Do-it-yourself lightning protection of a private house, country house and not only
Advice from professionals on lightning protection
The destructive power of lightning is quite understandable: its current reaches two hundred thousand amperes at a voltage of up to one hundred thousand kilovolts. Moreover, there are cases when several lightning strikes in the same place within one and a half seconds. And even one lightning strike on a structure without a lightning rod is enough to make it burst into flames like a candle. Despite this, small house Protecting against lightning is quite easy.
A conductor is stretched over the roof ridge (at a distance of at least 25 cm from it) - a steel wire 5-6 mm thick (Fig. 1 on page 16). On wooden beams to which it is attached, vertical lightning rods up to a meter high are installed. The chimney will be reliably protected by a steel cap, wire “plug” or loop connected to the conductor. The same conductor goes down the shortest route along the wall of the house and is connected to the ground. If the length of such a lightning rod is more than ten meters, then it should be grounded on both sides.
Lightning most often strikes roof ridges, gable edges, dormer and skylights. Therefore, the conductor can be laid over such protruding places, attached directly to a roof made of tiles, slate, or mounted on wooden pins or a solid block on a roof made of shingles, roofing felt and other combustible materials. Such a lightning rod is grounded at several points. Wooden parts painted with oil paint.
A house covered with iron will be completely safe if you ground its roof three or four times every 10-15 m around the perimeter. How to attach the grounding is shown in Fig. 2.
Easy to manufacture and lightning rod. With a height of 5 m, counting from the ridge, it can protect a house 15 m long and 7 m wide. Install the lightning rod on a pole 10-15 cm thick, nailed to the rafters in the middle of the roof or dug in next to the house. You can also strengthen the lightning rod on a tree growing near the house.
He is tied to the trunk above the branches soft wire 02-Zmm every 2-3 m. If the house is located closer than 5 m from the tree, then a conductor is laid along its wall, connected to the same ground as the lightning rod (Fig. 1).
The upper end of the lightning rod is made of wire of the same diameter as the rest of its parts (or larger - up to 14 mm, steel strips, angles or pipes with a cross-section of 50-60 mm2. The pipe at the top is flattened or welded into a cone, and a loop is made from the wire, securing by twisting it or using a wire bandage (Fig. 3).
Grounding can also be made of wire, but it is better to make it from steel pipes, for example, water pipes, 040-60 mm, steel strips, corners and other material with a cross-section of at least 50 mm2. Grounding is laid to a depth of at least 80 cm (the deeper, the better). In the simplest case, a wire or metal strip several meters long is laid in a ditch. You can drive two or three piles of pipes or angles into the ground so that their upper end is at a depth of 80 cm. The piles are connected by a horizontal bus made of steel strip or wire, to the middle of which a lightning rod is attached (Fig. 4).
If the soil is dry, sandy and does not conduct electricity well, then the grounding should be backfilled charcoal, mixed with table salt (about 0.5 kg of salt per bucket of coal). This will greatly reduce the soil resistance: coal is a good conductor, and salt is hygroscopic.
Grounding should be located at a distance of at least 5 m from paths and passages.
The lightning rod is strengthened on wooden walls ah and poles with staples or clamps nailed at a distance of one to two meters from each other. It is useful to place insulators made from a piece of rubber hose under the clamps. Conductors must be laid so that there are no loops or sharp corners on them, otherwise they may be torn apart by the forces generated by a lightning discharge. They are closed to a height of about 2.5 m from the ground steel pipe, corner or wooden box.
Methods for connecting lightning rod parts are shown in Fig. 5. The most reliable are welding or soldering, but you can also use twisting, bandage connection, special compression or overlap connections using bolts and rivets.
Contacting surfaces must be well cleaned of paint, dirt and rust. The joints (except welded ones) are wrapped with insulating tape, then with thick fabric, secured with thin wire or twine, and the whole thing is painted over without breaking the contact. The paint protects well from oxidation. There must be reliable electrical contact between all parts of the lightning rod.
