KR101400711B1 - Apparatus for preventing electric shock for use in an electric facility - Google Patents

Abstract

The present invention relates to transmission and distribution technologies, and more particularly to an apparatus installed on a transmission path or a terminal of the transmission path in order to prevent electric shock. The anti-electric shock apparatus is connected with a transmission and distribution path of the electric facility. The anti-electric shock apparatus prevents, from electric shock upon flooding, the electric facility connected with the anti-electric shock apparatus or another electric facility positioned around the anti-electric shock apparatus and electrically connected with the electric facility. The anti-electric shock apparatus includes a first flat plate conductor having one terminal fixed to a first input terminal, an opposite terminal fixed to a first output terminal, a width wider than the thickness of a first wire, and a length longer than the thickness of the first wire. The area obtained by multiplying the width by the length is 4 times to 100,000 times wider than a sectional area of the first wire. The anti-electric shock apparatus includes a second flat plate conductor having one terminal fixed to a second input terminal and an opposite terminal fixed to a second output terminal, and having the same standard as that of the first flat plate conductor; and a housing serving as a nonconductor electrically separating the first flat plate conductor from the second flat plate conductor and fixing the first and second flat pate conductors.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to transmission and distribution technology, and particularly relates to a device installed at a delivery path or at a terminal thereof to prevent an electric shock accident.

Electric shock is a phenomenon in which the human body reacts when the current flowing from the power source through the human body to the ground surface is greater than a predetermined value. Generally, currents exceeding 15mA cause spasticity and more than 50mA lead to death. The main cause of death is a heart attack in which the heart stops working as current through the heart damages the nerve. The risk of electric shock is related to the resistance of the human body when energized, which is highly dependent on the condition of the skin.

When electrical equipment, for example, an outlet, a heater, or a lamp, is immersed in water, a human body, such as a metal housing that is energized through water or water, may contact the exposed conductor of electrical equipment through water and the human body, Current flows. At this time, the human body is likely to be wet with rain, and in this case, the contact resistance is extremely low, which is very dangerous.

Open No. 2005-0,037,986 discloses a method in which a metal plate or metal net made of metal is attached to a charger and current leakage from the charger is conducted to a conductive metal plate or a metal net, To prevent a flooded electric shock. The metal plate or metal net is connected to the neutral and earth terminals among the terminal blocks by electric wires. The size of the metal plate is approximately 50 cm x 30 cm.

This technique does not explain the principle in detail, but it is possible to arrange the metal plate in parallel with the body by arranging the metal plate with a resistance much lower than the resistance between the water and the human body between the flooded conductors in the flooding, . However, such a metal plate or metal net is connected to the terminal block by a separate electric wire and is bulky, so that there is a space limitation in installation.

Patent Publication No. 1,197,414 discloses another electric leakage preventing device. The apparatus includes a connection terminal block disposed between an input terminal portion and an output terminal portion and having first and second connection terminals connected to a phase voltage terminal and a neutral point terminal, and a connection terminal block electrically connected to a second connection terminal block connected to the neutral point terminal, And an anti-leak conductor having a shape surrounding a side and an upper side of the dielectric.

Such a technique is complicated in configuration because it uses an electrode of a shape connected to a neutral point terminal while surrounding a connection terminal block. And it is also difficult to apply it to a small outlet or the like.

An object of the present invention is to provide an electric shock preventer which is simple in structure and easy to install.

It is another object of the present invention to provide an electric shock preventer which can be applied to various applications such as a small electric outlet and an outdoor streetlight.

In order to achieve this object, an electric shock preventive device according to an aspect is connected to a transmission / distribution path to an electric facility. An electric shock protection device prevents electric shock when the electric shockproof device is connected to the electric equipment to which the electric shock prevention device is connected or the other electric equipment which is located near the electric device is flooded.

According to an aspect of the present invention, there is provided an electric shock preventer comprising a first input terminal to which an input-side first electric wire is connected, a second input terminal to which an input-side second electric wire is connected, a first output terminal to which an output- And a second output terminal to which a wire is connected. The electric shock preventing device includes a first flat plate-like conductor and a second flat plate-like conductor. The first flat plate-like conductor has one end fixed to the first input terminal and the other end fixed to the first output terminal. The width is larger than the thickness of the first wire, the length thereof is longer than the thickness of the first wire, And the length is a multiple of 4 times or more and 100,000 times or less the cross-sectional area of the first wire. The second flat plate-like conductor has one end fixed to the second input terminal and the other end fixed to the second output terminal, and has the same standard as the first flat plate-like conductor. Further, the electric shock preventer may include a non-conductive housing for electrically separating and fixing the first plate-like conductor and the second plate-like conductor.

