JP2002271964A - Arrester structure of building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop an arrester structure of a building which can avoid erroneous operation of gages, burning of substrates and influence on a human body at the timing of lightning by equalizing the potential of all instruments and gages installed within the building. SOLUTION: The arrester is composed of a lighting rod (2) erected on the building (1), a grounding body (3) for potential equalization having high dielectric constant embedded to surround the periphery of the building (1), a low surge-impedance conductor (4) which is arranged along the building (1) to connect the lightning rod (2) and the grounding body (3) for potential equalization, and an earth terminal box (5) for connection devices of the building (1) having the common terminals (5a) to (5b) connected to the grounding body (3) for potential equalization.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device in a building which can instantaneously cause a lightning current generated at the time of lightning strike to flow to the ground, reduce the rise of the ground potential, and easily occur at the time of lightning strike. The present invention relates to a lightning arrester structure of a building capable of reducing the occurrence of disturbances due to electromagnetic induction of a kind.

[0002]

2. Description of the Related Art In general, a lightning rod (102) is installed on a high-rise building (101) such as a tall building or an apartment to guide lightning strikes and prevent lightning strikes in the vicinity. The lightning rod (102) has a conductor (104) connected to a grounding body (103) buried in the ground.
The lightning rod of the lightning rod (102) is grounded to ground the high-voltage high-frequency lightning current. The building (101) such as the condominium or the building is provided with a ground terminal box (105).
Various types of ground terminals (105a) to (105d) of Class A to Class D having a ground resistance of up to 00Ω are installed, and power receiving equipment (106) and other structures including transformers in the building (101) Devices (107) to (109) installed on each floor of the object (101) are connected to each floor, and these are grounded. The ground terminals (105a) to (105d) can be grounded in various ways. In the case of FIGS.
05a) to (105d) are independently grounded.

Recently, a large number of digital electronic devices (107) to (109) such as a personal computer and a fax machine have been installed on each floor of the building (101). Apart from high-rise buildings and high-rise condominiums, which are called intelligent buildings, where there is sufficient space, in the building (101) where such measures are not taken, even if the ground is taken on each floor, electrons generated by lightning strikes Electromagnetic induction in the devices (107) to (109) causes malfunctions of the electronic devices (107) to (109) and burnout of the board, which frequently causes serious damage to the electronic devices (107) to (109). are doing.

Hereinafter, a conventional lightning arrestering method for the building (101) will be briefly described. Fig. 4 shows the first conventional method (simplified method)
A lightning rod (102) is erected on the roof of a building (101) such as a high-rise building or high-rise apartment, and the steel frame of the building (101) is
(110) or rebar with a twisted conductor (104) to connect the building (1
The ground was connected to the independent lightning arrester (103) buried around the building (101a) through the steel frame (110) or the rebar of 01a).

The advantage of this method is that the lightning conductor (104)
It is not necessary to lay the lightning conductor (104) in that part because the steel frame (110) or the reinforcing bar of the building (101) is substituted for a part of the building, so the construction cost is low and the side of the new building (101) It is aesthetically pleasing because there is no need to lower the lightning conductor (104). Another advantage of this method is that if the ground resistance is low and the ground resistance can be easily secured, the method can be performed at low cost.

However, this method has a problem that when the ground resistivity is high, it is necessary to construct a large-area ground electrode (103) in order to secure the individual ground resistance, and the construction cost increases. In addition, since the reinforcing rod (110) and the steel frame of the building (101a) are used instead of the lightning conductor (104), the lightning strike current enters the house, and the inside of the building (101) is installed inside. The devices (106) to (109) (especially information and communication devices) generate a surge current, and the electromagnetic induction thereby causes the electronic devices (106) to (109) to cause dielectric breakdown and malfunction,
The electric current flowing at the time of the ground fault of the electric equipment or the surge current flowing due to the lightning strike may cause a potential difference between the individual grounding poles (103), which may cause a dielectric breakdown of the equipment (especially electronic equipment). This will be described in detail as a comparative example when describing the present invention.

