JPH05260642A - Circuit breaker system - Google Patents

Abstract

PURPOSE:To provide a circuit breaker system which can eliminate an output relay and can simplify wiring operation. CONSTITUTION:The title system is provided with a current detection means 1 which detects an abnormal current at a main circuit 7 between a power supply 5 and a load 6 and an alarm means 2 which generates an alarm signal if a signal level exceeds a reference value when the output signal of the current detection means 1 is input and the signal level is compared with a specified reference value. Also, it is provided with a circuit breaker 12 with a signal processing circuit 3 which converts an alarm signal to a multiplex transmission signal and a central monitor control device 4 which is connected to the signal processing circuit 3 through a multiplex transmission signal line 13 and inputs a multiplex transmission signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker system for detecting an earth leakage or an overcurrent of a load connected to a low-voltage power distribution line and issuing an alarm.

[0002]

2. Description of the Related Art The prior art example of FIG. 4 shows a circuit of a main part of an earth leakage alarm circuit breaker which detects an earth leakage state of a main circuit 56 and issues an alarm, in which a leakage current of the main circuit is changed by a zero-phase current transformer ZCT. It outputs a proportional output current, compares the signal level with a reference value in a leakage warning circuit 50 composed of a leakage detection circuit and an output circuit, lights up a leakage warning display light emitting diode LED, and has an a contact and a b contact. The output relay 51 is driven to output a contact signal. 52 is the main circuit 56
Is a circuit power source connected via a transformer, and 53 is a reset button for resetting an electrically latched alarm signal of the earth leakage alarm circuit 50, which is installed on the surface of the circuit breaker body.

The conventional example of FIG. 5 shows a circuit of a main part of a wiring breaker which detects an overcurrent state of the main circuit 56 and issues an alarm before the main circuit 56 is cut off. An output current proportional to the current is output, and an overcurrent detection circuit 50 'consisting of an overcurrent trip circuit and an overcurrent alarm circuit compares the signal level with a reference value and outputs an alarm signal when it exceeds the reference value. Then, before driving the trip coil 54, the trip coil 54 is input to the output circuit 55 and the light emitting diode L for displaying the overcurrent alarm is input.
While turning on ED ', the output relay 51 is driven to output a contact signal. The power supply circuit 52 receives electric power from an external power supply.

[0004]

However, these conventional examples require an output relay 51 for outputting an alarm signal, and have a drawback that the wiring processing work such as the wiring of three contact signals is troublesome. was there. Further, since the reset button 53 for resetting the alarm signal is arranged on the surface of the circuit breaker main body, when the alarm signal is reset after the occurrence of the earth leakage alarm or the overcurrent alarm, the place where the circuit breaker is installed is set. It is necessary to go and push the button.

Further, a voltage drop circuit (transformer) for securing the circuit power supply 52 is required, which causes an increase in the size of the circuit breaker, and wiring for supplying power from the outside is additionally required. The processing becomes troublesome, and the workability is deteriorated. Further, when it becomes necessary to shut off the main circuit 56 when a leakage occurs due to a change in load or the like, there is an inconvenience that the breaker must be replaced.

Therefore, an object of the present invention is to provide a circuit breaker system which can eliminate the need for an output relay and simplify the wiring processing work.

[0007]

A circuit breaker system according to claim 1 has current detecting means for detecting an abnormal current in a main circuit between a power source and a load, and inputs an output signal of the current detecting means. And a signal processing circuit for comparing the signal level with a predetermined reference value to generate an alarm signal when the signal level exceeds the reference value, and for converting the alarm signal into a multiplex transmission signal. And a central supervisory control device connected to the signal processing circuit via a multiplex transmission signal line and inputting the multiplex transmission signal.

A circuit breaker system according to a second aspect of the present invention is the circuit breaker system according to the first aspect, wherein the alarm means inputs and resets a reset signal, and the reset signal is sent from the central supervisory control device through the multiplex transmission signal line. It is something to send. The circuit breaker system of claim 3 is the same as that of claim 1.
Circuit power in the circuit breaker is supplied from the central supervisory control device via the multiplex transmission signal line.

