Protecting your home from lightning strikes. Lightning protection of a house with a metal roof. Making a lightning rod in the country with your own hands
Recently, we are increasingly faced with situations where lightning strikes houses and, due to the lack of appropriate protection, a fire occurs. To prevent this and protect yourself, you can make a lightning rod with your own hands.
Moreover, such a device will be quite functional and productive, if, of course, it is correctly mounted. It is worth saying that although the lightning rod has enough simple design and if there is free time and the necessary materials, everyone can make it, nevertheless, you need to take into account many factors to determine the correct installation parameters, since it is important not only to have protection for your home and electrical appliances, but also to be sure of its correct functioning.
How does a lightning rod of a country house work
A lightning rod is a special installation that attracts the electric charge of lightning and redirects it from the house along a conductor to the ground. Thus, the lightning will not cause any destruction or harm. The lightning rod consists of two blocks:
- outdoor;
- internal.
The outdoor unit is a current collector (lightning rod) connected to a current conductor (down conductor), which together act as receiving and distributing the lightning charge, as well as a ground electrode that dissipates this charge in the ground.
The indoor unit will protect your home from power surges, and therefore prevent electronics failure. Probably everyone has heard that if the electric charge of lightning is of great strength, then all electrical appliances in the house burn out.
So there is another reason to make a lightning rod.
Lightning conductor rules
For the right choice circuits of the device for a summer cottage lightning rod, it is first necessary to study the structure of the building and, in accordance with the "Instructions for the device of lightning protection of buildings and structures" (Instruction RD 34.21.122-87), determine the required level of protection. Low and small in size private houses usually belong to the III category of lightning protection.
An effective lightning protection is one that reliably protects the building and everything inside it from a direct lightning strike into it and from its secondary discharges in electrical networks. A summer cottage lightning rod is usually a lightning rod that is connected to ground using a down conductor system.
Lightning rod
A device that directly receives a lightning strike on itself is called a lightning rod. This is the most noticeable and significant element of an industrial or suburban lightning rod circuit. There are rod, cable, mesh receivers.
The most popular and famous thanks to Benjamin Franklin is the lightning rod, which is a metal rod made of stainless steel, aluminum or copper. It is usually installed 2 m above the highest point of the building to be protected. This type of lightning rods is the simplest in execution and quite cheap.
A catenary wire lightning rod consists of two masts installed along the perimeter of the protected object, and tensioned steel cables between them. An air terminal is a mesh made of metal rods laid on the roof of a building with a certain pitch.
For small private houses, a metal roof can be an excellent lightning receiver. If the roof of the house is made of a different material, then it is better to choose an air-termination mesh for the protection device, and active protection is often used for wooden country houses.
Down conductors
The current flows to the grounding device through down conductors. In accordance with the above-mentioned Instruction RD 34.21.122-87, down conductors in a residential building can be various building structures made of steel, aluminum or copper (frames, fire escapes, reinforcement of reinforced concrete slabs). Special down conductors are usually laid outside the perimeter of the building in 25 m increments. The efficiency of down conductors depends on the continuity of the electrical network. They are usually welded to the lightning rod and grounding devices.
Earthing
The lightning charge in the soil is dissipated using grounding devices. In accordance with Instruction RD 34.21.122-87, they are most often reinforced concrete foundations or vertical electrodes that go deep into the ground. The last type of grounding is necessarily protected from corrosion (therefore, it is usually made of copper-plated or galvanized steel), and the electrodes are securely connected to the horizontal bus and to each other by means of special connectors.
Making a lightning rod in the country with your own hands
So, if you come to the conclusion that you want to make a lightning rod for country house do it yourself, then you need to know how this device is made. First, it is necessary to make a rod collector, to which the current lead will then be attached, which can be made from ordinary iron wire. Just choose a wire with the largest possible cross-section, for example 6-8 mm. The current lead also connects the pantograph to the ground loop.
The ground loop can be made from an iron strip approximately 4x50 mm in size. The electrode should be made of a steel rod, choosing a diameter of at least 18 mm for this. Please note that all connections should only be made using welding machine... If this is not possible for you, then bolted steel clamps can be used, but such connections will be less effective.
