JPH09107625A - Overcurrent protective device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable warning of the possibility of a power supply trip before a user connects an apliance to a receptacle, by indicating whether the use of the receptacle is allowed or not, on the basis of a surplus current value. SOLUTION: An interface board 9 measures a surplus current value on the basis of comparison between a total current at the output side of a shunt determined by a current sensor 8 and the rated capacity of a shunt eddy current interrupter 4. With an ordinary shunt distribution line 5 used as a transmission line, an amplitude modulated carrier wave is sent from the interface board 9 to each receptacle 6A by a carrier wave superposition transmission system. In each receptacle 6A, a red warning lamp 12 is lighted by subjecting an incoming carrier wave signal to a threshold control by an indication unit 11. In other words, the lamp is lighted when a surplus current decreases to a numerical value corresponding practically to the maximum value in appliances to be connected and thereby a warning is given as to that the connection of the appliance to the receptacle is not allowed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overload protection device for outlets and the like.

[0002]

2. Description of the Related Art The structure of a conventional distribution line system will be described with reference to FIG. FIG. 3 is a diagram showing a conventional distribution line system.

In FIG. 3, 1 is a power line and 2 is a power line 1.
The distribution board connected to the 3 is a main overcurrent circuit breaker provided in the distribution board 2, 4 is also a shunt overcurrent circuit breaker, 5 is a shunt circuit connected to each shunt overcurrent circuit breaker 4. A distribution line, 6 is an outlet connected to the shunt distribution line 5.

Next, the operation of the above-mentioned conventional distribution line system will be described. Conventionally, a fuse for the purpose of protecting the distribution line from burning and deterioration due to overcurrent, or a no-fuse circuit breaker, has been in a state of tripping after the overcurrent actually flows.

In recent years, high-performance computers such as personal computers have been installed in buildings.
In many cases, high-value-added production equipment is connected to terminals with normal wiring. Generally, large computers, medical devices, and other devices that require high reliability are CVs.
There is no power loss because it is packed up with an uninterruptible power supply called CF.

However, if the power supply is cut off, the personal computer or the like cannot operate, resulting in direct and indirect opportunity loss, and the memory extracted by the data processing is a CPU even in a permanent storage device such as a floppy disk. There is a risk that stored data will be erased or lost.

In addition, depending on the time until the power is restored,
The tenants will never be dissatisfied with the lighting and air conditioning malfunctions.

On the other hand, due to the diversification and sophistication of equipment used in buildings, PCs, microwave ovens, large vacuum cleaners, etc. having a considerably large capacity, which exceed the current rating, are suddenly superposed and the power is tripped. Opportunities are increasing. In general households, it is a common experience that refrigerators, coolers, etc. also cause trips.

[0009] Above all, the large-sized vacuum cleaner is usually different from other equipment which allows tenants to manage their own experience by accumulating experience, so that an outside contractor is free to use a dedicated part such as a tenant building.
There are many cases where the user enters the common area and indifferently connects to a power source (outlet) and trips. At first glance, even if it looks like a room that can be cleaned, the next room may be quite busy, or it may be a room related to overseas business or financial business where OA equipment is operating 24 hours a day.

[0010] Here, for the protection of the electric wire, a warning is issued in advance that the overcurrent protection device may work in advance, in addition to the overcurrent protection device corresponding to the heat capacity of the electric wire. There is a need to prevent it.

[0011]

In the conventional distribution line system as described above, there is a problem that a power supply trip is caused by the careless use of an outlet.

The present invention has been made in order to solve the above-mentioned problems, and displays an allowance current in each outlet before the overcurrent device operates so that an amateur user can connect the power source to the outlet before connecting the equipment. It is an object of the present invention to provide an overload protection device that can predict the possibility of a trip and prevent the harmful effects of the trip.

[0013]

The overload protection device according to the present invention comprises the following means. [1] Current detection means for detecting the current flowing through the shunt distribution line. [2] Calculation control means for calculating a margin current value based on the detected current and the rating of the shunt circuit breaker and transmitting the information to the shunt distribution line. [3] Display drive means for driving a display means for displaying availability of the outlet based on the information transmitted by the shunt distribution line.

[0014]

In the present invention, the current detecting means
The current flowing through the shunt distribution line is detected. The calculation control means calculates a margin current value based on the detected current and the rating of the shunt circuit breaker, and the information is transmitted to the shunt distribution line. Further, the display driving means drives the display means for displaying the availability of the outlet on the basis of the information transmitted by the shunt distribution line.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. The configuration of the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing Embodiment 1 of the present invention. FIG. 2 is a diagram showing an outlet according to the first embodiment of the present invention. In each figure,
The same reference numerals indicate the same or corresponding parts.

In FIG. 1, 1 is a power line and 2 is a power line 1.
The distribution board connected to 3 is a main overcurrent circuit breaker provided in the distribution board 2, 4 is a shunt overcurrent circuit breaker, and 5 is a shunt circuit connected to each shunt overcurrent circuit breaker 4. A distribution line, 6A is an outlet connected to the shunt distribution line 5.

Further, 7 is a block filter provided on the shunt distribution line 5, 8 is a current sensor also provided on the shunt distribution line 5, 9 is an input side connected to the current sensor 8 and an output side is a shunt. Connected to the distribution line 5, for example CPU, RO
An interface board including M, RAM, etc., 10 is a block filter connected to the end of the shunt distribution line 5, 11
Is a display unit, and 12 is a warning light.

