JPH10285788A - Breaker for wiring provided with leakage alarm function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit the break of leakage to a remote monitor without fail, when performing the opening breaking action and the alarm output action at the same time by equipping a breaker with a leakage relay, which outputs a leakage alarm to an external device by a ground fault occurrence signal, and a delay circuit which opens an opening contact after passage of a specified delay time. SOLUTION: When a ground fault occurrence signal is outputted from a ground fault detecting circuit 5 in a state that a changeover switch 1 is closing the path, an electromagnetic tripper 6 is operated by delaying a ground fault occurrence signal with a delay circuit 16 and controlling a thyristor 17 to be electrically continuous. By setting the time when a leakage relay 8 can operate the delay time of a delay circuit 16 in advance, the control current of the leakage relay 8 from an AC electric path by the opening of an opening/closing contact 2 is does not become lost, and the leakage relay 8 can transmit the signal of the leakage break without fail via an alarm connector terminal 9. Moreover, the ground fault occurrence signal is not supplied at the same time to the thyristor 17 and a leakage relay driving thyristor 19, so that the output imposition of the ground fault detecting circuit 5 can be lightened.

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 function having a leakage alarm / leakage interruption function in addition to an overload / short circuit protection function. This is to generate a leakage alarm output.

[0002]

2. Description of the Related Art FIG. 3 is an internal connection diagram of a conventional circuit breaker with a leakage alarm function disclosed in Japanese Patent Application Laid-Open No. 3-210726. In FIG. 3, 1 is a circuit breaker for wiring,
2 is a switching contact for turning on and off the AC circuit, 3 is a zero-phase current transformer for detecting unbalanced current (leakage current) of the AC circuit, and 4 is a burden for converting the secondary output current of the zero-phase current transformer 3 into a voltage. circuit,
Reference numeral 5 denotes a ground fault detection circuit that amplifies the output of the zero-phase current transformer 3 and outputs a ground fault occurrence signal when the output exceeds a predetermined level.

An electromagnetic trip device 6 is driven by a ground fault occurrence signal from a ground fault detection circuit 5, and opens and closes the switching contact 2 via a switching mechanism (not shown). The display button 7 is projected to indicate that the ground fault has been interrupted. Reference numeral 8 denotes an earth leakage relay, which outputs an earth leakage alarm to the outside via an alarm device connection terminal 9 for earth leakage remote monitoring based on a ground fault occurrence signal from the ground fault detection circuit 5. Reference numeral 10 denotes a ground fault warning indicator which is turned on by a ground fault occurrence signal from the ground fault detection circuit 5. The control power for the ground fault detection circuit 5, the ground fault relay 8 and the ground fault warning indicator 10 is obtained from the AC circuit on the load side of the switching contact 2.

[0004] Further, reference numeral 11 denotes a changeover switch, which outputs a ground fault occurrence signal of the ground fault detection circuit 5 only to a ground fault alarm by the ground fault relay 8 or an open / close contact 2 of the electromagnetic trip device 6.
Select whether to shut off the AC circuit at the same time. 12
Is a reset switch.
Is released and the state is returned to the initial state. Reference numeral 13 denotes an overcurrent detection device that opens and closes the on-off contact 2 via the on-off mechanism due to short-circuit and overcurrent of the AC circuit.

Next, the operation of a conventional circuit breaker with a leakage alarm function will be described. If a short circuit or ground fault occurs in the AC circuit, the zero-phase current transformer 3 generates an output corresponding to the magnitude of the short circuit or ground fault, and the ground fault detection circuit 5 determines the magnitude and duration of the output. Is determined, and when it reaches a predetermined value or more, a ground fault occurrence signal is output. When the change-over switch 11 is open, the ground fault occurrence signal output from the ground fault detection circuit 5 is transmitted only to the ground fault relay 8 side, and the external ground fault remote monitoring device (not shown) through the alarm device connection terminal 9. For example, the occurrence of electric leakage or ground fault can be monitored remotely.

When the changeover switch 11 is closed,
Further, the electromagnetic trip device 6 is driven by the ground fault occurrence signal output from the ground fault detection circuit 5, and the switching contact 2 is opened, and as a result, the AC electric circuit is cut off. However, when the switching contact 2 is opened, the control power to the ground fault detection circuit 5 is cut off, and the ground fault detection circuit 5 loses the control power, so that the earth leakage relay 8 can be completely driven. In some cases, the earth leakage alarm output cannot be generated.

