How to make a lightning rod in the country house. Making a lightning rod with your own hands: complete instructions

Historical reference or Who invented the lightning rod?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 a lightning strike. Commonly known as "lightning rod".

It is generally accepted that the lightning rod is 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 , Nevyansk Tower, Jacques Rom's kites). 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 a situation where structures are located in open areas, which is why it is necessary to install a lightning rod to ensure the peace and safety of your family. 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 tools 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 a corrugation for a down conductor;
stainless steel for ground preparation;
welding machine;
saw with a disc for metal;
drill - electric;
multimeter;
sledgehammer or hammer;
bayonet shovel;
spanners;
bolts M8 or M10;
dowel;
clamps for fasteners;
powerful wooden pole;
holders.

Preparation stage

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

It should be noted 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 so that all objects located on the site fall under protection.

There are two types of structures:

Type A
Type B

Lightning rods type A provide 99% protection, which makes them the most effective lightning protection structures.

Type B structures are less efficient than type A structures and as a result protect the structure by only 95%.

Important! The security 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 over the territory of the site, will help solve the problem of lightning diversion. The lightning rod must be at a height of more than 2 meters from the surface in order to effectively perform the function of protecting the house from lightning.

Selection of a grounding installation site

The ground loop must be located at a distance of up to 1 meter from the foundation of the building that the lightning rod will protect, and a few meters from the sidewalks and the porch. The place of grounding during a thunderstorm is dangerous, therefore it is necessary to arrange it so as not to endanger households and guests. It would be best to find a place for her against 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 in advance and mark the locations of all structural elements.

Construction installation

Grounding installation.

After marking, a pit is created with a shovel in the shape of a triangle - each side of which must be at least 1200 mm, depth - 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 fit.

At the ends of the vertical parts of the grounding elements, corners are cut off with a grinder, then with pointed ends they are driven into the ground to a depth of 2 meters with a heavy metal sledgehammer. When digging the pointed ends of the ground 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 trenches.

Installation of a lightning rod (lightning rod).

There are two ways to install a lightning rod:

The current collector is laid on the roof, and then on the wall vertically down and attached to the roof and wall with semicircular plastic or metal clamps. The lower part of the current washer must be fixed to the ground, led out of the wall of the house.

To do this, a hole is made in the ground plate, into which a bolt with a washer, nut and lock nut is installed. The stripped (sharp) end of the down conductor is clamped with a washer, nut and bolt, together with a twisted pair wrapped around the bolt. The holes are then dug 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 readings of the device differ from the normative 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 rooftop lightning rod can protect your home and nearby buildings from lightning.

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

if the house is in a lowland, then the probability of a lightning strike into the house during a thunderstorm is extremely small;
if there is a higher-rise building near the house, then most likely it will be struck by lightning. Thus, the danger of a lightning strike is leveled by the presence of a higher structure next to it;
if a lightning rod is installed on a neighboring house, then your house may also fall within the coverage area of a neighbor's lightning rod.

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

How to protect against lightning private house

Types of lightning protection for summer cottages

Lightning rod can be:

Rod - a metal pin fixed to the frame (on the roof, near the house, on a tall tree growing near the house). By means of a metal wire, the pin is connected to the grounding system. Such a lightning rod looks aesthetically pleasing, but its coverage area is not large. It is easy for them to calculate the protection area: from the highest point of the pin, you need to mentally draw a line to the ground at an angle of 45º. Everything that will be in the zone of the triangle along the perimeter is protected from lightning strikes.

Rope - its feature consists in several masts (two or four), interconnected by steel or aluminum wire. Such a lightning rod is more efficient and covers a large area with protection.

These two types of lightning rods are the most common and are used in private houses and summer cottages, since their design is simple, and installation is not difficult to do with your own hands.

Lightning protection elements

Any type of lightning rod system consists of three essential elements:

Lightning rod. In a rod lightning rod, this is a pin fixed at least 1 m above the chimney, in a cable lightning rod - a wire connecting the masts on the roof. A metal roof can also act as a lightning rod if the coating thickness is 4-7 mm.
Down conductor is one of the main elements of lightning protection. It is a copper (d 16 mm²), aluminum (d 25 mm²) or steel (d 50 mm²) wire.
Grounding - a system of metal rods interconnected by a conductive material. It is located underground at a depth of at least 80 cm.

Materials and tools

For the construction of lightning protection with my own hands will need:

The lightning rod is a pointed pin. A TV mast or radio antenna can be used, you can also buy a lightning rod from one of the leading manufacturers: SCHIRTEC, OBO Bettermann, J Propste, GALMAR;
Copper, aluminum or steel wire of the recommended section;
Pins, pipes or metal strips for grounding;
Mast (bed);
plastic mounts;
Tools (hammer, drill, shovel).

