JP5166174B2 - Circuit breaker - Google Patents

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 that automatically controls power supply to the electric circuit according to the usage state of the working electric 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 electric wire constituting the primary circuit of the distribution board, and the branch switch is connected by drawing in the electric 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 from various industries, such as civil engineering, construction, and plumbing, to enter and exit the work, and the main switch installed on 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 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 power is continuously supplied to the electric circuit, there are the following inconveniences.

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.

Also, 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. It is to provide a reduced manufacturing cost while shortening the development period of the circuit breaker.

In order to solve the above problems, in claim 1 of the present invention, the current detection means for detecting the current flowing in the electric circuit, the contact opening / closing mechanism for turning on / off the electric circuit, and the contact opening / closing mechanism for acting on the contact opening / closing mechanism are opened. use a tripping means allowed to the state, the shut-off block with, on the basis of a signal outputted from said current detecting means provided in said shielding Danbu lock, the electric equipment for work that is supplied with power from the electrical path A determination means for outputting a signal when it is determined whether the work has been performed or not, and the tripping means is driven based on the signal output from the determination means and tripping the drive means, the decision block with, and connected by a connecting means, the decision block includes a power supply acquisition unit is connected to a path provided in the shield Danbu the lock to obtain the power, the current Output from detection means A current detection signal acquiring unit that acquires a signal, the through tripping tripping means drive path connecting unit driving means, the circuit is characterized in that transmitting and receiving power and signals to and from the decision block and the blocking block A circuit breaker is provided.

This makes it possible to separate and configure a blocking block that is connected to an electric circuit and a determination block that determines whether or not work is being performed. Because it is configured to be connected, the internal mechanism of a general circuit breaker with tripping means and other components can be used as much as possible, and it has a function to judge whether work is being performed. Compared to the development of a new circuit breaker from scratch, the development period can be shortened, and the circuit breaker can reduce the manufacturing cost because it can be manufactured without using parts in common or making significant changes to the production line. Can be provided. Therefore, when on-site work is not performed at the construction site or the like, electric power is not continuously supplied to the electric circuit, and environmental problems associated with consumption of excess energy can be solved. Therefore, it is possible to easily provide a circuit breaker that solves the safety problem.

Further, the determination by the determination means provides a circuit breaker, characterized in that if the detected current detected by the current detection means is equal to or less than a predetermined threshold, it is determined that no work is being performed. Also good.

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 differs at various work sites. By performing a comparison operation with, it is possible to appropriately grasp the state of work using the work electrical equipment.

In the determination by the determination means, the current data sampled every predetermined time is compared with the detected current detected by the current detection means over time, and the change width data as a result of the comparison is determined in advance. A circuit breaker may be provided in which it is determined that the operation is not performed if the threshold is not more than the threshold value.

Thus, in addition to being able to detect the current in a simple manner, by appropriately determining the threshold value, it is possible to cope with the current consumption state of the different working electrical equipment at various work sites, By grasping the change width of the magnitude of the current that changes between the use state and the stop state of the work electrical device, it is possible to appropriately grasp the state of the work using the work electrical device.

According to the present invention, a circuit breaker having a function of automatically stopping power supply when field work is completed and no work is performed, while shortening the development period of the circuit breaker. In addition, it is possible to provide a circuit breaker that can be provided at a reduced manufacturing cost, and that can eliminate environmental problems and safety problems associated with the consumption of excess energy at work sites. Can be provided.

Next, the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram when the circuit breaker of the present invention is connected to an electric circuit. In FIG. 1, 100 is a circuit breaker, and 1 to 3 are three-phase three-wire electric circuits to which the circuit breaker 100 is connected. In addition, as the electric circuit, a phase-wire type electric circuit that is commonly used in a work site such as a single-phase three-wire system, a single-phase two-wire system, and a three-phase three-wire system is assumed.

