JP3252444B2 - Circuit breaker with earth leakage alarm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker having a function of detecting a leakage in a main circuit and alarming the occurrence of a leakage.

[0002]

2. Description of the Related Art FIG. 3 shows an example of the appearance of this type of a circuit breaker with a leakage alarm. This type of circuit breaker usually includes a leakage indicator light 7 as an electric leakage display means and a leakage display button 5 as a mechanical leakage display means, and when the changeover switch 13 is set to an alarm position. When a short circuit occurs, the short circuit indicator light flashes to warn of the short circuit. FIG. 4 shows a circuit configuration inside the circuit breaker for the occurrence of the electric leakage.

[0003] Zero-phase current transformer 9 inserted in the main circuit of the circuit breaker
When the magnitude of the leakage current exceeds the set value, a signal is output from the output terminal C of the leakage detection circuit 3 . One of these signals is sent to the gate of the thyristor 51 for operating the blinking circuit 29 of the leakage indicator lamp, and the other is a tripping coil 17 of the circuit breaker indicated by AV in the figure, and a current is applied. Contact 15a
Is sent to the gate of the thyristor 52 in series with the AV relay 15 that operates the. The blinking circuit 29 of the earth leakage indicator lamp is already disclosed in Japanese Patent Application No. 3-23844 filed by the applicant of the present invention, and a DC voltage for its operation is supplied by a transformer connected to AC power terminals R and T. rectifying the secondary voltage of the vessel 1 by the rectifier 2 via the leakage detection circuit 3 outputs signal P,
Output from N, changeover switch 13, thyristor 51
Is input to the blinking circuit 29 via the. The blinking circuit 29
Leakage indicator lamp 7 as main circuit element, flicker mode
(A mode in which ON and OFF operations are continuously repeated in accordance with a predetermined sequence and time after the supply of the power supply voltage), for example, a timer circuit 26 comprising an integrated circuit device, When a signal is output from the output terminal C of the transistor 3 and the signal is input to the gate of the thyristor 51 via the resistor 16, the timer circuit 26 connects the resistor 24 to the base of the transistor 21 in series with the earth leakage indicator 7. The leakage indicator 7 flashes in synchronization with the transmitted signal. At the same time, the output relay 4 operates to alert the central monitoring panel (not shown) of the occurrence of a short circuit. In response to this alarm, the worker goes to the switchboard, confirms the situation of the earth leakage accident, performs necessary measures, switches the changeover switch 13 to operate the AV relay 15, and trips the trip coil (AV) 17 to supply a current.

FIG. 5 shows a conventional structure of an electric leakage display device for alarming occurrence of electric leakage by mechanical operation. The ground fault display device 30
An electric leakage display button 31, an electric leakage display piece 32 integrated with the electric leakage display button 31, an electromagnet 34 having a display solenoid connected in parallel with a circuit breaker trip coil (17 in FIG. 4), The armature 3 is rotatably supported by the electromagnet 34 and constantly engages with the engaging portion of the leakage indicating piece 32.
5 and a compression spring 33 which is always kept in an accumulating state by the electric leakage display piece 32, and a current flows through the display solenoid to disengage the armature 35 from the electric leakage display piece 32 and cut off. When the movable holder 37 holding the main movable contact 36 of the container rotates counterclockwise, the leakage indicator 32
Is driven upward by the extension force of the compression spring 33, and the leakage display button 31 at the tip protrudes from the breaker cover 38 to display the leakage.

[0005]

In a circuit breaker in which a leakage alarm device as a mechanical leakage alarm means is configured as described above, a leakage occurs in the main circuit, and the leakage naturally disappears before the operation of the circuit breaker. In such a case, since the operation of the leakage alarm device is restricted by the main circuit contact of the circuit breaker or a member interlocking with the circuit breaker, the leakage current temporarily exceeds the set value and the current flows to the leakage display solenoid, and the Even when the armature 34 is disengaged from the leakage display piece 32, the leakage display button remains stationary and does not display the leakage. Even if the earth leakage disappears naturally, if this is repeated,
It is conceivable that the conductors and insulation of the main electric circuit are damaged, and the frequency of occurrence increases as the number of turns increases, the damage of the conductors and insulation increases, and eventually an accident such as a short circuit occurs. For this,
It is important to grasp the occurrence of electric leakage without missing it each time. The earth leakage indicator is to electrically detect the occurrence of earth leakage regardless of the presence or absence of circuit breaker operation when the earth leakage current exceeds the set value. It is desirable to grasp the occurrence of electric leakage. On the other hand, in important circuits where it is necessary to accurately know the history of leakage by grasping the occurrence of leakage without escaping, if a leakage occurs, it will not be shut down immediately, and the leakage occurrence alarm will prompt the operator to take necessary measures Circuits are often interrupted.