Every year, before the onset of thunderstorms, parts of the lightning rod and their attachment points are inspected and, if necessary, they are replaced and painted.
Once every three years, check the serviceability of the connections, clean the contacts, tighten loose connections or replace them.
Once every five years, the grounding electrodes are opened, the reliability of their connections and the depth of corrosion are checked. If the cross-section of a rusted part has decreased by more than one third, it should be replaced.
Most owners of private houses, cottages and summer cottages try to create the most comfortable and comfortable conditions inside and outside their homes. safe conditions for accommodation. It is a completely understandable desire, but most often the owners of such real estate completely forget about such a natural phenomenon as a discharge of static atmospheric electricity, which in an instant can cause enormous harm to residential buildings and human health. By its natural essence, atmospheric lightning is a very powerful discharge electrical energy, which is capable of accurately hitting directly into a private house, destroy not only all household appliances and electrical appliances, but also the building itself as a whole.
If your private property is located next to a tall building, then you should not worry. The lightning rod system of a multi-storey building will provide reliable protection for your home from damaging factors atmospheric electrical discharge. But such an arrangement of cottages, private houses and dachas is practically never found in modern reality. Basically, such real estate objects are built far from tall buildings, therefore they must be protected from lightning by equipping modern blocks lightning protection.
Lightning most often discharges to the highest point, but even a huge tree growing next to a house is not able to protect it from the discharge. Only a lightning protection device can completely protect against atmospheric discharge your home with household appliances, as well as the people present in it. In this article we will consider all questions regarding the types of lightning protection and methods of their installation for all types of houses, cottages and cottages. We will also tell you in a concise form how to install a lightning rod with your own hands, but first we will tell you about the damaging factors of lightning.
Damaging factors of atmospheric discharges
The technology for creating protection against thunderstorms is directly related to the damaging factors of atmospheric electrical discharges. Any natural phenomenon affects environment with varying degrees of impact. Lightning is no exception and its damaging factors can be divided into the following two types.
You can protect your property from a secondary damaging factor by simply disconnecting electrical appliances from the power supply for the entire period of time the storm front passes. For effective protection from a direct lightning strike, it is necessary to install lightning protection in a cottage, private house or country house.
Installation of a lightning rod and additional protective equipment will avoid negative consequences from the impact of the discharge on your residential property and on the people living in it, regardless of the type of damaging factor. Next we will look at the types and categories of lightning protection.
Categories and types of external lightning protection
Atmospheric lightning is a powerful discharge of electricity that obeys the basic laws of physics. Everyone knows that electricity moves along the path of least resistance. The main task of any type of lightning protection unit is to create just such a path for the passage of electricity, bypassing the structure of the building. When lightning strikes a private house equipped with such a block, all the power electric charge It will simply go into the surface of the earth without causing damage to buildings, electrical appliances and people.
In popular slang, this type of protection of private buildings is called differently: grounding country house, lightning rod system, as well as lightning rods. The last version of the name is completely incorrect, because thunder is the sound of a lightning strike and there is no need to take it anywhere. But the term has long taken root and is used in colloquial speech. Regardless of what the home's lightning protection is called, it is designed to perform one task - discharging the energy of an atmospheric electrical discharge into the ground. Lightning protection blocks are divided into three categories: by method and type of protection, as well as by design features.
Choose better protection The next chapter of the article will help you against a discharge of atmospheric electricity for your home, in which we will talk about the design of the most popular passive external lightning protection, in addition to which it is necessary to install internal protection against a secondary damaging factor.
Design of passive external lightning protection
The design of an external lightning rod in a country house, cottage or private house is quite simple. It consists of three components: a lightning receiver, down conductors and a grounding circuit. Down conductors and grounding conductors have standard design. In contrast to them, lightning rods passive systems protection can be divided into three types, which we will discuss in detail below.
What type of lightning rod to use is up to you! It is impossible to give any strict recommendations in this regard. All three types of lightning rods are capable of reliably protecting a private home from the primary damaging factor of lightning.
