Types and differences of a lightning rod depending on the type of lightning rod.

Lightning is a monstrous phenomenon in its destructive power. The current strength in the charge, which breaks the stormy sky for just a fraction of a second, reaches half a million amperes, and the voltage amounts to tens and hundreds of millions of volts. Anything that lightning strikes, with the exception of metal and other conductors, instantly heats up and, if it reaches a critical temperature, catches fire. To prevent this from happening, it is necessary to divert lightning from a building or other object to the ground, which requires a lightning rod, a current collector and a grounding loop.

High-rise buildings, administrative and commercial buildings, factory workshops, television towers, monuments - all these structures must be equipped with lightning protection to avoid damage. The situation with private houses is completely different - cottages or dachas with installed lightning rods are rare. The reasons for this are different. Some owners are sure that the lightning rod, on the contrary, will attract lightning; someone believes that he is protected by a cell tower installed a kilometer from the cottage; someone simply saves in the belief that the likelihood of a lightning strike on the house is too small. Let's figure out which of this is true, and when lightning protection is needed in a private house, and when you can do without it.

Is a lightning rod needed on the roof of a private house?

From a safety point of view, a lightning rod is always needed - even if the probability of being struck by lightning is negligible, lightning protection and grounding will reduce it even more.
That is, it definitely won’t get worse. But the price of a lightning rod with installation starts from 30,000 rubles, and not everyone is ready to spend this money on reducing the likelihood of a lightning strike by thousandths of a percent. Therefore, they usually talk separately about situations in which a lightning protection device is mandatory, and separately about cases when installing a lightning rod is just a recommendation. Lightning protection of the roof is absolutely necessary:

• when the house is located in a cottage community, village, urban private sector, or stands alone and there are no high-rise buildings nearby;
• when covering the roof with any types of metal coverings, including corrugated sheets and metal tiles;
• when the house is built on a hill or there is shallow groundwater underneath it;
• if the building has a lot of working electronics or powerful equipment installed.

If any of these conditions are met, the need to install lightning protection is not a matter for discussion, since the risk is quite high. And the higher the house is built, the higher it is: in the southern regions, thunderstorms occur much more often than in the northern ones, therefore, the likelihood of lightning hitting the house increases. The map below clearly shows how the number of days with thunderstorms increases as you move south, with a few clusters near the mountain ranges.

Of course, no one can force you to install a lightning rod on your house - this can only be officially required for public, multi-apartment, commercial and industrial buildings. If we are talking about a private house, lightning protection is left to the discretion of the owner. But not making a lightning rod in a private house in such a situation is the same as not treating a wooden beam for a frame house with fire protection and making closed wiring in it.

It's a completely different matter when your home:

1. Located in close proximity to dominant heights: cell towers, water towers, high-rise buildings. But keep in mind that the immediate proximity is not a kilometer or even 500 meters. This is when the farthest point of the house is located no more than 1.2 × h from a high-rise object, where h is its height. That is, with a base station height of 100 m, each corner of your house should fall into a cone with the top at the highest point of the tower and a base with a radius of 120 m.
2. Built in a forest with tall trees. The protection radius from one tree, if it is not a sequoia, is not enough to cover the entire house, but there are a lot of trees in the forest. Sometimes, for better protection, a lightning rod is attached to the top of the tallest tree near the house.
3. Located in an area where thunderstorms are rare. In numbers, these are areas with an average annual duration of thunderstorms of up to 20 hours. In the map above, these are the red and pink zones.

In all these situations, the risk of being struck by lightning is very small, so many home owners do not do lightning protection, relying on chance. On the one hand, the probability is really low. On the other hand, the losses if “something goes wrong” will be very large: even if the house does not catch fire, then all the electronics, including the heating boiler control units, will definitely burn out. How justified such savings are, each home owner decides for himself.

Lightning is unpredictable, although rare, but it can strike a building protected by a commanding height.

History of the invention of the lightning rod

Back in the 18th century, humanity showed interest in studying magnetism and electricity. Benjamin Franklin, the founder of the American Constitution, an outstanding politician and scientist, began studying charged particles and drew attention to the fact that they are quite similar: electricity from the atmosphere, and that produced by friction. The subsequent discovery that the scientist came to is a theory about the nature of lightning.

Through research and repeated experiments, Franklin studied the effect of the pointed shape on the electrical properties of conductors. These properties have been proposed to prevent direct lightning strikes into high-rise buildings and completely deplete the electrical charge in thunderclouds. This is how Benjamin Franklin became the inventor of the greatest discovery, such as the lightning rod. It remains a huge success to this day.

In 1752, Franklin was in a hurry to share his success and tell his close comrade John Collinson about his achievements in the field of inventing the lightning rod. But his letters with ideas expressed only disbelief and grins among relatives and friends. He received his first significant support from French researchers in the same year. Thomas-François Dalibard became a translator of his works and, inspired, designed an invention based on the descriptions of Benjamin’s works.