2) The material of handicraft fasteners during the passage of the lightning current with a high degree of probability may not withstand huge temperatures and will simply melt. Therefore, it is always necessary to know the parameters of the materials used and perform the necessary calculations. But it is easier to buy ready-made components from lightning protection manufacturers, especially since the prices for fastening elements, especially those of good quality, are reasonable. Plus, you will receive the necessary expert advice on competent installation.
3) There is such a rule: you either make isolated lightning protection and maintain the required breakdown distance, or connect all the metal elements together and bring them to ground. Here the author uses insulators and, accordingly, the first method, which means that the air gap between the receiver / down conductor must be no less than the minimum distance R, which in this particular embodiment should be equal to 300-400 mm, which is not noticeable. Without grounding and the roof, a dangerous potential difference is guaranteed here.
4) The variant of a ground electrode system in the form of a single pin stuck into the ground cannot be considered reliable at any ground resistance, especially since the down conductor through which the discharge from the lightning rod comes is also the only one. Even in the days of the USSR, with a complete lack of knowledge and design parameters of soil resistance, focal grounding was always done in the form of a triangle or U-shaped contour.
Basic typical schemes of country lightning rods
Once again, in more detail, we will talk about three known types of protection devices installed on the roof of buildings.
The type of lightning rod selected for the country lightning rod determines the type and scheme of its protection. Typical schemes include the organization:
- lightning protection mesh;
- rod lightning rods;
- catenary wire lightning rods.
For flat and gable roofs for cottages, regardless of the roof material, experts recommend using a lightning mesh. For its organization, steel, copper or aluminum rods with a diameter of up to 8 mm are used. The mesh is installed directly on the roof or under the insulation, if the base of the roof is not combustible (Instruction RD 34.21.122-87).
Depending on the level of protection, the down conductors are mounted directly to the mesh along the entire perimeter with a step of 10 to 25 cm.
A lightning protection rod is a metal rod attached to a chimney or other roof structures at least 2 m above its highest point.
The installation of the rod is done correctly if the protected object completely falls into the base of the cone with the apex at the extreme point of the air terminal. Increasing the height of the bar widens the protected area. This type of lightning rod is suitable for both private and industrial facilities with complex roofs.
For gable roofs low buildings, you can also use the cable scheme of the country lightning rod. For this, a steel cable is pulled between the supports mounted on the skates. Its ends are usually adjoined by one down conductor, which transmits current to the ground in the ground, which looks like a "chicken's foot". If the scheme of the country lightning rod is executed correctly, lightning discharges go into the soil outside the protected house. When arranging lightning protection of this type, it is important to take into account the sagging of the cable.
The choice of the organization scheme for a country lightning rod is influenced by many factors, parameters and conditions. Therefore, this is a rather complex and responsible event that requires certain professional knowledge and experience. Our company will help you design and install the most effective lightning protection for your home. In addition, we provide turnkey lightning protection services. In the section "Our objects" there are photos of lightning rods and a description of our completed projects.
How and where to buy a lightning rod
A lightning conductor that protects against a direct lightning strike will work like a clock if you choose correctly and correctly necessary materials to create effective and reliable lightning protection of a building. The following parameters affect the price of a country lightning rod:
- level of protection;
- lightning rod circuit;
- technical difficulties in project implementation;
- type of materials used and amount of work.
Today, numerous online shops offer a large selection of rods and cables made of steel, copper and stainless steel, as well as holders and clamps, and give an excellent description of their products. However, it is difficult to make an impeccable quality lightning rod yourself. In addition, no one will give a guarantee for the operation of a system assembled from materials with different performance characteristics.
Our company offers from a warehouse in Moscow to buy components for lightning rods from well-known and well-proven manufacturers from Germany, Russia, France, Turkey and other countries: OBO Bettermann, J. Propster, BS-Technic, DEHN + SOHNE, Voltstream, Elmashprom, Duval Messien, Citel, Forend and others.
Our services
The specialists of our company will help you choose the most reliable and efficient country lightning rod at an affordable price, taking into account all the features of your home. Our consultants will answer in detail any questions of interest and make an estimate.
You can order from us the necessary measurements of transition resistances, resistance of grounding devices, checking the presence of a grounding circuit and grounded elements. Our experienced professionals can also design and install a turnkey lightning rod. We provide maintenance services different systems lightning protection before the start of the thunderstorm season and, upon agreement with the client, we repair them.
