Lightning protection does not need to be done on houses below. Protecting a private home from lightning - review of a good lightning rod

How to prevent lightning from striking an object?

Lightning protection systems can solve this problem. They “attract” the discharge to themselves and redirect it to the grounding system. While there are no technologies yet that would prevent the elements themselves, lightning protection equipment helps by directing overvoltage pulses into the circuit of the grounding system.

What is the difference between an internal lightning protection system and an external one?

Systems that protect buildings and industrial facilities from atmospheric electricity strikes are called external lightning protection systems. Such systems consist of a lightning conductor, a lightning rod and grounding conductors. In general, this design performs the functions of intercepting an incoming discharge and subsequently discharging electricity into the ground.
Internal lightning protection structures protect electrical wiring in a building, as well as electrical equipment installed indoors, from additional, secondary effects of a lightning strike (for example, pickup or current carryover through grounding or from other sources). The most important component of internal lightning protection systems is the SPD. It limits surge voltages.

What types and/or classes are SPDs divided into?

According to the three most common classifications - GOST, IEC (valid in the Russian Federation), as well as the DIM specification used in Germany, protective devices are divided into categories according to their testing methods and the location where the device is installed.
The first class of SPD test operations is equivalent to the class technical requirements under the letter “B” and Type 1; The second class of tests is identical to the class of requirements with the letter “C” and, accordingly, Type 2, the third class of tests corresponds to the class of requirements with the letter “D” and Type 3.

What is the difference between SPDs of the first type and protective devices of the second type?

Protective devices of the first type are usually installed at the entrance to the protected building if the power supply is carried out over the air or if an external lightning protection system is used. In such situations, an SPD is used to divert some of the forward discharge current. According to the GOST R-514352-2008 specification, protective devices of the first type (and, accordingly, the first test class) are tested with current pulses having a waveform of 10/350 μs.
Protective devices of the second type are used to protect structures from secondary, induced impulses. They are installed either near an SPD of the first type or at the entrance to the building (if the risk of part of the discharge entering the building is completely eliminated). When testing SPDs of the second type (and, accordingly, test class 2), current pulses of 8/20 μs are used.

Does the surge protector need to be replaced or inspected in any way after the storm has passed?

The design of any SPD provides for its automatic recovery. It can be turned on and off many times, providing constant protection against electrical surges in the network. Each device is equipped with a status indicator, which signals the need for replacement or any repair of the SPD.

Is the installation of an SPD required in cases where lightning protection equipment in a building or structure is installed in accordance with the standard and grounding is connected to it?

Yes, installation of an SPD is required. An external lightning protection system is designed to remove direct lightning strikes, but it is not able to protect equipment and wiring from the secondary effects of lightning and induced strikes. An external protection system cannot prevent the occurrence of sudden changes in potential differences in the grounding system. A protective system installed outside the facility is not capable of protecting the electrical network from induced pulses, which usually appear in metal structures located near the site of a lightning strike.

Where is the SPD installed: before the meter or after it?

If you need to protect electrical equipment and the meter from secondary surges, protective devices should be installed in front of the meter. The most important thing is to adhere to the main requirement: according to the standards, the protective device must not have leakage current. Therefore, it is best to choose surge protectors with VG technology developed by CITEL. Such meters, firstly, do not waste electricity when in standby mode, and, secondly, are able to reduce the voltage in the network to an acceptable level in accordance with the third class of protective devices. The specific connection diagram for protective equipment in front of the meter should be agreed upon with any branch of the MZK-Electro company.

Is it necessary to install a grounding system on site (in a cottage) if there is a functional SPD at the entrance?

According to the rules for electrical installations, it is necessary to install grounding at the entrance to the facility. Moreover, without connecting the grounding conductor, the protection device will not work.

Is it necessary to connect the grounding loop of the cottage to the grounding of the lightning rod?