The next elements in the lightning protection system are down conductors. Their main task is to transfer the energy of an atmospheric discharge from the lightning rod to the grounding device. Down conductors can be made from steel wire with a diameter of at least 6 mm, a special copper or aluminum cable or steel tape with a width of 30 mm and a thickness of more than 2 mm. Any down conductor is fixed to the ends of lightning rods using threaded connection, welding or soldering. In private houses built from non-combustible materials, this lightning protection element is mounted on the walls in an inconspicuous place using metal fasteners. Down conductors should not be placed close to windows and doors.
Special requirements apply to the installation of lightning protection down conductors wooden house. When lightning hits the lightning protection system in a private home, the down conductor wires can heat up to high temperatures. To prevent the fire of the wooden walls of a building, it is necessary to correctly install the current-carrying part of the lightning protection system. Down conductors must be located at a distance of at least 10 cm from the walls of the building. For one rod lightning rod, it is necessary to install one current conductor, and for cable and mesh discharge receivers, two current conductor elements. The number of down conductors depends on the number of ends of lightning rods and the area and structure of the roof.
The last element in the system external protection a private house from atmospheric electrical discharges is a grounding device. The simplest ground electrode is two metal rods with a diameter of at least 30 mm, driven into the soil layer 2–3 meters and connected by a jumper made of metal tape. The distance between these grounding elements must be at least 3 meters. The down conductor is connected to this structure exclusively by welding.
We examined the design of external passive lightning protection. It can effectively protect a private home from the primary damaging factor of lightning. To protect a house, cottage or cottage from overvoltages in the network that occur when exposed to the second damaging factor of a lightning discharge, it is necessary to install optional equipment. These devices provide internal lightning protection.
Internal lightning protection
Household appliances and electrical appliances in a private home should be protected from the effects of a powerful induction field that occurs as a result of an atmospheric discharge. External lightning protection is not able to cope with this task. To protect against lightning surges, it is necessary to use special electrical devices. They are called surge protection devices (SPDs) and are installed in distribution boards at the entrance electrical lines to a private house. Currently on the market a large assortment such devices, with different capabilities and levels of protection against surges.
Only after installing the SPD in distribution board and installation external lightning protection you can confidently say that your home is reliably protected from all damaging factors of lightning. We examined the design of lightning protection for a private home, both external and internal. The next part of the article will answer the question: how to make a lightning rod in a country house, cottage or private house with your own hands.
Self-installation of lightning protection
Based on the above, we can conclude that the installation of lightning protection can be done with your own hands without the involvement of hired workers. Of course, if you have basic skills installation work. Otherwise, you should invite a specialist. If you still decide to install a lightning rod with my own hands, then you must first perform the design and calculation of lightning protection. This process will not cause difficulties. We will briefly talk about the design of lightning protection and its self-installation using the example of installing a lightning rod with a lightning rod. This is the most popular option for protecting suburban real estate from thunderstorms.
A lightning rod with a lightning rod provides protection in the form of an imaginary cone, with the apex at the end of the lightning rod. In the inner zone of this cone, to ensure reliable protection buildings from lightning, the entire object must be hit.
In the above figure we see that part of the house did not fall into the protection zone, so it is necessary to move the lightning rod to the middle of the house or increase its height. The best place for mounting the lightning rod at the ridge of the roof or chimney. The calculation of the height of the receiver rod is calculated using the following formula.
- Rx is the lower radius of protection of an imaginary cone, which must be measured with a tape measure on the surface of the earth;
- Ha is the height of the active lightning protection zone, which is measured from the ground to the highest point of an imaginary cone;
- Hx is the highest point of a private house, which can be located on the roof ridge, chimney or other structural elements;
- H is the height of the lightning rod.
After calculating the length of the lightning rod, you should determine its location and lay an imaginary route for installing the down conductor from the rod to the installation site of the ground electrode. At this point, the design and calculation of lightning protection is completed and you can proceed directly to the installation of the lightning rod.
