JPH08227649A - Power distribution circuit breaker - Google Patents

Abstract

PURPOSE: To provide a circuit breaker having a function as an ordinary power distribution circuit breaker and a current limiter via the application of simple constitution by providing a control means with a control section for outputting a trip signal, when the sum of detected current vectors reaches a prescribed level. CONSTITUTION: A control section 10 receives a prescribed level of a signal corresponding to the first rated breaking current from the characteristic memory section 8 of a memory section 7, on the basis of an input signal from a variable means 2, and outputs a trip signal to an open/close drive means 12, when current detected with a current detection means 1 is equal to or above the rated breaking current and continues longer than the preset time. Also, a control section 11 receives the prescribed level of a signal corresponding to the second rated breaking current from the characteristic memory section 9 of the memory section 7, on the basis of an input signal from a variable means 3. When the sum of two current vectors detected with the means 1 is equal to or above the second rated breaking current and continues longer than the preset time for the value thereof, the section 11 outputs a trip signal to the means 12. According to this construction, a circuit breaker with the function of a current limiter can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker for electric power distribution, which interrupts an electric circuit when a current flowing through the electric circuit exceeds a predetermined level.

[0002]

2. Description of the Related Art Conventionally, a circuit breaker A for distribution used in a single-phase three-wire type electric circuit in a house or building as shown in FIG.
From the viewpoint of safety, is to shut off the electric circuit B when the current flowing through the electric circuit B exceeds a predetermined level, and has a current detection unit 1, a control unit 6, and an opening / closing drive unit 12. The current detecting means 1 includes two main circuit lines C1 and C2 of the electric circuit B.
The control means 6 outputs a trip signal when at least one of the detected currents is equal to or higher than a predetermined level, and the open / close drive means 12 detects the current attached to the main circuit line C1 or C2. Circuit B is shut off based on the trip signal. D is a current limiter that shuts off the circuit B when the current flowing through the circuit B is above the contract level with the electric power company. The vector sum of the currents flowing through the two main circuit lines C1 and C2 is a contract. Cut off circuit B when the level is exceeded. This current limiter D is intended to ensure stable power supply by preventing current from flowing beyond the contract. In areas where installation is obligatory, it is installed on the primary side of the breaker A for distribution. It

[0003]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention As described above, the circuit breaker for distribution cuts off the electric circuit at the time of abnormality from the viewpoint of safety,
The current limiter cuts off the electric line based on the contract with the electric power company. However, in the area where the current limiter is needed together with the distribution breaker, not only the extra space for installing the current limiter is needed, but also the distribution breaker and the current limiter control The portions having similar functions such as the means and the opening / closing drive means are duplicated.

The present invention has been made in view of the above circumstances, and its object is to provide a compact and simple structure when the vector sum of the currents flowing through the two main circuit lines is equal to or higher than the contract level. Another object of the present invention is to provide a circuit breaker for power distribution, which has a function of interrupting an electric circuit.

[0005]

In order to solve the above-mentioned problems, the distribution breaker according to claim 1 is connected to a single-phase three-wire type electric line, and has two main parts of the electric line. A trip signal is output when at least one of the detection currents of the current detection means attached to the circuit line and detecting the current flowing through each of the main circuit lines is at least a predetermined level based on the rated breaking current. In a distribution breaker having a control means for outputting and an opening / closing drive means for breaking an electric path based on a trip signal of the control means, the control means is provided with a sum current composed of vector sums of respective detection currents of the current detection means. Is provided with a second control unit that outputs a trip signal when the level is equal to or higher than the second predetermined level.

According to a second aspect of the present invention, there is provided a distribution breaker, wherein a second rated breaking current for variably setting a second predetermined level of the second control unit is input to the distribution breaker. The second variable means is provided.

The circuit breaker for distribution according to claim 3 has a structure in which the second variable means according to claim 2 is provided with a protection portion for protecting the second rated breaking current from being easily input. There is.