Installation of a wire lightning rod

At the first stage of installation of lightning protection, it is necessary to stretch the wire along the roof ridges, which will serve as a lightning rod.

If the roof is covered with flammable materials (wood, plastic tiles), the wire should be at a distance of 10-15 cm from the surface on special plastic fasteners. The ends of the wire are attached to metal masts (horizontal lightning rods), or bent vertically.

The down conductor is attached to the lightning rod by welding, bolts or rivets. Connection points are isolated. On the roof, the down conductor is fixed with brackets, on the walls of the house - plastic fasteners. The wire can be placed in a cable channel to avoid the negative impact of atmospheric phenomena on it.

The grounding system is mounted at a distance of at least 5 m from the house, paths, benches. Nearby there should be no playgrounds for children's games and walking animals. Grounding works only in wet ground, which must also be taken into account when choosing a location.

Order of lightning protection grounding device:

Dig a trench to a depth where the soil is always damp (at least 80 cm)
Drive metal pins into the bottom of the trench.

Connect the pins together with a steel tape or pipe by welding.
Extend the grounding with a steel tape to the place of its connection with the down conductor.
Connect the down conductor to ground.

Installation of a lightning rod

For a rod lightning rod, a high frame must be installed. Its role can be played by the mast of a television antenna. The rod lightning rod is attached to the mast by welding or bolts.

The installation of a down conductor and grounding of such lightning protection does not differ from that described above. After completion of work, it is necessary to check the resistance of the entire system. It should not exceed 10 ohms.

Service

Preventive maintenance of the lightning rod includes periodic cleaning of the rod pin from dirt, dust and oxide, as well as checking the integrity of all connections.

It is not difficult to independently mount a lightning rod in the country. If you follow all the recommendations and norms of the instructions for the lightning protection device RD 34.21.122-87, then at the right time it will work flawlessly.

Despite the fact that it is easy to make a lightning rod with your own hands, it is recommended to contact specialists to perform such work. Only professionals will be able to suggest which materials are better to use specifically in your situation, provide qualified assistance in choosing the right place for installation, and take into account negative factors from the influence of which protection may not work.

Arrangement of a lightning rod on suburban area- an important condition for the safety of being on it during bad weather. Discharges of electric current of enormous strength in the presence of a lightning rod do not affect the structure of the house and other elements located in the protection zone. However, do not think that a lightning rod prevents lightning strikes. Everything is different. It becomes a conductor to divert the discharge from the house, diverting a current of up to 100 thousand amperes to the ground electrode.

Lightning device options

A classic lightning rod can be made in one of two versions: in the form of a single rod or a system of cables stretched between lightning rods. The first option is usually used to protect an individual house, while the second is to create a safe zone on the whole site. A cable lightning rod is also recommended for buildings that are of considerable length.

Components of a lightning rod

First of all, houses with a roof made of metal or metal tiles need lightning protection, since such options do not have grounding, therefore, during a thunderstorm, they accumulate electric charges on themselves.

In case of metal roof without an insulating layer, having a coating thickness for iron - 4 mm, for copper - 5 mm or for aluminum - 7 mm, a simplified lightning rod device is possible, when its surface takes on the role of a lightning rod. In this case, every 20 meters of the roof is grounded. Here it is necessary to take into account the quality of the roof, because if there are any gaps, then the desired effect from such a lightning rod will not be.

In other cases, the lightning rod should consist of the following elements:

lightning rod (1) in the form of a thin electrode or a system of electrodes installed above the house at a certain height;
down conductor (2) - cable connecting the receiver with grounding;
grounding conductor (3), leading the current to the ground.

Lightning rod

The element in which lightning strikes in the presence of a lightning rod is a lightning rod. It is usually performed in the form of a rod made of steel, copper or other material with similar conductivity. No need to cover it with paint or varnish to avoid corrosion, otherwise it will lose the desired properties.

Cross-sectional area: for steel - 50 square meters. mm, for copper - 35 sq. mm, for aluminum - 70 sq. mm.

You can install lightning rods on different sides or in the center of the roof. If several lightning rods are installed, they are connected to a common circuit closed to the ground electrode. The rod can be placed not only on the roof surface, but also on chimney or the nearest tall tree. The optimal height will be no more than 15 meters. If it is installed on a tree, then the fastening is done in such a way that the rod rises above the crown by at least 0.5 m and 10-15 cm above the house.

In addition to the rods, options for a protective mesh (reinforcement 6 mm thick) and a cable system are possible. The second method is more rational for a country house, since the cable is pulled at a height above the roof level, and the mesh is placed on the roof itself. A cable with a diameter of at least 5 mm is pulled along the roof ridge on the racks, after which it is lowered down, where it is connected to the ground electrode. Thus, it performs both the function of a lightning rod and a down conductor.