Installation of ground electrode
First of all, you should install a grounding loop. To complete the work you will need the following tools and materials:
- grinder with cutting wheels, welding machine, sledgehammer, hammer and shovel;
- 40x40 steel angle for the vertical pins and 40x5 strip for the jumpers.
The ground electrode should be mounted near the wall of the house. We choose a place and dig an equilateral triangular trench 70 cm deep with sides of 1.2 meters. It is also necessary to dig a trench up to the wall of the house to lay the down conductor. In the corners of the triangle we hammer in pieces of steel angle to a depth of 2 meters.
A strip is welded to the ends of the pins. A steel strip is welded to one corner of the circuit and brought out onto the wall of the house, where a down conductor from the lightning rod will be connected to it. The trench is dug and compacted. The ground electrode is ready to connect the down conductor.
Installation of lightning receiver
The best place to attach the lightning rod is a chimney located near the ridge of the roof. The most convenient way to secure the mast is with brackets with clamps at the ends.
An alternative option for fastening the lightning rod is to install it on a special support on the ridge of the house.
On final stage After installation, the down conductor is attached to the lower end of the rod using a clamp with a threaded connection.
Installation of down conductors
A down conductor, a metal wire with a diameter of at least 6 mm, is laid directly along the roof and wall of the house, to the point where the connecting steel strip exits from the ground loop. The entire structure is attached to the roof and walls of the house with plastic or metal clamps with support.
The lower end of the down conductor wire is fixed to the metal grounding strip using a threaded connection.
At this point, the installation of external lightning protection is completed, but if you do not install the unit internal protection from surges, then your lightning protection system will be incomplete.
SPD installation
The surge protection device completely de-energizes electrical network at home when a powerful induction field occurs, that is, a secondary damaging factor of lightning. The module is installed in the distribution panel according to the following diagram.
After installing an SPD, your lightning protection for a private home receives a fully finished, functional look. With this system your property and Appliances reliably protected from atmospheric electrical discharges.
Conclusion
High-quality installation of a lightning rod will ensure you a comfortable stay in your home. In this case, protection from all damaging factors of lightning will be provided. But it should be noted that lightning protection must be periodically checked for damage. During a preventive inspection, the main attention should be paid to all connections. Only if the lightning rod is operational will your home be reliably protected from lightning strikes.
Video on the topic
Technical measures defined as lightning protection of a country house in accordance with the requirements of the PUE must be considered taking into account the specifics of their implementation in each specific case. And, indeed, only rare private buildings are located near high-rise buildings with a lightning protection device placed on them. Many of these structures are in an isolated position and require special protection from lightning, which most often strikes single objects.
Standards
According to current standards (SNiP, in particular), all suburban residential buildings belong to the 3rd fire safety class and are subject to mandatory installation of lightning protection equipment.
At the same time, the arrangement of effective lightning protection for a cottage, for example, should be provided for at the preparation stage construction project. This approach to solving the problem allows us to obtain reliable system fire prevention, naturally integrated into the architecture of the house being built.
However, many owners of ready-made private buildings would like to protect their home themselves, which requires certain knowledge and skills. We will talk further about how to correctly and without unnecessary problems install effective lightning protection with your own hands.
What to consider during installation
The type and effectiveness of lightning protection, selected individually for each rural building, depends on a number of factors. Here are the most important of them:
- technical condition of a private house;
- its location in relation to other objects;
- the quality of the soil at the location of the protected private building, ensuring good grounding of the entire structure as a whole.
In the case of dilapidated and poorly protected from exposure natural factors structure, the likelihood of it being damaged by a lightning discharge increases sharply, which will require the owner additional accessories for lightning protection.
Proximity of high-rise objects
On the other hand, even brand new private homes can be affected by lightning if they are located in close proximity to antenna towers, large and tall trees or poles.
All of the listed high-rise objects are good targets for lightning strikes and have the so-called “screen effect”, the zone of which also includes a nearby residential building. When calculating the dimensions of the lightning rod mast, the presence of such objects nearby must be taken into account.