The ground (103) of the lightning rod (102) is the equipment ground.
(105d) and separate ground, so both
A potential difference may occur between (103) and (105d), which may cause damage to the human body. In addition, the lightning conductor (10
Since the rebar (110) and the steel frame of the building (101) are used instead of 4), the dielectric constant is low, surge current is unlikely to flow, and the ground potential increases and at the same time the steady state return is slow. There are also problems.

FIG. 5 shows a second conventional method (direct method) in which a lightning rod is provided on the roof of a building (101) such as a high-rise building or a high-rise apartment building.
(102) is erected and connected to the lightning rod (102).
In this example, 4) is laid on the outer surface of the building (101) and connected to independent lightning arrestors (103), which are buried around the building (101).

According to this method, a surge current that strikes the lightning rod (102) causes an on-strand wire (10) that crawls on the outer surface of the building (101).
4) Grounded through, so surge currents directly
Electronic equipment in the building (101) because it does not flow into (101a)
There is an advantage that failures due to the electromagnetic induction of (106) to (109) are less likely to occur.

However, similar to the above-mentioned simplification method, when the ground resistivity is low and the ground resistance can be easily secured, the construction can be performed at low cost. However, when the ground resistivity is high, a large area is required to secure the individual ground resistance. In addition to the necessity of construction of the ground electrode (103), construction costs increase, and the electric current (103) is generated at each ground electrode due to the current flowing at the time of ground fault or lightning strike, and the ~ (109)
However, the possibility of causing dielectric breakdown has not been solved.

In addition, since the lightning conductor (104) is used as the lightning conductor, the surge impedance is relatively high,
There is also a problem that a surge current during a lightning strike is unlikely to flow as in the case of the reinforcing bar (110) and the steel frame.

[0012]

The problem to be solved by the present invention is as follows.
Firstly, there is the development of a lightning arrester that allows the lightning current generated in a building that has been struck by lightning to flow quickly to the ground. Secondly, all equipment installed in the building It is an object of the present invention to develop a lightning protection structure for a building that can equalize potentials to prevent malfunctions of equipment and a burnout of a board during a lightning strike and prevent the human body from being affected.

[0013]

[Claim 1] Claim 1 is based on the lightning protection structure of a building (1) such as a building or condominium according to the present invention and is based on "a lightning rod (2) erected on the building (1)". And an equipotential grounding body (3) with a high dielectric constant buried around the building (1), and a lightning rod installed along the building (1)
(2) and a low surge impedance conductor (4) connecting the equipotential grounding body (3), and the common terminals (5a) to (5d) connected to the equipotential grounding body (3). And a ground terminal box (5) for connecting equipment to the building (1). "

Buildings such as high-rise buildings and high-rise apartments
Common terminal (5) of earth terminal box (5)
Since a) to (5d) are connected to the equipotential grounding body (3) disposed so as to surround the construction surface of the building (1) or the entire surrounding area, the ground terminal box (5) Common terminal (5a)-
The potential of all devices (from the upper level to the lower level) in the building (1) connected to (5d) is equal, no potential difference occurs between any devices, and the high-voltage high-frequency surge current during lightning strikes There is no damage such as burnout of the substrate. A conductor that connects the lightning rod (2) and the grounding body for equipotential (3)
By making (4) a low surge impedance, a high-voltage, high-frequency surge current during a lightning strike can flow instantaneously to the ground, and the equipment (6) to (8) in the building (1) will be The fluctuation of the potential wave head due to the high-frequency high-frequency surge voltage is small and can be converged to a steady value in a short time, so that it is possible to prevent the surge voltage from adversely affecting the devices (6) to (8).

