configuration, when a leakage is detected by the leakage detector, the switching element is turned on by the first control circuit, and the leakage alarm relay is energized. When the set time has elapsed from the start of energization, the second
The transistor of the constant voltage circuit for driving the relay is turned off by the control circuit, and the leakage alarm relay is cut off. As a result, the power is only supplied to the leakage alarm relay for the set time, so that the power consumed by the transistor of the constant voltage circuit for driving the relay can be significantly reduced. Therefore, a transistor having a small capacity can be used as the transistor, and a radiation fin is not required, so that the relay driving constant voltage circuit can be downsized. In addition, since the leakage alarm relay is energized for a set time longer than a predetermined time, the operation state of the leakage alarm contact is reliably latched.

In this case, instead of the structure in which the transistor in the relay driving constant voltage circuit is directly turned off by the second control circuit, a transistor is provided between the relay driving constant voltage circuit and the leakage alarm relay. Circuit interrupting means for interrupting energization to the earth leakage alarm relay, and a third control circuit delays a set time from a point in time when an ON control signal for turning on the switching element is input from the first control circuit. The circuit breaking means may be configured to perform a breaking operation at the point of time (Claim 2), or a current limiting means for limiting a current supplied to the earth leakage warning relay is provided, and
May be configured to operate the current limiting means at a point in time that is delayed by a set time from a point in time when an ON control signal for turning on the switching element is input from the first control circuit. Item 3). Again,
Since the power leakage alarm relay is only energized for the set time, the power consumed by the transistor of the relay driving constant voltage circuit can be significantly reduced.

A constant voltage circuit for a control circuit, which receives an output from the rectifier circuit and supplies a constant voltage for driving to a first control circuit, is provided between an output terminal of the constant voltage circuit for the control circuit. A series circuit in which a transistor that is turned on by an on-control signal from the first control circuit and a resistive voltage dividing circuit are connected in series, wherein the resistive voltage dividing circuit is used as an on-control signal from the first control circuit; It is also a good configuration to provide the divided voltage signal from the circuit to the second control circuit (claim 4) or the third control circuit (claim 5).

According to this configuration, the voltage dividing resistor having an appropriate resistance value is appropriately selected regardless of the magnitude of the driving constant voltage supplied from the control circuit constant voltage circuit to the first control circuit. As a result, a voltage signal having an appropriate voltage value
To the third control circuit or the third control circuit.

Further, it is a good configuration that the switching element is constituted by a transistor. According to such a configuration, after the leakage current flows in the main circuit and the leakage alarm relay is energized, when the leakage current stops flowing, when the ON control signal from the first control circuit is not input, Since the transistor is turned off,
The earth leakage alarm relay can be cut off.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. It should be noted that the same parts as those in FIG. First, in FIG. 1 showing an electrical configuration of a circuit breaker with a leakage alarm, a three-phase main circuit 1 is composed of three conductors 1a, 1b and 1c.
One end side is connected to the power supply side terminals 3a-3 via the contacts 2a-2c.
c and the other end is connected to the load terminal 4a.
To 4c. The contacts 2a to 2c are configured to be opened and closed by operation of a handle (not shown) and to be opened when an overcurrent flows, for example, in response to energization of an actuator (not shown).

The main circuit 1 is provided with a zero-phase current transformer 5 serving as a leakage detector. The zero-phase current transformer 5 is connected to the ground through the main circuit conductors 1a to 1c. )
A secondary voltage (detection voltage) corresponding to the magnitude of
It is configured to supply a next voltage to an operation control circuit 7 as a first control circuit via a current-voltage conversion resistor 6. The operation control circuit 7 is configured to amplify the secondary voltage and output an amplified signal (ON control signal) from an output terminal 7a.

The input terminals of a rectifier circuit 11 composed of bridge-connected diodes are connected to the main circuit conductors 1a and 1c via resistors 12a and 12b, respectively. Between the positive output terminal and the negative output terminal of the rectifier circuit 11, a control circuit constant voltage circuit 21 and a relay drive constant voltage circuit 22 are connected in parallel.