Further, the distribution circuit breaker according to claim 4 has a constitution in which the distribution circuit breaker according to claims 1 to 3 is provided with variable means for inputting a rated breaking current for variably setting a predetermined level. There is.

According to a fifth aspect of the present invention, there is provided a circuit breaker for power distribution, wherein the control means according to the first to fourth aspects determines whether at least one of the detected currents is at a predetermined level or higher.
The second control unit is formed so as to have priority over the determination as to whether the sum current, which is the vector sum of the detected currents, is equal to or higher than the second predetermined level.

[0010]

According to the structure of the first aspect, the trip signal of the second control section can interrupt the electric circuit by the opening / closing drive means. Therefore, when at least one of the detected currents is equal to or higher than a predetermined level, each detection current is detected. In two cases where the sum current, which is the vector sum of the currents, is equal to or higher than the second predetermined level, the electric circuit can be cut off.

According to the structure of claim 2, in addition to the operation of claim 1, the second predetermined level can be variably set by the second variable means.

According to the third aspect of the invention, in addition to the operation of the second aspect, the second predetermined level cannot be easily changed by the protection portion.

According to the structure of claim 4, in addition to the operation of any one of claims 1 to 3, the predetermined level can be variably set by the variable means.

Further, according to the structure of claim 5, in addition to the operation of any one of claims 1 to 4, when one of the detection currents exceeds a predetermined level, a trip signal is immediately output to the opening / closing drive means. Then, the electric circuit is cut off.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram of a distribution breaker A according to the present invention. The distribution breaker A is a current detecting means 1,1.
Variable means 2, second variable means 3, control means 6,
The opening / closing drive means 12 is a main constituent member. Members having the same functions as those in the conventional example are designated by the same reference numerals.

The current detecting means 1, 1 is a single-phase three-wire type electric circuit B.
It detects the current flowing in the main circuit and is attached to the main circuit lines C1 and C2, which are formed by a current transformer and are connected to the circuit breaker A for distribution. The current detecting means 1, 1 are connected to the main circuit line C
Control means 6 which will be described later using the current flowing in 1, C2 as the detected current.
Output to. C3 is the neutral line.

In the variable means 2, the control means 6 described later is an electric circuit.
Input the rated breaking current for setting the predetermined level of the detection current for breaking B. For example, by moving the dip switch 2a as shown in FIG. 2, either 30A or 60A is set as the rated breaking current. You can enter. Specifically, this DIP switch 2a is
It is linked with the variable resistor 2b as shown in FIG. And
The input rated breaking current is input to the control means 6 described later as an input signal.

The second variable means 3 inputs the second rated breaking current for setting the second predetermined level of the detection current for breaking the electric circuit B by the controlling means 6 which will be described later.
By rotating the dial 3a as shown in, any of 30A, 40A, 50A and 60A can be input as the second rated breaking current. Specifically, this dial 3a is interlocked with two switches 3b as shown in FIG. 3, and four kinds of signals can be sent in the open / closed state. The input second rated breaking current is also input to the control means 6 described later as an input signal. The dial 3a is arranged at a position one step lower than the surface 5a of the casing 5 of the distribution breaker A.

Numeral 4 is a protection portion for easily rotating the dial 3a so that the second rated breaking current cannot be inputted.
It is attached so as to cover the dial 3a. Specifically, the protection unit 4 has a flat plate-shaped protection plate 4a and a screw 4b, 4b having a special shape in a portion which is rotated by inserting a rotary tool (not shown). The dial 3a is protected by attaching it to the casing 5 with screws 4b, 4b ....

The control means 6 controls the opening / closing drive means 12 which will be described later based on the current detected by the current detection means 1, 1.
It has a storage unit 7, a control unit 10, and a second control unit 11. Memory 7
Stores the predetermined level and the second predetermined level of the detection current flowing through the electric circuit B, and the rated breaking currents 30A and 60A
The characteristic storage unit 8 sets the predetermined level X as shown in FIG.
The second rated breaking current 30A, 40A, 50A and 60
The second predetermined level Y is stored in the second characteristic storage unit 9 for each A. In this figure, the horizontal axis represents the detected current, and the vertical axis represents the delay time until the switching drive means 12 starts the breaking operation at each detected current.