The device that Dalibar mounted was a pointed iron pin mounted on a wooden platform. 40 feet tall and non-conductive. Then on March 10, 1752, when a severe thunderstorm began, sparks of about 4-5 centimeters were clearly visible on the invention. Of course, the invention was not similar to modern lightning rods, but even then it was proven that atmospheric electricity could be brought to the ground. When Dalibar demonstrated his miraculous invention in front of King Ludwig XV, he was awarded lifelong monetary compensation.

That same summer, Franklin conducted his famous experiment of flying a kite into the clouds. Using a kite, he collected an electrical charge and transferred atmospheric electricity through a metal cord to the ground. This experience finally solidified his guesses about the similarity of the properties of atmospheric electricity and earthly electricity.

In the fall of 1752, Benjamin constructs a 9-foot-tall metal rod structure on the roof of his Philadelphia home and connects it with wire to a well. The scientist ran a wire through the house and connected an electric bell. Lightning that struck the rod was supposed to activate the bell. This invention became the predecessor of modern grounded lightning rods. Successful application led to widespread distribution throughout Philadelphia, and by 1783 there were more than four hundred of them. Moreover, the inventor’s house was subject to a lightning strike, but was not damaged in any way, which made it possible to verify the operation of the invention in practice.

At first, Europe showed no admiration for such a device. Many hardened scientists and religious fanatics were skeptical about the installation of lightning rods. But practical action has proven the usefulness of this design.

The merits of Benjamin Franklin can hardly be overestimated. This includes political activity, art, natural science, conducting important experiments and research, and diplomacy. All this is highly valued by followers and contemporaries. Thanks to his merits and distinctive qualities, he has been awarded a permanent image on the $100 bill since 1914. Previously, only outstanding presidents of the United States of America received such honors.

Where to order the installation of a lightning rod

Offers services for calculation and installation of lightning protection. Professionals solve problems not only of direct lightning strikes, but also of neutralizing secondary impacts, use advanced technologies and guarantee an effective solution to any problem. The contractor is responsible for the high quality of work and components, which are ordered from leading and trusted manufacturers, in particular from the well-known company that supplies components for lightning protection, Dehn. The service is provided on flexible terms, all necessary documents are provided.

DIY making

There are many folk ways to make a lightning rod at your dacha with your own hands. It is best to entrust this matter to a professional team specially engaged in the installation of protective anti-lightning systems. However, for those who decide to act independently, it is recommended to follow a proven algorithm. First, you need to correctly calculate the design, then select the right materials, as well as determine the installation location, and only then proceed with the installation procedures. Let's look at each of these stages in detail.

Correct calculation

The first thing you should start building lightning protection with is determining the height of the top point of the receiver. The easiest way is to calculate it for the pin modification using the following formula:

H=(Rx+1.63Hx)/1.5

H – distance from the ground surface of the highest point of the receiver,

Hx – height of the ridge of the house,

Rх – protective radius of action,

The numbers 1.5 and 1.63 are calculated coefficients.

For example, if it is necessary to create protection within a radius of 15 meters on a site with a house 7 meters high, the height of the top point of the lightning rod, according to the formula, should be:

(15+7x1.63)/1.5=17.6 meters.

In this case, it is necessary to take into account that the protective zone in space has the shape of a cone with its apex at the receiver’s peak point and its base.

Video description

Watch the video on how to inexpensively make a lightning rod with your own hands:

Selection of materials

You can effectively solve the problem of how to make a lightning rod in a wooden house if you choose the right materials. It is recommended to use copper, steel or aluminum as conductors. For example, to build a standard pin lightning rod, you will need to purchase the following consumables:

• Steel rod for the receiver with a diameter of at least 50 mm².
• Copper wire for down conductor with a cross section of 16 mm².
• Asbestos cement pipe of suitable height.
• Copper pins for ground loop.
• Fastening elements.

It is cheaper to use steel to construct a lightning rod for a private house, but copper has the best conductive properties and requires a smaller cross-sectional area of ​​conductors, which means the installation will be easier and faster.

Rod for lightning rodSource ytimg.com

Installation location

Another important aspect regarding how to make a lightning rod in a private house yourself is the correct choice of its installation location. There are two main options:

1. Directly on the roof.
2. On a nearby structure.

In the first case, the receiver is installed using brackets on the roof, in the second - on a special match, a pole, a pipe from a boiler room, or a tree. Moreover, the closer the structure is to the house, the smaller the protective radius is required and the lower the rod needs to be mounted.

Not least important is the location of the grounding loop. To avoid accidental breakdown of electric current during a lightning strike and damage to surrounding buildings, animals or people through the ground, it is located at a minimum distance - 1 meter from the walls of the dwelling and 5 meters from sidewalks, enclosures, paths.