According to still another aspect, the material of the first planar conductor and the second planar conductor may be copper (Cu).

According to a further aspect, the housing can fix the first plate-like conductor and the second plate-like conductor so that they face each other.

According to a further aspect, the electric shock preventer may be installed in a state where the first planar-type conductor and the second planar conductor are opposed to each other, and may be installed at a lower position than the target electric device to be protected from flooding.

It has been experimentally proven that the current flowing through the human body in contact with the electric current leaked near by the simple structure can be substantially reduced by providing a pair of the planar conductors in the delivery path.

Fig. 1 shows an appearance of an electric shock preventer according to an embodiment.
FIG. 2 is a cross-sectional view taken along the center line of the four terminal screws in FIG. 1; FIG.
Figure 3 shows the arrangement of the instruments of the first experiment.
Figure 4 shows the arrangement of the instruments of the second experiment.

The foregoing and further aspects will become more apparent from the following examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

Fig. 1 shows an appearance of an electric shock preventer according to an embodiment. FIG. 2 is a cross-sectional view taken along the center line of the four terminal screws in FIG. 1; FIG. An electric shock preventing device according to an embodiment will be described with reference to Figs. 1 and 2. Fig.

An electric shock prevention device according to an embodiment is connected to a transmission and distribution path to a domestic or industrial electric facility such as a lamp, a streetlight, an outlet, a plug, a motor, and the like. As will be described later, the electric shock preventer prevents electric shock when immersed in the electric equipment to which the electric shock preventer is connected or the other electric equipment which is electrically connected to the electric equipment.

As shown in the figure, the apparatus for preventing an electric shock according to an embodiment includes a first input terminal 11 to which a first input wire is connected, a second input terminal 13 to which an input second wire is connected, And a second output terminal 33 to which the output-side second wire is connected. Further, the apparatus for preventing electric shock according to one embodiment includes a first plate-like conductor 110 and a second plate-like conductor 130. The first flat plate-like conductor 110 has one end fixed to the first input terminal and the other end fixed to the first output terminal. The width of the first flat plate-like conductor 110 is wider than the thickness of the first wire and longer than the thickness of the first wire , And the area which is a product of the width and the length is four times or more and 10,000 times or less the cross-sectional area of the first wire. The second flat plate-like conductor 130 has one end fixed to the second input terminal and the other end fixed to the second output terminal, and has the same standard as the first flat plate-like conductor 110. In addition, the electric shock preventer may include a housing 300, which is a nonconductive body that electrically isolates and fixes the first flat plate-like conductor 110 and the second flat plate-like conductor 130 to each other.

The input first side wire which is screwed to the first input terminal 11 and the input side second wire which is screwed to the second input terminal 13 are physically and electrically identical to each other. However, the present invention is not limited thereto. Likewise, the output-side first wire to be screwed to the first output terminal 31 and the output-side second wire to be screwed to the second output terminal 33 are physically and electrically identical to each other. However, the present invention is not limited thereto. Since the electric shock prevention device is installed in the transmission and distribution path, the first input-side cable and the first output-side electric wire are physically and electrically identical to each other, and the input-side second electric wire and the output-side second electric wire are physically and electrically identical to each other. However, the present invention is not limited thereto.

In one embodiment, the first input terminal 11, the second input terminal 13, the first output terminal 31, and the second output terminal 33 are all formed in the same form. However, they may be configured differently or in pairs. As shown in the figure, in one embodiment, these terminals are screwed directly to both ends of the second flat-plate-like conductor, and a screw inserted into and screwed into the screw hole and screwed to the housing, And an auxiliary plate for helping to fix the stripped wire between the strips. In another example, the terminals may be constituted by a terminal block which is press-fixed to one end of the plate-like conductor. The terminals may be configured in various forms connecting the wires to both ends of the planar conductors.

The housing 300 physically fixes the terminals and the planar conductors. Since the illustrated embodiment is applied to a two-wire system, the housing fixes two planar conductors, but in the case of a three-wire system, three planar conductors may be fixed. The housing may be made of non-conductive plastic or ceramic material.