Soil condition
The quality of the soil at the location of the house is very important from the point of view of the effectiveness of the ground electrode used as part of lightning protection, the protective effect of which is based on the flow of discharge current into the soil.
In cases where the soil at a dacha or at the location of a private country house has low electrical conductivity, it is necessary to take care in advance about artificial measures to increase it. This can be done by adding an aqueous solution to the soil. table salt or other chemicals.
It is also possible to compensate for the insufficient electrical conductivity of the soil by reducing the resistance of the down conductor and ground electrode, to which the lightning rod is connected in a private house.
However, this option for increasing the efficiency of lightning protection usually leads to increased costs for Consumables and an increase in the cost of the entire system as a whole.
Particular attention should be paid to the selection of reliable lightning protection in a situation where there is a natural body of water or a spring in the immediate vicinity of a private house. In areas with more than 40 hours of thunderstorm activity per year, the risk of damage in this case will be maximum.
Lightning rod design
In order to build a private country house yourself, you need to familiarize yourself with the operating principle of lightning protection.
At the moment of a lightning discharge, lightning strikes the receiving device ( metal pin, cable or mesh), after which it is discharged along a special steel tape directly to the ground electrode.
In this part of the protective chain, current flows into the ground, accompanied by a sharp drop in the power of the electric charge.
Thus, independent installation of a lightning rod for a private house involves the manufacture of the following mandatory elements thunderstorm protection:
- lightning rod of pin or mesh type;
- reliable down conductor (descent);
- grounding device (lightning protection grounding circuit).
A typical lightning rod is made in the form of a thick steel rod with a cross-section of about 10-20 millimeters and a length of about 2.5 meters. During installation, the pin is securely attached to any high point of the roof so that its pointed end rises above this place by at least 2 meters.
Please note that either the ridge of the roof of a private house or a smoke exhaust pipe can be chosen as the attachment point.
Let’s immediately make a reservation that this version of the lightning rod is ideal for. In the case where the roof of a private house is covered with slate, it is recommended to use a metal cable stretched along the ridge and securely fastened to insulating supports as a receiver.
For tiled roofs most optimal solution is to lay a special lightning protection mesh over their entire area with a system of wires extending from it.
Such down conductors (or descents) are made of wire with a diameter of at least 0.6 centimeters or a strip of the same metal with a standard size of 2x30 millimeters.
During installation, they are laid along the walls of the building, and then welded on one side to the lightning rod, and on the other to the ground loop, manufactured according to standard scheme(see PUE).
The procedure for arranging a lightning rod
It is best to start a lightning protection device for a private country building with the manufacture of a lightning rod. In this case, the lightning protection rod itself is securely fixed to the highest point of the building (on a pipe or on a wooden antenna mast). If a mesh is used, it is laid over the entire roof area to form cells measuring no more than 12x12 meters (this value is selected based on the dimensions of the roof and the required quality of lightning protection).
At the intersections of the wires, the mesh is attached by welding, and then fixed on the roof of the house using special holders that are well insulated from the coating material.
Several contact pads are arranged along the lower edge of the grid, intended for connecting a system of down conductors (in standard project For lightning protection, two descents are usually laid on each wall of the house).
Part of the lightning protection mesh structure adjacent to chimney, can be designed in the form of a loop of the appropriate size, which is thrown over it from above and then attached to the base.
A lightning diversion device prepared in this way will provide high-quality lightning protection to any non-metallic roof of a private house.
We also note that for the manufacture of a pin lightning rod, a material that cannot be oxidized (galvanized steel or copper) must be used, since painting it is not allowed by regulatory requirements. In the case when such lightning rods are made from a hollow steel pipe, one of its ends is tightly welded.
The procedure for manufacturing a ground electrode
The main purpose of lightning protection grounding is to provide ideal conditions for the discharge current to spread into the ground.