Design and types of lightning rods

The operating principle of a lightning rod is directly related to its design, which consists of three mandatory parts:

• Ground electrode. Provides lightning discharge discharge into the ground, located in the thickness of the earth.
• Down conductor. Serves as a connector between the grounding conductor and the lightning rod. It is an aluminum or copper conductor of large cross-section. It is insulated using a plastic cable duct.
• Lightning rod. Designed to intercept lightning and transmit it along a down conductor to a ground electrode in the ground, where the discharge spreads and dissipates.

The effectiveness of the design is due to the fact that lightning most often strikes grounded metal structures, which are much higher than those that surround them. For this reason, the installation height of the lightning rod is a particularly important parameter. It must be higher than the building it is intended to protect.

There are different types of lightning rods:

• Rod. The most common due to ease of installation and low price. Represented by one or more rods. They are mounted on the structure itself or at some distance, but at a higher altitude. The length of the structure ranges from 30 cm to several meters.
• Cable. It is often used to organize lightning protection of low structures and power lines. Provides a larger area of ​​protection than the rod one. The design is based on one or more galvanized steel cables fixed to special masts.

Video description

Watch in this video how complex lightning protection for a cottage is designed and works:

DIY installation instructions

Self-installation of a lightning rod is carried out as follows:

1. The installation height of the receiver is calculated based on the required protective radius.
2. The material is selected.
3. The installation location is determined.
4. The lightning rod is being secured.
5. A down conductor is being carried out.
6. A trench or pit is dug, the grounding rods are driven in and connected to each other.
7. The down conductor is connected to the ground loop.

Briefly about the main thing

A properly constructed lightning rod protects a house from fire, equipment from damage, and people and animals from the terrible consequences of electric shock. The device does not prevent lightning, but effectively catches and safely transmits it to the ground. There are several options for how to make a lightning rod at your dacha

• Kernel.
• Cable.
• Net.

All of them consist of a lightning rod, a down conductor and a grounding circuit. When making a lightning rod with your own hands, first of all you need to correctly calculate the height of its installation, based on the required protective radius. Next, you need to choose the right materials for its main parts, correctly determine the installation location and perform installation in accordance with recommended safety requirements.

Structure of external lightning protection

External protection consists of a lightning rod (lightning rod), a down conductor and a grounding conductor.

Important: the grounding of the lightning rod must be separate from the general grounding loop of the house. A lightning rod directly catches lightning on itself, this happens primarily due to the material from which it is made, after which, with the help of a down conductor, the energy goes into the ground

A lightning rod directly catches lightning, this happens primarily due to the material from which it is made, after which, with the help of a down conductor, the energy goes into the ground.

Depending on the principle of operation, the external lightning protection system is divided into passive and active.

Passive system

The most commonly used is a passive lightning protection system. Due to the simplicity of the design, you can install it yourself without the help of specialists. But with all this, several nuances should be taken into account - roofing material, type of roof, type of soil. When installing such a system, the cost of an annual operational inspection should be taken into account.

The following types of passive protection are distinguished:

pin - the lightning rod is installed on the roof and with the help of a down conductor (wire with a cross-section of at least 6 mm), which is attached to the ground electrode, the charge is discharged into the ground. The system is simple in design, most often used on metal roofs, inexpensive, but has a small operating area.

Important: the lightning rod for metal roofs is made of round steel and installed 1.5 - 2 m above the highest point of the house. cable - here a cable stretched between two supports is used as a lightning rod, which is connected to a down conductor and a grounding conductor

This design is preferable for temporary structures, pavilions, as well as for roofs covered with slate.

cable - here a cable stretched between two supports is used as a lightning rod, which is connected to a down conductor and a grounding conductor. This design is preferable for temporary structures, pavilions, as well as for roofs covered with slate.

Important: the cable or wire is stretched at a height of up to 50 cm from the roof. mesh - the most complex installation system, used on roofs covered with metal tiles, and is a mesh

mesh - the most complex installation system, used on roofs covered with metal tiles, and is a mesh.

Active system

The operating principle of active lightning protection is that the lightning rod ionizes the air around it, thereby intercepting the lightning charge. Such a system costs much more than a passive one, but its range of action is about 100 meters, which will allow you to protect not only your home, but also nearby buildings. The main advantages include: compactness, non-obtrusiveness, and autonomy of operation.

Lightning rod

First, let's understand the essence of the concept. Lightning rod means the same thing as Lightning Protection or Lightning Protection and differs from Lightning Rod , which most often refers to only the lightning rod part of the protection system for buildings and structures. That is, a lightning rod is an “lightning rod + down conductor + grounding”, or an external component of the system. If you look at the diagram of any comprehensive lightning protection, be it a private home or an industrial, office and administrative building, then this is the part that is designed specifically for protection against direct lightning strikes.

Designs (types) of lightning rods

In total, there are 3 basic schemes: rod (Figures a, b), cable (c) and lightning rod in the form of an lightning rod mesh (or mesh) (d). The combined scheme involves a combination of basic options.

By the number of identical lightning rod parts - single, double, etc.