Devices can be specialized electronic circuits and arresters designed to be triggered when a certain electric field strength is reached, and even small amounts of radioactive materials. Active protection systems are much more expensive and more complex than passive ones.
The propagandists of active lightning protection argue that their lightning rods generate longer response streamers earlier than passive ones. This allows using fewer lightning rods, and they can be placed lower. But, despite such statements, active lightning rods did not find unconditional recognition from specialists.
Passive lightning protection
The principle of operation of passive lightning protection devices is quite simple and is based on the property of lightning strikes the highest and most grounded structures with good electrical conductivity. It consists in intercepting lightning heading towards an object and leading it to the ground, where she will not be able to harm anyone, as well as in mitigating the consequences of her blow for the internal communications of the house.Passive lightning protection can have rod or cable structure... A rod lightning rod, towering over the protected object, is a classic of lightning protection. In this case, the lightning is intercepted in the protected area at the moment of discharge.
The lightning rod is made in the style of accompanying
Due to the elevation above the protected object and the special material from which it is made, the lightning rod takes the blow on itself and transfers it further through the down conductor to the ground.
Another option for passive lightning protection is cable systemwhen the "interceptor" is a stretched metal cable. Cord lightning rods are used only for the protection of narrow and long buildings (for example, cowsheds) or if it is not possible to install a sufficient number of lightning rods.
The cable system includes lightning protection mesh... It fits on with a certain step. All these systems are made of a durable material of high conductivity - steel, copper, aluminum - which intercept the discharge according to the general laws of physics without generating additional actions.
Lightning protection for a country house
What is lightning protection country house? This device to prevent a direct lightning strike... A lightning conductor designed to receive lightning and discharge it into the ground serves as a protective device.
The device consists of three interconnected parts, namely:
- an air terminal located in the zones of expected contact with lightning, that is, above the object;
- a grounding conductor (down conductor), which removes the charge from the lightning rod to the ground electrode (most often it is a metal wire with a large section);
- ground electrode - rods and strips buried in the ground.
All parts of lightning protection can be made as a single stand-alone structure. For example, it can be a metal mast, which is a lightning rod, support, conductor and ground at the same time.
The probability of lightning striking the protection zone is very small. These zones are conventionally divided into two categories - A and B.
- In the category A zone, located closer to the lightning rod, the probability of protection is from 99.5%.
- In the zone of category B, the degree of reliability is somewhat less - 95%.
Lightning protection of a country house is conventionally divided into:
- external, to neutralize a direct lightning strike into the house;
- internal- to reduce possible damage internal systems houses.
How to make a lightning rod?
So, a lightning rod consists of three parts: a lightning rod in the form of a rod or cable or mesh, a down conductor for transmitting the resulting discharge to the ground electrode and the ground electrode itself - several metal conductors that are in direct contact with the ground.
For an approximate calculation, you can use a simple rule: the radius of the protected area is 1-1.5 times the height of the lightning rod. Those. with a lightning rod height of 20 m, a circle with a radius of 20-30 m falls under its protection. If this area does not cover the area occupied by the house, two or more rods are installed at its different ends.
For the device of the simplest rod lightning rod a steel, aluminum or copper rod of the required cross-section, without insulation and stripped of rust and paint, is used as a lightning rod and down conductor. For example, steel wire rod with a diameter of 8 mm. If it is a hollow tube, the open end facing up must be welded.
When such a lightning rod cannot be arranged, the roof of a house can serve as it if:
- She herself, the supporting beams and joints are metal;
- The thickness of the steel roofing sheet is not less than 4 mm;
- There are no flammable or flammable materials under the roof.
If the options considered for some reason are not suitable, then alternatively, you can place a lightning rod at the top of a standing tall tree (the tree should be much higher than the roof of the house).
A catenary wire lightning rod is arranged along the roof ridgeby pulling a metal cable between the two supports. If the supports are not wooden, but metal, then they are isolated from the cable with reliable electrical insulators. The earthing switch can be metal corners, a strip or sheet buried in the ground to a depth of at least 0.7 m and at a distance of 1 m from the wall of the house.