Separate parts of the structure can also be used as receivers ( drainpipes, metal railings). Their use is permitted if they have a larger section than is necessary for normal protection.

The down conductor is designed to connect the lightning rod and the ground electrode. It is made of aluminum or copper wire large section. For these purposes, a twisted wire is suitable, which is used for laying overhead power lines. The down conductor is fastened using terminal blocks, couplings or crimp tubes.

The distance between the lightning rod and the ground electrode must be minimal, so the wire is directed straight down. The number of down conductors depends on the area of the house. For cottages with an area of about 200 square meters. m, it is recommended to install 2 down conductors at a distance of approximately 20 m from each other.

It is fixed on a special pole or directly on the wall of the house using plastic fasteners. To protect the down conductor, you can isolate it from the environment using a cable channel.

grounding conductor

Since the grounding conductor is needed to divert the lightning discharge into the ground, it must have a small electrical resistance. For these purposes, both expensive materials such as copper, aluminum, brass and other stainless metals, as well as cheaper ordinary steel, are suitable. The grounding conductor must not have damage and traces of rust, as they can cause a decrease in the diameter of the rods due to the destruction of the metal.

For high-quality grounding, not one, but several rods can be used, which are immersed in the ground away from the paths and the roof, especially if it is made of flammable material. In country conditions, as a grounding conductor, you can also use any large metal object that is at hand: the back of an old bed, cast iron bath, reinforcing mesh and the like.

The type of grounding depends on the parameters of the house and the characteristics of the soil. Dry soil has a low level ground water. In order for the current to reach wet soil, a vertical ground is required. The ground electrode in this case is made of two rods with a cross section of 100 mm and 2-3 m in height, driven in at a distance of 3-4 m from each other. The rods are interconnected by a wire, a cable (copper, aluminum) or tinned iron plates, to the center of which a down conductor is welded.

Wet soil is characterized by a higher level of groundwater, so you can not perform vertical grounding by replacing the rods with strip steel corners, water pipes or other similar metal elements. A horizontal grounding conductor is laid to a depth of 1 m.

In this case, the role of a ground conductor can also be performed by a down conductor laid in the ground in such a way as to occupy the largest possible area of contact with the soil. The connected structure can be in the form of a scallop (letter W) or a triangle. When fastening the wire, the use of manual twisting and pliers is unacceptable; only ordinary or cold welding is allowed.

The placement of the ground electrode must be given special attention. This should be a place remote from the house and paths, inaccessible to children and pets, preferably fenced. The minimum distance to the house must be at least 1 m.

Since water is an excellent conductor of electric current, it is better if the soil around the ground electrode is wet, then the discharges will quickly go into the ground without accumulating on the rod. Additional moisture can be provided by the flow of rainwater from the runoff from the roof or by targeted irrigation of the soil.

For each building, it is necessary to calculate the lightning rod, since each configuration is able to provide a protective zone of various sizes. The parameters of this zone can be calculated independently, taking into account the features and dimensions of the country house.

A single rod forms a protective zone, which is close in geometry to a cone having an angle at the top of approximately 45°. The top of this cone will be at the highest point of the lightning rod. In a cable-type lightning rod, the protection zone has a more complex geometry, in which the cable serves as a rib, and each rod forms its own cone.

Calculation protection zone single rod can be produced by the following formula:

where R is the radius of the zone above the highest point of the house, h is the distance from the highest point of the house to the peak of the lightning rod.

The following calculation can be used to determine if a rod is high enough to protect a certain area at ground level. Let's say the height of the cone will be indicated h o, radius on the ground - R o, building height - h x, radius at the height of the building - Rx, rod height - h. Then, taking into account the height of the existing lightning rod and the height of the house, the unknown values will be calculated by the formulas:

R x \u003d 1.5 * (h-h x / 0.92).

In practice, the calculations look like this: if the rod has a length of 10 m, then the radius of the protection zone on the ground will be 1.5 * 10 = 15 m, the rest of the parameters are calculated similarly.

To calculate the required length of the rod, you can use the same formulas, substituting in them the desired radius of the protective zone. In the case of a complex geometry of the lightning rod, you need to draw a graphical model of the house and the lightning rod and calculate the protection zone geometrically.

The height of the lightning rod should not exceed 12 m, therefore, if it is not possible to meet these restrictions using a single rod, it is recommended to use several masts to expand the protective zone.

Installing a lightning rod

In order for the installation of the lightning rod to be carried out correctly, it is worth adhering to the following methodology:

Measure the height of the roof and determine its geometry. For clarity, draw a diagram by which you can determine the future protective zone.
Decide on the type of lightning rod. For square houses, a single rod is sufficient; for long buildings, the use of a cable system is optimal.
Calculate the protective zone and determine the desired height of the rod (rods). The minimum cross section of the lightning rod should be related to its height in the proportion of 5 square meters. mm per meter.
Determine the mounting point of the lightning rod and fix it on the roof or wall.
Dig a hole for the earth electrode and place it at the desired depth.
Connect the ground electrode and the lightning rod together.
Check the lightning rod with a multimeter. Its resistance should not exceed 10 ohms.