According to the nature and location of installation, rods are divided into lightning rods, prefabricated rods, which can be installed on flanges, brackets, special supports or be free-standing. Lightning rods usually have a telescopic design and a method of installation on or into the ground.

Cable is a cable stretched between supports. The circuit can be anything, including closed. This essentially includes the simplest and cheapest version of a lightning rod for a private house or cottage, when instead of a cable at a short distance from the roof ridge, a conductor with a radius of 8-10 mm (aluminum, steel or copper, depending on the material and color of the roof) is pulled at a distance at least 20 mm from the ridge itself, bring its ends beyond the extreme points to a distance of approximately 30 mm and bend slightly upward.

Lightning protection mesh is used on flat or slightly sloping roofs.

So, as we said, the external lightning protection system can be isolated from the structure (free-standing lightning rods - rod or cable, as well as neighboring structures that act as natural lightning rods), or can be installed on the protected building and even be part of it.

Lightning rod calculation

It is recommended to select lightning rods using special computer programs that can, based on the dimensions of buildings, roof plans and structural elements on it, calculate the probability of a lightning breakthrough and protection zone. That is why it is safer to contact specialized organizations that will quickly provide you with various options and configurations of lightning rods.

Although, if the configuration of the protected object allows you to get by with the simplest lightning rods (single rod, single cable, double rod, double cable, closed cable), their dimensions can be determined independently, using those specified in Instructions SO 153-343.21.122-2003 and RD 34.21.122 -87 protection zones.

An object is considered protected if it falls entirely within the protection zone of the lightning rod, which is assigned the required level of reliability.

Protection zone of a single rod lightning rod (according to SO 153-34.21.122-2003)

The standard protection zone in this case is a circular cone with an apex that coincides with the vertical axis of the lightning rod. The dimensions of the zone in this case are determined by 2 parameters: the height of the cone h0 and the radius of its base r0.

The table below shows their values ​​depending on the required protection reliability for lightning rods up to 150 m high from ground level. For high altitudes, it is necessary to use special programs and calculation methods.

For other types and combinations of lightning rods, see variations in the calculation of protection zones in Chapter 3.3.2 SO 153-343.21.122-2003 and Appendix 3 of RD 34.21.122-87.

Now, to determine whether your object X falls into the protection zone, calculate the radius of the horizontal section rx at the height hx and set it aside from the axis of the lightning rod to the extreme point of the object.

Rules for determining protection zones for objects up to 60 m high (according to IEC 1024-1-1)

The SO Instructions contain a methodology for designing lightning rods for ordinary structures according to the IEC 1024-1-1 standard, which can only be accepted if the calculations for it are more “strict” than the requirements of the specified Instructions.

The following 3 methods can be used for different cases:

• Protective corner method for simple or small parts of large structures
• fictitious sphere method for structures of complex shape
• protective mesh in general and in particular for surface protection

The table for different categories (levels) of lightning protection (more about the categories or classes here) shows the corresponding values ​​of the parameters of each method (radius of the fictitious sphere, maximum permissible protection angle and grid cell pitch).

Protection Angle Method for Roof Superstructures

The angle value is selected according to the graph on the diagram for the corresponding height of the lightning rod, which is measured from the protected surface, and the lightning protection class of the building.

The protection zone, as mentioned above, is a circular cone with its apex at the top point of the lightning rod.

Fictitious sphere method

It is used when it is difficult to determine the size of the protection zone for individual structures or parts of a building using the protective angle method. Its boundary is an imaginary surface, which would be outlined by a sphere of selected radius r (see table above), if it were rolled along the top of the structure, bypassing lightning rods. Accordingly, an object is considered protected if this surface does not have common points of intersection or contact with it.

Lightning protection mesh

This is a conductor laid on top of the roof with a cell pitch selected depending on the lightning protection class of the building. In this case, all metal elements on the roof (skylights, ventilation shafts, air intakes, pipes, etc.) must be connected to the mesh. Otherwise, it is necessary to install additional lightning rods for them. More details about the design features and installation options can be found in the material “Lightning protection on a flat roof”.

According to Russian standards, the cell pitch is chosen based on the lightning protection category of the building (maybe less, but not more).

The lightning protection mesh is installed subject to a number of conditions:

• conductors are laid along the shortest paths
• in the event of a lightning strike, the current must be able to select at least 2 different paths for draining to grounding
• if there is a ridge and the roof slope is more than 1 in 10, the conductor must be laid along it
• no parts or elements made of metal should protrude beyond the outer contour of the mesh
• an external contour of a conductor mesh is required, mounted along the edge of the roof perimeter, and the edge of the roof must protrude beyond the dimensions of the building

Materials and cross-sections of lightning rod conductors

The materials used for the production of lightning protection equipment and down conductors are galvanized and stainless steel, copper and aluminum. They are subject to requirements for corrosion resistance and mechanical strength; if a protective coating is used, it must have good adhesion to the base material.

