How to make a lightning rod with your own hands step by step instructions. Do-it-yourself lightning rod for a country house: will there be an effect? How to protect your cottage from lightning strikes

People living in private houses are afraid of lightning striking their home. Some of them, in order to protect themselves from this, are thinking about protecting the building. Their concern is understandable, since there are regions where lightning intensity can reach up to 80 hours a year. In such areas it is necessary to install lightning rods. The construction of such a structure naturally requires certain costs. However, in some cases they can be minimized if you do all the work on creating a lightning rod yourself.

Protection zone

It should be understood that any structures designed to protect against lightning have a limited radius of action. They only protect the space around them. Therefore, when creating a lightning rod structure, work must be carried out so that all objects located on the site fall into the protection zone. Only in this case will they be provided with protection from lightning strikes.

IN currently Based on the degree of reliability, structures that protect against lightning are distinguished. There are two types:

• type A;
• type B.

Lightning rods of the first type provide 99% protection, which allows them to be called the most reliable designs against lightning. Structures of the second type provide 95% protection.

Device

If you are seriously afraid of lightning getting into your home and, in order to protect yourself from this, you have decided to install a lightning rod, then in this case, during work you will need to create the following elements of this building:

• lightning rod;
• down conductor;
• ground electrode.

Lightning rod

This is a device that looks like a metal rod. After installation, it will rise above the roof of the building. This is where lightning strikes will fall. This ensures reliable protection of the structure. In addition, such a device is able to withstand severe voltage loads that occur when struck by lightning. When creating this element, you can use various materials.

The best choice - strip or round steel, whose cross-sectional area is at least 60 square meters. m. This element has certain requirements in terms of length. This parameter must be at least 20 cm. The device must be placed strictly in a vertical position. The tallest building on the site is perfect place to secure it.

Down conductor

The current conductor has the form of a thick wire with a diameter of 6 millimeters. To create it the best choice- Cink Steel. Regarding its location, it is better to choose areas where lightning is most likely to strike. For example, good place the edge of the pediment can be used to accommodate it. It can also be placed on the ridge. This lightning rod element is secured close to a private house, but with a slight offset of 20 cm.

If the house has a roof made of materials that are easily flammable, then in this case a gap is all the more necessary. To secure the down conductor special fasteners must be used: nails and staples. For greater reliability of fastening this element, you can use clamps.

Ground electrode

It is necessary to divert a current strike from lightning to the ground. When choosing a material to create this lightning rod element, it is necessary to use one that conducts electrical charge well. It is also necessary that the material has minimal resistance. If we talk about its location, then this lightning rod element is placed not far from the porch of a private house, at least 5 m. It is not recommended to install the ground electrode in the immediate vicinity of paths, as well as in places where people may be. After placing it, you can create a fence around it to make sure it doesn't cause harm.

When installing a fence from the ground electrode, it is necessary to make an indent of 4 meters, and the fence itself should be arranged along a radius. If the weather is good outside, it will not do any harm. But if it’s cloudy, and especially if a thunderstorm has begun, then standing in close proximity to it can be dangerous to your health. The ground electrode is installed in the ground. The decision regarding the depth of the depth of this element is made by the owner of the house himself. The following points must be taken into account:

• soil type;
• availability of groundwater.

For example, if the site is dominated by dry soil and the groundwater level is low, a ground electrode consisting of two rods is installed. The length of each of them should not exceed 3 meters. Components of this element must be secured to the jumper, whose cross-sectional area should be 100 square meters. m.

When this is done, the grounding conductor is secured to the down conductor by welding. After this, it is immersed in the ground to a depth of 0.5 meters. In the event that the soil on the site is peaty and has high humidity, and there are groundwater, then there is no possibility of grounding for half a meter. Therefore in this case metal corners must be used, which will act as a grounding conductor. They are immersed to a depth of 80 cm.

If under construction multi-storey building, then in this case, work on installing a lightning rod is carried out by specialists. These structures have their own protection zone radius, which makes it possible to place them on every building. Before installing this structure, it is checked whether the already installed lightning rods are capable of providing lightning protection to the constructed building or whether it is necessary to construct a new one.

In case of individual houses The issue with the lightning rod is decided by the owner himself. There are a number of factors in the placement of buildings that can minimize the risk of lightning striking a house:

• if a house is located in the lowest place on the site, the probability of lightning striking it during a thunderstorm is small;
• if there is a building next to the dwelling high altitude, then when lightning strikes it is more likely to be hit by lightning. This way your home will be safe;
• If a lightning rod is installed on a neighboring house, then its protective zone may extend to your house. And in this case there is no great need for a lightning rod.