Claim 2 relates to an improvement of Claim 1 by describing a lightning rod (2) erected on the building (1) and buried so as to surround the construction surface of the building (1) or its periphery. Grounded body for equipotential (3) having a high dielectric constant and a low surge impedance conductor that is arranged along the building (1) and connects the lightning rod (2) and the grounded body for equipotential (3) Body (4), a ground terminal box (5) for equipment connection of the building (1) having common terminals (5a) to (5d) connected to the equipotential grounding body (3),
And a deep hitting electrode (20) buried in the ground connected to the equipotential grounding body (3). "

In this case, a deep hit electrode is attached to the grounding body for equipotential (3).
In the case where (20) is connected, in addition to the effect of the first aspect, the grounding effect of the deep hitting electrode (20) is added. In other words, the deeper the ground electrode is driven, the smaller the surge impedance becomes and the higher the ground effect becomes.The deeper the ground electrode (20) buried deep in the ground is, the faster the surge current during lightning strikes will be. And the fluctuation of the potential wave head can be further reduced, and the surge voltage can be converged to a steady value in a short time.

The third aspect of the present invention relates to a method of installing a low surge impedance conductor (4) in which the low surge impedance conductor (4) is disposed along the outer wall (1a) of the building (1). "
It is characterized by the following. By doing so, the building (1)
The steel frame (10), reinforcing steel or concrete works as an electromagnetic shielding material, and can reduce the influence on internal devices due to electromagnetic induction during lightning.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 is a schematic configuration diagram showing a lightning arrester structure of a high-rise building (1) such as a building or an apartment according to the present invention which may be subjected to a lightning strike. Inside the walls, floor slabs and rooftop slab of the building (1), reinforcing bars and steel frames (11) are stretched vertically and horizontally, and they have an electromagnetic shielding function together with concrete that composes the wall surface, floor surface, and rooftop surface .

On the roof of the building (1), one lightning rod (2) or a plurality of lightning rods (2) are erected at predetermined intervals, and a low surge impedance conductor (4) is derived from the lightning rod (2). Have been. The low surge impedance conductor (4) is, for example, a thick copper wire having a large surface area, a high dielectric constant, and a capacitor capacity. In this embodiment, the low surge impedance conductor (4) is a lightning rod.
It is drawn out from (2) in all directions (of course, it is not limited to four sides, but may be smaller or larger) and is arranged along the side wall of the building (1). As a method of arranging the low surge impedance conductor (4), there are a case where it crawls outside the side wall of the building (1) and a case where it passes through the wall, but in order to obtain an electromagnetic shielding effect, Even when passing through the inside, it is preferable to dispose it outside the reinforcing bar or the steel frame (11) in the wall surface.

A ground terminal box (5) for connecting equipment is installed in the building (1), and each ground terminal A type (5a) to
Type D (5d) is provided. Class A of each ground terminal (5a)
Of the ~ D types (5d), the ground terminal type C (5c) is connected to the ground terminal (not shown) provided at each level of the building (1),
The equipment (7) (8) installed on each level of the building (1) is grounded, and all the electronic devices (7) (8) are connected to a common ground.

The grounding terminal type A (5a) is a terminal having a grounding resistance of 10 Ω or less, and is used as a transformer or power receiving equipment for the building (1).
The ground line of (6) is connected. Ground terminal B
(5b) is a neutral terminal of the transformer of the building (1). As described above, the ground terminal C class (5c) has a ground resistance of 10Ω or less, and is a ground terminal for various devices (7) and (8) installed at each level of the building (1). is there. The ground terminal D type (5d) is a ground terminal of other equipment having a ground resistance of 100Ω or less. In the present invention, the ground terminals (5a) to (5d) of the ground terminal box (5) are commonly connected to the equipotential grounding body (3) described below, and the ground terminals (5a) to
(5d) Everything is held at the same potential as the equipotential grounding body (3). FIG. 2 is an equivalent circuit diagram in that case.

The grounding body for equipotential (3) is, for example, a copper mesh body having a high dielectric constant and buried so as to surround the construction surface of the building (1) or the entire periphery thereof. A copper flat plate may be used.) In the case of the figure, an equipotential grounding body (3) is buried so as to surround the entire periphery of the building (1). Each of the ground terminals (5a) to (5d) of the ground terminal box (5) and the steel frame (1) of the building (1)
1) and the rebar are commonly connected to the equipotential grounding body (3). This ensures that all electronic devices in the building (1)
(6) The potential of (7) and the steel frame (11) of the building (1) will have a common ground potential.