The table shows the requirements for the profile of conductors and rods in terms of minimum cross-sectional area and diameter (according to GOST 62561.2-2014)

Installation of a lightning rod for a private home and industrial building

Let's consider what installation elements are usually included in an external lightning protection system. The figures below show examples of lightning rods for a private home and an industrial building.

The following products and their names are indicated here by the corresponding numbers:

Round and flat conductors, cables

Lightning protection components for flat roofs, lintels and compensators

Lightning protection components on pitched roofs, roof conductor holders

Lightning protection components on metal roofs, roof conductor holders

Down conductors, down conductor holders

Earth entry rods, connecting conductors, manholes, conductor holders

Gutter terminals, terminals, connection components

Lightning rods, components

Isolated lightning protection

Installation can be divided into three stages: installation of the lightning rod part of the external lightning protection system (lightning rods and their fastening elements), laying down conductors (roofing and facade parts of the building) and earthworks for grounding. As a rule, for all companies the cost of work is a certain percentage of the price of materials.

Buy a lightning rod, prices for components

The MZK-Electro company offers excellent prices for lightning rods and components. The range of products in our warehouse is more than 1,500 items; purchases are carried out directly under dealer contracts from direct manufacturers, which implies mandatory certification and a guarantee. All products have the necessary quality certificates and guarantee. We also design and install any lightning protection systems for buildings and structures, both for private homeowners and industrial enterprises. You can get acquainted with our prices in the corresponding section.

Organization of lightning protection: how to do everything right

An economical option for protection against lightning strikes is an ordinary vertically installed rod. It must be placed separately from the building on a pole or tall tree. The height of the installation directly affects the probability of a discharge entering the house: the higher the rod, the lower the probability.

Before making a lightning rod in a wooden house, you need to familiarize yourself with the implementation of comprehensive protection. It is this that will be able to protect the building and equipment not only from the direct threat of a discharge, but from the destructive effects of lightning, which sometimes occurs even at a distance of several kilometers from your home.

Table Materials and minimum cross-sectional values ​​of elements of the external inter-branch structure

The operating principle of a complex type lightning rod is based on the close interaction of external and internal leads converging in grounding. The choice of material for the external structure depends on the angle of inclination of the roof slopes, their size, decorative roofing covering and its properties, the absence or presence of additional elements on the roof, antenna, etc.

For the internal branch, the fundamental element is the potential equalization bus. Its purpose is to counteract a strong powerful pulse charge that causes overvoltage entering the building from power lines or through various communications. Down conductors are installed as close as possible to the outer corners of the house.

With the traditional method of organizing a lightning rod, you need to ensure that all conductive (metal) parts of the roof of the house are connected to the lightning protection. A roof covering made of metal decking, if it is not thinner than 0.5 mm, can serve as a kind of conductor.

In the case of an active set of measures to protect against electric shock, the mating of all protruding metal parts of the roof frame is not required: the discharge passes along the path of the shortest extent.

As statistics show, in recent years there have been more and more natural disasters. And if a tsunami or earthquake cannot be avoided, then reducing the mortality and destruction from lightning is within the reach of any of us. Anyone can carry out simple activities that do not require significant capital investments with appropriate training. You just need to follow a strict algorithm for performing the work, use reliable materials, and not neglect the requirements of the standards.

Lightning rod control

To ensure sufficiently effective operation of the lightning rod, the condition of the latter must be periodically monitored. Control consists of a thorough inspection of the above-ground part and, in particular, the contact points and measuring the spreading resistance of the ground electrodes. For ordinary structures, periodic monitoring should be carried out every 3-5 years, and for especially critical structures - before each thunderstorm season.

It must be borne in mind that lightning rods are intended only for protection against ordinary line lightning. Meanwhile, there are a number of cases where even well-protected structures were struck by ball lightning. Ball lightning penetrated through open windows, doors, and small holes in walls and often caused significant destruction inside buildings. The physical nature of ball lightning is currently not yet fully understood and sufficiently effective methods of protection against it have not been developed. However, the fact that ball lightning apparently does not have the ability to pierce wooden walls, window glass, etc., gives reason to assume that a dense wire mesh that completely encloses the protected object (for example, an explosives warehouse) may be an effective means and against penetration of ball lightning into such a structure

Installation of the structure

After the calculations have been made and the materials have been prepared, the installation location has been selected, you can proceed to installation. First of all, excavation work is carried out and grounding is installed.

Lightning rods for a dacha or a private house require the installation of a linear or closed ground electrode. In the first case, a trench is dug in which the grounding electrodes are lined up and welded together. The second type of grounding involves immersion in the ground of a triangular structure of three grounding electrodes connected to each other by a metal strip.

The depth of the pit, straight or triangular, should be 0.5-1 meter - the rods are driven into the ground. A deep trench is dug to the place where the down conductor is attached for a connecting lead for the ground loop.

In order for an electric discharge to easily go into the ground, you need soil with good electrical conductive properties. If the soil is sandy, then to improve electrical conductivity, it is watered with an electrolyte - saline solution.