Fulfillment of this requirement is possible only with a minimum electrical resistance the entire structure of the ground electrode, made from a set of metal blanks. As a rule, it is constructed from 3 thick steel rods or profiles at least 2.5 meters long, driven into the ground not far from the house (no closer than 5 meters).
These blanks are fixed in the ground in such a way that their vertices form a regular triangle with sides about 1.2 meters long.
After this, they are connected to each other by welding using jumpers of the appropriate length, forming a strong and reliable grounding structure.
The structure obtained in this way can be used as protective grounding private house. If the house already has grounding, it can be combined with a lightning protection grounding electrode into one system.
A reliable lightning rod in a summer cottage will not only protect a person from being struck by lightning, but also protect the house from fire, especially if it is made of wood. Consists of good system lightning protection consisting of a grounding conductor, down conductor and lightning rod. Next, we will tell readers what all the elements of the system should be like and how to make a lightning rod in a private house with your own hands!
How the system works
First, let's figure out how lightning protection for a private home works and what is needed to create it. You can clearly see all the components of the system in this diagram:
As you already understood, the metal rods on the roof are lightning rods that discharge a dangerous discharge to the ground through a down conductor and a special one.
There is an opinion that if a telephone tower is installed near the house, there is no need to install a lightning rod in a private house. This is wrong, because... It’s better to spend a little time and ensure yourself complete protection from lightning strikes. So that you know what a lightning rod should be like and how to make it correctly with your own hands, below we will separately consider the features of choosing each of the system elements.
Brief overview of lightning protection installation
Components of protection
Lightning rod
The main task is to choose the right lightning rod, which should provide complete protection of the country house in its coverage area. Today, a pin, mesh, cable, or the roof itself can act as a lightning receiver. Let's take a closer look at the features of using each option in a private home.
As for the pin, there already exist finished goods from manufacturers that have a suitable shape and convenient fastening. As a rule, the metal used to make the lightning rod is copper, aluminum or steel. The most suitable and effective is the first option. In order for the receiver to cope well with its task, its cross-section must be at least 35 mm 2 (if copper) or 70 mm 2 (steel rod). Regarding the length of the rod, in living conditions It is recommended to use receivers with a length of 0.5 to 2 meters. The pins are convenient to use to make a lightning rod on garden house, bathhouse or other small building. 
Metal mesh can also be sold in already finished form. As a rule, a mesh lightning rod is a cellular frame made of reinforcement, 6 mm thick. The cell size can range from 3 to 12 meters. Most often, this type of lightning protection is used in apartment buildings and large buildings, for example, shopping centers. 
The cable is more practical at home and does the job better than the mesh. To make a lightning rod in a private house using a cable, you need to stretch it along the roof (along the ridge) by wooden blocks, as shown in the photo below. Minimum diameter cable for lightning protection of a building should be 5 mm. As a rule, this option is used if you want to make a lightning rod on a house with a slate roof with your own hands. 
Well, the last option - the roof as a receiver, can be used if the roof of a residential building is covered with corrugated sheets, metal tiles or other metal roofing material. With this version of the lightning rod, two important requirements. Firstly, the thickness of the metal must be at least 0.4 mm. Secondly, there should be no flammable materials under the roof. Make a lightning rod in a private house with metal roof can be done much faster and at the same time saving on the purchase of special lightning rods.
Please note that if you use a mesh, it must be installed at a height of at least 15 cm above the roof itself!
Down conductor
Ground electrode
Well, the last element of the lightning rod is the grounding circuit. In order not to make the material too voluminous, we have dedicated a separate article to this issue -. We recommend that you read the information so that you know all the intricacies of this stage.