According to a fourth aspect of the present invention, there is provided a circuit breaker system according to the first aspect, wherein the current detecting means detects a leakage current.
A switching signal for inputting the output signal of the current detecting means to shut off the circuit, and switching means for switching the operation of the alarm means and the interrupting portion, and a switching signal for switching the switching means are provided. It is transmitted from the central supervisory control device via the multiplex transmission signal line.

[0010]

According to the circuit breaker system of the present invention, when an accident such as an electric leakage or an overcurrent occurs in the load, an abnormal current is generated in the main circuit between the power source and the load, which is detected by the current detecting means and an alarm means is provided. Is activated and an alarm signal is generated. The alarm signal is converted into a multiplex transmission signal by the signal processing circuit and input to the central supervisory control device via the multiplex transmission signal line.
In this case, since the alarm signal is transmitted to the central supervisory control device by the multiplex transmission signal, the output relay can be omitted and the wiring processing work can be simplified.

According to a second aspect of the circuit breaker system of the present invention, in the first aspect, the reset signal for resetting the alarm means is inputted from the central supervisory control device through the multiplex transmission signal line. Besides, since the reset signal can be input from the central supervisory control device via the multiplex transmission signal line, it is not necessary to go to the place where the circuit breaker is installed and press the button. Moreover, since the number of wires does not increase, the wiring work is simplified.

According to the circuit breaker system of claim 3, in claim 1, the circuit power supply of the signal processing circuit is supplied from the central supervisory control device via the multiplex transmission signal line. Besides, since it is not necessary to secure a power supply circuit in the circuit breaker, the circuit breaker can be downsized and extra wiring work can be omitted. Claim 4
According to another aspect of the present invention, in the circuit breaker system according to claim 1, the current detecting unit detects a leakage current, has a breaking unit that cuts off a circuit by inputting a signal from the current detecting unit, and the alarm unit. Since the switching of the cutoff unit is input from the central supervisory control device through the multiplex transmission signal line, in addition to the function of claim 1, multiplex switching of outputting an alarm or shutting off the main circuit when a leakage occurs. Since it can be performed via the signal line, it is possible to easily cope with a change in the operating state of the circuit breaker due to a change in load.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. That is, this circuit breaker system is intended for an earth leakage warning, and includes a current detection means 1 and an alarm means 2.
It has a circuit breaker 12 equipped with a signal processing circuit 3 and a central supervisory control device 4. The current detecting means 1 of the circuit breaker 12 detects an abnormal current in the main circuit 7 between the power source 5 and the load 6. The current detecting means 1 comprises a zero-phase current transformer ZCT that outputs a current proportional to the leakage current of the three-phase circuit, and a leakage detection circuit 9 that amplifies the output signal of the zero-phase current transformer ZCT.

The alarm means 2 inputs the output signal of the current detection means 1, compares the signal level with a predetermined reference value, and issues an alarm signal when the level of the output signal exceeds the predetermined reference value. In the embodiment, the trip coil 1 receives an alarm signal.
It has a trip coil drive unit (not shown) that operates 0, and a display drive unit (not shown) that drives a light emitting diode LED for displaying an earth leakage warning. The contact portion 11 is opened by the operation of the trip coil 10. The alarm signal is reset by inputting a reset signal to the alarm means 2.

The leakage detection circuit 9, the alarm means 2, the trip coil drive section and the display drive section are carried out by a microcomputer A using known means as shown in FIG. Further, data such as a reference value of the leakage sensible current is stored in the storage means RAM of FIG. 2, and the reference value is written by the setting section C. Further, the microcomputer A is provided with switching means for switching between the trip coil drive section and the display drive section, and at least one of the trip coil 10 and the light emitting diode LED is generated when an alarm is issued by inputting a switching signal to the switch means. Is selected.