Only moist soil can pass electric current. You can provide for the drainage of the roof drainage to the appropriate area or bury the ground loop at a depth where the soil always remains moist.

Linear ground loop

In order for the ground electrode that you have made to meet the requirements for the protective system for many years, metal with a large margin of cross-sectional area is used for the manufacture of its elements

. This is due to the fact that the thickness of steel elements decreases over time due to accelerated corrosion in conductive soil. For the manufacture of the structure, a steel profile is usually used - pipe, strip, corner.

At the next stage of work, a support for the lightning rod is installed in a pre-selected location. The support is firmly fixed so that it can withstand sharp gusts of wind and lightning strikes. A rod lightning rod with a suitable cross-sectional area is attached to the support. In the absence of rolled metal of the required length, this element is welded from several sections.

It is convenient to use a tall tree growing near the house as a support. The lightning rod is attached to the tree using a synthetic halyard in such a way that the entire house falls into the protective cone. If there is no suitable wood, the lightning rod is connected to the television antenna on the roof, since its mast is made of unpainted metal. If the antenna is mounted on a wooden pole, a wire of a suitable cross-section is attached along it.

Small home protection options

The current conductor in the form of rolled wire or metal strip is firmly connected to the lightning rod mounted on the support. Check how the pantograph is laid, the lower part of which is welded to the ground loop outlet. A correctly installed pantograph does not touch the metal elements of the house anywhere. Otherwise, the electric discharge of lightning will not go into the grounding loop, but into the metal structure that is in contact with the current collector.

Installation of a down conductor involves welding a metal wire or strip to the horizontal part of the ground loop along its entire length. The ground electrode is driven into the ground at the bottom of the trenches, then the trenches and pits are filled with the excavated soil.

Structure care

Lightning protection mounted from metal should be regularly inspected to identify pockets of corrosion. Every spring, before the start of the thunderstorm season, the contacts of the protective system are checked. If necessary, they are cleaned, since poor contact can cause the system to open and catch fire when hit by a lightning discharge.

Corrosion of metal circuit

At least once every three years, the degree of corrosion of the grounding circuit is checked, for which it is dug up and inspected. Elements that are severely damaged by corrosion must be replaced with new ones. Otherwise, at some point the lightning rod will not be able to cope with its functions.

Proper calculation and correct installation of a lightning rod will protect your home. All work can be done on your own.

https://youtube.com/watch?v=6MIOsXp7Tso

Varieties

Types of lightning rods, or more precisely, lightning protection systems, are classified into three categories, each of which is used in strictly specified cases. But before we talk about categories, let’s look at the types of lightning protection used.

In principle, lightning protection of any type, except active, based on early streamer emission (a separate discussion about that), acts the same. Lightning strikes the lightning rod, descends along the down conductor and goes into the ground, while other dangerous effects associated with the appearance of voltage on the metal parts of the building, sparking due to electrostatic and electromagnetic induction are also leveled.

From a design point of view, the types of lightning rods differ in:

1. typologies of lightning rods;
2. type of descent;
3. type of grounding conductors.

The lightning rod can be made in the form of a grid with a certain step between cells (the step depends on the category), in the form of a rod or cable. Also, in special cases, the roof covering of a building can be used to catch lightning if it is made of steel with a thickness of at least 4 mm, copper - at least 5 mm, or aluminum - at least 7 mm.

Sometimes pipes—smoke pipes, exhaust pipes, and other high-height metal structures—can serve as lightning rods. A nearby tree can serve as a support for a cable or rod lightning rod.

The role of down conductors can be the reinforcement of reinforced concrete structures, as well as fire escapes, elevator guides or specially laid metal busbars.
They are connected to the lightning rod by welding or bolting (the latter is only for protection category III). The type of ground electrode used for each lightning rod depends on the category of the entire system, as well as on the electrical resistance of the soil in a particular area (sand, chernozem, and clay have different resistance values).

In soils with weak resistance, it can be a reinforced concrete foundation of a building, in other cases it can be vertical, horizontal, ring structures made of copper or steel, placed in the ground at a certain depth.

Classification of external protection of buildings

Atmospheric lightning is usually understood as a high-power electrical discharge that obeys all known physical laws. It is well known that the propagation of electric current occurs along paths that have the least resistance. A lightning rod is, in fact, a path that will pull danger away from a structure that has high resistance values. A building equipped with such a device will not be damaged during a lightning strike, because the entire flow of energy will be directed along the contour deep into the earth's cover.

In common parlance, this protection of buildings is usually called differently: “lightning rod”, “lightning rod”, “grounding”, etc. Interestingly, the concept of "lightning rod" is not entirely correct, since thunder, which is the sound effect during a lightning strike, does not require a lightning rod. However, the name has taken root deeply in colloquial speech. The main task of all of the above devices is to remove atmospheric electricity from housing, and they do an excellent job of it.

A lightning rod in a private house, as a rule, is divided according to three factors: design specifics, as well as the method and type of protection.