To connect structural elements lightning protection is welded or threaded. The main thing that the connection was necessarily strong, then a strong gust of wind or a fall of a snow layer will not be able to break it.
If your house is made of stone, then the down conductor bus can be "run" right along the wall. And if the house? In this case, the down conductor is made at a distance of about 10 cm and is mounted on electrically insulated brackets.
When installing lightning protection even for a small one-story country house need to be guided:
- Instructions for the device of lightning protection of buildings and structures RD 34.21.122-87 and
- Instruction on lightning protection of buildings, structures and industrial communications SO 153-34.21.122-2003.
However, the lightning protection system of a country house, with all its simplicity, has subtleties to consider during its design and operation. For instance:
- For a metal roof, lightning protection using a rod is possible, and for a polymer roof, a mesh.
- For slate or wooden roof it is better to use a catenary wire lightning rod.
- inspect all parts of the lightning rod,
- check the serviceability of connections and fasteners,
- change damaged places,
- clean contacts, etc.
Today, when putting a house into operation, the presence of lightning protection is not required, so each homeowner decides for himself whether it is advisable to install it. Let's not wait for the thunder to strike. Moreover, it is heard only a few seconds after the next “fiery arrow” pierces the ground.
Is your home reliably protected from lightning strikes?
A private house and country cottages are often located in an open space, where the only elevation is the buildings themselves. Because of this, during a thunderstorm period, there is a significant threat of lightning striking buildings. This situation threatens not only electric shock to all people in it, but also the possibility of fire, which will lead to a fire and significant damage to property. Since no one can foresee the location of the discharge, the most effective way preventing its negative consequences is a lightning rod.
That is why for most owners of private houses and summer cottages, it is important to install a lightning rod with your own hands. An exception may be buildings located in a lowland, the roof of which is below the top point of the ground or falling into the protection zone of a neighboring building and its lightning rod.
The device and principle of operation of a typical lightning rod
Figure 1: lightning rod deviceThe entire structure of the lightning rod is represented by three elements: a lightning rod, a down conductor and a ground electrode. Depending on local conditions and your preferences, each of them may have a different design. Now we will analyze why each of them is needed, and which option to choose in a given situation.
Lightning rod
From the very name of this element, its purpose comes, in fact, it plays the role of an electrode that receives an electric lightning discharge. The main criterion for it is good conductivity and thermal stability, since the current value can reach 100-200 kA, which can easily burn through thin conductors. The following can be installed as a lightning rod:
- bar structures;
- lattice;
- cable;
- the roof surface itself.
Rod lightning rods can be installed either directly on the roof itself or on a special metal mast. Moreover, their height should provide the necessary protection zone for all structures of the building. Therefore, such a lightning rod is relevant for buildings with a small area and height.
Figure: 2: rod lightning rod Such rod devices can be copper, aluminum, or steel. The first two have good resistance to corrosion destruction, due to which such a lightning rod practically does not lose its conductivity and cross-section even during long-term operation. A metal pin made of steel, unlike the previous two, is much less susceptible to melting from the flow of high currents, which is why it is much better suited for areas with frequent lightning strikes.
Figure: 3: mesh lightning rod The grille is used as a lightning rod for a large area, for example, multi-storey buildings or shopping centers. Unlike the previous version, it does not affect the design of the building, therefore it can be used in any modern exteriors. Such a lightning rod must have a given cross-section and mesh size, as a rule, reinforcement of at least 6 mm 2 is chosen. Its installation is carried out at a safe distance from the roof (at least 15 cm) through thermal insulating bearing structures.
Figure 4: catenary wire lightning rod Catenary wire is a flexible wire that is stretched over the protected area or building. Allows you to protect a long section at a lower cost of materials for a lightning rod. It is carried out both on free-standing supports and on the roof of a summer cottage. In the first case, the supports are installed at the beginning and end of the section, and in the second, at the beginning and end of the roof.
If conductive options are used as roofing material (corrugated board, metal tiles, etc.), they can be used as a lightning rod for a lightning rod. But at the same time, the following conditions must be observed:
- the thickness of the metal layer is not less than 4 mm for steel, 5 mm for copper or 7 mm for aluminum;
- under roofing material there are no flammable materials (insulation, rafters, etc.);
- outside the metal is not covered with a dielectric material.