The structure of the housing is designed so that the housing fixes both ends of the planar conductors and exposes most of the planar conductors in a suspended state in the air because it is advantageous that the planar conductors are exposed to each other as much as possible in the flooded state. In the illustrated embodiment, the plate-like conductor is fixed at a lower height than the outer contour of the housing, and the operator inadvertently contacts the plate-like conductor exposed at the time of installation or after installation to prevent electric shock. Specifically, the four pillars protruding from the upper portion of the housing fix the planar conductors with terminals, which project slightly higher than the planar conductors fixed to the pillars. Additionally, the housing may further include an additional lid on the exterior. The lid can be of a form with perforated holes of sufficient number and size so that the water can easily enter when it is submerged, while blocking the contact due to carelessness of the human body.

According to a further aspect, the housing can fix the first plate-like conductor and the second plate-like conductor so that they face each other. Although the present invention can not be fully explained by the theory of electric circuits, the electric shock prevention device of the electric shock prevention apparatus is filled with water between the two plate-like conductors when immersed in water, And becomes an electrical resistor to be formed. Since the electrical resistance is proportional to the length of the resistor and inversely proportional to the cross-sectional area, the cross-sectional area is maximized and the length is minimized when the plate-type electrodes face each other. Thus, when connected in parallel to the human body and the ground plane, the current flowing to a human body having a higher resistance can be minimized.

According to still another aspect, the electric shock preventer is installed in a state in which the first planar-type conductor and the second planar conductor are opposed to each other, and is installed at a lower position than the target electric device to be protected from flooding. For example, in the case of streetlight, the controller exposed at the bottom is installed in a waterproof space. However, when rainwater or the like gets in this space, people around the house are in danger of electric shock. The electric shock preventive device is installed in the waterproof space and is installed at a position lower than the controller, so that the controller floods before the flooding, thereby enabling the controller to operate first.

According to still another aspect, the material of the first planar conductor and the second planar conductor may be copper (Cu). According to the experiment, the effect of the anti-electrostatic device was excellent when the material of the plate-like conductor was copper rather than iron or aluminum.

Figure 3 shows the arrangement of the instruments of the first experiment. In the first experiment, water is filled in the water tank 502, the electric shock preventer 503 according to one embodiment, one end of which is connected to the plug, is immersed in the water tank 502, the lamp 505 at the other end is exposed outside the water tank, Water is not grounded. At this time, plug 501 is connected to a power outlet to supply power. At this time, it can be confirmed that the lamp 505 is lit even though the electric shock preventer 503 is immersed in water. Next, the experimenter 509 grasps the exposed end of the electric wire and measures the current flowing through the electric wire with the ammeter 507 while the exposed end is immersed in the water tank. It may be dangerous if the experimenter (509) conducts the experiment directly, so it may be replaced by an animal having a similar conductive property to the human body instead of the human body. Table 1 below shows the result of repeating the experiment shown in Fig. 3 for a flat plate type conductor having various lengths and lengths. A commercial power source of 220 V / 60 Hz was used as the power source, a load of 120 W incandescent lamp was connected, and a gap between the two flat plate conductors facing each other was 10 mm. The wires used also include a cylindrical conductor with a diameter of 1.8 mm. In the following table, the width is the width of the plate-like conductor, the length is the length, and the measured value is mA.
Length Width 0.9mm 1.8mm 3.6mm 7.2mm 14.4 mm 28.8 mm 0.9mm 13.12 12.51 12.07 11.42 11.03 10.02 1.8mm 12.52 2.52 1.10 0.90 0.75 0.67 3.6mm 12.05 1.10 0.95 0.75 0.67 0.37 7.2mm 11.41 0.90 0.75 0.67 0.37 0.21 14.4 mm 11.02 0.75 0.67 0.37 0.21 0.11 28.8 mm 10.03 0.67 0.37 0.21 0.11 0.05 57.6 mm 9.81 0.37 0.21 0.11 0.05 0.01

The experimental results show that the current passing through the human body is insignificant with respect to the size of all flat plate conductors. In this experiment, when a single-phase alternating current flows through the water in a water tank, a voltage drop occurs in the water, which is a three-dimensional resistor. When the human body touches, the current flowing through the human body between the water and the ground is shifted to the middle value It is presumed to result in exposure to a much lower AC power than in the case of direct contact with a typical single-phase AC. It is not clear, however, how the two flat conductors play a role to further limit the current through the body.