In short, we can say that the grounding loop should be located next to the house, but not in the walking part of the site, but, on the contrary, closer to the fence. The charge is discharged to the ground by metal rods buried in the soil to a depth of 0.8 meters. It is better to place all the rods according to the diagram, which is exactly shown in the photo: 
Avoiding the tragic consequences of lightning is not only possible, but also very easy. Multi-storey urban buildings, as a rule, are equipped with lightning protection at the construction stage. But for owners of private housing, country houses and dachas, it is important to understand that no one will take better care of the safety of their property and life than they themselves. A lightning rod, or more precisely, a lightning rod, is metal structure to attract and capture the electrical discharge of lightning. It has a rather unassuming design, but is very effective during bad weather. Precisely because it will not take a lot of money, time and effort to install, it is important to make a lightning rod in a private house with your own hands. Serve like this homemade design will be trouble-free, which has been repeatedly tested in practice.
Consequences of lightning strikes.
Thunder and lightning or why a lightning rod is needed
In the mid-latitudes of the European continent, May Day marks the beginning of a season when rain may be accompanied by thunderstorms. Most people are afraid of thunder and lightning flashes. And not without reason. Statistics inexorably show that dozens of people die from lightning strikes in the country every year, and fires in private buildings due to lightning discharges and sparks occur even more often.
A lightning rod in a private house is relevant for both owners country cottages, and for those who like to spend time in the country. Due to the characteristics of electrostatics, in last decades the probability of being hit by an electrical impulse during a thunderstorm has increased significantly. The reason for this is the abundance of electrical appliances and electrical equipment in homes that use air channels to exchange information. In addition, as you know, lightning is more likely to strike metal objects, if they are nearby, than trees. In modern housing there is a lot metal objects: metal roofing, antenna, chimney protective cone, etc. Of course, there is a greater need for lightning protection wooden buildings, but also when hitting brick house, the listed facts will be enough to cause a fire.
Here are several factors that can influence the decision whether or not to install a lightning rod in a private home:
- soil composition;
- height of the site above sea level;
- climatological characteristics of the area (frequency of thunderstorms, air humidity, etc.).
Although in general, the feasibility of installing a lightning rod in a private house is beyond doubt. If possible, it is better to provide your home and site with the necessary protection.
How does a lightning rod protective system work?
The lightning rod (lightning rod) structurally consists of three parts:
- lightning rod - a high-rise metal structure above the house (rod, cable or mesh version);
- support for the lightning rod, sometimes necessary in cases where the lightning rod is installed not on the roof of the building, but separately on the site;
- down conductor (lowering) – conductor from the lightning rod to grounding;
- grounding - a device for draining a lightning discharge into the ground.
Anyone can understand how a lightning rod works: a lightning rod made of metal, which is installed on an area higher than other buildings and elements, during bad weather “causes” lightning discharges of electricity and, along the down conductor, redirects them into the thickness of the soil through the grounding circuit. The action of any lightning rod has a cone-shaped character, limited by area and height. In practice it is called the cone of safety. Geometric parameters of this volumetric figure are individual for each area and lightning rod under consideration.
Three types of lightning rod designs are known and allowed for installation:
- rod (pin);
- linear (cable);
- mesh.
Designs of lightning rods
Rod protection
Rod protection is a lightning rod made of metal rod(tube, angle or rectangular profile) and installed on the roof of a dwelling or on free-standing mast. Suitable for any roof with metal coating. Fig 3.
Linear (cable) lightning rod
For low buildings with slate or wood roofs, a linear lightning rod is recommended - a cable with a cross-section of at least 0.5 cm stretched along the ridge of the roof, connected to grounding at each end. It is attached to wooden supports at a height of at least 0.5 m above the ridge of the roof. In this case, the down conductors run along the walls of the house, in protective pipes. If the support masts are located correctly, then lightning electricity will go into the soil beyond the boundaries of the protected area. Fig 1.
Mesh lightning rod
Such protective structure It is made in the form of a mesh of metal rods and laid on top of the roof of the house being protected. Its nodes are fixed by welding. It is fixed on special holders or laid directly on the roof, if the increase in temperature does not pose a danger to the roofing material.
When making a lightning rod from a mesh, down conductors are made along its entire perimeter. The grounding conductor in this case is a closed horizontal circuit with reinforcement at the points where down conductors are connected. Fig 2.