Manufacturing a lightning rod from a metal roof saves money on a lightning rod.
Down conductor
It is a conductor that leads the electric current from the lightning rod to the ground electrode. It can be made of metal wire or tires. It must have a cross section of at least 16 mm 2 if made of copper, 25 mm 2 from aluminum, 50 mm 2 from steel. The following requirements are imposed on the down conductor:
- Should be insulated from walls and other structures of the house;
- For it, the shortest path of current flow is chosen;
- The absence of bends and turns, on which a breakdown of the air gap can occur;
- Sufficient conductivity at electrical connections.
If necessary, the down conductor is isolated from the surface of the house using a cable duct or in any other way. This procedure is especially relevant for buildings with a conductive finish or a combustible surface.
Earthing switch
It is made in a form that is buried in the ground. The material used is steel or copper elements that are buried in the ground. It is formed from reinforcement or tires, the requirements for which are established by clause 1.7.111 of the PUE and are given in Table 1
Table 1
| Material | Section profile | Diameter, mm |
Cross-sectional area, mm | Thickness walls, mm |
| Steel | Round: | |||
| black | 16 | — | — | |
| 10 | — | — | ||
| Rectangular | — | 100 | 4 | |
| Angular | — | 100 | 4 | |
| Pipe | 32 | — | 3,5 | |
| Steel | Round: | |||
| galvanized | for vertical earthing; | 12 | — | — |
| for horizontal earthing | 10 | — | — | |
| Rectangular | — | 75 | 3 | |
| Pipe | 25 | — | 2 | |
| Copper | Round: | 12 | — | — |
| Rectangular | — | 50 | 2 | |
| Pipe | 20 | — | 2 | |
| Multi-wire rope | 1,8* | 35 |
All parts of the grounding loop can either loop back and form a closed circuit, or line up in a solid line. Of course, the closed version is considered more reliable. The dimensions of the circuit are selected according to local conditions.
Figure: 5: example of earthing switch installation The main requirement for the grounding loop is to ensure the established value of the metal-to-earth transition resistance, therefore it is better to place it in a wet layer, periodically watered with water or treated with materials that reduce the transition resistance and increase the spreading current area (charcoal and salt). According to clause 1.7.103 of the PUE, the resistance should be no more than 5, 10 and 20 ohms for networks with phase voltages of 380, 220 and 127 V, respectively.
The location of the earthing switch is made no closer than 1 m from the walls and 8 m from the footpaths. Since at this point a step voltage arises, capable of delivering an electric shock to anyone within the radius of the affected area, therefore, it is strictly forbidden to approach the circuit during a thunderstorm, as well as to touch its current-carrying elements.
Training
At the preparatory stage, before installing lightning protection, it is necessary to calculate the parameters of the future lightning rod and select all the elements. This will allow you to determine whether the buildings will fall into the protection zone and what parameters need to be changed in case of deficiencies.
Calculation of the protection zone
If the lightning protection device provides a grid or roof surface as a receiver, then the protection zone will completely cover the building. But for catenary wire and rod lightning rods, it is necessary to calculate the protective zone.
Figure: 6: protection zone of the lightning rod Look at the picture, the protection zone is a cone in space where the probability of a lightning strike is significantly reduced. To determine the parameters of this cone in relation to the lightning rod itself and the building, a calculation is made. Methods for calculating the lightning rod zone for each type are carried out on the basis of SO 153-34.21.122-2003.
Figure: 7: parameters of the protection zone of the lightning rod Look at the picture, the following parameters are shown here:
- x and y are the distance from the installation site of the lightning rod to the contour of the building boundary.
