JP2010063246A - Circuit breaker device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit breaker device which stops power supply automatically when a decision is made that a work is not done after a construction work using an electrical apparatus for work is completed. <P>SOLUTION: The circuit breaker device includes an apparatus use condition detection means 3 for detecting the use condition of an electrical apparatus for work which is connected with an electric circuit and used as a construction work progresses and outputting a signal according to the use condition of an electric load, a decision means 4 for deciding whether a work is done or not based on a signal outputted from the apparatus use condition detection means and outputting a signal when a decision is made that a work is not done, a tripping means 5 which operates based on a signal outputted from the decision means, and a contact open/close means 6 which opens the electric circuit in response to action of the tripping means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a circuit breaker that monitors the usage state of a working electrical device or the like that is connected to an electric circuit, and automatically shuts off the power supply to the electric circuit according to the usage state of the working electrical device. About.

At construction sites, etc., where temporary power usage is required depending on the progress of work, a temporary distribution board is installed to supply power to the work electrical equipment. Is going.

As such a temporary distribution board, for example, a distribution board as disclosed in Patent Document 1 is used. The temporary distribution board includes a main switch and a branch switch connected to the load side of the main switch in a casing that forms an outer shell. The main switch in the housing is connected by drawing in the wire constituting the primary circuit of the distribution board, and the branch switch is connected by drawing in the cable constituting the secondary circuit of the distribution board. , Used to supply power to the working electrical equipment.
Japanese Patent Laid-Open No. 2001-157328 FIG.

As described above, the temporary distribution board is often used by turning on the main switch and branch switch at the start of each day and turning off at the end of work.

However, at construction sites, etc., it is common for a large number of workers in various industries, such as civil engineering work, building work, and plumbing work to enter and exit the work, and the main switch installed in the temporary distribution board and The ON / OFF operation of the branch switch is usually performed by each contractor or worker as necessary.

And who is responsible for turning off the switch at the end of each day depends on the progress of the work at that time and the workers entering and leaving, and the switch is not turned off even after the end of work. In the case of forgetting to cut, there are cases where power is continuously supplied to the working electrical equipment until the start of work the next day.

When the switch is not turned off even after the work is completed in this way and the power continues to be supplied to the electric circuit, there are the following disadvantages.

First, there is an environmental problem due to the consumption of excess energy.

For example, the power consumption during welding work of an AC arc welder used at a work site is about 1 kW to several kW, depending on the output, and the standby power is about 200 W to 300 W per unit.

That is, as long as the power supply to the welding machine is continued, the standby power alone consumes several hundred watts of extra power per unit, and there is a problem that the environmental load such as CO ₂ emission becomes high.

Temporarily, the standby electric energy for 15 hours at night from the end of work (17:00) to the start of the next morning (8:00) is 200 W × 15 h = 3 kWh. In January, 3 kWh × 30 days = 90 kWh, and in 1 year, 90 kWh × 12 months = 1080 kWh. This is equivalent to approximately 50 kg of carbon dioxide emissions per month when converted to carbon dioxide according to the “Enforcement Ordinance on Promotion of Global Warming Countermeasures”, and approximately 600 kg of carbon dioxide emissions per year. The amount is equivalent to

Second, there are safety issues.

Electrical circuits at temporary sites are mostly electric wires and equipment for movement, and electrical and mechanical protection is often insufficient compared to other facilities. If electricity supply is continued in such an electric circuit and in an unattended state, there is a risk that a discovery may be delayed and a fire may occur when an accident such as a short circuit or leakage occurs.

In addition, when changing the wiring of equipment at the start of work, it may be mistaken that the switchboard of the temporary distribution board is turned off the previous day, and the live parts may be touched directly, resulting in electric shock and personal injury. is there. For this reason, it is desirable that the switch is turned off after the work is completed at the construction work site.

Therefore, the object of the present invention is to provide a circuit breaker that automatically stops the power supply to the electric circuit when it is determined that the work has not been done at the construction site. Is to provide.

In order to solve the above-mentioned problems, in claim 1 of the present invention, the use state of the working electrical equipment used by being connected to the electric circuit in connection with the construction work is detected, and a signal is output according to the use state of the electric load. Based on the device usage state detection means to be performed and the signal output from the device usage state detection means, it is determined whether or not work is being performed, and if it is determined that the work is not being performed, a signal is output. A circuit breaker characterized by comprising: a judging means; a tripping means that operates based on a signal output from the judging means; and a contact opening / closing means that turns off the electric circuit when the tripping means operates. Equipment was provided.