Yes, it's necessary. All documents defining the installation of a facility’s lightning protection system, as well as the organization of power supply to industrial structures, require the creation of a circuit of grounding elements covering all the facility’s protective systems. As a result, the risk of sparking or perforation of the protective system is reduced, and, accordingly, the level of safety at the facility increases. To ensure adequate protection of devices located indoors from secondary effects following a lightning strike, protective devices must be used. When an external lightning protection system is installed in the protected building, the use of a class 1 SPD is mandatory.

What are active lightning rods intended for?

Such devices are mounted on a high metal match. They are used to ionize the surrounding air before being struck by atmospheric electricity. The conductivity of the air increases, and the lightning that follows the path with least resistance environment, is “attracted” to the receiver. Active devices - this is one of the differences from passive ones - have a much larger radius of the protective zone.

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 if the developed instructions are violated.

Thunder is air waves that appear as a result of a sharp increase in air pressure after the contact of a lightning discharge. The current strength in lightning can reach 500 thousand amperes, and the voltage can reach several million volts. Such a powerful eclectic discharge causes the air to heat up to high temperatures, and its volume sharply increases. 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; buildings must be protected not from it, but from lightning.

Accordingly, 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 a house will attract all the lightning along a cylindrical circle above it and lead them to the ground along a 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 into the ground near the house and tied to a rod on a ridge will not bring any benefit. Why?

1. Where can I find a wire that can withstand a current of 500,000 A and a voltage of 1000000000 V? This is exactly the type of discharge that lightning has when it hits the ground.
2. Why, in principle, attract lightning and direct it along the wire, risking setting the building on fire due to overheating of the down conductor?
3. What to do if summer cottage several buildings of different heights? Will we have to make a lightning rod system for everyone?

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

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

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Lightning protection and grounding

When 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 connect and form stepped leaders. They are the ones who glow brightly and quickly head towards the ground.

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 them. It connects to the leader, the circuit is closed, and the electrical discharge goes into 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 install lightning rods on a house.

1. If the earth in a given area has a large number of ions. Such zones are located in waterlogged areas; they are the ones that can accumulate a large amount of charge. Pay attention to how often lightning occurs in your area, talk to old-timers. If they cannot remember cases of lightning hitting any objects, then there is no need to install a lightning rod.
2. The house is located on lands capable of accumulating 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 does a lightning rod work?

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 electrical potential of the earth in a given area must be minimal and necessarily much less than in neighboring ones. Lightning rods should perform this task. They constantly, and not just during a thunderstorm, send into the atmosphere electric charges and thereby significantly reduce the voltage potential. The conditions for the appearance of oncoming streamers disappear, lightning finds other energy outlet points.

Important. If a lightning rod is struck by lightning, it means that it is not installed correctly and is causing harm instead of benefit.

The size of the protected area depends on the number and quality of grounding pins; they collect electrons and send them through wires to the vertical pin of the lightning rod. From there, the electrons gradually move into the atmosphere. Due to this continuous process, the potential under the house is reduced and the likelihood of lightning striking it 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 begin installing home protection.

Step-by-step installation instructions

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

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

Step 1. Bend the wire fastening tendril and 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 throughout the entire period of operation, spontaneous unscrewing is completely excluded.

Step 2. Attach the down conductor holders to the ridge. If you are purchasing a lightning rod system industrial production– excellent, it has all the elements necessary to install the equipment. You can make them yourself, but this will require additional time. In addition, handmade holders significantly lose out in design and do not decorate the building in any way.

The distance between them is approximately one meter; care must be taken that the wire does not touch the roof covering. Try to mount with the same pitch, this way the system looks much better and does not affect negative influence on appearance Houses.

Practical advice. Always use a safety rope when working on roofs, especially on metal roofs. If it is not possible to purchase industrial equipment for climbers, then make some basic equipment yourself.