Reference numeral 110 denotes a blocking block. The blocking block 110 includes a current detecting means 111 for detecting a current flowing in the electric circuit, a contact opening / closing mechanism 112 for turning on / off the electric circuit, and a tripping means 113 for acting on the contact opening / closing mechanism 112 to open the contact. And.

As the current detection means 111, a current transformer provided through the electric circuit is used. Further, in the present embodiment, the current detection means 111 is provided in the U phase and the W phase in the electric circuit in the figure, and detects the current generated by performing work using the work electrical equipment. In the case of a single-phase three-wire system, a current transformer may be provided for each voltage line. In addition to this, the current detecting means may be configured using a shunt resistor, a Hall element, or the like.

The tripping means 113 is configured using a trip coil having an iron core that acts on the opening / closing mechanism 112. When a current flows through the trip coil, the iron core is drawn into the coil by electromagnetic force, and the latch provided in the opening / closing mechanism 112 is pulled off to open the contact. The tripping means may be configured using a piezoelectric element or an actuator that performs mechanical displacement by supplying energy. As a base of the interruption block 110, a current detection means may be appropriately incorporated and configured using a circuit breaker provided with a tripping means.

Reference numeral 120 denotes a determination block that is used by being connected to the blocking block 110 by a connecting means constituted by a mechanical engagement portion or the like.

The determination block 120 determines based on the signal output from the current detection means 111 provided in the interruption block 110 whether or not the work using the work electric device supplied with power from the electric circuit is being performed. , A judging means for outputting a signal when it is judged that the work is not performed, and a trip driving means for driving the tripping means based on the signal outputted from the judging means.

In this embodiment, the determination unit is configured using a microcomputer 121 having an I / O port, a program data storage area, an arithmetic processing unit, and the like, and a signal output from the microcomputer 121 is used as a trip driving unit. It is configured using a thyristor 122 that is driven as a trigger and becomes a part of the power supply path of the tripping means. The trip driving means may be configured using other relays or semiconductor switches.

The determination block 120 includes a power acquisition unit 130 that acquires power by being connected to an electric circuit provided in the blocking block 110, a current detection signal acquisition unit 140 that acquires a signal output from the current detection unit 111, A tripping means driving path connection unit 150 for driving the removing means is provided, and power and signals are transmitted to and received from the blocking block 110.

In the present embodiment, lead wires constituting the power source acquisition unit 130, the current detection signal acquisition unit 140, and the tripping means drive path connection unit 150 are disposed in a part of the body constituting the outline of the blocking block. The hole is provided and drawn into the judgment block.

The power acquired from the power acquisition unit 130 is full-wave rectified in the determination block, stepped down to a voltage suitable for driving the microcomputer 121, and supplied to the microcomputer 121.

The signal output from the current detection means acquired from the current detection signal acquisition unit 140 is amplified by a voltage amplification circuit as input preprocessing before being input to the microcomputer 121, and unnecessary noise is removed by a low-pass filter. Then, it is adjusted to an input level suitable for the input port of the microcomputer by the signal level adjusting circuit and input to the microcomputer. In the present embodiment, a plurality of current detection means are provided, and the number of input preprocessing systems is provided.

The signal input to the microcomputer 121 determines whether or not the work is being performed by a determination program stored in the microcomputer, and if it is determined that the work is not being performed, the trip driving means A drive signal is output to 122. When the drive signal is received and the trip drive means 122 has an output, a voltage is applied to the trip means 133, and the trip means operates to bring the contact of the contact opening / closing mechanism 112 into an open state. As a result, the supply of power to the electric circuit is stopped. In the single-phase three-wire system and the three-phase three-wire system, the outputs of the two current detection elements such as current transformers and shunt resistors, which are current detection means installed in two of the three wires, are respectively output. It may be configured so that it is determined that no work is performed when either output falls below the threshold, or when the sum of the outputs falls below the threshold It may be configured to determine that no work is performed.