The control section 10 outputs a trip signal to the opening / closing drive means 12 when at least one of the two detection currents of the current detection means 1 is equal to or higher than a predetermined level X based on the rated breaking current. Specifically, the control unit 10 inputs a predetermined level X corresponding to the rated breaking current of the input signal from the characteristic storage unit 8 of the storage unit 7 based on the input signal of the variable unit 2 and the current detection unit 1 When at least one of the current values of the detection current is equal to or more than the rated breaking current and the detection current continues for a delay time of a predetermined level X with respect to the current value,
The trip signal is output to the opening / closing drive means 12.

The second control unit 11 outputs the trip signal to the open / close drive unit 12 when the sum current, which is the vector sum of the two detection currents of the current detection unit 1, is equal to or higher than the second predetermined level based on the second rated breaking current. Output to. Specifically, the second control unit 11
On the basis of the input signal of the second varying means 3, the predetermined level Y corresponding to the second rated breaking current of the input signal is input from the second characteristic storage section 9 of the storage section 7, and 2 of the current detecting means 1 is input. A trip signal is output to the opening / closing drive means 12 when the sum current, which is the vector sum of the individual detection currents, is the second rated breaking current or more and the detection current continues for a delay time of a predetermined level Y with respect to the current value or more. .

The opening / closing drive means 12 shuts off the electric circuit B based on the trip signal from the control means 6, and has contacts (not shown) for opening / closing the main circuit lines C1 and C2 of the electric circuit B. Both of these contacts are closed by the trip signal.

As shown in FIG. 3, the control means 6 is
CPU 13 having control unit 10 and second control unit 11, and storage unit
Microcomputer 15 with ROM 14 having 7
Is formed.

Next, the operation of this device will be described with reference to the flowchart of FIG. First, the variable means 2 inputs the rated breaking current, and the second varying means 3 inputs the second rated breaking current. When the rated breaking current and the second rated breaking current are input, the input signal is input to the control means 6,
The control unit 10 has a predetermined level X corresponding to the rated breaking current.
From the characteristic storage unit 8 of the storage unit 7, the second control unit 11 inputs the predetermined level Y corresponding to the second rated breaking current from the second characteristic storage unit 9 of the storage unit 7. In the state where this setting is completed, the current detecting means 1 starts detecting the current of the electric circuit B.

The control unit 10 trips when at least one of the detection currents detected by the current detection means 1 and 1 is the rated breaking current or more and when the detection current is the delay time or more determined by the predetermined level X. A signal is output to the opening / closing drive means 12 to cut off the electric circuit B. When both of the detection currents detected by the current detecting means 1, 1 are less than the predetermined level X, the second
The control unit 11 obtains a sum current, which is a vector sum of two detection currents detected by the current detection means 1, 1, and when the sum current is the second rated breaking current or more, and the sum current. Is longer than the delay time determined by the second predetermined level Y,
The trip signal is output to the opening / closing drive means 12 to cut off the electric circuit B. If the sum current is less than the second predetermined level, the opening / closing drive means 12 does not operate. Then, this series of operations is continuously performed.

This means that when at least one of the two detection currents of the current detection means 1 is above a predetermined level X, and the sum current which is the vector sum of the two detection currents of the current detection means 1 is the second predetermined value. When the level is exceeded, the circuit B is cut off, so it is possible to combine the functions of a normal distribution breaker and a current limiter based on a contract with a power company. Therefore, it is possible to reduce the size of the distribution board that stores these functions, reduce duplication of parts, and reduce costs.
In addition, the operation of interrupting the electric circuit B when at least one of the two detection currents, which is a function of the distribution circuit breaker, is equal to or higher than the predetermined level X, the sum current that is the vector sum of the two detection currents is the second predetermined level. In the above case, since the operation to cut off the electric circuit B is prioritized, the electric circuit B can be quickly interrupted when a large current such as a short circuit occurs.