[0007]

In the above-mentioned conventional circuit breaker with a leakage alarm function, the alarm output from the leakage relay 8 and the interruption of the AC circuit by the electromagnetic trip device 6 are simultaneously selected. At this time, when the AC circuit is interrupted by the operation of the circuit breaker 1 due to the earth leakage or the ground fault, the earth leakage alarm output from the earth leakage relay 8 may not be generated due to the loss of the control power supply. There is a problem that it is not possible to remotely determine whether the breaking operation of the circuit breaker 1 is caused by overload / short circuit of the AC circuit, or ground fault / leakage.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems of the prior art, and has a remote monitoring device based on an open / close operation of an open / close contact of a circuit breaker at the time of earth leakage or ground fault, and an earth leakage relay. When performing the alarm output operation to
It is an object of the present invention to provide a circuit breaker with a leakage alarm function that can reliably transmit a signal for leakage leakage to a remote monitoring device outside the circuit breaker.

[0009]

A circuit breaker with a leakage alarm function according to the present invention detects a leakage or a ground fault in an AC circuit and cuts off the AC circuit by opening and closing a switching contact.
In addition, in a circuit breaker with an earth leakage alarm function that outputs an earth leakage alarm to an external device, earth fault detection that detects earth leakage or ground fault of the AC circuit and outputs a ground fault occurrence signal when the detection level is a predetermined value or more. A device, a ground fault relay that obtains its control power from the load side of the switching contact of the AC circuit, and outputs a ground fault warning to an external device based on the ground fault occurrence signal, and a predetermined delay time elapses upon receiving the ground fault occurrence signal And a delay circuit for opening the switching contact later.

The earth leakage relay is a self-holding relay for maintaining an earth leakage alarm state.

Further, the delay circuit is an integration circuit whose integration time constant can be selected, and the delay time can be variably set.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a circuit configuration diagram showing a circuit breaker with a leakage alarm function according to Embodiment 1 of the present invention.
1, reference numerals 1 to 13 denote the same parts as those of the conventional device shown in FIG. 3, and a description thereof will be omitted. As a new code, 1
Reference numeral 6 denotes a delay circuit, which delays the ground fault occurrence signal from the ground fault detection device 5 by a predetermined time and turns on the thyristor 17 by the delayed ground fault occurrence signal to thereby operate the electromagnetic trip device 6 with a delay. Reference numeral 18 denotes an earth leakage relay driving power supply that transforms a control power supply of a system different from that of the ground fault detection circuit 5 from an AC electric circuit and supplies the control electric power to the earth leakage relay 18 side. The earth leakage relay drive power supply 18 may be provided when power required for the relay operation of the earth leakage relay 8 cannot be obtained from the ground fault detection circuit 5. Reference numeral 19 denotes an earth leakage relay drive thyristor that activates the earth leakage relay 8 in response to an earth fault occurrence signal from the earth fault detection circuit 5.

The operation of the circuit breaker with a leakage alarm function configured as described above will be described. The process from the detection of a ground fault current when a ground fault or a ground fault occurs to the output of a ground fault occurrence signal in the ground fault detection circuit 5 is the same as that of the conventional device. Also,
The operation of generating an alarm output via the earth leakage relay 8 when the change-over switch 11 is open is the same as that of the conventional device, and a description thereof will be omitted.

When the ground fault detection signal is output from the ground fault detection circuit 5 due to the leakage or ground fault when the changeover switch 11 is closed, the ground fault signal is delayed by the delay circuit 16 to delay the ground fault generation. Thyristor 17 by signal
The electromagnetic trip device 6 is operated by controlling the conduction of the relay. Therefore, if the time during which the earth leakage relay 8 can be sufficiently operated is set as the delay time of the delay circuit 16, the leakage of the earth leakage relay 8 from the AC electric circuit due to the opening of the on-off contact 2. The control power is not lost, and the earth leakage relay 8 can reliably transmit the earth leakage cutoff signal to the remote monitoring device (not shown) connected via the alarm device connection terminal 9. Further, the ground fault occurrence signal from the ground fault detection circuit 5 is not supplied to the thyristor 17 and the earth leakage relay driving thyristor 19 at the same time due to the time difference in the delay circuit 16. The burden can be reduced.