Tighten the wing nuts firmly, use open-end wrenches or pliers. Remember that it is difficult to correct the mistake you made later; you will have to climb onto the roof again. Make sure that all vertical posts for installing wire are positioned strictly on the same line.

Step 3. Proceed with laying the wire on the ridge holders. It must 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 the performance characteristics are significantly improved.

1. The wire does not rust, and brown streaks do not appear on the roof. Traces of rust greatly worsen the appearance of the building.
2. Due to the fact that the wire does not rust, long time resistance indicators remain unchanged. And this is a very important parameter of any lightning rod.
3. Resistance is reduced at the connection points; during operation it does not deteriorate the physical and electrical characteristics.

You should not skimp on the quality of all lightning protection elements, otherwise the effectiveness will be insufficient, and money for purchase and installation can be considered wasted. Clamp the wire with special tongues and pliers.

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

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

Step 6. Proceed to attach the wire to the slopes in the longitudinal direction. Here, the installation technology depends on the type of roofing material.

1. Single-wave metal tiles. You need to loosen the screws a little, lift the sheet and insert the mounting bracket into the resulting gap. It has a curved leg shape that fits into the recesses of the metal tile and is firmly fixed in it. Tighten the roof fastening screw. Install the wire and clamp it with the tabs.

   

   

   

2. Piece tiles. There are special brackets for such a roof; 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, thereby increasing the strength of the fastening. Then you should lift the tiles and slide a bracket under it; when the roof is lowered, it is fixed in a stationary position. The wire is attached to it in the usual way.

   

   

   

   

3. Sheet metal tiles. To attach the wire, special brackets are sold that need to be fixed on top of the roof with self-tapping screws. It is necessary to ensure that the screws always fit into the sheathing boards. To seal the hole, two rubber gaskets. One is installed between the bracket and the roof surface, and the second is installed between the bracket and the self-tapping washer.

   

   

   

   

   

4. Flexible bitumen shingles. This roofing covering has a solid base, which greatly simplifies the technology for fixing the brackets. They are screwed to the surface with ordinary wood screws, and rubber pads are used to seal the holes.

   

   

   

   

Practical advice. There are situations when the design of a lightning rod requires moving one wire from the front slope to the rear. It is recommended to connect them at the intersection with the ridge wire; for this, use elements with bolted ties. This way you will achieve reliable contact between the 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.

The down conductors installed on the house are connected to grounding.

Making grounding

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

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Surge Protectors

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

To make or not to make a lightning rod is up to each developer. Strict requirements are established only for government buildings and premises with a large number of people. There are no exact statistics on the performance of the system; no one knows how many lightning strikes were managed to be diverted from the building and how efficient the device is.

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

Video - Installation of a lightning rod

Do you need lightning protection?

Lightning and atmospheric discharges are a constant and almost ubiquitous companion of people. Their terrifying power seemed to our ancestors as a manifestation of the will of the gods. Worldwide science and practice have developed effective methods of protection against the consequences of atmospheric discharges. Lightning protection is a set of measures to protect the life and health of a person and his property. IN currently Lightning protection, as a set of standards, techniques and means, is a dynamically developing part of world technology.

Lightning and its damaging factors.

Atmospheric discharges have devastating power and their various consequences pose a serious threat to human life and property.

There are several lightning theories, but the main thing is that a potential difference of up to 1000 kV in the clouds relative to the surface of the earth causes a discharge of monstrous power up to 200 kA, which is accompanied by flashes and thunderclaps. The heating of the atmospheric discharge channel reaches 30,000 degrees. The average discharge duration of the most commonly occurring cloud-to-ground lightning strike is approximately 60-100 µs. It is more convenient to analyze the variety of damaging factors and consequences using the example of a table.

From the above we can draw conclusions:

• Lightning and thunderstorm potential pose a real and varied threat to human life and property.
• The human environment, as it becomes saturated with sensitive modern electronic equipment, has become extremely vulnerable to the effects of atmospheric and switching overvoltages.