[0006] An object of the present invention is to provide an alarm for the occurrence of earth leakage by mechanical means irrespective of the duration of an earth leakage current exceeding a set value. Another object of the present invention is to provide a configuration of a circuit breaker capable of interrupting a main circuit.

[0007]

In order to solve the above-mentioned problems, according to the present invention, there is provided a zero-phase current transformer inserted into a main circuit, and a main circuit connected to a secondary side of the zero-phase current transformer. Leakage detection circuit that outputs a signal when the leakage current exceeds the set value, and receives the output signal from the leakage detection circuit when a leakage occurs
Turns on the ground fault indicator light, and when the ground fault disappears,
A blinking circuit that turns off the power indicator and a display
Leakage display button and to alert the occurrence of leakage by the movement of the location
And a spring that always keeps the earth leakage display button in the charged state.
In leakage alarm means and leakage alarm with circuit breaker having a composed, the flasher circuit, solution retention of the holding means by a current flowing in the output of the holding means and the signal holding said spring constantly loaded state And an earth leakage display circuit provided with a solenoid for releasing a spring.
Actuates the solenoid of the earth leakage display circuit
Activate the electric leakage display button.

[0008] In addition, the above-mentioned circuit breaker with a leakage alarm is provided.
When a short circuit occurs in the main circuit,
Built-in timer circuit to delay
Switching between power indication and delayed shutdown operation by timer circuit
Switching with a switch.

[0009]

As described above, the mechanical leakage alarm means is released by releasing the holding means by the leakage indication button, the spring, the holding means for always keeping the spring in the charged state, and the current flowing when the leakage is detected. And a solenoid device having a solenoid for releasing the electric current, the alarm operation of the electric leakage alarm means, that is, the movement of the electric leakage display button to the display position is performed by the main movable contact or a member interlocked therewith. Regardless, it is activated only by the current flowing into the solenoid by the signal output from the leakage detection circuit, and
Since this movement is performed by the spring force, even if the electric leakage naturally disappears before the operation of the circuit breaker, the occurrence of the electric leakage can be continuously displayed. Further, since the operation of returning the electric leakage display button moved to the display position to the display standby position is performed manually, the history of the occurrence of electric leakage can be confirmed again by this return operation.

In the case of a circuit breaker that does not immediately shut off even if a leakage occurs, a timer circuit is built in the circuit breaker, and after confirming the leakage with a leakage indicator light, a predetermined period of time is determined. After that, the circuit breaker can be turned off. If the circuit breaker incorporates the leakage alarm means and the timer circuit, and the leakage display by the leakage alarm means and the shutoff operation delayed by the timer circuit are switched by a changeover switch, the alarm of the leakage is generated. Since the electrical and mechanical operations are performed, the occurrence of electric leakage is grasped without any substantial leakage, the maintenance of important circuits is performed more reliably, and the breaker operation of the circuit breaker is performed after switching the changeover switch. Therefore, the safety in the operation of the circuit breaker is improved.

[0011]

[0012]

FIG. 1 shows an embodiment of the present invention. In the figure, the same circuit elements as those in FIG. A mechanical leakage display circuit 54 including a solenoid of a leakage warning means whose structure will be described in detail below is added to the blinking circuit 29 of the leakage display lamp. When the leakage of the main circuit is detected on the secondary side of the zero-phase current transformer 9 and a signal is output from the leakage detection circuit 3 , this signal is sent to the gate of the thyristor 51, the thyristor 51 is turned on, and the blinking circuit is turned on. 29 operates to cause the electric leakage indicating lamp 7 to start blinking, and at the same time, a voltage is applied to the base of the transistor 43 of the mechanical electric leakage indicating circuit 54 , the transistor 43 is turned on, and the thyristor 48 is turned on. The thyristor 48 is connected in series with the solenoid 57 of the leakage alarm means, so that a current flows through the solenoid 57 to release the spring of the leakage alarm means which has been stored in advance, and drives the leakage display button (not shown) to the display position. I do. As a result, the occurrence of the leakage is displayed by the two display means of the leakage display lamp and the leakage display button.

On the other hand, a timer circuit 55 is built in the circuit breaker, and after performing the necessary measures after confirming the occurrence of the electric leakage, the changeover switch 13 is switched to the timer circuit side and the switch 14 is turned on. Signal is sent from the leakage detection circuit 3 to the gate of the AV relay 1 after the time set in the timer circuit 55.
5, a current flows through the trip coil 17 of the circuit breaker by turning on the contact 15a, and the circuit breaker performs a breaking operation.