The deeper the earth electrode (= the grounding body for equipotential (3) and the deeply striking electrode (20) described below) is buried in the ground, the lower the surge impedance becomes, and the surge current becomes lower. The grounding effect can be further enhanced by connecting the deep-punched electrode (20) brought deep into the ground to the equipotential grounding body (3). Therefore, the deep hitting electrode (20) is installed as needed, and is connected to the equipotential grounding body (3). When the deep hitting electrode (20) is connected to and connected to the equipotential grounding body (3), lightning current can flow more smoothly to the ground, and negative reflection of voltage from the ground is suppressed. be able to.

The deep hitting electrode (20) has a structure such as a copper wire or a copper rod in a conductive concrete column (21) mixed with a conductive powder (23) such as metal powder, carbon powder or short carbon fiber. What has inserted the suitable conductor (22) is used. The method of manufacturing the deep-hit electrode (20) is as follows. A boring hole is drilled at a predetermined depth at a predetermined location, a conductor (22) is arranged in the boring hole, and cement milk mixed with the above-described conductor powder (23) is injected and solidified. It forms by doing. Of course, the existing deep hitting electrode (20) having the above-mentioned structure is inserted into the boring hole, and the above-mentioned cement milk is injected into the gap between the boring hole and the deep hitting electrode (20) to thereby form the boring hole and the deep hitting electrode. You may make it contact with (20).

Next, the operation of the present invention will be described in comparison with a conventional example. When a lightning strike occurs on a lightning rod (2) of a building (1) such as an apartment or building having the lightning protection structure, a lightning current passes through a lightning conductor (4) to an equipotential grounding body (3) as shown in FIG. Flows. If a deep-depth electrode (20) is provided,
Flows through the ground through (20). If the deep hitting electrode (20) is not installed, the grounding body for equipotential (3) flows into the ground from the place where the surge impedance is the lowest on the ground where it is buried.

Now, assuming that the amount of surge current input to the lightning rod (2) is 100, the amount of lightning current grounded in the ground is about 98, and the remaining few percent are in the building (1) having a common ground. Although it will flow back to the various devices (6) to (8), the electricity is connected to the common ground terminals (5a) to (5d) because the surge impedance does not flow in the direction of infinity due to its nature. In the devices (6) to (8), almost no device failure occurs due to the backflow. Accordingly, there is no problem even if the ground terminals (5a) to (5d) are connected to the equipotential grounding body (3) to which the lightning conductor (4) is connected.

The dashed line of the chevron in FIG. 3 indicates a building during a lightning strike.
The potential trend of (1) is shown.
The intersection between the dashed line vertically rising from each of the devices (6) to (8) and the dashed line indicating the potential tendency indicates the potential difference between the devices (6) to (8). . As before, each device (6) to (8) installed in the building (1) is connected to the ground terminals (5a) to (5c), and if individually grounded, a lightning rod The electric potential of the device (7) located immediately below (2) becomes the highest, and the electric potential gradually decreases as the distance from the device (7) increases. That is, equipment (6) in building (1) during lightning strike
(8), a potential difference occurs between them, a current flows between them, and the devices (6) to
(8) Malfunction or dielectric breakdown may occur, and in severe cases, electric shock may occur, affecting the human body.

On the other hand, in the case of the present invention, the building (1)
Since all the devices (6) to (8) are connected to the common terminals (5a) to (5d) of the ground terminal box (5) and are connected to the potential grounding body (3), The ground potential of the common terminals (5a) to (5d) is equal to the potential grounding body (3) and the conventional devices (10
6) It becomes lower than the ground potential of (108). The ground potential is further reduced when the deep hitting electrode (20) is used together. Therefore, even if there is a lightning strike, there is no potential difference between the devices (6) to (8) in the building (1) and the ground potential itself is lower than before, so the devices (6) to ( 8) Influence on human body such as malfunction, insulation breakdown or electric shock can be eliminated.