Depending on the height of the lightning rod installation and the required reliability, the formula for determining the zone that it protects is selected. For this, data from table 2 are used.
table 2
| Reliability of protection | Lightning rod height h, m | Cone height h 0, m | Cone radius r 0, m |
| 0.9 | 0 to 100 | 0,85h | 1,2h |
| 100 to 150 | 0,85h | (1,2-10 -3 (h-100))h | |
| 0,99 | 0 to 30 | 0,8h | 0,8h |
| 30 to 100 | 0,8h | (0.8-1.43 · 10 -3 ( h-30))h | |
| 100 to 150 | (0,8-10 -3 (h-100))h | 0,7h | |
| 0,999 | 0 to 30 | 0,7h | 0,6h |
| 30 to 100 | (0.7-7.14 · 10 -4 ( h-30))h | (0.6-1.43 · 10 -3 ( h-30))h | |
| 100 to 150 | (0,65-10 -3 (h-100))h | (0.5-2 · 10 -3 ( h-100))h |
To determine the radius of the lightning rod zone at a certain height, the formula is used: r x \u003d r 0 × (h 0 -h x) / h 0
Figure: 8: cable lightning protection zone The figure shows circuit diagram protection zones for a wire rope lightning rod with its short length. At large distances, due to poor tension at the midpoint, sagging can occur, which slightly distorts the boundaries of the area protected by the lightning rod.
Figure: 9: Parameters of the protection zone of a catenary wire lightning rod Look at the figure, here the lightning rod zone is characterized by the following parameters:
- h is the height of the lightning rod itself;
- h 0 - height of the lightning rod protection zone;
- h x - height at a certain point (set at the level of the building's roof);
- r 0 - radius of the lightning rod protection zone on the ground;
- r x - radius of the lightning rod protection zone at the selected point;
- L is the length of the lightning rod.
In terms of the required reliability, depending on the height of the lightning rod, the parameters of the protection zone are calculated using the formulas from Table 3.
Table 3
| Reliability of protection | Lightning rod height h, m | Cone height h 0, m | Cone radius r 0, m |
| 0.9 | 0 to 150 | 0,87h | 1,5h |
| 0,99 | 0 to 30 | 0,8h | 0,95h |
| 30 to 100 | 0,8h | (0.95-7.14 · 10 -4 ( h-30))h | |
| 100 to 150 | 0,8h | (0,9-10 -3 (h-100))h | |
| 0,999 | 0 to 30 | 0,75h | 0,7h |
| 30 to 100 | (0.75-4.28 · 10 -4 ( h-30))h | (0.7-1.43 · 10 -3 ( h-30))h | |
| 100 to 150 | (0,72-10 -3 (h-100))h | (0,6-10 -3 (h-100))h |
The radius of the lightning rod zone at the height of the building is calculated by the formula: r x \u003d r 0 × (h 0 -h x) / h 0
The choice of material for the lightning rod
It is customary to use three options as a material for a lightning rod: copper, aluminum and steel. Copper lightning rods are characterized by a long service life and are distinguished by their ability to maintain their parameters throughout the entire installation period, even in underground areas. But the main disadvantage of a copper lightning rod is its high cost.
Aluminum is characterized by a much lower weight, therefore, it creates an insignificant load on the supporting structures of the building. Also has good electrical conductivity. But, over time, it undergoes destruction from atmospheric factors and easily lends itself to mechanical deformation.
Steel is the most durable, they can easily withstand wind loads, and the elements of such a lightning rod can be connected by welding, unlike copper and aluminum. It is also characterized by a low cost price. The disadvantages of a steel lightning rod are high resistivity and susceptibility to corrosion.
Installation location
The highest point must be selected to install the lightning rod. Therefore, it is placed on the roof of the building, if its height is not enough for the entire structure to fall into the protection zone, special supports or nearby trees can be used. To determine the actual location of the lightning rod installation, it is necessary to apply the protection zone obtained during the calculation to the site plan.
Figure: 10: protection zone in the building plan The roof is the most advantageous option since the peak of the protection zone will be located above the building. A freestanding support or several support allows you to shift the area protected by the lightning rod to the desired point on the site, and is great for situations where buildings are dispersed over the site. The use of wood as a support allows you to save on the purchase and installation of a metal or reinforced concrete structure, but it causes a number of difficulties during operation, therefore, it is considered an undesirable option.
Step-by-step instructions for making a lightning rod
Most simple options for a summer cottage lightning rod is a rod and cable, you can implement them yourself. To avoid mistakes and unnecessary costs when installing a lightning rod, follow the following sequence.
Rod
To construct a rod-type lightning rod, perform the following manipulations:
The distance between them and their height is selected so that the conductor does not sag to the surface of the roof and walls.