[0014] The solenoid 57 is a mechanical leakage display circuit 54.
FIG. 2 shows an embodiment of the structure of the electric leakage warning means inserted into the device. In this embodiment, the leakage alarm means 60 is provided with the solenoid 5
7, a fixed iron core 61a, a movable iron core 61b, a U-shaped yoke 62 made of a steel plate, two square rod-shaped permanent magnets 58 fixed inside the yoke 62, and a magnetic core 61b , A spacer 64 made of a non-magnetic metal, a compression spring 59 which is always kept in a charged state as shown in the figure, and a leakage display button 65. When a current flows through the solenoid 57 at the time of leakage detection, the magnetic flux generated by the solenoid 57 cancels out the magnetic flux of the permanent magnet 58 passing through the movable iron core 61b and the fixed iron core 61a. The power causes the leakage display button 65 to be driven upward.

[0015]

According to the present invention, since the circuit breaker with a leakage alarm is configured as described above, the following effects can be obtained. In the circuit breaker according to the first aspect, the operation of the earth leakage display button for mechanically displaying the occurrence of earth leakage by moving from the rest position is not restricted by the main movable contact of the circuit breaker or a member interlocked with the main movable contact. Operation is started only by the signal output from the leakage detection circuit at the time of detection,
Since the spring is brought to the leakage display position, even if the leakage naturally disappears before the operation of the circuit breaker, a history of the occurrence of the leakage can be left. With this, the occurrence of electric leakage is grasped by electric means by the electric leakage indicator lamp and mechanical means by the electric leakage display button, and the occurrence of electric leakage can be substantially completely grasped. The main circuit to which the circuit breaker is applied can be more completely maintained.

[0016] In circuit breaker of claim 2, occurrence of leakage is reliably grasped by double display means by the leakage display button and leakage indicator, maintenance is more fully line the main electric circuit breaker is applied In addition, since the main circuit is shut off after the changeover operation of the changeover switch after the necessary measures are taken due to the occurrence of the earth leakage, even if it takes more time than expected to perform the necessary measures, Since the circuit breaker is operated after the necessary measures are completed, the safety in the operation of the circuit breaker is improved.

[0017]

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of a wiring breaker with a leakage alarm according to the present invention.

FIG. 2 is a front view showing an embodiment of a ground fault warning unit according to the present invention.

FIG. 3 is a front view of an external appearance of a circuit breaker showing a main part of a circuit breaker with a leakage alarm;

FIG. 4 is a circuit diagram showing an example of a conventional circuit breaker with a leakage alarm;

FIG. 5 is a front view showing an example of a conventional leakage alarm means.

[Description of Signs] 3 Leakage detection circuit 5 Leakage display button 7 Leakage display lamp 9 Zero-phase current transformer 13 Changeover switch 29 blinking circuit 31 Leakage display button 54 Leakage display circuit 57 Solenoid 58 Permanent magnet (holding means) 59 Spring 60 Leakage Alarm means 65 Leakage display button

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-95252 (JP, A) JP-A 63-26951 (JP, U) JP-A 57-103658 (JP, U) 35248 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 83/02

Claims (2)

(57) [Claims] 1. A zero-phase current transformer inserted into a main circuit, and a leakage detection circuit connected to a secondary side of the zero-phase current transformer and outputting a signal when a leakage current of the main circuit exceeds a set value. , When a short circuit occurs
Off the leakage indicator during leakage disappears with operating point <br/> light leakage indicator in response to an output signal from the leakage detecting circuit
A blinking circuit for causing the electric power to flow, a leakage display button for alarming the occurrence of leakage by moving from the rest position to the display position, and the leakage display button
Leakage warning hand consisting of a spring that keeps the
A wiring breaker with a leakage alarm having a step , wherein the flashing circuit releases the spring by releasing the holding of the holding means by a current flowing at the time of outputting the signal, and a holding means for constantly holding the spring in an energized state. An earth leakage display circuit equipped with a solenoid for discharging is added, and by the operation of the blinking circuit,
Driving the solenoid of the earth leakage display circuit to display the earth leakage
A circuit breaker with a leakage alarm, characterized by operating a button . 2. The circuit breaker with an earth leakage alarm according to claim 1, wherein when an earth leakage occurs in the main circuit, the earth leakage is interrupted for a predetermined time.
Built-in timer circuit to delay disconnection operation ,
Leakage display by timer circuit and delayed shut-off operation by timer circuit.
Circuit breaker with an earth leakage alarm, wherein the switching is performed by a changeover switch .