The control circuit constant voltage circuit 21 includes an NPN transistor (power transistor) 23 having a collector connected to the positive output terminal of the rectifier circuit 11, a base of the transistor 23, and a negative terminal of the rectifier circuit 11. It comprises a constant voltage diode (Zener diode) 24 connected to the output terminal and a resistor 25 connected between the collector and base of the transistor 22.

The operation control circuit 7 is connected between the positive output terminal and the negative output terminal of the control circuit constant voltage circuit 21. The control circuit constant voltage circuit 21 Is supplied with a constant voltage. In this case, the control circuit constant voltage circuit 21 supplies a constant voltage required by the operation control circuit 7 (for example, an appropriate voltage value in a range of 5 to 10 V). The main circuit 1 has 100 to 400
It is configured such that an AC voltage of about V flows.

An NPN transistor 26 and, for example, two voltage dividing resistors 27a and 27b are connected in series between the positive output terminal and the negative output terminal of the control circuit constant voltage circuit 21. Are connected. The voltage dividing resistors 27a and 27b constitute a resistance voltage dividing circuit.

On the other hand, the relay driving constant voltage circuit 22
Is an NPN transistor (power transistor) 28 whose collector is connected to the positive output terminal of the rectifier circuit 11.
A constant voltage diode (Zener diode) 29 connected between the base of the transistor 28 and the negative output terminal of the rectifier circuit 11, and a resistor 30 connected between the collector and the base of the transistor 28. Have been. A leakage alarm relay 31 and, for example, a transistor 32 as a switching element are connected in series between the positive output terminal and the negative output terminal of the relay drive constant voltage circuit 22. In this case, the relay driving constant voltage circuit 2
2 supplies a constant voltage of, for example, 24 V to the leakage alarm relay 31.

The leakage alarm relay 31 is constituted by a latch type electromagnetic relay (latching relay).
When energized for a predetermined time (for example, 10 ms) and operated,
The operation state (for example, the ON state) of the leakage alarm contact 33 is latched.

A common connection point of the voltage dividing resistors 27a and 27b is connected to an input terminal Vcc of a power supply monitoring circuit 34 which is a second control circuit described later in detail. Furthermore,
The base of the transistor 26 is connected to the operation control circuit 7.
Is connected to the output terminal 7a. In this configuration, when the amplified signal is output from the output terminal 7a of the operation control circuit 7, the transistor 26 is turned on, and the constant voltage from the control circuit constant voltage circuit 21 is applied to the voltage dividing resistor 27.
a, 27b, and the divided voltage (for example, 5
V) is applied to the input terminal Vcc of the power supply monitoring circuit 34.
Given to.

The output terminal 7a of the operation control circuit 7
Is connected to the base of the transistor 32.
Thus, when an amplified signal is output from the output terminal 7a of the operation control circuit 7, the transistor 32 is turned on, so that the leakage alarm relay 31 is energized and the leakage alarm contact 33 is turned on. Have been.

The output terminal A of the power supply monitoring circuit 34
Are connected to the base of a PNP transistor 35. The emitter of the transistor 35 is connected to the base of the transistor 28 of the relay driving constant voltage circuit 22, and the collector is connected to the negative output terminal of the relay driving constant voltage circuit 22. The power supply monitoring circuit 34
The transistor 26 is turned on by the amplified signal (ON control signal) from the operation control circuit 7, and the voltage dividing resistor 2
7a and 27b (ie, when the divided voltage Sa is received)
A control signal for turning on the transistor 35 is output at a set time, for example, 50 ms later from the time when the transistor 32 is turned on). Specifically, the operation is performed as follows.

First, the power supply monitoring circuit 34 normally operates at the terminal V
signal Sb having the same voltage level as signal Sa input to cc
Is output from an output terminal A, and this signal Sb is applied to the base of the transistor 35. The voltage level of the signal Sa is low (0 V) until the transistor 26 is turned on by the control signal output from the operation control circuit 7. Therefore, at this time, since the signal Sb is at the low level, the transistor 35 is turned on.