Although the variable means 2 and the second variable means 3 are provided in the embodiment, the variable means is not always required when it is not necessary to variably set the predetermined level or the second predetermined level.
2 and the second variable means 3 are not limited to being installed, and the priority order of the operations of the control unit 10 and the second control unit 11 may be the second control unit depending on the use condition of the wiring breaker.
You may give priority to 11 actions. Further, although two kinds of rated breaking currents and four kinds of second rated breaking currents are provided, the number and the numerical value are not limited, of course.

[0029]

In the distribution circuit breaker according to the first aspect of the present invention, since the opening / closing drive means can cut off the electric circuit in response to the trip signal from the second control unit, at least one of the detected currents is at a predetermined level or higher. Since the electric path can be cut off in two cases where the sum current consisting of the vector sum of each of the detected currents is equal to or higher than the second predetermined level, the function of the current limiter can be provided with a compact and simple configuration. .

Further, in addition to the effect of claim 1, the distribution circuit breaker according to claim 2 can variably set the second predetermined level by the second variable means, so that it is different for one type of distribution circuit breaker. It is adaptable to the installation environment and improves usability.

In addition to the effect of the second aspect, the distribution circuit breaker according to the third aspect can not easily change the second predetermined level by the protective portion, so that the reliability is improved without erroneous operation.

In addition to the effect of any one of claims 1 to 3, the distribution circuit breaker according to claim 4 can variably set a predetermined level by the variable means, so that the usability is further improved.

In addition to the effect of any one of claims 1 to 4, the circuit breaker for distribution according to claim 5 provides a trip signal to the opening / closing drive means immediately when one of the detected currents exceeds a predetermined level. Since it is output and the electric circuit is cut off, reliability is improved in terms of safety.

[Brief description of drawings]

FIG. 1 is a block diagram of a circuit breaker for distribution showing an embodiment of the present invention.

FIG. 2 is a perspective view of the distribution breaker.

FIG. 3 is a block diagram of control means of the distribution breaker.

FIG. 4 is a diagram showing operating characteristics of the distribution breaker.

FIG. 5 is a flowchart of the operation of the distribution breaker.

FIG. 6 is a front view showing a mounted state of a conventional circuit breaker of the present invention.

[Explanation of symbols]

 A Circuit breaker B Distribution circuit C1, C2 Main circuit line 1 Current detection means 2 Variable means 3 Second variable means 4 Protective section 6 Control means 7 Storage section 8 Characteristic storage section 9 Second characteristic storage section 10 Control section 11 Second Control unit 12 Opening / closing drive means

Claims (5)

[Claims] 1. A current detecting means which is connected to a single-phase three-wire type electric line and which is attached to two main circuit lines of the electric line and detects a current flowing through each main circuit line, Control means for outputting a trip signal when at least one of the detected currents of the current detection means is equal to or higher than a predetermined level based on the rated breaking current; and an opening / closing drive means for breaking the electric path based on the trip signal of the controlling means, In the distribution circuit breaker having the above, the control means is provided with a second control section that outputs a trip signal when the sum current, which is the vector sum of the detected currents of the current detection means, is equal to or higher than the second predetermined level. A characteristic circuit breaker. 2. The circuit breaker for power distribution according to claim 1, further comprising second variable means for inputting a second rated breaking current for variably setting the second predetermined level of the second control section. . 3. The distribution breaker according to claim 2, wherein the second variable means is provided with a protection portion for protecting the second rated breaking current from being easily input. 4. The distribution breaker according to claim 1, further comprising a variable means for inputting a rated breaking current for variably setting the predetermined level. 5. The control means determines whether at least one of the detected currents is at or above a predetermined level, and whether or not the sum current, which is a vector sum of the detected currents of the second control section, is at or above a second predetermined level. 5. The power distribution breaker according to claim 1, wherein the breaker is formed so as to have priority over the determination in (1).