As an example, the following statistics can be cited: more than 25% of insurance payments in Germany cover damage from lightning and surges.

The need for lightning protection and surge protection is beyond doubt for anyone who has witnessed the consequences of atmospheric discharges.

A short list of problems related to the security of existing structures, the design and implementation of lightning protection of buildings on the territory of the Russian Federation.

At their core, the problems of Russian lightning protection are of a regulatory nature. The current standards in the field of lightning protection in the Russian Federation do not fully reflect the achievements modern science and technology. Effective methods and means of lightning protection are most fully presented in the IEC (International Electrotechnical Commission) standards and are confirmed by widespread practical application in industrialized countries.

For easy perception of the text of the article, it is necessary to provide the functional names of the basic sections of the lightning protection system adopted in international practice.

With a very general comparison of world and Russian standards a number of fundamental conclusions can be drawn.

Regarding the section of external lightning protection:

• In contrast to the norms of the Russian Federation, the IEC standards have developed in detail a method of protection by applying lightning protection circuits (grids) to complex roofs of buildings in combination with the protection of protruding parts.
• In Russian guidance document"Instructions for the installation of lightning protection of buildings and structures" (RD 34.21.122-87) does not establish the world practice of using anti-corrosion materials and factory-ready elements, including grounding conductors and bolted connectors made of galvanized steel in grounding devices.
• The same instructions stipulate the unambiguous practice of receiving a lightning strike with a metal roof covering. At the same time, in IEC regulatory documents, this method is used only in cases where there is no need to ensure the safety of this coating.

Regarding the section of internal lightning protection:

On this moment The international concept of zonal surge protection for electrical installations of buildings, information and telecommunication systems, electronic equipment and terminal devices is practically outside the field of activity of Russian specialists.

• The IEC standards carefully elaborate the rules and recommendations for the use of surge suppressors in accordance with the zonal concept of internal lightning protection, as well as the requirements for them. At the same time, the new edition of the PUE contains only fragmentary instructions about the need to install arresters on input electrical cabinets with air input of the supply line.
• Russian standards have not developed a set of methods and means to protect modern low-current networks, equipment and devices from lightning and switching overvoltages.

As a result, this is not an exhaustive list of the real-life problems faced by developers, contractors and property owners.

In the absence of practice of using factory-ready elements, it is possible to implement effective external lightning protection of cottages, estates and similar buildings only with the use of free-standing high rod lightning rods. As a rule, developers and owners are not satisfied with this decision, because the architectural individuality of the building is violated, and its implementation is associated with significant costs.

Using metal roofing (especially metal tiles) as an air terminal can lead to deformation and destruction sheet material, as well as fire of the combustible materials of the roof structures located below.

Difficulties arise when installing external lightning protection on reconstructed industrial, public and administrative buildings. At such facilities, it is cheaper to carry out external lightning protection and grounding, regardless of current-carrying building structures, than to determine their suitability and reconstruct. Given the practical unavailability of factory-ready elements on the market, it is difficult to effectively and economically implement lightning protection of these objects.

Lightning protection parts and grounding devices made from improvised materials under construction conditions, as a rule, have low durability, an insufficient degree of protection from direct strikes, and lack means of protection against carried and induced lightning potential.

Public and industrial building urban areas that are protected from direct lightning strikes using conductive building structures are, as a rule, equipped with electrical installations without internal lightning protection devices. Owners and operating organizations may incur significant costs to eliminate the consequences and cover damage from lightning and switching overvoltages in networks.

Every year, expensive and pulse-voltage sensitive information technology equipment, telecommunications and automation systems are increasingly used in everyday life, management, industry and communications. Their uninterrupted operation and safety require complex and high-quality equipment for limiting lightning and switching overvoltages with rules of application, installation and operation that are understandable to specialists.

In these conditions, the topic of possible reduction in the risks of insurance companies, and, accordingly, the size of tariffs for insurers of real estate and property, is of keen interest.