Option for a building lightning protection projectSource terrazn.by

Protection method

This concept can be divided into two subcategories: active and passive lightning protection.

The active option provides for the presence of an air ionizer in the design, designed to accumulate static electricity from the atmosphere for discharge. In fact, the function of the active type of protection is the ability to attract lightning to itself, thereby protecting the structure (and buildings located nearby).

The design of the passive version does not provide anything additional. This does not provide a 100% guarantee that lightning will hit it, but it significantly increases this chance, especially when there is a discharge of electricity above a building.

It should be noted that household appliances will not be protected from the accompanying electromagnetic effects of a lightning strike. Installation of additional elements will be required.

Installation of lightning protection on a metal tile roof Source 2gis.com

Types of protection

The division of building protection by type can be internal or external. The task of the first is to preserve housing from the effect of the concomitant impact of the discharge, and the second - from the discharge itself. Due to the rather rare use of active protection by ordinary people, a lightning rod device for a private building is usually equipped with two subsystems - external and internal.

Specifics of the structure

The external part of the lightning protection system for private housing is usually divided according to the design features of the external part of the lightning rod. They exist in three main types: pin (rod), mesh or cable version. Everyone has their own strengths that make them apply. Thus, the pin type of lightning rod is the cheapest, but not as effective as other options for receiving elements.

Organization of a lightning protection systemSource prezentacii.info

Design and principle of operation of a typical lightning rod

Figure 1: lightning rod design
The entire structure of a 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 let’s look at why each of them is needed, and which option to choose in a given situation.

Lightning rod

From the very name of this element comes its purpose; in fact, it acts as an electrode that receives an electrical discharge from lightning. 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:

• core 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. At the same time, their height must 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.

Rice. 2: 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 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.

Rice. 3: mesh lightning rod

The grating is used as a lightning rod for large areas, for example, multi-storey buildings or shopping centers. Unlike the previous option, it does not affect the design of the building, so it can be used in any modern exterior. Such a lightning rod must have a given cross-section and cell size; as a rule, reinforcement of at least 6 mm2 is selected. Its installation is carried out at a safe distance from the roof (at least 15 cm) through thermally insulating load-bearing structures.

Figure 4: cable lightning rod

A cable lightning rod is a flexible wire that stretches over the protected area or building. Allows you to protect a long area with less material consumption for a lightning rod. It is carried out both on free-standing supports and on the roof of a country house. 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 sheeting, metal tiles and others), they can be used as a lightning rod for a lightning rod. But the following conditions must be met:

• the thickness of the metal layer is at least 4 mm for steel, 5 mm for copper or 7 mm for aluminum;
• there are no flammable materials under the roofing material (insulation, rafters, etc.);
• the outside of the metal is not covered with dielectric material.

Making a lightning rod from a metal roof allows you to save money on lightning rods.

Down conductor

It is a conductor that diverts electric current from the lightning rod to the ground electrode. Can be made of metal wire or tire. Must have a cross-section of at least 16 mm2 if made of copper, 25 mm2 of aluminum, 50 mm2 of steel. The following requirements apply to the down conductor:

• Must be insulated from walls and other structures of the house;
• The shortest path for current flow is selected for it;
• The absence of bends and turns where 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 channel or any other method. This procedure is especially relevant for buildings with conductive finishes or flammable surfaces.

Ground electrode

It is made in the form of a grounding loop, which 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

All parts of the grounding loop can either be looped and form a closed circuit, or line up in a continuous line. Of course, the closed version is considered more reliable. The contour dimensions are selected depending on local conditions.

Rice. 5: example of installation of ground electrode

The main requirement for the grounding circuit is to ensure the established value of the metal-to-earth transition resistance, so it is better to place it in a damp layer, periodically water it with water or treat it with materials that reduce the transition resistance and increase the area of ​​the spreading current (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 ground electrode should be no closer than 1 m from the walls and 8 m from the pedestrian paths. Since at this point a step voltage arises that can cause an electric shock to anyone within the radius of the affected area, therefore it is strictly prohibited to approach the circuit during a thunderstorm, as well as to touch its current-carrying elements.

The principle of operation of a lightning rod

Builders claim that violations in the installation of protective structures can cause devastating consequences from a lightning strike, and this is true - structures assembled incorrectly can cause a fire. Why this happens and how a lightning rod works, we’ll look into it further.

Many people misunderstand how a lightning rod works. Based on the name, you might think that it completely prevents lightning from entering the area that is under its protection. In fact, in a private home, these devices are installed with one simple purpose - to avoid not a chaotic lightning strike, but to direct it to a specific target.

You may remember from physics class that lightning primarily strikes metal objects in contact with the ground. To be most effective, the soil should be moist. A lightning rod is installed on the roofs of buildings and connected to a grounding element buried in the ground. If you take the work seriously, you will be able to make this structure with your own hands.