The signal processing circuit 3 converts the alarm signal into a multiplex transmission signal. The signal processing circuit 3 of the embodiment uses a well-known microcomputer B as shown in FIG. 2, and through the multiplex transmission signal line 13 to the central supervisory control device 4, for example, when multiplex transmission is 8 bits, 1 bit out of 8 bits is used. Use to transmit. The microcomputer A also has a signal processing circuit for converting a multiplex transmission signal input from the central supervisory controller 4 through the transmission signal line 13 into a predetermined signal.

The central supervisory control device 4 uses the multiplex transmission signal line 13
It is connected to the signal processing circuit 3 via and inputs the multiplex transmission signal. The multiplex transmission signal line 13 uses a two-core cable line. This multiplex transmission signal is converted into an alarm signal by a signal processing circuit of a microcomputer (not shown), and various accident processing and management are performed based on the alarm signal. Further, in the embodiment, a reset unit (not shown) for resetting the alarm signal of the circuit breaker 12 is provided, and the reset signal generated by the reset unit is converted into a multiplex transmission signal by the signal processing circuit. In this case, 1 bit out of 8 bits is transmitted to the circuit breaker 12 via the multiplex transmission signal line 13, converted into a reset signal by the signal processing circuit of the circuit breaker 12, and the reset signal is input to the alarm means 2. The alarm means 2 is reset. Further, the reference value of the leakage sensitive current in the circuit breaker 12 is stored in the storage means RAM through the multiplex transmission signal line 13.
A setting unit (not shown) for writing or rewriting to the circuit breaker 1 and the reference value of the leakage-sensing current to know the rating of the circuit breaker 12 installed through the multiplex transmission signal line 13
It has a reading section for reading from the second storage means RAM. Further, when switching the alarm means 2 and the interruption section 12, there is a switching signal generating section (not shown) for inputting a switching signal to the switching means via the multiplex transmission signal line 13. Further, the central supervisory control device 4 has a power supply unit (not shown) for supplying the DC voltage of the circuit power supply such as the signal processing circuit in the circuit breaker 12 through the multiplex transmission signal 13.

According to this embodiment, when an accident such as an electric leakage occurs in the load, an electric leakage current, which is an abnormal current, is generated in the main circuit 7 between the power source 5 and the load 6, and this is detected by the current detecting means 1 to generate an alarm. The means 2 operates and an alarm signal is generated. The alarm signal is converted into a multiplex transmission signal by the signal processing circuit 3 and input to the central supervisory control device 4 via the multiplex transmission signal line 13. In this case, since the alarm signal is transmitted to the central supervisory control device 4 by the multiplex transmission signal, the wiring processing work can be simplified. In addition, the alarm relay can be omitted, so the size can be reduced, and even if the trip coil is added, the size does not increase.

Further, since the reset signal for resetting the alarm means 2 is inputted from the central supervisory control device 4 via the multiplex transmission signal line 13, the reset signal can be inputted from the central supervisory control device 4 via the multiplex transmission signal line 13. It is not necessary to go to the place where the circuit breaker 12 is installed and press the button. Moreover, since the number of wires does not increase, the wiring work is simplified.

Since circuit power for the signal processing circuit 3 and the like is supplied from the central supervisory control device 4 via the multiplex transmission signal line 13, it is not necessary to secure a power circuit in the circuit breaker 12, so that the circuit breaker 12 is small in size. It is possible to eliminate the need for extra wiring work. The current detecting means 1 is for detecting an electric leakage, and has a breaker 12 for inputting a signal from the current detecting means 1 to break the circuit, and switching between the alarm means 2 and the breaker 12 is performed by a multiplex transmission signal line 13. Since it is input from the central monitoring control device 4 via the central monitoring control device 4, it is possible to switch whether to output an alarm or shut off the main circuit 7 via the multiplex transmission signal line 13 when a leakage occurs. It is possible to easily respond to changes in the usage state of.