Thus, it cannot be said that a house that does not have a lightning rod is susceptible to high risk lightning strikes.

Options for creating a lightning rod

If you have inspected your and neighboring houses and as a result discovered that nearby buildings do not have such protection as a lightning rod, then in this case the most reasonable thing is to do the work to create it yourself. Particularly dangerous are buildings whose roofs are covered with metal tiles or steel sheets. Although such a roof looks attractive, the lack of grounding increases the risk of lightning striking such a house.

In most cases, the installation of this roofing is carried out on a sheathing made of wood. This ensures charge accumulation. Discharge of such a device can only occur after a thunderstorm. A person touching it can receive a current discharge of several thousand volts. In addition, do not forget that a spark may occur after a lightning strike, from which a wooden house can easily ignite.

If you want to avoid such unpleasant situations, then you need to think about grounding, which should be located every 20 cm. If your home has a metal roof, then in this case you can refuse to create a lightning rod. The roofing material itself will be an excellent lightning rod.

To save your home from lightning strikes, you can install a lightning rod on its roof. However, other options are also possible. If there is a tall tree, then you can install a lightning rod on it with your own hands, but provided that it is located at a distance of three meters from the building, and its height is 2.5 times greater than that of your house.

If you find this lightning rod option attractive and decide to arrange it, then you will need 5 mm wire. First you need to prepare it, then one end needs to be buried in the ground, having previously welded it to the ground electrode. The other end will act as a lightning rod. It must be placed at the very top of the tree.

If there is no tall tree on your site, you can use an air-termination mast with two metal rods instead. Their installation is carried out at opposite ends of the roof. The drain in this case will act as a down conductor. Great importance has the material of its manufacture. It must be metal. In this case, you should also not forget about the device of the grounding electrode.

Conclusion

Regardless of which method you choose to install the lightning rod, you must remember that by properly installing this structure, you will ensure comfortable living in your wooden house. But it is necessary to periodically check the condition of the lightning rod created with your own hands. Special attention must be paid to its connections. There should be no violations in them. Only in this case you can not be afraid of lightning striking your house.

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, so they need to be protected from lightning by equipping them with modern lightning protection units.

Lightning is most often discharged at its most high point, but even a huge tree growing next to the house is not able to protect it from the discharge. Only a lightning protection device can completely protect your home from atmospheric discharge. 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 a 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.

Installing a lightning rod and additional protective equipment will allow you to avoid negative consequences from the impact of a 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 a standard design. In contrast, lightning rods of passive protection systems 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 are imposed on the installation of down conductors for lightning protection of a 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 fire wooden walls 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 of electrical lines to a private house. Currently, there is a large assortment of such devices on the market, with different capabilities and levels of protection against surges.

Only after installing an SPD in the distribution panel and installing external lightning protection can you confidently say that your home is reliably protected from all damaging lightning factors. 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 installation of lightning protection can be done with your own hands without the involvement of employees. 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.

At the final stage of 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 an internal surge protection unit, 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 the SPD, your lightning protection of a private home is completely complete functional view. With this system, your property and household appliances are 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. The main attention when preventive examination attention must 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

Historical background or Who invented the lightning rod? A lightning rod (or lightning rod) is a mechanism that is installed on structures and performs the function of protection against lightning strikes. Colloquially also known as a “lightning rod”.

It is generally accepted that the lightning rod was an invention of Benjamin Franklin, which he made in 1752, but there is also evidence that similar structures existed before this date (for example, the high masts of ancient temples in Ancient Egypt, there were also structures at the Temple of King Solomon in Jerusalem, the Nevyansk Tower, paper kites by Jacques Rom). In Russia, the first lightning rods were created by M. V. Lomonosov and G. V. Richman in 1753.

In this article we will talk about what a lightning rod is and how it works, who invented the lightning rod and how to make a lightning rod for country house with your own hands.

Lightning discharges are an extremely dangerous natural phenomenon, especially in situations where structures are located in open areas, precisely because in order to ensure the peace and safety of your family, it is necessary to install a lightning rod. Installing a lightning rod will not require a huge amount of time, but in the end you will be sure that the buildings are reliably protected from various weather troubles.