Next, the first determination method performed by the above-described determination means will be described in detail. The first determination method is to detect the current flowing in the electric circuit and compare the detected current magnitude with a predetermined threshold value to determine whether or not work using the work electrical equipment is being performed. is there. If the magnitude of the detected current is equal to or less than the threshold value, it is determined that the work is not being performed.

In FIG. 1, 123 is a threshold value setting means. The threshold setting means 123 is configured so that various thresholds can be alternatively selected by a changeover switch. This threshold value can be assumed at various sites such as 5A, 10A, 15A, 20A, 25A, and 30A so that it can be appropriately selected according to the scale of the work site and the number of work electrical devices to be used. Current value is provided. In addition, you may comprise using the stepless switch which can change the value of a threshold value continuously instead of a changeover switch.

Also, when the detected current value falls below the threshold value, if a determination is made immediately that “no work is being performed”, the circuit will be used even when the use of electrical equipment for work is temporarily stopped. It is assumed that the circuit breaker breaks down and hinders work. For this reason, when the state where the detected current value is equal to or less than the threshold value continues for a certain period of time before the determination operation is performed, the determination operation is performed as “no work is performed”.

In this embodiment, a timer function is provided inside the microcomputer, and when the detected current value is below the threshold value continues for a certain period of time, the timer is counted up, and the operation of determining that “no work is being performed” is performed. Like to do. The timer count-up time can be set to 30 minutes or 1 hour by the timer setting means 124 constituted by a changeover switch.

In addition, the detected current signal varies finely over time due to voltage fluctuations, noise, etc., in addition to the use of electrical equipment for work. For this reason, in order to more accurately determine whether or not work is being performed, the detected current signal is not subjected to determination processing for each wave, but is divided into a certain amount of time width as one break, and the magnitude of the current between them. Are averaged to avoid misjudgment due to unnecessary fluctuations.

More specifically, the average value of the current magnitude is calculated by the microcomputer 121 every 10 waves of the commercial frequency, and it is determined whether the average value is equal to or less than a threshold value determined in advance by the threshold value setting means 123. When the following state continues for the time set by the timer setting means 124, a determination operation is performed as “no work is performed”, and the timer is reset when the threshold value is exceeded in the middle.

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.

Next, the second determination method performed by the above-described determination means will be described. In the second determination method, the current flowing through the electric circuit is detected by the current detection means 111, and the current data sampled by the determination means for a predetermined time with respect to the detected current detected by the current detection means 111 is stored as one. It is treated as unit data, and the magnitude of current for each unit data obtained over time is compared. If the comparison result shows that the magnitude change width data of the current is equal to or smaller than a threshold set in advance by the threshold setting means 123. It is determined that no work is being performed.

The second judgment method differs from the first method in that the judgment means compares the current magnitude for each unit data over time when performing judgment processing, and the magnitude of the current 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 timer 622 is reset to count, and the change width data and the threshold value are continuously compared.

In order to correctly perform the determination process 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 10A to 20A including the reactive current, and the ratio is higher than the current of about 30A to 40A during welding work. 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 welding operation of a single welding machine, the threshold set in advance according to the first method is not to reflect the standby current at the site appropriately. 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, Regardless of the size of the standby current, 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 troublesome. There will be no more.

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.

In FIG. 2, the external view of the circuit breaker 100 of this invention was shown. The blocking block 110 and the determination block 120 are configured to be connected by connecting means. In order to use various circuit breakers for the general purpose as the connecting means, a sheet coated with an adhesive is used.

In the determination block 120, reference numeral 123 denotes threshold setting means, which is configured using a changeover switch that can be set in increments of 5A from 5A to 30A according to the second determination method. Also, the function OFF can be selected so that the function of the determination operation itself can be turned OFF.

Reference numeral 124 denotes timer setting means for setting a timer time, which can select either 30 minutes or 1 hour.

Reference numeral 125 denotes a power lamp, which is configured using LEDs. The power lamp is electrically connected to the output port of the microcomputer 121 and is lit when the determination block is functioning.