The potential difference between the communication line and the power supply line outside the building (1) cannot be controlled by the potential grounding body (3). By installing a lightning arrester (23) at the terminal, input of surge current from the communication line or power source to the equipment is prevented.

Next, an embodiment of the present invention will be described in comparison with a conventional example. As described above, in a building such as a building or a condominium, there is a possibility that the effect on electronic / digital devices in the building during a lightning strike may become a problem. In a building, there are a lightning rod ground, a building ground, a floor ground, and the like. When these grounds are independent, a potential difference occurs between the respective grounding poles. Therefore, in order to examine the difference between various grounding methods, an experimental study was conducted using a scale model.

The grounding model experimental circuit has a length of 20 m and a height of 4 m.
The pulse was applied to the 1/10 scale model of the building using the application line of. The model simulates a three-story building,
The height was 1,280 mm, the width was 1,835 mm, and the height was 1,200 mm. The radius of the copper pipe simulating the reinforcing steel is 70 mm for columns and 30 mm for beams. In addition, grounding poles corresponding to building floor grounding (i) (ii) (iii), building grounding, lightning rod grounding, etc. were installed. FIG. 7 shows the arrangement of each point of the scale model. A ground electrode was set at a distance of 20 m as a potential reference point for potential measurement. Hereinafter, the measurement results by the above model are shown.

(1 = conventional example) At the time of independent grounding; in this case, each floor grounding, building grounding, and lightning rod grounding are all independent. As shown in FIG. 8 (a), the ground electrode of 1F was connected to the ground electrode (i), the ground electrode of 2F was connected to the ground electrode (ii), and the ground electrode of 3F was connected to the ground electrode (iii). Fig. 8 (b) shows the measurement results.
Shown in In the figure, the horizontal axis is time, the vertical axis is voltage, and the solid line is
A surge voltage of 1F, a broken line indicates a surge voltage of 2F, and a thin broken line indicates a surge voltage of 3F. As shown in FIG. 8B, the difference in potential rise between the floors is large in each floor independent grounding. The first wave of the surge voltage has a maximum of 3F closest to the lightning strike position and a minimum of 1F, which is considered to be induction from the applied line. The second wave is a rise in the ground potential. The magnitude of the surge voltage depends on the distance between the application point and each ground electrode, and the farther the distance, the smaller the rise of the ground potential.

(2 = conventional example) At the time of common grounding of each floor; in this case, as shown in FIG. 9 (a), the common grounding of each floor and the grounding of the floor, the building, and the lightning rod are independent. FIG. 14B shows the measurement results. As can be seen from the figure, the solid line, the dashed line, and the fine dashed line almost coincide with each other, and there is almost no difference in the potential rise between the floors at the common ground of each floor. The rise in the ground potential of the second wave is (1 = conventional example)
Although it is smaller than that at the time of independent grounding,
The wave, the second wave, is large.

(3 = conventional example) When connecting each floor to a building; in this case, as shown in FIG. 10 (a), each floor ground is connected to a steel frame or a reinforcing bar of the building. This is the case where the intervals are independent. FIG. 10 shows the measurement results.
It is shown in (b). From the figure, a potential rise is observed on each floor, which is considered to be because each floor potential is equal to the potential of each point of the connected building.

(4 = the present invention) When connecting the lightning rod to the bottom of the building;
As shown in FIG. 11A, each floor ground is connected to a reinforcing bar or a steel frame of a building, and furthermore, a lightning rod ground and a building ground are connected. The lightning rod ground is connected to the potential grounding body. FIG. 11B shows the measurement results. From the figure, it can be seen that the fluctuation of the surge voltage at each floor potential wave head is small and the convergence to the steady value is fast.

(5 = conventional example) When a lightning rod is used as a substitute for a building reinforcing bar; in this case, as shown in FIG. 12 (a), each floor ground is connected to the building, and the grounding wire for the lightning rod is a building steel frame. In this case, the measurement results are shown in FIG. As shown in the figure, the maximum voltage value is almost the same as in the case of all independent grounds. However, the potential difference between floors is small.