Necessary funds and building materials

To install a lightning rod in a private house you will need:

• pin for lightning rod;
• metal wire made of copper or aluminum with a cross-section of 6 mm and corrugation for the current conductor;
• stainless steel for grounding preparation;
• welding machine;
• saw with a blade for metal;
• drill - electric;
• multimeter;
• sledgehammer or hammer;
• bayonet shovel;
• spanners;
• M8 or M10 bolts;
• dowels;
• clamps for fastening;
• powerful wooden pole;
• holders.

Preparation stage

Planning must begin with determining the height of the structure. The top of the lightning rod must be located up to 12 meters above the ground.

It is necessary to take into account that structures designed to protect buildings from lightning strikes protect buildings only in a limited area. The space around the structure itself can be considered protected. Therefore, when building a lightning rod, it is necessary to take this into account and build them in such a way that all objects located on the site are protected.

There are two types of structures:

• Type A
• Type B

Type A lightning rods provide 99% protection, making them the most effective lightning protection structures.

Structures of type B, compared to structures of type A, are less efficient and, as a result, protect the structure by only 95%.

Important! The safety zone created by the lightning rod will be within a radius of 1.5 times the height of the mast.

That is, at a height of 10 meters, the lightning rod will cover an area with a diameter of 30 meters. If it is necessary to protect a larger area with buildings, then the construction of two or three masts, evenly spaced throughout the area, will help solve the problem of lightning removal. The lightning rod must be at a height of more than 2 meters from the surface to effectively perform the function of protecting the house from lightning.

Selection of grounding installation location

The grounding loop must be located at a distance of up to 1 meter from the foundation of the building that will be protected by the lightning rod, and a few meters from the sidewalks and porch. The grounding point during a thunderstorm is dangerous, so it is necessary to position it so as not to put household members and guests at risk. It would be best to find a place for it near a wall or fence enclosing the house. One option is to place some kind of flower bed or other composition of boulders, stones, etc. around the grounding zone.

Most suitable materials for components:

It is also necessary to determine and mark in advance the locations of all structural elements.

Installation of the structure

• Installation of ground electrode.

After marking, a triangle-shaped hole is created using a shovel - each side of which must be at least 1200 mm, with a depth of 600 - 700 mm. A trench is laid from the top of the triangle towards the wall of the house. At the end point the end of the down conductor will be suitable.

At the ends of the vertical parts of the grounding elements, the corners are cut off with a grinder, then the pointed ends are driven into the ground to a depth of 2 meters with a heavy metal sledgehammer. When digging the pointed ends of the grounding into the ground, it is necessary to strike with a sledgehammer strictly vertically so as not to bend the structure.

Using welding machine pieces of the same material are welded, from which a metal triangle is formed in the trenches.

• Installation of a lightning rod (lightning rod).

To install an air terminal, you can use two methods:

The pantograph is placed on the roof and then vertically down on the wall and is attached to the roof and wall with semicircular plastic or metal clamps. Bottom part The current washer must be fixed to the grounding lead from the wall of the house.

To do this, a hole is made in the grounding plate into which a bolt with a washer, nut and locknut is installed. The stripped (sharp) end of the down conductor is clamped using a washer, nut and bolt, along with a twisted pair wire wrapped around the bolt. Then the holes are filled in.

Examination

The installed system must be checked with a multimeter. Perform a resistance measurement - the device should have a value no higher than 10 ohms. If the device readings differ from the standard ones, check all the joints of the structure - there should be good electrical conductivity along the entire contour of the structure.

Conclusion

A properly installed lightning rod on the roof can protect your home and nearby buildings from lightning.

It is important to note that in the case of private houses, the issue of lightning rod is decided by the owner. There are a number of factors when locating buildings that, in principle, minimize the likelihood of a lightning strike into a house:

• if the house is located in a low area, then the probability of a lightning strike to the house during a thunderstorm is extremely low;
• If there is a higher-rise building next to the house, it will most likely be struck by lightning. Thus, the danger of a lightning strike is mitigated by the presence of a taller building next to it;
• If a lightning rod is installed on a neighboring house, then your house may also fall within the coverage area of ​​the neighbor's lightning rod.

Thus, in some cases there may not be an urgent need to install a lightning rod. The feasibility of installation must be assessed depending on the above factors.

Sometimes owners of private houses think about how to protect themselves and their home from lightning strikes. After all, there are regions where the intensity of thunderstorms ranges from 80 hours per year. Therefore, there is a need to install a lightning rod. And this may require additional costs. But you can always make a lightning rod at your dacha or in a private house with your own hands.

You must understand that any lightning rod will only operate at a certain distance and will only protect the space around it. It is necessary to install it in such a way that this zone includes all buildings located on the site, thereby ensuring their protection from lightning.