Rope
The installation of a cable lightning rod is identical. Depending on the specific situation, the cable can be stretched with a flexible cable between the supports or mounted on brackets. In the first case, the lightning rod will sag when the tension changes, therefore, fixing a rigid copper or steel wire to the bracket is much more profitable. This procedure is performed in the following sequence:
After completing the installation of any of the proposed types, be sure to check the resistance of the entire structure. Ideally, the check is performed using a bridge, but at home, a regular multimeter or control light is also suitable.
Video instructions
A thunderstorm with its bright flashes and deafening peals of thunder is a mesmerizing natural phenomenon. How much power and beauty it conceals in itself!
Private house owners need to protect themselves from lightning. Modern technology has many means to protect a home from thunderstorms and its dangerous consequence - lightning.
They can be divided into two types:
- Lightning protection devices
- Lightning protection devices
These remedies give the best effect when combined. Let's take a closer look at the lightning protection device.
External lightning protection devices
This explains the fact that lightning strikes the nearest point: lonely standing tree, in a person on the field, in tall buildings. Lightning has tremendous electrical power.
therefore lightning strike into the house, or even near the house, can cause serious damage to electrical equipment. It is impossible to prevent the appearance and strike of lightning.
The only thing that can be done is to direct the lightning along the path where it will cause as little harm as possible.
The principle of operation of external lightning protection is based on this: the lightning rod attracts lightning to itself, the energy of which goes into the ground through grounding, without causing harm to anyone.
A lightning rod (or, as it is also called, a lightning rod) can be:
- a tall metal pin on the roof of the house;
- a cable stretched between two pins installed on the edges of the roof ridge;
- metal mesh on the roof or metal roof.
The lightning rod is connected to ground using a steel or copper conductor with a cross section of at least 16 mm 2. Here the rule is true: "The thicker the better." The steel conductor is connected to the grounding device by welding to exclude the possibility of corrosion of the connection.
To lightning protection at home was effective, it is recommended to use a separate grounding device, independent of the ground loop of the house.
Active external lightning protection
This type of protection has become popular lately. Its advantage is that there is no need to install bulky lightning rods that spoil appearance houses.
They are replaced by a small device that is installed on a single lightning rod. It generates high voltage pulses and attracts lightning. Energy dissipation into the ground is carried out in the same way as in classical lightning protection.
Lightning protection equipment
As already mentioned, even if lightning does not strike directly into the house, it can cause impulse overcurrents in the home network. These very high currents can damage expensive electronic household appliances.
To prevent this from happening, protection of a private house from lightning carried out by installing surge suppressors or arresters in the electrical panel. Their purpose, when an impulse overvoltage occurs, to remove it from the protected section of the circuit, which is the wiring and equipment of the house.
We strongly recommend that you take seriously your home's lightning protection device. Let it not seem too expensive to you, because replacing electrical equipment and the consequences of a fire are much more expensive.
We know what lightning is from the school desk. An electric discharge with a capacity of 100-200 thousand amperes destroys all objects where it falls. Most likely, tall buildings and trees attract lightning.
Lightning protection of a private house today is more relevant than ever. Our homes are literally packed with electronics, household electrical appliances, mobile phones, which increases the risk of lightning. Danger of lightning for private homes,not equipped with lightning rods is great - fire, destruction in the event of a direct discharge. The consequences of a discharge in the immediate vicinity of a building may be a failure of the electrical network or a separate device - a TV, computer, etc.
- Internal, which protects against a discharge that did not enter the house, but, for example, into the power line that feeds the internal wiring. In this case, an overvoltage occurs in the power grid, the consequences of which can be dire. The internal protection is not visible, it is a small device - a limiter, an arrester, an SPD installed in a switchboard.
- External protection is a familiar lightning rod (as lightning protection is often incorrectly called) installed on the roof.
External protection of a private house from lightning
The system is passive and active. The principle of operation of the first is simple, like everything ingenious. A metal lightning rod on the roof catches (attracts, intercepts) a lightning discharge and, by means of a current conductor, directs it to the ground, to the ground electrode.
Active lightning protection
Such lightning protection is more effective, it operates within a radius of 100 meters from the "cunning" lightning rod, which, ionizing the surrounding air, intercepts the lightning discharge. Then it works like passive protection. The main advantage of the device is the lightning protection "covering" of neighboring residential buildings and outbuildings on a fairly large territory.