Thereafter, as shown in FIG. 2, when transistor 26 is turned on at time t1, the voltage level of signal Sa rises. When the signal Sa reaches, for example, 4.7 V (time t2), the power supply monitoring circuit 34 is configured to start an operation of measuring a predetermined time, for example, 50 ms. In addition, since the signal Sb is at a high level from the time t1 to the time t2,
The transistor 35 is turned off.

When the power monitoring circuit 34 completes the clocking of 50 ms (time t3), it switches the signal Sc to a high level and switches the signal Sb to a low level. Thereby, the transistor 35
Is turned on. Thereafter, when the control signal output from the operation control circuit 7 changes to low level and the transistor 26 is turned off, the voltage level of the signal Sa decreases. Then, when the signal Sa drops to, for example, 4.6 V (time t4), the power supply monitoring circuit 34 switches the signal Sc to a low level internally and outputs the signal Sa as the signal Sb as it is. ing. After that, the level of the signal Sb (signal Sa) becomes low (0
V). During the period from the time t4 until the signal Sb falls to the low level, the transistor 35
Are turned on.

Next, the operation of the above configuration will be described. When a leakage or ground fault occurs on the load side of the main circuit 1, a leakage current flows through the main circuit conductors 1a to 1c. As a result, a secondary voltage corresponding to the leakage current is generated in the zero-phase current transformer 5, and the zero-phase current transformer 5 supplies the secondary voltage to the operation control circuit 7 via the resistor 6. Then, the operation control circuit 7 amplifies the secondary voltage and supplies an amplified signal (control signal) to the transistor 32, whereby the transistor 32 is turned on.

At this time, the transistor 26 is turned on by the control signal output from the operation control circuit 7, and the signal Sa is input to the input terminal Vcc of the power supply monitoring circuit 34. The voltage level of the signal Sa is low (0 V) until the transistor 26 is turned on by the control signal output from the operation control circuit 7. Therefore, at this time,
Since the signal Sb is at the low level, the transistor 35 is on and the transistor 28 of the constant voltage circuit 22 is off.

Then, as shown in FIG. 2, when the transistor 26 is turned on at time t1, the voltage level of the signal Sa rises. Then, when the signal Sa reaches, for example, 4.7 V (time t2), the power supply monitoring circuit 34 starts an operation of measuring a predetermined time, for example, 50 ms. In addition, since the signal Sb is at a high level from the time t1 to the time t2, the transistor 35 is turned off. As a result, the transistor 28 of the relay driving constant voltage circuit 22 is turned on, and the constant voltage circuit 22 enters a state of supplying a constant voltage. Therefore, at this time, since the transistor 32 is turned on as described above, the leakage alarm relay 31 is energized, and the leakage alarm contact 33 is turned on.

Subsequently, when the power supply monitoring circuit 34 completes the time measurement of 50 ms (time t3), the signal Sb goes low, so that the transistor 35 is turned on. Thus, the transistor 28 of the relay driving constant voltage circuit 22 is turned off, and the supply of the constant voltage from the relay driving constant voltage circuit 22 is stopped. As a result, energization of the leakage alarm relay 31 is cut off. At this time, since the leakage alarm relay 31 has been energized for more than a predetermined time (10 ms), the ON operation state of the leakage alarm contact 33 is latched.

On the other hand, when the transistor 32 is turned on and the energization of the leakage alarm relay 31 is started, a time shorter than a predetermined time for latching the operation state of the leakage alarm relay 31, for example, 5 ms, elapses. When the control signal output from the operation control circuit 7 changes to a low level,
As a result, the transistor 32 is turned off, and the energization to the leakage alarm relay 31 is cut off. As a result, the operation state of the leakage alarm contact 33 is released without being maintained.
At this time, since the transistor 26 is turned off, the signal S
The voltage level of a decreases. Then, when the voltage level of the signal Sa decreases to 4.6 V (time t4), the power supply monitoring circuit 34 outputs the signal Sa as the signal Sb as it is,
While the level of the signal Sb falls from 4.6 V to the low level, the transistor 35 is turned on.