You can also equip a lightning rod on a tree, which is 2.5 times higher than the house and is located at a distance of at least three meters from it. In this case, the lightning rod is mounted on a long metal pole, fixed on a tree with the help of clamps made of synthetic halyard. The connection to the grounding conductor is carried out with a wire of at least 5 mm in cross section.

Further operation

The installed lightning rod does not need special care. It only needs to be periodically checked for damage and the quality of metal connections. If the lightning rod has decreased in diameter or the joints have lost their integrity, then these elements need to be replaced. The location of the earth electrode must also be checked, and the earth around it must be kept moist.

Dear readers! The instruction is voluminous, therefore, especially for your convenience, we have made navigation through its sections (see below). If you have any questions on the selection, calculations and design of grounding and lightning protection systems, please write or call, they will be happy to help!

Introduction - about the role of grounding in a private house

The house has just been built or bought - in front of you is exactly the cherished home that you recently saw on a sketch or photograph in an ad. Or maybe you have been living in your own house for more than a year, and every corner in it has become familiar. Owning your own personal home is great, but along with the feeling of freedom, in addition you get a number of responsibilities. And now we will not talk about household chores, we will talk about such a need as grounding for a private house. Any private house includes the following systems: electrical network, water supply and sewerage, gas or electric heating system. Additionally, a security and alarm system, ventilation, a smart home system, etc. are installed. Thanks to these elements, a private house becomes a comfortable living environment modern man. But it really comes to life thanks to the electrical energy that powers the equipment of all the above systems.

The need for grounding

Unfortunately, electricity also has a downside. All equipment has a service life, each device has a certain reliability, so they will not work forever. In addition, when designing or installing the house itself, electricians, communications or equipment, mistakes can also be made that can affect electrical safety. For these reasons, part of the electrical network may be damaged. The nature of accidents is different: short circuits can occur, which are turned off by automatic switches, or breakdowns to the case can occur. The difficulty is that the breakdown problem is hidden. Damage has occurred to the wiring, so the case electric stove was under stress. With improper grounding measures, damage will not manifest itself in any way until a person touches the stove and receives an electric shock. An electric shock will happen due to the fact that the current is looking for a path to the ground, and the only suitable conductor will be the human body. This cannot be allowed.

Such damage poses the greatest threat to people's safety, because for their early detection, and, therefore, to protect against them, it is imperative to have a ground connection. This article discusses what actions need to be taken to organize grounding for a private house or cottage.

The need to install grounding in a private house is determined by the grounding system, i.e. the neutral mode of the power source and the method of laying the zero protective (PE) and zero working (N) conductors. The type of power supply may also be important - overhead line or cable. The design differences in grounding systems make it possible to distinguish three options for power supply of a private house:

The main potential equalization system (OSUP) combines all large conductive parts of the building, which normally do not have an electrical potential, into a single circuit with the main ground bus. Let's consider a graphical example of the implementation of the EMS in the electrical installation of a residential building.

First, let's look at the most progressive approach to electrical power at home - the TN-S system. In this system, PE and N conductors are separated throughout, and the consumer does not need to install grounding. It is only necessary to bring the PE conductor to the main ground bus, and then separate the ground conductors from it to electrical appliances. Such a system is implemented both as a cable and overhead line, in the case of the latter, a VLI (isolated overhead line) is laid using self-supporting wires (SIP).

But such happiness does not fall to everyone, because the old air lines transmissions use the old system grounding - TN-C. What is its feature? In this case, PE and N are laid along the entire length of the line by one conductor, in which the functions of both the zero protective and zero working conductors are combined - the so-called PEN conductor. If earlier it was allowed to use such a system, then with the introduction in 2002 of the PUE 7th edition, namely clause 1.7.80, the use of RCDs in the TN-C system was banned. Without the use of RCDs, there can be no talk of any electrical safety. It is the RCD that turns off the power when the insulation is damaged, as soon as it occurs, and not at the moment when a person touches the emergency device. To meet all the necessary requirements, the TN-C system must be upgraded to TN-C-S.

In the TN-C-S system, a PEN conductor is also laid along the line. But, now, paragraph 1.7.102 PUE 7th ed. says that re-grounding of the PEN conductor must be performed at the inputs of the overhead lines to electrical installations. They are performed, as a rule, at the electric pole from which the input is performed. When re-grounding, the PEN conductor is divided into separate PE and N, which are brought into the house. The re-grounding norm is contained in paragraph 1.7.103 of the PUE 7 ed. and is 30 ohms, or 10 ohms (if there is a gas boiler in the house). If grounding at the pole is not completed, you must contact Energosbyt, in whose department the electric pole is located, switchboard and entering the consumer's home, and indicate the violation that needs to be corrected. If the switchboard is located in the house, PEN separation must be done in this switchboard, and re-grounding should be done near the house.