As a result, it becomes easy to construct a network for monitoring the system of the low-voltage distribution line. The second embodiment of the present invention is shown in FIG. That is, this circuit breaker system is an example applied to a circuit breaker that detects an overcurrent, and the current detection means 1 includes a current transformer CT for each electric path of the main circuit 7 and a current transformer CT.
And an overcurrent detection circuit 9'which amplifies and outputs the signal of (1), and the output signal is converted into a DC voltage signal (0 to 5V). The setting of the overcurrent alarm level is performed by the changeover switch 14 mounted on the surface of the circuit breaker 12 and the central monitoring control device 4. The microcomputer constituting the alarm means 2 has a built-in A / D conversion circuit 15 to reduce the circuit configuration.

Other than that, there is no means for switching between the leakage alarm and the leakage interruption, and the description is omitted because it is the same as the first embodiment.

[0023]

According to the circuit breaker system of claim 1, since the alarm signal is transmitted to the central supervisory control device by the multiplex transmission signal, the output relay can be omitted and the wiring processing work can be simplified. .. According to the circuit breaker system of claim 2, since the reset signal for resetting the alarm means is input from the central supervisory control device through the multiplex transmission signal line in claim 1, in addition to the effect of claim 1, Since the reset signal can be input from the central supervisory control device through the multiplex transmission signal line, it is not necessary to go to the place where the circuit breaker is installed and press the button. Moreover, since the number of wires does not increase, the wiring work is simplified.

According to the circuit breaker system of claim 3, in claim 1, the circuit power supply of the signal processing circuit is supplied from the central supervisory control device through the multiplex transmission signal line. Besides, since it is not necessary to secure a power supply circuit in the circuit breaker, the circuit breaker can be downsized and extra wiring work can be omitted. Claim 4
According to another aspect of the present invention, in the circuit breaker system according to claim 1, the current detecting unit detects a leakage current, has a breaking unit that cuts off a circuit by inputting a signal from the current detecting unit, and the alarm unit. Since the switching of the cutoff unit is inputted from the central supervisory control device via the multiplex transmission signal line, in addition to the effect of claim 1, switching between outputting an alarm and shutting off the main circuit when an electric leakage occurs is multiplexed. Since it can be performed via the signal line, it is possible to easily cope with a change in the operating state of the circuit breaker due to a change in load.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram of a microcomputer that constitutes a current detection means, an alarm means, and a signal processing circuit of a circuit breaker.

FIG. 3 is a circuit diagram of a second embodiment.

FIG. 4 is a circuit diagram of a conventional example.

FIG. 5 is a circuit diagram of another conventional example.

[Explanation of symbols]

 1 current detection means 2 alarm means 3 signal processing circuit 4 central supervisory control device 5 power supply 6 load 7 main circuit 12 circuit breaker 13 multiplex transmission signal line

Claims (4)

[Claims] 1. A current detection means for detecting an abnormal current in a main circuit between a power supply and a load, wherein an output signal of the current detection means is input and the signal level thereof is compared with a predetermined reference value. A circuit breaker having alarm means for generating an alarm signal when the signal level exceeds the reference value and having a signal processing circuit for converting the alarm signal into a multiplex transmission signal; and a circuit breaker via a multiplex transmission signal line. A circuit breaker system comprising a central supervisory control device connected to a signal processing circuit and inputting the multiplex transmission signal. 2. The circuit breaker system according to claim 1, wherein said alarm means inputs a reset signal for resetting, and transmits the reset signal from said central supervisory control device through said multiplex transmission signal line. 3. The circuit breaker system according to claim 1, wherein circuit power in the circuit breaker is supplied from the central supervisory control device via the multiplex transmission signal line. 4. The current detecting means is for detecting electric leakage, has a cutoff portion for cutting off the circuit by inputting the output signal of the current detecting means, and the operation of the alarm means and the cutoff portion. 2. The circuit breaker system according to claim 1, further comprising switching means for switching the switching means, wherein a switching signal for switching the switching means is transmitted from the central supervisory control device via the multiplex transmission signal line.