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The data below are the same as in the above experiment except that the ground wire (511) is immersed in the water in the tank and the water is grounded. If a streetlight is flooded, the water is grounded because of electrical contact with the ground. In reality, it is closer to the state where electric equipment is flooded. In this state, it was confirmed that the amount of leakage current did not change greatly.
Length Width 0.9mm 1.8mm 3.6mm 7.2mm 14.4 mm 28.8 mm 0.9mm 13.21 12.79 12.21 11.68 11.12 10.13 1.8mm 12.79 2.54 1.12 0.92 0.77 0.69 3.6mm 12.21 1.12 0.97 0.77 0.69 0.39 7.2mm 11.68 0.92 0.77 0.69 0.39 0.23 14.4 mm 11.12 0.77 0.69 0.39 0.23 0.13 28.8 mm 10.13 0.69 0.39 0.23 0.13 0.07 57.6 mm 10.01 0.39 0.23 0.13 0.07 0.03

The data below is the result of measuring the amount of leakage current around the watertight flat-plate conductor by distance. The purpose of this experiment is to confirm the correlation between the leakage current on the conductive line and the leakage current around the flat plate-like conductor.

Area \ Distance 0cm 5cm 10cm 15cm 14.4mm x 28.8mm 0.304 0.230 0.170 0.120 28.8mm x 28.8mm 0.605 0.054 0.009 0.005

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The experimental results suggest that most of the current flows around the space between the opposing planar conductors. An electric field of 943 V / m was formed between the two exposed wires before the plate-type conductor was installed, but it was confirmed that the measurement limit between the two plate-type conductors exceeded 1,999 V / m after the plate-type conductor was installed.

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This experiment can be modeled electronically with the middle part of the electrical resistor called water between two planar conductors grounded. The human body can be modeled as another resistor connected between this electrical resistor and the ground plane. The resistance of human body and the resistive bodies of water connected between the two planar conductors and the ground plane are electrically connected in parallel to limit the current flowing into the human body.

As shown in Table 1 and Table 2, there is no significant difference in measured values between the case where the water in the water tank is grounded or not, and there is no significant difference in the risk of electric shock. Also, it can be seen that the amount of current flowing rapidly increases when either the width or the length of the planar conductor is narrower or shorter than the diameter of the conductor. This means an increased risk of electric shock.
In addition, the results of Table 1 and Table 2 show that the current flowing through the human body is also related to the ratio of the area of the planar conductor to the cross-sectional area of the cylindrical wire. Here, the area of the plate-like conductor refers to a value obtained by multiplying the width and the length by the plate-like shape of the plate-like conductor. If the radius of the wire is r, the width of the wire is 2r and the cross-sectional area of the wire is πr ^2. Thus, for example, in the first row of Table 2, is (r) (r) = r 2, (r) 2r = 2r 2, (r) (4r) = 4r 2, (r) (8r) = 8r 2, (r) (16r) = 16r 2, ( r) (32r) = 32r ² the like, and the ratio of the area of the wire cross-sectional area of the plate-like conductor is 1 / π = 0.32, 2 / π = 0.64, 4 / π = 1.27, 8 / π = 2.55, 16 /? = 5.09, 32 /? = 10.19, and so on.

If in reality an electrical facility is an a bit closer to the state of the water in the submerged state of the ground state <Table 2> in area and the cross-sectional area of the cylindrical wire ratio is about 1.27 or less than the current reference value 2.54mA when the plate-like conductor is At 5.09 times, a current of 0.97 mA flowed. In this experiment, if the area of the planar conductor is four times or more the cross-sectional area of the cylindrical wire, it can be seen that the current flows to the human body in a normal state.

The larger the flat-plate-shaped conductor, the higher the manufacturing cost is, and the more space is occupied, resulting in a practical problem. If the wire diameter is about ² mm, the cross-sectional area is 3.14 mm ^2. If the wire diameter is 100,000 times, it is 3,140 cm ² , which is 314 cm when the width of the flat type conductor is 10 cm. .