Types of external lightning protection at home
By the type of construction, there are modular-pin, catenary wire and mesh lightning protection.
Pin
The pin system is called because of the lightning rod, which is installed in the highest part of the roof, and is a metal rod (pin). This design is suitable for lightning protection of a private house with a roof made of metal or any other material.
Rope
Installation of this type of protective device is allowed if the roof is slate, tiled, but not metal.
The lightning rod is a cable (thick wire, wire rod) stretched at a height of 0.3-0.5 m along the ridge of the house.
Mesh
The system is considered the most complex in terms of installation. It is made of wire rod with a diameter of 6-8 mm, which is in the form of a mesh with cells of 6x6 meters, fits over the entire roof area. At the intersection of horizontal and vertical rods, it is welded. Attached to the roof with brackets.
Mesh lightning protection of a house is installed, like cable, on a slate or tiled roof.
Down conductor
For this element of the system, round steel (copper, aluminum) with a diameter of at least 6 mm is used. On the roof and walls, the down conductor is fastened with brackets. Usually, during installation, they try to lay the "route" away from the window and doorways, as required by regulatory documents, and so as not to spoil the exterior of the building.
When laying the conductor, you need to follow some simple rules:
- On wooden surfaces the conductor must be fixed at a distance of 15-20 cm from the wall;
- If a cable receiver of a long length, a mesh large area or a pin receiver consists of several elements, then there should be several down conductors (SO 153-34.21. 122-2003)
During the construction of a new structure, the lightning protection of a cottage or house is already “incorporated” in the design documentation. But if vacation home or country house just purchased and there is no "lightning rod" on it, the most reasonable solution would be to protect yourself and your loved ones from lightning discharges on your own, or with the help of hired specialists.
If you have the skills to perform construction works, lightning protection of a private house with your own hands will not become a problematic issue, but it will save money.
Ground loop
The principle of the earthing switch is extremely simple. Three steel pins-modules, 1.5-2 meters long, 16-20 mm in diameter, with a zinc coating, are driven into the ground and connected in series with each other.
This design has several advantages:
- Possibility of installation to any depth without the use of special equipment;
- Low labor intensity. The work can be done by one person;
- Large immersion depth of the pin-electrode increases the efficiency of grounding;
- The connection of elements does not require welding (on special clamps);
- The entire system is hidden underground.
The contour is hammered into the ground no closer than 1 m to the foundation of the house, and no closer than 5 m to the front door.
The principle of operation of internal protection of a house against lightning
It is hard to imagine life today without electronic and household electrical devices and appliances. All this equipment is included in the power grid, and cables also go from the computer and TV to local network and a satellite dish.
Data transmission lines through receivers, servers, switchgear, power lines, are subject to lightning strikes, the influence of electromagnetic fields. Under certain circumstances high voltage and high current flows through the cables to low potential, i.e. TV, refrigerator, computer. The result can be a breakdown of electrical appliances, fire, a threat to human life.
To protect yourself and your home, you need internal organization lightning protection of a private house or surge protection.
Such protection works simply - instantly equalizes the potentials between the conductors of the electric current. This task is performed by an SPD - a special surge protection device.
Installation of this device is possible only after a reliable external protection device. To implement the lightning protection system of a private house, a project is being developed, which takes into account all the ways of entering a high-voltage building.
After installing the SPD, the non-current-carrying elements are connected to the grounding bus, and the lines that cannot be grounded are connected to the bus through the SPD.
For the selection of an SPD device, there are rules that can be divided into groups depending on:
- Indicators of the protected network - current, voltage, frequency, wire cross-section;
- Network type - power supply, cable TV, telephone line, alarm, etc .;
- Significance of the protected object - PC, TV or bank server.
Do I need lightning protection for a private house
You can definitely answer - you need it! There is still a lot of unknown in the world, especially the mysteries of nature. If in a city a television tower or a high-rise building "protects" many neighboring houses from lightning, then in the area of \u200b\u200bprivate development there are usually no such structures. But not far from the house there is a tall pine tree, which serves as a natural "lightning rod". But this is a theory, it’s still better and calmer to feel safe in “your fortress”.