There are different degrees of reliability of a lightning rod - type A and type B. In this case, we are talking about the protection zone. The first type protects by 99.55% and is defined as the most reliable, the second - by 95%. There is a term “conditional zone boundary” - here the reliability will be the weakest.

Zone defense can be calculated. The parameters will depend on the type and height of the lightning rod. Suppose a single lightning rod is mounted on it, having a height (h) of 150 meters. If you imagine this using a diagram, then the lightning rod protection zone looks like a cone. Let's look at the formulas and example of calculation:

Knowing the height of the lightning rod, you can calculate the values ​​of R x, R o and h o.

For zone A the calculation will look like this: h o = 0.85h; R o = (1.1-0.02)h; R x = (1.1-0.02)*(h-h x /0.85).

For zone B: h o = 0.92h; R o = 1.5h; R x = 1.5(h – h x /0.092).

Where h o is the height of the cone, R o is the radius at ground level, h x is the height of the building, R x is the radius at the height of the building.

This formula can also be used to calculate other unknowns. For example, we need to know the height of the lightning rod, but we know the values h x And Rx, then for type B the calculation will look like this:

h = R x + 1.63h x /1.5.

Carrying out such a calculation is not at all difficult, but it will guarantee that your home is reliably protected from thunderstorm lightning strikes.

Device

In order to build a lightning rod, the following elements are needed:

• lightning rod,
• down conductor,
• ground electrode.

Lightning rod looks like a metal rod. It will rise above the roof and receive direct lightning strikes, providing protection to the house and withstanding high voltage loads. The best material is strip or round steel with a cross-sectional area of ​​at least 60 sq. mm. There are also requirements for the length of such a lightning rod - the rod must be greater than or equal to 20 cm. It must be placed exclusively in a vertical position. It is best to choose the highest point of the building as a location.

Down conductor is a thick wire with a diameter of 5-6 mm. Good stuff will become galvanized steel. The down conductor is located in a place where lightning is expected to strike. For example, such a place could be a ridge or the edge of a pediment. The down conductor is not attached very close to the building. It is necessary to leave a distance of 15-20 cm. If we are talking about a roof made of flammable materials, then you need to be especially careful and be sure to leave a gap. As fastening elements You can use staples, nails or clamps.

Ground electrode necessary to go into the ground. When choosing a material, you need to take into account that this element should easily conduct an electric charge, so you should choose the material that will have minimum value resistance. It is located at some distance from the porch of the house - at least five. Also, you should not place it near paths and other places where people are often found. To finally make sure that it will not harm anyone, it can be fenced off. It is necessary to retreat from the ground electrode at least 4 meters, placing the fence along a radius. In good weather there is no harm in it, but during a thunderstorm it can be dangerous to be near it. As already mentioned, the ground electrode is installed in the ground. But you need to decide how deep to install it for each case individually. The criteria by which this is done are the following: soil type and availability of groundwater.

For example, for dry soil with a low groundwater level, it is usually mounted from two rods, the length of which is 2-3 meters. These rods must be fixed to a lintel with a cross-sectional area of ​​100 sq. mm. Next, we fix the workpiece by welding to the down conductor and immerse it in the ground at least half a meter.

If the soil is wet or peaty, and the groundwater is close enough to the surface and it is not possible to drive the ground electrode half a meter in, then it should be made from metal corners, which are immersed horizontally into the ground to a depth of 80 cm.

DIY lightning rod

If we are talking about multi-story construction, then the installation of the lightning rod is carried out by specialists. Such structures also have a protection zone radius, which allows them to be placed on every building. Before installation, they check whether the building is protected by existing lightning rods or whether a new one needs to be installed.

At a dacha or in a private house, such issues are resolved exclusively by the owners themselves. There are building placement factors that can, to some extent, protect you from lightning strikes. For example, if the house is located along the terrain in the lowest place. In addition, a building located next to yours, which has a large height, can take the blow. And a lightning rod located on your neighbor’s house may protect you from harm. Therefore, one cannot be firmly sure that a house that does not have one is at risk.

If you have examined your and neighboring areas and have not found such protection, then it is best to worry about creating it yourself. Houses that use or are used as roofing are more dangerous. steel sheets. Behind the attractive appearance the problem of lack of grounding is hidden. As a rule, this roofing mounted on a wooden sheathing or roofing material, which contributes to the accumulation of electrical charge from the atmosphere. Such a device can discharge after a thunderstorm during normal contact with a person, passing a current of several thousand volts. We must not forget that lightning can give a spark, from which wood can so easily ignite.