Features and types of lightning rods: where and how they are used

Lightning rods are special structures that are installed on buildings and structures to prevent lightning from striking them. Other names are lightning protection and lightning protection. The term “lightning rod” refers only to the lightning rod part of the structure. For one purpose, lightning rods may differ in design features, sizes and a number of other parameters.

Preparatory activities

Before making a lightning rod it is necessary to carry out preparations

Moreover, in terms of importance, this stage is no different from the actual process of installing a lightning protection system. You will need to make calculations according to the formula, select materials and find the right place to install lightning protection

Calculation formula

Lightning protection is a rather complex and responsible system due to the tasks it performs. When planning it, accurate calculations and assessment of potential risks are required. At the same time, there is no need for overly complex mathematical calculations. You just need to determine the coverage area of ​​the system based on the formulas. For a rod lightning rod, there are coefficients used to calculate the required height of the device. The following formula is used:

It is suitable for lightning rods up to one and a half meters high, which is quite enough to protect a private home from lightning strikes.

Lightning rod material

To create a protective system you will need structural materials. You will have to make a choice from steel, copper or aluminum. In this case, the required cross-sectional area will differ, which is dictated by the different resistance of each type of the listed metals. To explain this more clearly, below is a table that shows the minimum requirements for lightning protection components, based on the type of metal:

Based on the data presented in the table, the optimal choice of material is copper. However, the cheapest option for a lightning rod made by yourself is steel.

The current conductor has a smaller cross-section compared to other components of the protective system. It is recommended to gradually increase its thickness from the receiver to the ground loop.

To manufacture lightning protection, the following materials and tools are required:

1. Lightning rod. In the case of a rod system, you will need a metal pointed pin. A TV mast or antenna for receiving radio signals is also suitable. Ready-made receivers are available for sale, for example, GALMAR or SCHIRTEC.
2. Metal wire of the required section.
3. Grounding devices (metal pins, pipes or tape).
4. Plastic clamps, brackets, bolts.
5. Tools to do the job (welding machine, electric drill, hammer, shovel).

Installation location

The lightning rod should be located at the highest point available on the site. In this case, you need to remember about the protective cone-shaped zone. The lightning rod must be located in such a place that the building is completely covered with protection. It turns out that the more distant the lightning rod is from the house, the higher it should be.

For financial reasons, it is preferable to place the lightning rod on the roof of the building. In this case, there will be no need to build a high support, which, moreover, is unlikely to be aesthetically attractive.

A separate issue is the correct placement of the grounding device. When lightning strikes, a high-power discharge passes into the ground and at this moment no living creatures should be near the ground electrode. Therefore, requirements have been developed for the minimum distances from grounding to the wall of the house - 1 m and to pedestrian paths - 5 m. The grounding device must be installed in a place where there is no likelihood of people being present. In addition, a fence should be installed around the ground electrode and a warning sign should be placed nearby.

Kinds

In general, the following types of lightning rods used in practice can be distinguished:

• the most common, due to their low cost and simple design, but therefore no less effective, are rod lightning rods;
• cable lightning rods provide protection for extended objects such as long buildings or high-voltage power lines;
• Mesh lightning rods, which have the greatest efficiency, are preferred in the case of protecting particularly important objects.

The cost of a mesh lightning rod is very high. Therefore, despite the high degree of protection, such devices are used extremely rarely when lightning protection is of particular importance. Cable and rod systems are approximately equivalent in efficiency, but due to ease of maintenance and slight difference in cost, the latter have priority in use.

A separate type of lightning rods is active lightning protection systems. Externally, they are practically no different from rod devices.

The only difference is that an electronic device is built into the lightning rod (the very tip), which helps generate high-voltage pulses during a thunderstorm. By creating such a “bait” for lightning, active systems literally catch it. This type of device is considered to be the most effective.

There are companies that have mastered the production of lightning rods on an industrial basis, but often these devices, given their simplicity, are made independently.

Why does each of us care about quality?

Using a quality item brings pleasure and does not bring unexpected problems. A quality item always lasts longer than a low-quality item, and owning a quality item gives inner peace and strength for new achievements. Quality is an integral attribute of installation work performed by Amnis personnel.

Installation of lightning protection for a private house takes place directly on the roof and chimneys, on the walls and drainage system on blind areas and the lawn. A mistake made when performing any part of the lightning rod installation can damage the structure of the house. For example, an incorrectly secured lightning rod conductor holder may, over time, lead to a roof leak with accompanying consequences - rotting of roof structures, damage to the interior decoration of the house, furniture, etc. To eliminate the leak itself and its consequences, you will most likely need to call a team of roofers to look for the leak location , open the roof, replace the damaged part of the insulation, restore the interior of the house. A lightning rod that is not securely installed on a roof can fall over time, not only damaging property on the ground, but also causing harm to the health of the occupants of the house.

High-quality installation of a lightning protection and grounding system is ensured by modern installation technologies using professional tools and the personal interest of each installer in creating a durable lightning rod!