DIY lightning rod
Choosing an installation location
Before directly approaching the question of how to make a lightning rod in a country house, you should choose a place to install it. One option could be the roof of the building. It is simple and does not require high support, 3-4 meters is enough. If there are elevations on the site that exceed the height of the roof ( tall tree, television antenna mast, weather vane, chimney pipe), then it would be reasonable and convenient to place the lightning rod there, taking care of its reliable fixation. It is important to ensure that the entire house falls within the protected cone.
But if for some reason the above options do not suit you, then there is always the opportunity to install a lightning rod on a mast some distance from your home. Although this method is more labor-intensive, because a high, strong mast is required, and has nuances:
- the further from the building, the higher the mast is needed;
- The lightning rod should not create a danger to neighbors.
Equipment selection
Since this article is devoted to how to make a lightning rod in a private house, the most universal and a budget option– arrangement of a lightning rod at the dacha. This fully complies with the requirements of domestic standards in the field of electrical safety, in particular the manual to RD 34.21.122-87 “Instructions for the installation of lightning protection of buildings and structures”, which states that:
"…ToIII categories include small buildings in rural areas, where combustible structures are most often used......their lightning protection is carried out using simplified methods that do not require significant material costs.”
Everything you might need to make a lightning rod can be purchased at regular store construction goods. To build a typical lightning rod, you will need:
- for an air terminal: a metal rod - steel, copper or aluminum with a cross-section of 50, 70 or 35 square millimeters, respectively.
- for down conductor: preferably copper cable, at least 16 square millimeters in diameter;
- for the mast: asbestos cement pipe (2-4 meters above the house);
- copper pins for grounding;
- fasteners.
Having everything you need at hand, you can begin installing the lightning rod.
Preparation for installation
When making a lightning rod with your own hands at the dacha, the owner of the dacha plot must understand that the issue of reliability and safety of the structure falls entirely on his shoulders. Therefore, already at the installation stage, he must take care of safety. What should be done:
- carefully consider and prepare the fastenings of the lightning rod parts. In the absence of reliable fixation, all high-rise elements can be blown away by the wind, which means that the building itself, cars parked near it, or injuries to residents may occur;
- smoke ducts located above the roof also require the installation of lightning rods. A chimney made of a ceramic pipe or brick inevitably loses its insulating properties during operation, which means it can easily transfer a lightning charge into a home. Stainless steel and similar chimneys require grounding;
- antennas (including satellite ones) must be connected to grounding, because they are connected to the electrical network and attract lightning very well.
Manufacturing instructions
Lightning rod installation
Installation of a lightning rod begins with digging a hole or trench 1-1.5 meters deep and 3 meters long for laying the ground electrode. The ground electrode should not pass near the house itself (porch, walls), or garden paths.
If during digging in the hole you find groundwater, then this is only a plus: moist soil is an excellent conductor, a lightning discharge will evenly flow into the soil.
Next, the lightning rod is secured to the top of the support or roof with metal clamps. The next step is to attach a down conductor cable to the existing structure, which will run in an asbestos cement pipe.
The lower end of the cable is pinched with contacts or welded to a grounding electrode. Then the grounding circuit is buried (driven) into the soil and, tamping well, is covered with earth.
Important! The lightning rod should not have decorative covering(coloring), because it can significantly worsen its conductive function!
Design calculation
In order to mount a lightning rod with your own hands, you need a simple calculation. There is a formula for this:
h=(r x +1.63h x)/1.5
In it, h is the height of the lightning rod,
h x – height of the house,
r x – radius of the base of the protection cone,
1.63 and 1.5 – calculated coefficients.
That is, if it were necessary to protect country cottage area with a radius of 10 meters, having in its center a house 5 meters high, on the roof of which a lightning rod is installed, then by substituting these numbers into the formula, you can get the result:
h=(10+1.63×5)/1.5 = 12.1 meters.
When making calculations, you must take into account that all buildings on the site must fall within the radius of the lightning rod, and correctly calculate the height.