Note that the method of turning on the power lamp may be changed according to the determination status of the determination unit. For example, the lighting may be normally performed, but the determination process may be performed based on the detected current, and when the timer operation starts, it may blink to notify that the power supply will be shut off soon.

126 is a test button. When the test button 126 is operated, the microcomputer 121 performs a self-check to check whether the functions of both the determination block and the blocking block are normal.

In this embodiment, when the test button 126 is operated, the shutoff signal of the microcomputer 121 is output after 5 seconds. Since the trip driving means receives the shut-off signal and becomes conductive between the anode and the cathode, power is applied to the trip means 113 provided in the shut-off block. Then, the tripping means 113 is driven and acts on the contact opening / closing mechanism 112 to open the contact.

Reference numeral 114 denotes a cut-off display button. The shut-off display button 114 is configured to protrude from the casing that forms the outline of the shut-off block when the shut-off operation is performed according to the judgment of the judgment block. Specifically, when the iron core provided in the tripping means 113 is operated, it is configured to project / retract in conjunction with the movement of the iron core.

As a result, when the operation handle of the blocking block 110 is in the OFF position, it is determined whether or not the blocking operation has been performed by determining that the work is not being performed by checking the protruding state of the blocking display button 114 to determine whether the operation is being performed. Judgment can be made.

In this way, when work is not being performed, a circuit breaker having a function of automatically stopping power supply is provided while reducing the development period of the circuit breaker and reducing the manufacturing cost. In addition, it is possible to easily provide a circuit breaker that can solve environmental problems and safety problems associated with the consumption of excess energy at work sites.

In the present embodiment, an example is shown in which a microcomputer is used to compare and determine the detected current and a predetermined threshold value, and to output to the trip driving means. A capacitor is used to compare the output value obtained from the current detection means with the threshold setting value in an analog manner, and when the threshold setting value becomes large, a circuit for driving the trip driving means is configured. May be. Thus, an inexpensive analog circuit can be used without using an expensive microcomputer.

The circuit breaker of the present invention can be used for temporary distribution boards at construction sites and construction sites. In addition, since it is possible to prevent forgetting to turn off electricity, it can be used for household purposes, factories and other business purposes as much as possible for the same purpose.

The block diagram of the circuit breaker of a 1st Example. The external view of the circuit breaker of this invention.

1, 2, 3 Electric circuit 100 Circuit breaker 110 Breaking block 111 Current detection means 112 Contact opening / closing mechanism section 114 Breaking display button 120 Determination block 121 Microcomputer 123 Threshold setting means 124 Timer setting means 125 Power lamp 126 Test button 130 Power acquisition section 140 Current detection signal output unit 150 Tripping means drive path connection unit

Claims (3)

Current detection means for detecting current flowing in the electric circuit;
A contact switching mechanism for turning on and off the electric circuit;
A tripping block that includes a tripping means that acts on the contact opening / closing mechanism to open the contact;
Based on the signal outputted from said current detecting means provided in said shielding Danbu lock, determined row work whether work is being carried out using a working electrical equipment supplied with power from path A determination means for outputting a signal when it is determined that the
A tripping driving means for driving the tripping means on the basis of the signal output from said determination means, the determination block with,
Connected by connecting means,
The decision block includes a power supply acquisition unit is connected to a path provided in the shield Danbu the lock to obtain the power,
A current detection signal acquiring unit that acquires a signal output from said current detecting means,
Through tripping driving the tripping unit means drive path connection unit,
Circuit breaker, characterized in that transmitting and receiving power and signals to and from the decision block and the blocking block.
The determination in the determination means is
2. The circuit breaker according to claim 1, wherein if the detected current detected by the current detecting means is equal to or less than a predetermined threshold value, it is determined that no work is performed.
The determination in the determination means is
For the detected current detected by the current detecting 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.

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