Experts suggest you create new level safety of the houses in which you live, which you build, equip and design. Comprehensive equipment with system equipment from the leading German manufacturer OBO Bettermann - time-tested effective solution on protection against lightning and surge voltages.

Country houses are usually built from flammable materials, and the fire station is located far away. Yes, and you can drive up not to every building, but from strong wind, accompanying any thunderstorm, one should also not expect anything good.

Sometimes from a lightning strike Entire holiday villages are burning down.

We’ll tell you how to make an effective lightning rod on your own and eliminate the risk of a direct hit from a “heavenly discharge” into your house.

In simplified terms, the physics of the process can be described as follows: source lightning are cumulonimbus clouds.

During a thunderstorm, they turn into peculiar giant capacitors. On the upper plus part, a huge positively charged ion potential accumulates in the form of ice crystals, and in the lower minus area, negative electrons accumulate in the form of water drops.

During the discharge (breakdown) of this natural battery, lightning appears between the ground and the thundercloud - huge electrical spark discharge:

This discharge will always flow through the circuit least local resistance electric current. The fact is well known and verified. Such resistance usually occurs in high-rise buildings and trees. Most often, lightning strikes them.

The idea of ​​a lightning rod is to install it near the house area of ​​minimum resistance so that the lightning discharge passes through it and not through the structure.

If you don’t have a lightning rod at your dacha, it’s time to think about building one. The cheapest and easiest way to make it is to do it yourself. What do you need to know for this?

So, a lightning rod (lightning rod) is a lightning protection (lightning protection) device, ensuring the safety of the building and people's lives, located in it, from the destructive effects that can occur during a thunderstorm with a direct lightning strike.

This corrosion protected, bare conductor - that is, a well-conducting material with as large an area and a larger cross-section as possible (minimum 50 mm²).

A lightning rod (lightning rod) is assembled from thick copper wire or steel rod, pipes of the required section or from steel, aluminum, duralumin rods of various profiles, angles, strips, and so on.

It is better to use galvanized steel materials. Since they are less susceptible to air oxidation.

What does lightning protection consist of: device

Lightning rod (lightning rod) simplest design comprises 3 parts:

(descent).

Let's talk about each element in more detail.

A metal conductor mounted on the roof of a building or on a separate support (tower). Structurally divided into three type: pin, cable And mesh.

When choosing a lightning rod design focus on the material, which covers the roof of the house.

1. Shtyrevoe(or rod) lightning rod device is a metal vertical rod rising above the house (see figure below).

Suitable for roofs made of any material, but it is still preferable for metal roofing . The height of the lightning rod should not exceed 2 meters. And it is attached either to a separate load-bearing support, or directly to the house itself.

Materials for production:

Steel pipe (20 -25 mm diameter, with wall 2,5 mm thick). Its upper end is either flattened or welded into a cone. You can also make and weld a special needle-shaped plug to the upper edge of the pipe.

Steel wire (8 -14 mm). Moreover, the down conductor must be exactly the same diameter.

Any steel profile(for example, angle or strip steel of at least 4 mm in thickness and 25 mm in width).

The main condition for all these steel materials is the cross-section minimum 50 mm².

2. Trosovoye the lightning rod device is stretched along the ridge at a height of up to 0,5 m from the roof cable with a minimum cross-section 35 mm² or wire.

Galvanized steel rope is usually used. This type lightning rod is suitable for wooden or slate roofs.

It is fixed on two ( 1-2 meter) supports made of wood or metal, but insulators must be installed on metal supports. The cable is connected to the down conductor using die clamps.

3. Mesh the device of the lightning rod system is a mesh laid over the roof with a thickness 6 -8 mm. This design is the most difficult to implement. Used for roofs covered with tiles.

4. Well, it’s very rarely used covering device lightning protection is when metallic lightning rods act as lightning rods structural elements the house itself (roof, trusses, roof railing, drainpipe).