As described above, in the present embodiment, when a leakage current flows through the main circuit conductors 1a to 1c and a control signal is output from the operation control circuit 7, the transistor 32 is turned on by the control signal to cause the leakage. The alarm relay 31 is energized and the transistor 26 is turned on to input the signal Sa to the power supply monitoring circuit 34. This allows the power supply monitoring circuit 34 to output 50 V from the time when the signal Sa reaches 4.7V.
When the time of ms elapses, the low-level signal Sb is output to turn on the transistor 35, thereby turning off the transistor 28 of the relay driving constant voltage circuit 22. Therefore, the earth leakage alarm relay 31 is 50 m
Since power is only supplied for s, the power consumed by the transistor 28 of the relay driving constant voltage circuit 22 can be significantly reduced. Therefore, a transistor having a small capacity can be used as the transistor 28, and a radiation fin is not required, so that the relay driving constant voltage circuit 22 can be downsized. Further, since the leakage alarm relay 31 is energized for a time longer than 10 ms, the operation state of the leakage alarm contact 33 is reliably latched.

In this embodiment, when the transistor 26 is turned on by a control signal from the operation control circuit 7, the constant voltage from the control circuit constant voltage circuit 21 is divided by the voltage dividing resistors 27a and 27b. The divided voltage Sa is input to the power supply monitoring circuit 34. Therefore, irrespective of the magnitude of the constant voltage supplied to the operation control circuit 7 by the control circuit constant voltage circuit 21, by appropriately selecting the voltage dividing resistors 27a and 27b having an appropriate resistance value, an appropriate voltage value can be obtained. The voltage signal Sa can be supplied to the power supply monitoring circuit 34.

Further, in this embodiment, the switching element for turning on / off the leakage alarm relay 31 based on the control signal output from the operation control circuit 7 is constituted by the transistor 32. Therefore, the earth leakage alarm relay 3
Even if the control signal output from the operation control circuit 7 changes to a low level in a time shorter than the time required for latching the operation state of the leakage alarm contact 33 after the start of energization of 1, On / off control of the leakage alarm relay 31 can be easily performed.

In this embodiment, the power supply monitoring circuit 34 is configured to turn off the transistor 28 of the relay driving constant voltage circuit 22 after measuring a predetermined time of, for example, 50 ms. Is not limited to 50 ms, and may be longer than the time required to latch the operation state of the leakage alarm relay 31. In addition, the power supply monitoring circuit 34 normally performs a time counting operation for a predetermined time using a counter, but a time constant circuit including a resistor and a capacitor may be used.

FIG. 3 shows a second embodiment of the present invention.
As shown in (5), the collector of the transistor 35 may be connected to the positive output terminal of the constant voltage circuit 22 for driving the relay. In this case, as in the first embodiment, when the transistor 35 is turned on by the low-level signal Sb output from the power supply monitoring circuit 34, the transistor 28 of the relay driving constant voltage circuit 22 is turned off, and The energization of the alarm relay 31 is cut off.

Next, FIG. 4 shows a third embodiment of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted. In FIG. 4, an intermediate connection point between the voltage dividing resistors 27a and 27b is connected to an input terminal of a third control circuit, for example, a mono-multi vibrator 41. This mono multi vibrator 4
1 is configured to output a high-level signal (pulse signal) from the output terminal for 50 ms after receiving a high-level signal at the input terminal. A transistor 4 serving as a circuit interrupting means is provided between the positive output terminal of the constant voltage circuit 22 for driving the relay and the leakage alarm relay 31.
2 are connected. The output terminal of the monomultivibrator 41 is connected to the base of the transistor 42.

In this embodiment, when a leakage or ground fault occurs on the load side of the main circuit 1 and a leakage current flows through the main circuit conductors 1a to 1c, the zero-phase current transformer 5 responds to the leakage current. 2
The next voltage is applied to the operation control circuit 7 via the resistor 6. As a result, a control signal is output from the operation control circuit 7 to turn on the transistor 32, and the monomultivibrator 41 is turned on.
The signal Sa is input to the input terminal of. Since the voltage level of the signal Sa is high, the monomultivibrator 41 outputs a high-level pulse signal from the output terminal for 50 ms. As a result, the fourth transistor 42 is turned on, the constant voltage is supplied from the relay driving constant voltage circuit 22 to the leakage alarm relay 31, and the leakage alarm contact 33 is turned on.