As described above, the operation time of the earth leakage relay 8 is ensured by the delay circuit 16. However, if the earth leakage relay 8 outputs a contact only during the excitation period, the switching contact 2 is also opened after the delay time has elapsed. Since the earth leakage relay 8 is separated and loses the contact output state, if the earth leakage relay 8 is a self-holding relay, the contact output state can be maintained even when the on-off contact 2 is opened. Reference numeral 8a denotes a reset coil of the self-holding earth leakage relay 8, and the self-holding is released when the reset switch 12 is pressed.

Embodiment 2 FIG. 2 is a circuit configuration diagram showing a circuit breaker with a leakage alarm function according to Embodiment 2 of the present invention. In FIG. 2, reference numerals 1 to 13 and 16 to 19 are the same as those described in the first embodiment. As a new code, reference numeral 20 denotes a delay time changeover switch provided in the delay circuit 16, and the delay circuit 16 is an integration circuit whose integration time constant can be selected by the changeover switch 20, that is, with respect to one resistor. It has a plurality of capacitors, and the time constant of the integration circuit can be selected by selecting an arbitrary capacitor by the changeover switch 20, and the operation start time of the electromagnetic trip device 6 from the ground fault occurrence signal can be arbitrarily varied. It can be set. 10 m depending on the configuration of the sequence of the earth leakage relay 8 and the external monitoring device connected to the outside, and the protection coordination with other circuit breakers.
Arbitrary selection of a delay operation of seconds to several seconds is possible.

[0017]

As described above, according to the present invention, a leak or ground fault in an AC circuit is detected, the AC circuit is cut off by opening and closing a switching contact, and a leak alarm is output to an external device. In a circuit breaker for wiring with a ground fault alarm function, a ground fault detecting device that detects a ground fault or a ground fault in the AC circuit and outputs a ground fault occurrence signal when the detection level is equal to or higher than a predetermined value,
A ground fault relay that obtains its control power from the load side of the switching contact of the AC circuit and outputs a ground fault warning to an external device based on the ground fault occurrence signal; and By providing a delay circuit that opens the contacts, when the earth leakage or ground fault occurs, the opening / closing operation of the open / close contacts of the circuit breaker and the alarm output operation to the remote monitoring device by the earth leakage relay are performed simultaneously. In addition, it is possible to reliably transmit the signal of the earth leakage interruption to the remote monitoring device outside the circuit breaker.

Further, the above-mentioned earth leakage relay is constituted by a self-holding relay for maintaining an earth leakage alarm state,
Even if the switching contact is opened after the delay time of the delay circuit has elapsed, the contact output state can be maintained.

Further, the delay circuit comprises an integration circuit with a selectable integration time constant, and the delay time can be variably set, so that the opening / closing operation of the switching contact based on the ground fault detection signal of the ground fault detection device is performed. It can be arbitrarily set variably.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram showing a circuit breaker with a leakage alarm function according to Embodiment 1 of the present invention.

FIG. 2 is a circuit configuration diagram showing a circuit breaker with a leakage alarm function according to Embodiment 2 of the present invention.

FIG. 3 is a circuit diagram showing a conventional circuit breaker with a leakage alarm function.

[Description of Signs] 1 Breaker for wiring, 2 Open / close contact, 3 Zero-phase current transformer, 4
Burden circuit, 5 Ground fault detection circuit, 6 Electromagnetic trip device, 7 Leakage cutoff display button, 8 Leakage relay, 11
Changeover switch, 12 reset switch, 16 delay circuit, 20 delay time changeover switch.

Claims (3)

[Claims] 1. A circuit breaker with a leakage alarm function for detecting a leakage or a ground fault in an AC circuit, disconnecting the AC circuit by opening and closing a switching contact, and outputting a leakage alarm to an external device. A ground fault detecting device that detects a ground fault or a ground fault in an AC circuit and outputs a ground fault occurrence signal when the detection level is equal to or higher than a predetermined value; and obtains a control power from the load side of the switching contact of the AC circuit and obtains the ground fault. An earth leakage relay that outputs an earth leakage alarm to an external device in response to an earth fault occurrence signal; and a delay circuit that opens the on-off contact after a predetermined delay time has elapsed in response to the earth fault occurrence signal. Circuit breaker with function. 2. The circuit breaker with a leakage alarm function according to claim 1, wherein the leakage relay is a self-holding relay for maintaining a leakage alarm state. 3. The circuit breaker according to claim 1, wherein the delay circuit is an integration circuit having a selectable integration time constant, and the delay time can be variably set.