All considered designs of lightning rods securely connected by welding with a down conductor and through a down conductor with a single- or double-sided grounding conductor welded seam minimum 100 mm in length.

(descent) - the middle part of the lightning rod, which is a metal conductor with a minimum cross-section for steel 50 , for copper 16 and for aluminum 25 mm squared.

Main purpose down conductor is to ensure the passage of discharge current from the lightning rod to the ground electrode.

Ideal path for electric current to pass- the shortest straight line directed straight down. Avoid turning at sharp angles when installing the lightning rod. This is fraught with the occurrence of a spark discharge between nearby sections of the down conductor, which will lead to inevitable ignition.

The most popular material for current conductor- bare steel wire rod or strip. It is carried out only on fireproof surfaces. Metal brackets should be installed on flammable walls, which themselves, being in contact with the flammable surface, will protect the down conductor.

Minimum distance from the wall to the down conductor 15-20 cm.

It must be laid out so that there were no points of contact with home elements such as a porch, front door, window, metal garage door.

We know that It is better to connect parts of a lightning rod by welding, but if this is not possible, it is allowed to interface the down conductor with the grounding conductor and lightning rod using three rivets or two bolts. The length of application of the current conductor to other parts of the system with a rivet connection is equal to 150 , and with a bolted one - 120 mm.

The end of the non-galvanized wire rod and the point where the down conductor wire is attached to the steel parts to ensure reliable contact needs to be cleaned, and it is enough to wash the galvanized one from dust and dirt. Then a loop or hook is made at the end of the wire, washers are placed on both sides and the whole thing is tightened as tightly as possible with a bolt.

The joints (if this is not welding) also need to be wrapped in several layers of electrical tape, then with a coarse cloth, twisted on top with a thick thread and covered with paint.

To improve contact you can treat the ends of the wire with tin and solder.

(grounding electrodes) - the lower part of the lightning rod located in the ground, ensuring reliable contact of the down conductor with the ground.

How to properly arrange grounding is described in GOST oh and SNIP ah, but for the most simple option it is enough to have at least one meter from the edge of the foundation and no closer 5 meters from the entrance to the building to bury P-shaped structure made of metal conductors.

Able to cope with the task conventional ground loop(it is made for household electrical appliances).

This 3 electrodes driven and buried in the ground, connected to each other at the same distance by horizontal ground electrodes. The grounding structure should be buried below the maximum soil freezing level. From 0,5 before 0,8 meters deep.

For a grounding conductor take rolled steel cross section 80 mm, less often copper cross-section 5o mm squared. Vertical grounding electrodes are 2-3 meters in length, but the closer the groundwater level, the shorter they are.

If the soil at your dacha is constantly wet, then a meter or half meter pin will be enough.

On what depth to drive and how many electrodes will be necessary can be found in energy service at your place of residence.

It must be remembered that the quality of grounding depends on the size of the contact area of ​​the ground electrode with the soil and the resistivity of the soil itself.

Grounding conductor for lightning rod need a separate one, you should not ground the lightning rod to the household circuit. Categorically We do not recommend experimenting. It is fraught with consequences.

We invite you to watch a video with a visual diagram of lightning protection installation:

According to regulatory documents, installation of lightning protection systems for private residential buildings optional. And only you can decide the feasibility of installing a lightning rod (lightning rod) at your dacha. We hope that the article will help you make the right decision.

Lightning protection at home: why install a lightning rod. What risks do we face if lightning strikes our home or near it? What should you do to feel safe during a thunderstorm? Today there is no shortage of protective equipment, but you need to know when and how to use them.
Russia and Ukraine experience an average of 25–30 thunderstorm days per year. Most of them occur in spring and summer, and it is at this time that atmospheric discharges, that is, lightning, most often occur. During a thunderstorm, from several to several dozen, and sometimes even over a hundred lightning bolts can strike the ground. The likelihood that lightning will strike a residential building is usually not very high, which is why most private houses are not equipped with an external lightning protection system (this is regulated by the relevant regulatory document). But the probability of lightning striking various objects located in the vicinity of the house is much higher.