When 50 ms has elapsed since the high-level signal Sa was input to the mono-multivibrator 41, the signal output from the mono-multivibrator 41 is switched to the low level. Thus, the transistor 42 is turned off. At this time, the earth leakage alarm relay 31
Since the power is supplied for more than the predetermined time (10 ms), the ON operation state of the leakage alarm contact 33 is latched.

In this embodiment as well, the first
As in the embodiment, when the control signal is output from the operation control circuit 7 and the leakage alarm relay 31 is energized, the energization to the leakage alarm relay 31 is cut off after a lapse of 50 ms from the start of energization. The first configuration
The same effect as that of the embodiment can be obtained.

In the third embodiment, the transistor 3
2 can be omitted. In the third embodiment, the positive output terminal (ie, the emitter of the transistor 28) of the relay driving constant voltage circuit 22 and the earth leakage alarm relay 3
1, a circuit interrupting means (transistor 42) is provided. Alternatively, in the relay driving constant voltage circuit 22, the base of the transistor 28 and the intermediate connection point of the resistor 30 and the constant voltage diode 29 are connected. A circuit breaker may be provided between the transistors to cut off the base current of the transistor. In the case of this configuration, the same operation and effect as in the third embodiment can be obtained.

Furthermore, in the third embodiment, a one-shot pulse signal for a predetermined time is output by using the mono-multivibrator 41. Instead, a substantially similar signal is output by using an appropriate capacitor. May be output. Furthermore, in the third embodiment, the output current from the relay driving constant voltage circuit 22 is interrupted by the circuit interrupting means (transistor 42). However, the present invention is not limited to this. Instead, a current limiter may be provided, and the current limiter may be configured to limit the output current from the relay drive constant voltage circuit 22 after the predetermined time, thereby suppressing the heat generation of the transistor 28. .

[0047]

As is apparent from the above description, according to the present invention, the leakage time alarm relay which is energized when the leakage detection is detected by the leakage detector is configured to be only the set time. As a result, the power consumed by the transistors in the relay driving constant voltage circuit is significantly reduced, a transistor having a small capacity can be used, and a radiation fin is not required, so that the relay driving constant voltage circuit can be downsized. The effect is obtained. In addition, the leakage alarm relay is configured by a latch type relay that latches the operation state of the leakage alarm contact when energized for a predetermined time, and operates when the energization is performed for a set time longer than the predetermined time, thereby operating the leakage alarm contact. Can be reliably latched.

[Brief description of the drawings]

FIG. 1 is a diagram showing an electrical configuration according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a relationship between an input signal and an output signal of a power supply monitoring circuit.

FIG. 3 is a view corresponding to FIG. 1, showing a second embodiment of the present invention.

FIG. 4 is a view corresponding to FIG. 1, showing a third embodiment of the present invention;

FIG. 5 is a diagram corresponding to FIG. 1 showing a conventional example.

[Explanation of symbols]

In the figure, 1 is a main circuit, 2a, 2b, 2c are contacts, 5 is a zero-phase current transformer (leakage detector), 7 is an operation control circuit (first control circuit), 11 is a rectifier circuit, and 21 is a control circuit. Circuit constant voltage circuit, 22 is a relay driving constant voltage circuit, 27a and 27b are voltage dividing resistors, 28 is a transistor, 31 is a leak alarm relay, 32 is a transistor (switching element), 33 is a leak alarm contact, and 34 is a power supply. A monitoring circuit (second control circuit), 35 is a transistor, 41 is a monomultivibrator (third control circuit), and 42 is a transistor (circuit cutoff means).