Figure 4 shows the arrangement of the instruments of the second experiment. The second experiment was conducted in the same manner as in Example 1 except that the electric shock preventer 503 according to one embodiment of the present invention was placed outside the water tank 502 and water was filled in the water tank 502, , For example, a socket 513 is immersed in the water tank 502, and another electric equipment, for example, the lamp 505 connected to the outlet is exposed outside the water tank. The plug 501 is connected to a power outlet to supply power. At this time, the electric shock preventer 503 can confirm that the lamp 505 is turned on even though the outlet 513, which is another electric equipment, is not immersed in water. Next, the experimenter 509 grasps the exposed end of the electric wire and measures the current flowing through the electric wire with the ammeter 507 while the exposed end is immersed in the water tank. It may be dangerous if the experimenter (509) conducts the experiment directly, so it may be replaced by an animal having a similar conductive property to the human body instead of the human body. At this time, a commercial power source of 220 V / 60 Hz was used, a load was connected to an incandescent lamp of 120 W, and a gap between two facing plate type conductors was 10 mm. The wires used also include a cylindrical conductor with a diameter of 1.8 mm. In the following table, the width is the width of the plate-like conductor, the length is the length, and the measured value is mA. The results are similar to those of Table 1. Although the present applicant can not explain the results of this experiment by using electrical modeling, it is presumed that the two plate-like conductors may have deformed the electrical flow to the human body when they are exposed to air.

The data below are the same as in the above experiment except that the ground wire (511) is immersed in the water in the tank and the water is grounded. If a streetlight is flooded, the water is grounded because of electrical contact with the ground. In reality, it is closer to the state where electric equipment is flooded. In this state, more current flows than in the above experiment.
Length Width 0.9mm 1.8mm 3.6mm 7.2mm 14.4 mm 28.8 mm 0.9mm 13.71 13.21 12.71 12.18 11.62 10.63 1.8mm 13.21 3.02 2.63 1.67 1.82 1.74 3.6mm 12.71 2.63 1.85 1.46 1.30 1.22 7.2mm 11.18 1.67 1.46 1.30 1.21 0.80 14.4 mm 11.62 1.82 1.30 1.21 0.77 0.62 28.8 mm 10.63 1.74 1.19 1.80 0.62 0.65 57.6 mm 10.51 1.21 0.80 0.69 0.65 0.62

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. For example, the present invention can be applied to three-phase power. The claims are intended to cover such obvious variations. For example, although an embodiment of the present invention is described as an electric apparatus, which is a separate electric shock preventer, the electric shock preventer may be incorporated in other electric equipment such as a circuit breaker, a terminal block, a socket, a plug, a battery, This can be applied through a design change to insert two planar conductors having substantially the same size on the transmission and distribution path inside the electric device. Accordingly, the expression &quot; electric shock prevention device &quot; in this specification should be construed to encompass these various electric facilities.

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11: first input terminal 13: second input terminal
31: first output terminal 33: second output terminal
110: first flat plate-like conductor 130: second flat plate conductor
300: housing

Claims (4)

An electric shock prevention device connected to a transmission / distribution path to an electric facility and electrically connected to the electric facility or the electric facility to prevent electric shock in flooding of nearby electric facilities,
A first input terminal to which an input-side first wire is connected;
A second input terminal to which an input-side second wire is connected;
A first output terminal to which an output-side first wire is connected;
A second output terminal to which the output-side second wire is connected;
The first input terminal is fixed at one end and the other end is fixed at the first output terminal. The width of the first input terminal is larger than the thickness of the first electric wire and the length thereof is longer than the thickness of the first electric wire. 1 &lt; / RTI &gt; and less than or equal to 100,000 times the cross-sectional area of the first conductor;
A second flat-plate-like conductor having one end fixed to the second input terminal and the other end fixed to the second output terminal and having the same size as the first flat-plate-like conductor;
A housing which is non-conductive to electrically isolate and fix the first flat-plate-like conductor and the second flat-plate-like conductor;
And an electric shock prevention device.
The apparatus according to claim 1, wherein the first planar conductor and the second planar conductor are made of copper (Cu).
The apparatus according to claim 1 or 2, wherein the housing fixes the first plate-like conductor and the second plate-like conductor so as to face each other.
The electric shock preventing device according to claim 1 or 2, wherein the electric shock preventing device is installed in a state in which the first planar-type conductor and the second planar conductor are opposed to each other and is installed at a position lower than the target electric device Electric shock protection device.

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