In this form, TN-C-S is successfully operated, but with some reservations:

if the condition of the overhead line raises serious concerns: the old wires are not in the best condition, because of which there is a risk of breakage or burnout of the PEN conductor. This is fraught with the fact that on the grounded cases of electrical appliances there will be overvoltage, because the current path to the line through the working zero will be interrupted, and the current will return from the bus on which the separation was performed through the zero protective conductor to the device case;
if re-groundings are not made on the line, then there is a danger that the fault current will flow into the only re-grounding, which will also lead to an increase in the voltage on the case.

In both cases, electrical safety leaves much to be desired. The solution to these problems is the TT system.

In the TT system, the PEN conductor of the line is used as a working zero, and individual grounding is performed separately, which can be installed near the house. Paragraph 1.7.59 PUE 7th ed. stipulates such a case when it is impossible to ensure electrical safety, and allows the use of a TT system. An RCD must be installed, and its correct operation must be ensured by the condition Ra * Ia<=50 В (где Iа - ток срабатывания защитного устройства; Ra - суммарное сопротивление заземлителя). «Инструкция по устройству защитного заземления» 1.03-08 уточняет, что для соблюдения этого условия сопротивление заземляющего устройства должно быть не более 30 Ом, а в грунтах с высоким удельным сопротивлением - не более 300 Ом.

How to make grounding at home?

The purpose of grounding for a private house is to obtain the necessary grounding resistance. For this, vertical and horizontal electrodes are used, which together should provide the necessary current spreading. Vertical earthing switches are suitable for installation in soft ground, while in stony soil their penetration is associated with great difficulties. In such soil, horizontal electrodes are suitable.

Protective grounding and lightning protection grounding are carried out in common, one grounding conductor will be universal and fulfill both purposes, this is stated in paragraph 1.7.55 of PUE 7th ed. Therefore, it will be useful to learn how to unify lightning protection and grounding. To visually see the installation process of these systems, the description of the grounding process for a private house will be divided into stages.

Protective grounding in the TN-S system should be highlighted as a separate item. The starting point for the installation of grounding will be the type of power system. The differences in power systems were discussed in the previous paragraph, so we know that it is not necessary to install grounding for the TN-S system, the zero protective (grounding) conductor comes from the line - you only need to connect it to the main grounding bus, and there will be grounding in the house. But one cannot say that the house does not need lightning protection. This means that we, without paying attention to stages 1 and 2, can immediately go to stages 3-5, see below
TN-C and TT systems always require grounding, so let's move on to the most important thing.

Protective grounding is installed at the pole or at the wall of the house, depending on where the PEN conductor is separated. It is advisable to place the ground electrode in close proximity to the main ground bus. The only difference between TN-C and TT is that in TN-C the grounding point is tied to the PEN separation point. Grounding resistance in both cases should be no more than 30 ohms in soil with a resistivity of 100 ohm * m, for example, loam, and 300 ohms in soil with a resistivity of more than 1000 ohm * m. The values are the same, although we rely on different standards: for the TN-C system 1.7.103 PUE 7th edition, and for the TT system - on clause 1.7.59 PUE and 3.4.8. Instructions I 1.03-08. Since there are no differences in the necessary measures, we will consider general solutions for these two systems.

For grounding, it is enough to hammer a six-meter vertical electrode.

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Such grounding turns out to be very compact, it can be installed even in the basement, no regulatory documents contradict this. The necessary steps for grounding are described for soft ground with a resistivity of 100 ohm*m. If the soil has a higher resistance, additional calculations are required, contact ZANDZ.ru technical specialists for help in calculations and selection of materials.

If a gas boiler is installed in the house, then the gas service may require grounding with a resistance of not more than 10 ohms, guided by paragraph 1.7.103 of PUE 7 ed. This requirement should be reflected in the gasification project.
Then, in order to achieve the norm, it is necessary to install a 15-meter vertical ground electrode, which is installed at one point.

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You can install it at several points, for example, at two or three, then connecting it with a horizontal electrode in the form of a strip along the wall of the house at a distance of 1 m and at a depth of 0.5-0.7 m. Installing a ground electrode at several points will also serve for the purpose of lightning protection To understand how, let's move on to its consideration.