As a result, the tripping means is driven based on the output signal from the output circuit, so that the contact switching mechanism does not cut off the electric circuit and power is not continuously supplied to the electric circuit after the work is completed. As well as solving environmental problems associated with the consumption of energy, safety issues can also be solved.

The device usage state detection means is a current detection means for detecting a current flowing in the electric circuit, and the determination means determines that the detected current detected by the current detection means is not more than a predetermined threshold value. A circuit breaker may be provided that is characterized in that it is determined that work is not being performed.

As a result, the current can be detected by a simple method, and by appropriately setting the threshold value, it becomes possible to cope with the current consumption state of the different working electrical equipment at each work site, and the construction work is completed. Therefore, it is possible to perform appropriate control based on the output signal from the output circuit, solve the environmental problems associated with the consumption of excess energy, and ensure safety. The above problem can be solved.

The device usage state detection means is a current detection means for detecting a current flowing in the electric circuit, and the determination means is sampled at a predetermined time with respect to the detected current detected by the current detection means. The circuit breaker may be provided by comparing the current data with time and determining that the operation is not performed if the change width data as a result of the comparison is equal to or less than a predetermined threshold value.

As a result, the current can be detected by a simple method, and by appropriately setting the threshold value, it becomes possible to cope with the current consumption state of the working electrical equipment that is different for each work site. By comparing the change in the magnitude of the current that changes between the operating state and the stopped state, it is possible to more accurately determine that the construction work has been completed. It is possible to appropriately grasp the current state when the device is not used.

According to the present invention, the power supply can be automatically stopped at the construction site or the like after the work is completed, which eliminates environmental problems and safety problems associated with the consumption of excess energy. A circuit breaker that can be eliminated can be provided.

Next, the present invention will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of the present invention. In FIG. 1, 1 is a single-phase three-wire system, a three-phase three-wire system, etc., and is omitted from the single-line diagram. Reference numeral 2 denotes a contact device, which may be an electromagnetic contactor, a circuit breaker for wiring, or a circuit breaker. 3 is a detection means for inputting a signal to the determination means 4. Determining means 4 determines whether or not the work using the work electrical equipment has been completed based on a predetermined procedure from the signal of the detecting means 3. If it is determined that the work has been completed, 6 contact breaking means are driven from 5 output circuits to stop supplying power to the electric circuit.

Next, the first determination method of the above-described determination means 4 will be described. The first determination method is a method of detecting a conduction current and providing a threshold value for the current. A threshold value is provided for the detected current, and if it is equal to or less than the threshold value, it is determined that work is not being performed.

The first determination method will be described in more detail with reference to FIG. In FIG. 2, reference numeral 321 denotes a current detection means as a device use state detection means, and a method using a current transformer or a shunt resistor can be considered. For single-phase two-wire system, the current on one of the two lines, for single-phase three-wire system, on the voltage-side two lines, and for three-phase three-wire system, current on two lines of UVW Install to detect.

Reference numeral 421 denotes current value determination means for determining whether the current value is less than or equal to a threshold value determined in advance by the threshold setting means 423 based on the current information output from the current detection means. To do. More specifically, the average value of the current is calculated by the current value determining means 421 for every 10 waves of the commercial frequency, and it is determined whether or not the average value is less than or equal to the threshold value previously determined by the threshold setting means 423. The timer 422 may be reset when the above is reached.

The count-up time of the timer is set to about 30 minutes or 1 hour by a changeover switch, and if the current is below the threshold value continues for the count-up time, it is determined that the work has been completed, and tripping means is output by the output circuit 5 6 is driven to open the contact 2.

The threshold is set instead of whether the current is zero or not because the dark current flows due to the capacitance between the circuit and the ground even if no load is connected, and there is a standby current due to forgetting to switch off the equipment. It is taken into consideration. It is preferable that the threshold can be switched according to the situation at the site.

As this threshold value, it is preferable to use a changeover switch or the like so that it can be switched to a current value that can be assumed at various construction sites, such as 5A, 10A, 15A, 20A, 25A, and 30A. In addition, you may comprise using the stepless switch which can change the value of a threshold value continuously instead of a changeover switch.