To protect yourself from fire and death, grounding must be provided every 20 m. In the case of a metal roof, you can do without a lightning rod. Myself roofing material will be an excellent lightning rod.

Tree as a lightning rod

You can save a building from lightning charges not only by installing a lightning rod on the roof. Installing it on a tall tree will also help, provided that it is located at a distance of at least 3 m from your house and 2.5 times higher than it.

To construct such a structure you will need wire with a diameter of 5 mm. One end of it must be buried in the ground, having previously been welded to the ground electrode. The other end of the wire will be a lightning rod. It is placed at the top of the tree.

If there is no tall tree on the site, then a mast with a lightning rod and two metal rods, which are installed at opposite ends of the roof, can help. In this case, a drain is used as a down conductor. It is important that it is made of metal. But here, too, you should not forget about the device of the ground electrode.

Important: When installing a ground electrode, its resistance to electric current should be no more than ten ohms.

Whatever method of installing the lightning rod you choose, it is worth remembering that it high-quality installation will provide you with a comfortable stay only if you periodically check its condition. For proper operation It is necessary to ensure that all connections are not broken.

No one is safe from money or prison, and even more so from a lightning strike. After a blinding flash and a deafening roar, the most pleasant thing is to get away with a slight fright and delight from the impressions you experienced. It's not good if the electronics in the house burn out. It's even worse when there's a fire. It is completely unacceptable for a person to be struck by lightning. The conclusion is simple: we make a lightning rod!

Where does lightning come from?

The reason for this is cheerful clouds, which, as a thunderstorm approaches, gradually grow and turn into dark cumulus-type masses. The upper layers of moisture in the air turn into small ice crystals, while the lower layers remain as water droplets. This is how we got two plates of a giant capacitor.

Huge structures move in the air and are charged as a result of friction: the upper layers accumulate positive ions, the lower ones – negative electrons. There is a limit to everything, and the accumulated potential turns into an electrical discharge. As a result, it “breaks through” where there is the least resistance: tall trees, roofs of houses and... lightning rods!

How does lightning protection work?

From the above, the strategy for a lightning protection device follows: to direct a possible electric discharge along a path that is safe for us and thus insure ourselves against troubles. For this purpose, an lightning rod is installed at a sufficient height, which is designed to capture a lightning discharge.

Next, an electric current of about 100,000A passes through the down conductor to the ground electrode. The latter provides communication protective system with soil. Thus, the lightning strike bypasses the protected objects and is absorbed by the ground.

This protection system is widespread and is called passive. There are active lightning rods that have an ionizer that provokes a lightning strike. This increases the likelihood of protecting the target from damage. This type of lightning rod costs a lot, and its installation is difficult to do with your own hands.

Lightning rod options for a private house

There are three main types of lightning rods based on the type of design:

• rod lightning rod;
• in the form of a grid;
• cable lightning rod;
• roof covering as a lightning rod.

An air terminal in the form of a rod is the most famous and widespread. There are industrial products with ready-made fasteners. For those who like to create with their own hands, it is possible to make an elegant structure that decorates a building. In any case, a steel pin must have a cross-section of at least 70mm2, and for a copper product 35mm2 is sufficient. Thus, its diameter can be 7-10mm.

The length of the rod can vary between 0.5-2 m, and it must protrude at least half a meter above all objects surrounding the building. The lightning rod accepts the charge at one point and is especially effective in protecting small buildings.

An air terminal in the form of a mesh is made of wire with a diameter of about 6 mm. In the photo you can see what a structure of this kind looks like in practice. Already exist ready-made designs with cell size 3-12m. Lightning protection of this kind is convenient for use on a large roof area. To prevent the fire of the sheathing, the lightning rod is mounted at a distance of 0.15 m from the roof surface.

In a private home, it is more convenient to use an lightning rod in the form of a cable. It is mounted on the roof ridge, secured to two supports on opposite gables. It is also possible combined option, when pin lightning rods are installed on the mentioned supports in addition to the cable.

The cable must have a diameter of more than 5 mm and be mounted on safe height from the roof. This type of construction is usually used on a roof with a non-metallic covering.

Metal roofing The roof, under certain conditions, can also act as a lightning rod. In this case, the thickness of metal tiles, corrugated sheets or galvanized sheets must be at least 0.4 mm. It is tempting to provide lightning protection without using additional materials.

In practice, this is not easy to do, since there should be no flammable materials under the decking, while the sheathing is most often made of wood.