Before installing the grounding, you need to immediately decide whether the house will be protected from lightning. So, if the configuration of the grounding conductor for protective grounding can be any, then the grounding for lightning protection must be of a certain type. A minimum of 2 vertical electrodes 3 meters long are installed, united by a horizontal electrode of such length that there is at least 5 meters between the pins. This requirement is contained in clause 2.26 of RD 34.21.122-87. Such grounding should be mounted along one of the walls of the house, it will be a kind of connection in the ground of two down conductors lowered from the roof. If there are several down conductors, the right solution is to lay a ground loop for the house at a distance of 1 m from the walls at a depth of 0.5-0.7 m, and install a vertical electrode 3 m long at the junction with the down conductor.

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Now it's time to learn how to make lightning protection for a private house. It consists of two parts: external and internal.

It is carried out in accordance with SO 153-34.21.122-2003 "Instruction for the installation of lightning protection for buildings, structures and industrial communications" (hereinafter referred to as CO) and RD 34.21.122-87 "Instruction for the installation of lightning protection for buildings and structures" (hereinafter RD).

Protection of buildings from lightning discharges is carried out with the help of lightning rods. A lightning rod is a device that rises above the protected object, through which the lightning current, bypassing the protected object, is diverted to the ground. It consists of a lightning rod that directly perceives a lightning discharge, a down conductor and a ground electrode.

Lightning rods are installed on the roof in such a way that the reliability of protection is more than 0.9 for CO, i.e. the probability of a breakthrough through the lightning protection system should be no more than 10%. For more information about what protection reliability is, read the article "Lightning protection of a private house". As a rule, they are installed along the edges of the roof ridge, if the roof is gable. When the roof is mansard, hipped or even more complex, lightning rods can be fixed on chimneys.
All lightning rods are interconnected by down conductors, down conductors are carried out to the grounding device, which we already have.

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Installing all these elements will protect the house from lightning, or rather from the danger posed by its direct strike.

Surge protection of the house is carried out with the help of SPDs. For their installation, grounding is necessary, because the current is diverted to the ground using zero protective conductors connected to the contacts of these devices. Installation options depend on the presence or absence of external lightning protection.

Has external lightning protection
In this case, a classic protective cascade is installed from devices of classes 1, 2 and 3 arranged in series. SPD of class 1 is mounted on the input and limits the current of a direct lightning strike. SPD class 2 is also installed either in the input panel or in the distribution panel, if the house is large and the distance between the panels is more than 10 m. It is designed to protect against induced overvoltages, it limits them to a level of 2500 V. If there is sensitive electronics in the house, then it is desirable to install a class 3 SPD that limits overvoltages to the level of 1500 V; most devices can withstand such a voltage. SPD of class 3 is installed directly at such devices.
No external lightning protection
A direct lightning strike into the house is not taken into account, so there is no need for a class 1 SPD. The rest of the SPDs are installed in the same way as described in paragraph 1. The choice of SPD also depends on the grounding system, to be sure of the correct choice, contact ZANDZ.ru technical specialists for help.

The figure shows a house with a protective earth, an external lightning protection system and a combined SPD of class 1 + 2 + 3 installed, designed for installation in a TT system.

Comprehensive home protection: protective grounding, external lightning protection system and
combined SPD class 1+2+3, designed for installation in a TT system
(click to enlarge)

An enlarged image of a shield with an installed SPD for the house
(click to enlarge)

No. p / p	Rice	vendor code	Product	Qty
Lightning protection system
1		ZANDZ Air terminal mast vertical 4 m (stainless steel)	2
2		GALMAR Holder for lightning rod - mast ZZ-201-004 to the chimney (stainless steel)	2
3		GALMAR Clamp to lightning rod - mast GL-21105G for down conductors (stainless steel)	2
4		GALMAR Copper-plated steel wire (D8 mm; coil 50 meters)	1
5		GALMAR Copper-clad steel wire (D8 mm; coil 10 meters)	1
6		GALMAR Downpipe clamp for down conductor (tin-plated copper + tin-plated brass)	18
7		GALMAR Universal roof clamp for down conductor (height up to 15 mm; painted galvanized steel)	38
8		GALMAR Clamp to the facade/wall for a down conductor with an elevation (height 15 mm; galvanized steel with painting)	5
9

Before considering the process of calculating and installing a lightning rod in a private house, you need to find out the physical causes of the phenomenon. This will allow you to better understand all the actions and possible consequences in case of violations of the developed instructions.

Thunder - air waves that appear due to a sharp increase in air pressure after the contact of a lightning discharge. The current in lightning can reach 500 thousand amperes, and the voltage is several million volts. Such a powerful eclectic discharge causes the air to heat up to high temperatures, and its volume increases sharply. As a result, sound waves from lightning arise, which are called thunder. Thunder is a consequence of lightning and does not pose any danger to the house; it is necessary to protect buildings not from it, but from lightning.

Accordingly, to build not a lightning rod, but a lightning rod.