Claims (6)

[Claims] A main circuit provided with a switching contact; a ground fault detector that detects a ground fault current flowing through the main circuit when a ground fault or a ground fault occurs on a load side and outputs a ground fault detection signal; A leak alarm relay having a leak alarm contact, a rectifier circuit for rectifying alternating current flowing in the main circuit, a transistor, and an output from the rectifier circuit is input to supply a constant drive voltage to the leak alarm relay. A constant voltage circuit for driving a relay, a switching element that cuts off the leakage alarm relay, a first control circuit that controls on / off of the switching element based on a leakage detection signal from the leakage detector, A transistor of the constant voltage circuit for driving the relay is turned off at a point in time when a set time is delayed from a point in time when an ON control signal for turning on the switching element is inputted from the first control circuit. A second control circuit comprising: a latch-type relay having a function of latching an operation state of the leakage alarm contact when the electric leakage warning relay is energized and operated for a predetermined time; A circuit breaker with a leak alarm, wherein a set time of the circuit is set longer than a predetermined time of the leak alarm relay. 2. A main circuit provided with a switching contact, a ground fault detector that detects a ground fault current flowing in the main circuit when a ground fault or a ground fault occurs on a load side and outputs a ground fault detection signal, A leakage alarm relay having a leakage alarm contact; a rectifier circuit for rectifying an alternating current flowing through the main circuit; and a relay drive constant for inputting an output from the rectifier circuit and supplying a constant driving voltage to the leakage alarm relay. A voltage circuit; a switching element that cuts off the leakage alarm relay; a first control circuit that controls on / off of the switching element based on a leakage detection signal from the leakage detector; and a constant voltage circuit for driving the relay. And a circuit breaker provided between the ground fault relay and the ground fault relay, for turning on the switching element from the first control circuit. A third control circuit for shutting off the circuit interrupting means at a time delayed by a set time from the time at which the signal is input; and A circuit breaker with an earth leakage alarm, comprising a latch type relay having a function of latching an operation state, wherein a set time of the third control circuit is set longer than a predetermined time of the earth leakage alarm relay. 3. A main circuit provided with a switching contact, a ground fault detector for detecting a ground fault current flowing in the main circuit when a ground fault or a ground fault occurs on a load side and outputting a ground fault detection signal, A leakage alarm relay having a leakage alarm contact; a rectifier circuit for rectifying an alternating current flowing through the main circuit; and a relay drive constant for inputting an output from the rectifier circuit and supplying a constant driving voltage to the leakage alarm relay. A voltage circuit, a switching element that cuts off the leakage alarm relay, a first control circuit that controls on / off of the switching element based on a leakage detection signal from the leakage detector, and energization of the leakage alarm relay. Current limiting means for limiting a current; and a current limiting means at a time delayed by a set time from a time when an ON control signal for turning on the switching element is input from the first control circuit. A third control circuit for operating the leakage alarm relay, wherein the leakage alarm relay comprises a latch-type relay having a function of latching an operation state of the electric leakage alarm contact when the relay is operated by being energized for a predetermined time; A circuit breaker with a leak alarm, wherein a set time of the third control circuit is set longer than a predetermined time of the leak alarm relay. 4. A constant voltage circuit for a control circuit that receives an output from the rectifier circuit and supplies a constant voltage for driving to the first control circuit, and is provided between output terminals of the constant voltage circuit for the control circuit. A series circuit in which a transistor turned on by an on-control signal from the first control circuit and a resistor voltage dividing circuit are connected in series, wherein the on-resistance signal is supplied as an on-control signal from the first control circuit. 2. The circuit breaker with an earth leakage alarm according to claim 1, wherein a voltage division signal from a voltage circuit is provided to the second control circuit. 5. A constant voltage circuit for a control circuit which receives an output from the rectifier circuit and supplies a constant voltage for driving to the first control circuit, and is provided between an output terminal of the constant voltage circuit for the control circuit. A series circuit in which a transistor turned on by an on-control signal from the first control circuit and a resistor voltage dividing circuit are connected in series, wherein the on-resistance signal is supplied as an on-control signal from the first control circuit. 4. The circuit breaker with a leakage alarm according to claim 2, wherein a voltage division signal from a pressure circuit is provided to said third control circuit. 6. The circuit breaker with a leakage alarm according to claim 1, wherein said switching element is constituted by a transistor.