Moreover, it will be necessary to ensure the connection of the down conductor with each separate sheet coating, which is labor-intensive. This option is suitable for seam roofing, where the metal sheets are already securely connected. In this case, ignition of the sheathing is impossible if the coating is laid on a metal sheathing.

How does a down conductor work?

Ideally, for a self-made structure, the material of the lightning rod, down conductor and grounding conductor should be the same and connected by welding, that is, steel. This solution ensures reliability and durability of protection. In practice, it is possible to use galvanized and copper-plated elements, as well as various materials. Their connection is ensured by using clamps with bolts and nuts.

A steel conductor in the form of a rod or strip must have a cross-section of at least 50mm2, an aluminum conductor allows a size of 25mm2, and a copper wire can be used with a cross-sectional area of ​​16mm2, which approximately corresponds to a diameter of 8.6 and 5mm, respectively.

The down conductor is placed so that it connects the lightning rod and the ground electrode along the shortest path.

In this case, sharp bends are not allowed, which can lead to a spark discharge and ignition in this area. For the same purpose, the conductor is placed at a distance of at least 100 mm from the surfaces of combustible materials of walls and other elements of the building.

Requirements for the ground electrode

Please note that it is not recommended to use a protective ground loop to connect a lightning rod. In the case of using a common grounding conductor during lightning discharge on surfaces household appliances Dangerous voltage may occur. To protect electrical wiring and household appliances In a private house, against lightning strikes, impulse noise protection devices (SPDs) are installed on the input switchboard.

Grounding for the lightning rod is placed no closer than 5 m from the porch and paths and the horizontal connector is buried at least 0.8 m. This is necessary to reduce the likelihood of injury to people in the event of a lightning discharge.

Lightning rod protection zone

You should not be under the illusion that a lightning rod on a neighboring house or a nearby metal tower will completely protect your home from a lightning strike. The lightning rod's protective zone has very specific boundaries. In any case, the dacha will have to arrange its own lightning protection.

The safety cone created by the rod lightning rod has an angle of 45-50°. This rule is valid for lightning protection installation heights of up to 15 m. The above sketch shows that at an angle of 45°, the radius of the protective zone is equal to the height of the top point of the rod above ground level. At a value of 50° the protection zone will be slightly larger.

Thus, the higher we place the lightning rod, the larger the protected surface area will be.

In the case of a large area, it may be necessary to install another lightning rod. It can be mounted on a special mast.

We install lightning protection with our own hands

First of all, you need to select an air terminal in accordance with the above recommendations and the materials at hand. The easiest way to install an ordinary steel pin on the roof of a country house. Galvanized pipe or aluminum rod will work even better. When using a pipe, its upper end should be plugged.

If there is a piece of cable required length and diameter it will not be difficult to stretch it along the ridge. On a large roof area it is more effective to use a grid option. An air terminal of any design should be secured so that it is not disturbed by the wind.

Please note: it is easier to ensure electrical contact of the entire system by making all three components of the lightning rod from the same material.

If you do not have welding in mind, it is easier to make a down conductor from thick copper wire in accordance with the recommendations above. A reliable connection to the lightning rod can be ensured using galvanized clamps with bolts and nuts. Practical to secure the conductor to the supports drainpipes.

It is best to install a grounding loop where there is the least likelihood of people being present. It is also beneficial to place it in a place where moisture is always present. This will improve the contact of the ground electrode with the ground. It wouldn't hurt to install a warning sign next to it. Bolted connection with a grounding conductor, it is better to perform it above the ground on the base of the building, and ensure contact in the ground by welding.

After installing the entire system electrical connection from the lightning rod to the grounding can be checked with a multimeter. The resistance of the ground loop can only be checked special device. Its value should be no more than 10 Ohms if there may be people nearby. For a separate lightning rod installed far from the house, the grounding resistance should not exceed 50 Ohms.

At least once a year, it makes sense to check the integrity of the entire system visually. Once every few years, you should dig up the grounding and assess the degree of metal corrosion. If the rods in the ground become noticeably thinner, they need to be replaced.

The tall tree will help us

To set up a lightning rod in your dacha, you can use a tall tree growing nearby as a mast. The lightning rod should be fixed to its crown so that it protrudes at least 0.5 m above the crown. It should not be forgotten that the tree grows and changes its size.

This means that the lightning rod and down conductor should be secured with plastic clamps that will not damage the barrel. It is better to use flexible stranded copper wire and it should be laid with a spare length. In addition, once every few years you will have to climb up and move the lightning rod above the top of your head.