Next, the second determination method of the determination means 6 will be described with reference to FIG. In the second determination method, the current flowing through the electric circuit is detected by the current detection unit 321, and current data sampled by the current value determination unit 421 for a predetermined time with respect to the detected current detected by the current detection unit 321. Are compared as one unit data, the magnitude of the current for each unit data obtained over time is compared, and the change width data of the magnitude of the current as a result of the comparison is a threshold set in advance by the threshold setting means 423. If it is below, it is judged that the work is not performed.

As the predetermined time, in this embodiment, 10 cycles of the commercial frequency are treated as one unit data, and the average value between them is treated as current data in the unit data.

The second determination method is different from the first method in that the current value determination means 421 in the figure compares the current magnitude for each unit data over time, and compares the current magnitude as a result of the comparison. The difference is the change width data, and the change width data is used as the determination material. The change width data is compared with a preset threshold value by calculation. When the change width data exceeds the threshold value, the count of the timer 422 is reset and the change width data and the threshold value are continuously compared.

In order to correctly perform the determination by the first determination method, it is important to set a predetermined threshold value. In other words, there remains an inconvenience that the threshold value must be frequently adjusted according to the number and type of work electrical devices used at the work site, the magnitude of the current consumption, and the standby current state.

For example, in an AC arc welder frequently used at construction sites, the standby current is about 10 A to 20 A including the reactive current, and the ratio of the standby current is about 30 A to 40 A compared to the welding current of about 30 A to 40 A. There are many. In addition, the number of welding machines used varies depending on the work site, and the standby current and welding current differ depending on the type of welder used, so the standby current is usually significantly different at each site.

Under these circumstances, if it is attempted to detect the operation of one welding machine, the threshold value set in advance according to the first method is not set unless the standby current at the site is appropriately reflected. However, according to the second method, since the determination is made based on the change in the magnitude of the current for each unit data, the standby current is not detected. Regardless of the size, it is possible to properly determine whether work is being performed or not. Therefore, compared to the first method, it is possible to accurately determine the threshold without setting the threshold frequently, and the setting is cumbersome. Disappear.

The first or second method described above can be used alone as a determination method performed by the determination means, or can be used in combination.

The first determination method and the second determination method described above may be performed for each of the current transformers and shunt resistors of the current detection means installed in the above-described electric circuit, In the three-phase three-wire system, determination may be made by summing the outputs of two current detection elements such as current transformers installed on two of the three wires or shunt resistors.

As another embodiment, the contact device 2, the detection means 3, the determination means 4, the output circuit 5, and the contact release means 6 are, for example, a circuit breaker for wiring or a circuit breaker In addition, it may be configured integrally in the same box, or an electromagnetic contactor is used for 2 contact devices and 6 contact opening means, and 2 detection means to 5 output circuits are configured as separate units. May be.

The present invention can be used for a temporary distribution board at a construction site or a construction site. In addition, since it is possible to prevent forgetting to turn off electricity, it can be used for household purposes and other business purposes as much as possible for the same purpose.

The block diagram which shows the circuit interruption apparatus of a 1st Example. The block diagram which shows the circuit interruption apparatus of a 2nd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric circuit 2 Contact apparatus 3 Detection means 4 Judgment means 5 Output circuit 6 Contact release means

Claims (3)

A device usage state detection means for detecting a usage state of a working electrical device used by being connected to an electric circuit in connection with construction work, and outputting a signal according to the usage state of the electrical load;
A determination means for determining whether or not work is being performed based on the signal output from the device usage state detection means and determining that the work is not being performed;
Tripping means that operates based on a signal output from the determination means;
Contact opening / closing means for turning off the electric circuit by the tripping means acting;
A circuit breaker comprising:
The device usage state detection means is a current detection means for detecting a current flowing in the electric circuit,
2. The circuit breaker according to claim 1, wherein the determination unit determines that the operation is not performed if the detected current detected by the current detection unit is equal to or less than a predetermined threshold value.
The device usage state detection means is a current detection means for detecting a current flowing in the electric circuit,
The determination means is for the detection current detected by the current detection means,
Compare the current data sampled every predetermined time with time,
2. The circuit breaker according to claim 1, wherein if the change width data as a result of the comparison is equal to or less than a predetermined threshold value, it is determined that no work is performed.

Images