As described above, from the consideration of the mutual influence between the grounding electrodes, when all the grounding electrodes are integrated, the various grounding electrodes have the same potential at the time of the lightning strike in the building, so that no potential difference occurs between the grounding electrodes and the equipment is affected. Hateful. The most effective grounding method is a case where the building is connected to each floor of the building and the lightning rod ground is connected to the building, that is, the case (4) can be said. Further, it is more preferable to connect the deep hitting electrode to the potential grounding body.

[0038]

According to the present invention, a lightning arrester erected on a building and a grounding body for equipotential having a high dielectric constant buried so as to surround the construction surface of the building or its surroundings have a low surge. Since the common terminal of the ground terminal box of the building is connected to the equipotential grounding body by connecting with the impedance conductor, the potentials of all devices (from the upper hierarchy to the lower hierarchy) in the building are equal. In addition, no potential difference occurs between any of the devices, and there is no damage such as burning of the substrate due to the high-voltage high-frequency surge current at the time of lightning. In addition, the ground voltage can be further reduced by using a deep hitting electrode.

By arranging the above-mentioned low surge impedance conductor along the outer wall of the building, the steel frame, the reinforcing steel or the concrete of the building functions as an electromagnetic shielding material,
It is possible to reduce the influence on the internal devices due to the electromagnetic induction during a lightning strike.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a building (a building or an apartment) to which the structure of the present invention is applied.

FIG. 2 is an equivalent circuit diagram of FIG.

FIG. 3 is a diagram showing a potential tendency of the building of FIG. 1 during a lightning strike;

FIG. 4 is a schematic perspective view of a building (building or condominium) having a conventional lightning arrester structure.

FIG. 5 is a schematic perspective view of a building (building or condominium) having a conventional lightning arrester structure 2;

FIG. 6 is a schematic front view showing a lightning damage situation of a building (building or condominium) having a conventional lightning arrester structure according to the second related art.

FIG. 7 is a plan view of a model in a comparative experiment of the present invention and a conventional example.

FIG. 8 is a partial front view of a conventional model in which the floor ground, the building ground and the lightning rod ground of each floor are independently grounded.

FIG. 9 is a partial front view of a conventional model when the floor ground of each floor is set to a common ground and grounded independently of the building ground and the lightning rod grounding.

FIG. 10 is a partial front view of a conventional model in which the floor ground of each floor is connected to a building steel frame to form a common ground, and a lightning rod ground is independently grounded.

FIG. 11 is a partial front view of the model of the present invention in which the floor ground of each floor is connected to a building steel frame to form a common ground, and the building ground is connected to a lightning rod ground;

FIG. 12 is a partial front view of a conventional model in which the floor ground of each floor is connected to a steel frame of a building to form a common ground, and the building ground is replaced with a lightning rod ground;

[Explanation of symbols]

 (1) Building (2) Lightning rod (3) Grounding body for equipotential (4) Low surge impedance conductor (5) Earth terminal box (5a) to (5d) Common terminal

Claims (3)

[Claims] 1. A lightning rod erected on a building, an equipotential grounding body having a high dielectric constant buried so as to surround the construction surface of the building or its periphery, and arranged along the building. A low surge impedance conductor connecting the lightning rod and the equipotential grounding body, and a ground terminal box for connecting equipment of the building having a common terminal connected to the equipotential grounding body. A lightning protection structure for buildings. 2. A lightning rod installed upright on a building, an equipotential grounding body having a high dielectric constant buried so as to surround the construction surface of the building or its periphery, and disposed along the building. A low surge impedance conductor for connecting the lightning rod to the grounding body for equipotential; a ground terminal box for connecting equipment of the building having a common terminal connected to the grounding body for equipotential; A lightning arrester for a building, comprising: a deep hitting electrode connected to a grounding body and buried underground. 3. The lightning protection structure for a building according to claim 1, wherein the low surge impedance conductor is disposed along an outer wall of the building.