Why do you need a lightning rod

Some not very literate developers think that a metal pin attached to the ridge of the house will attract all the lightning along a cylindrical circle above it and lead them to the ground along the wire. For this purpose, a piece of wire rod is specially buried near the house. Such ideas are very far from science, a metal pin stuck in the ground near the house and tied to a rod on a skate will not bring any benefit. Why?

Where can I find a wire that can withstand a current of 500,000 A and a voltage of 1,000,000,000 V? It is this kind of discharge that lightning has when it meets the ground.
Why, in principle, attract lightning and direct it along the wire, risking setting fire to the building due to overheating of the down conductor?
What to do if there are several buildings of different heights on the summer cottage? Will we have to make a lightning rod system for everyone?

Conclusion. It is necessary to mount not a lightning rod, but a lightning rod. All actions should be aimed not at attracting lightning, but on the contrary, at creating conditions that minimize the likelihood of it entering the structure.

These are very complex calculations, simplified formulas give a big error. Sometimes it is not possible to fulfill the initial technical conditions, there may be several reasons, some of them are objective and not amenable to human influence.

Prices for lightning protection and grounding

Lightning protection and grounding

When you need to install a lightning rod in a private house

Again, we need to remember a little theory about lightning - the actions during the installation of a lightning rod will become clearer. There can be several types of lightning, but we are only interested in the cloud-to-ground direction. At the initial stage, streamers appear, which later combine and form stepped leaders. It is they who glow brightly and are rapidly heading towards the earth.

As it approaches, the voltage of the eclectic field on the earth increases, all the electrons in it rush upward and at the highest point throw out a response streamer towards. It connects to the leader, the circuit closes, the electric discharge goes to the ground. The channel heats up to 20,000–30,000°C, the air expands and creates strong sound waves (thunder).

Now it will be clearer when it is necessary to mount lightning rods on the house.

If the earth in the area has a large number of ions. Such zones are located in waterlogged areas, they can accumulate a large amount of charge. Pay attention to how often lightning occurs in your area, talk to the old-timers. If they cannot remember cases of lightning strikes in any objects, then there is no need to mount a lightning rod.
The house is located on lands capable of accumulating a charge, lightning strikes are not uncommon in this area. Installation of a lightning rod is mandatory, but you must strictly follow the installation rules and perform preliminary calculations.

How lightning rod works

An effective lightning protection system is aimed at minimizing the direction of stepped lightning leaders into the building area. And for this there is only one condition - the electric potential of the earth in this area must be minimal and necessarily much less than in neighboring ones. This task should be performed by lightning rods. They constantly, and not only during a thunderstorm, direct electric charges into the atmosphere and thereby significantly reduce the voltage potential. The conditions for the appearance of oncoming streamers disappear, lightning finds other points of energy removal.

Important. If lightning strikes a lightning rod, it means that it is installed incorrectly and causes harm instead of good.

The size of the protected area depends on the quantity and quality of the ground rods, they collect electrons and send them through the wires to the vertical rod of the lightning rod. From there, the electrons gradually pass into the atmosphere. Due to this continuous process, the potential under the house is reduced and the probability of lightning strikes is automatically minimized.

Now that the principle of operation of a lightning rod is clear, the tasks of each element of the system are clear, you can proceed to install protection at home.

Step by step installation instructions

As it is already clear from the above, lightning protection should be installed only in combination with effective grounding, otherwise the system will not function.

It is recommended to proceed to the work only after calculating the number, size and location of the ground electrodes. Only qualified specialists can perform such calculations. By the way, after installation, they must check the effectiveness of grounding with special devices (megohmmeters), if the indicators turn out to be unsatisfactory, then it will have to be corrected or completely redone.

Step 1. Bend the tendril of the wires, assemble the two halves of the ridge holders.

They are made in such a way that with the help of adjusting holes and screws it is possible to change the main parameters. The elements can be firmly fixed to skates of various sizes, while the reliability of fastening is maintained for the entire period of operation, spontaneous unscrewing is completely excluded.

Step 2 Attach down conductor holders to the ridge. If you are buying an industrial lightning protection system, great, it has all the elements necessary to install the equipment. You can make them yourself, but this will take additional time. In addition, handicraft holders are significantly inferior in design and do not decorate the building in any way.

The distance between them is about one meter, care must be taken that the wire does not touch the roof covering. Try to fasten with the same pitch, so the system looks much better and does not adversely affect the appearance of the house.

Practical advice. On rooftops, always work with a safety rope, especially metal roofing. If it is not possible to purchase industrial equipment for climbers, then make an elementary one yourself.

Lambs (nuts) tighten strongly, use open-end wrenches or pliers. Remember that it is difficult to correct the mistake made later, you will have to climb onto the roof again. Pay attention that all vertical racks for installing the wire are located exactly on the same line.