The power line power supply voltage flowing through the shunt distribution line 5 is AC100 / 200V, 50/60 Hz, and the shunt distribution line 5 is a single-phase two-wire type power line. The transmission method of information from the interface board 9 to each display unit 11 is a power line carrier method of amplitude modulation, and the carrier frequency is 125 KHz, for example.

The current sensor 8 measures one total value of the used currents of all the corresponding shunts per one shunt. The interface board 9 draws a marginal current from the measured current and the current-carrying capacity of the shunt overcurrent circuit breaker 4, one for each shunt, and performs the presence or absence of output by the threshold control of the carrier wave or amplitude modulation. Similarly, the block filter 7 is provided for each shunt so as to prevent external leakage of the modulated wave signal and suppress external noise. The display unit 11 turns on the warning lamp 12 with the presence or absence of the signal carrier wave or the amplitude value, one for each outlet.

The current detecting means according to claim 1 of the present invention corresponds to the current sensor 8 in the first embodiment of the present invention described above, and the arithmetic control means according to claim 1 of the present invention is the first embodiment. Then, it corresponds to the interface board 9,
The display means according to claim 1 of the present invention corresponds to the warning light 12 in the first embodiment, and the display drive means according to claim 1 of the present invention corresponds to the display unit 11 in the first embodiment.

Next, the operation of the above-described first embodiment will be described. The interface board 9 measures the margin current value by comparing the total current at the outlet of the shunt obtained by the current sensor 8 with the rated capacity of the shunt overcurrent circuit breaker 4. The rated capacity is stored in advance in the RAM or the like. Then, the amplitude-modulated carrier wave is sent from the interface board 9 to each outlet 6A by using the normal shunt distribution line 5 as a transmission path by the carrier wave superposition transmission method.

At each outlet 6A, the display unit 11
The red warning lamp 12 is turned on by threshold control of the incoming carrier wave signal. That is, a value that corresponds to the maximum value of the devices that are expected to be connected, for example, 10 A
When the margin current decreases to, turn it on and warn you that you should not connect to an outlet.

The first embodiment of the present invention, as described above,
On the shunt distribution line 5 from the distribution board 2 of the power line 1 to each outlet 6A, a block filter 7 is arranged to prevent leakage of high frequency to the distribution board 2, and a current sensor 8 is connected to detect a used current. The value is sent to the interface board 9. On the other hand, each outlet 6A is provided with a block filter 10 to prevent leakage of high frequency to a device connected to the outlet, and the display unit 11 is provided at the input portion of the outlet 6A.
Is connected to turn on the warning light 12.

Then, the current value picked up by the current sensor 8 is fetched into the interface board 9, and a high frequency signal corresponding to the margin current value is passed through the shunt distribution line 5, and the outlet 6A is connected.
The warning lamp 12 is turned on by the threshold control of the display unit 11 of.

As a result, it is possible to determine whether or not the device to be used can be connected, and it is possible to prevent a sudden power supply trip. The first embodiment is applicable not only to general buildings but also to general households in some cases.

Embodiment 2 FIG. In the first embodiment described above, the block filter 7, the current sensor 8 and the interface board 9 are provided for each shunt unit, but even if one is provided for each of the distribution board 2 and the application range is a plurality of shunts, the same operation is performed. You can expect an effect. In this case, there is an effect that the cost can be reduced as a whole.

Embodiment 3 Further, in the above-described first embodiment, the visual warning is given by the warning light 12 as shown in FIG. 2 (a), but an audible warning such as the buzzer 12B as shown in FIG. 2 (b) is also intended. It goes without saying that can be achieved. When used in combination with a visual warning, the effect is increased.

Fourth Embodiment Furthermore, if the device user understands that the current value is about the current used by the device, and if he / she can expect a certain degree of caution in comparing with the displayed value, as shown in FIG. Is versatile.
In this case, the incoming carrier signal is A / D converted by the A / D converter in the display unit 11 and the margin current value is digitally displayed by the display device 12C.

Embodiment 5 Further, as shown in FIG. 2D, if the mechanical lid 13 is used to block the insertion port of the outlet 6D so that it cannot be inserted, the trip can be prevented more safely.

[0030]

As described above, according to the present invention, the current detecting means for detecting the current flowing through the shunt distribution line and the margin current value calculated based on the detected current and the rating of the shunt circuit breaker An arithmetic and control means for transmitting to the shunt distribution line, and a display driving means for driving a display means for displaying the availability of the outlet based on the information transmitted by the shunt distribution line. The user can notice the possibility of a power supply trip before connecting the device to an outlet, and the harmful effect due to the trip can be prevented in advance.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing an outlet according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a conventional distribution line system.

[Explanation of symbols]

2 distribution boards, 5 distribution lines, 6A, 6B, 6C, 6D
Outlet, 7 block filter, 8 current sensor, 9 interface board, 10 block filter, 11 display unit, 12 warning lights.

Claims (1)

[Claims] 1. A current detection means for detecting a current flowing through a shunt distribution line, a calculation of a margin current value based on the detected current and a rating of a shunt circuit breaker, and an operation for transmitting the information to the shunt distribution line. An overload protection device comprising: a control means, and a display drive means for driving a display means for displaying availability of an outlet based on the information transmitted by the shunt distribution line.