Step 3 Start laying the wire on the ridge holders. It should be even, the diameter is calculated by a specialist, but in most cases it cannot be less than 6 mm. It is desirable that the surface of the wire be coated with a layer of zinc, due to this, performance characteristics are significantly improved.

The wire is not covered with rust, brown streaks do not appear on the roof. Traces of rust greatly worsen the appearance of the structure.
Due to the fact that the wire does not rust, the resistance indicators remain unchanged for a long time. And this is a very important parameter of any lightning rod.
At the joints, the resistance decreases, during operation it does not worsen the physical and electrical characteristics.

It is not worth saving on the quality of all lightning protection elements, otherwise the efficiency will be insufficient, the money for the purchase and installation can be considered wasted. Clamp the wire with special tongues with pliers.

Step 4 Bend the end of the wire protruding beyond the slope at a right angle, leave a piece about 50 cm high, cut off the excess with special wire cutters.

Step 5 Spread the threaded connections with special mastic, if it is not available, then you can use ordinary grease. Mastic additionally protects metal surfaces from oxidation. The fact is that during the tightening of the nuts, the zinc on the thread breaks off due to strong friction, and the opening of the metal requires protection.

Step 6 Proceed with fastening the wire on the slopes in the longitudinal direction. Here the installation technology depends on the type of roofing material.

Single wave metal tile. It is necessary to loosen the screws a little, lift the sheet and insert the mounting bracket into the gap formed. It has a curved leg shape that goes into the recesses of the metal tile and is firmly fixed in it. Tighten the roof fixing screw. Install the wire and clamp it with tabs.
Piece tile. For such a roof there are special brackets, they have an increased leg length and several notches with tongues. Before installing the bracket, the tongue must be bent at a distance equal to the length of the piece tile, due to this, the strength of the fastening increases. Then you should lift the tile and slip the bracket under it; when the roof is lowered, it is fixed in a fixed position. The wire is attached to it in the usual way.
Sheet metal tiles. For fastening the wire, special brackets are sold, which must be fixed on top of the roof with self-tapping screws. It is necessary to ensure that the self-tapping screws must fall into the boards of the crate. Two rubber gaskets are used to seal the hole. One is installed between the bracket and the roof surface, and the second between the bracket and the washer of the self-tapping screw.
Flexible bituminous tile. This roofing has a solid base, which greatly simplifies the technology of fixing the brackets. They are screwed to the surface with ordinary wood screws, rubber linings are used to seal the holes.

Practical advice. There are situations when, according to the lightning rod project, it is required to transfer one wire from the front slope to the rear one. At the intersection with the ridge wire, it is recommended to connect them, use elements with bolted tightening for this. Thus, you will achieve reliable contact of down conductors.

Prices for down conductor holders

Holders for down conductor

Step 7 Screw the brackets to the edge of the gutter of the drainage system, the wire is fixed to them with bolts. Tighten connections with great force.

Down conductors installed on the house are connected to grounding.

Grounding manufacturing

This is the most important element of a lightning rod, as already mentioned above, only a specialist with a special education should calculate the parameters. He must know the resistance of the soil, its composition, the proximity of groundwater and other initial data. Based on the calculations, the material is selected, the manufacture of metal pins, the distance and quantity, the depth of instillation for each grounding. Depending on the size of the house, a specific location of ground electrodes is selected.

Prices for voltage stabilizers

Surge Protectors

For steel pins, the cross-sectional area must be at least 80mm2, for copper 50mm2. It must be remembered that both steel and copper oxidize at different rates, and oxides negatively affect current conductivity. The cross section and surface area of the rods must be chosen with a margin, and resistance measurements should be taken annually. When critical values are reached, it is recommended to dig out the rods and clean them from rust.
The depth of the trenches is not less than 5.0 m, the length is not less than three meters. These indicators largely depend on the physical characteristics of the soil, decisions are made by a specialist at the work site.
All ground connections are best done by welding, clamps quickly lose their initial resistance values. Welding must be done on both sides, the seam length is at least five centimeters.
Professionals advise instead of round pins to use a metal strip with a thickness of at least 1 mm and a width of about three to four centimeters. Such metal is not only cheaper, but also significantly increases the operating time of the lightning rod due to the large area of contact with the ground.

To make or not to make a lightning rod is the business of every developer. Strict requirements are set only for public buildings and premises with a large number of people. There are no exact statistics on the system's performance, no one knows how many lightnings were managed to be removed from the building and what the efficiency of the device is.

Now you know how to properly mount a lightning rod in a private house. But once again we remind you that before starting work, you must carefully analyze all the factors that affect the likelihood of a lightning strike into a building, and only then make a final decision. In order for the installation of a lightning rod to give the expected effect, the roof of the house must comply with existing building codes.

Video - Installation of a lightning rod

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