Do you need lightning protection?

Every home should be protected from possible consequences lightning discharge by installation internal system protection against resulting overvoltages.

Lightning protection: how to assess the risk

To determine the likelihood of a particular building being struck by lightning, several factors must be taken into account, including:

• The frequency of thunderstorms in this region and the power of atmospheric discharges - the most thunderstorms are observed in the western regions of Ukraine - more than 100 hours a year, the least - in Autonomous Republic Crimea - from 40 to 60 hours of thunderstorms (see map on page 113);
• Type of development - a house with a height of more than ten meters, moreover, located in an open area, is much more susceptible to the threat of direct lightning strikes compared to a lower house next to which they grow tall trees or other tall buildings are located. Homes with steep roofs or tall, sharp architectural features such as turrets are also at risk from lightning. Houses with a height of more than 15 m must be equipped with an external lightning protection system;
• Terrain – a much higher risk of being struck by lightning exists if the house is located on a hill.

Consequences of a lightning strike

One of the most serious consequences of a lightning strike is a fire - usually as a result of a lightning strike hitting a structure that does not have lightning protection. Last year, more than 378 such cases were recorded in our country.

But much more often, the consequence of atmospheric discharges is overvoltage in the electrical network, which causes significant damage to electrical household appliances installed in homes. The resulting damage can be very serious.

Lightning is a powerful electrical discharge, so not only a direct hit is dangerous, but also one that occurs at a certain distance, even 1.5 km. This applies to both lightning discharges moving towards the ground and passing between clouds. Then so-called pulse overvoltages arise, which move at a speed close to the speed of light; Therefore, before thunderclaps are heard, electronic devices connected to the electrical network may already fail.

Attention! There are no statistics regarding surge protection, but it can be assumed that more than 80% of residential private houses in Ukraine do not have this type of protection, although they are all susceptible to this threat.

What happens when lightning strikes

Depending on whether the lightning strikes directly at home, or whether the discharge occurs next to it, the electrical network in the house is subject to overvoltages of varying magnitudes.

1. A lightning strike occurs directly into a house - the lightning current can reach 100,000 A, it flows to the ground through all elements of the house that are conductors.
2. A lightning strike occurs in a nearby high (>1000 V) or low (220 or 380 V) voltage overhead line. A power line experiences a surge that can reach 150,000 V and induces a current pulse of several thousand amperes that reaches the home's electrical system. The consequences of lightning striking an overhead telephone line are similar.
3. A lightning strike occurs in the ground next to the house. As a result, an overvoltage pulse occurs in the electrical network, the magnitude of which is electrical outlet can even reach 50,000 V.
4. A lightning strike occurs in a nearby body of water. As a result, an overvoltage pulse occurs in the electrical network, the magnitude of which in an electrical outlet can reach up to 5000 V.

2. Lightning strike to a high or low voltage line. 1.Lightning strikes directly into the house
3. A lightning strike occurs in the ground next to the house. 4. A lightning strike occurs in a body of water located in the vicinity.

What threatens electrical wiring?

If the home's electrical system and the appliances connected to it are not equipped with adequate surge protection, the following may occur:

• Damage (breakdown) of wire insulation in the electrical system of the house;
• Damage to motors, coils, transformers in electrical appliances (due to insulation breakdown);
• Damage to electronic equipment: televisions, computers, telephones, heating system software, as well as home appliances;
• Failure of information systems, fire and security alarms.

How to protect your home's electrical system

Electronic devices are very sensitive to surges that occur in the electrical network to which they are connected. Overvoltages can occur not only due to atmospheric discharges, but also as a result of switching processes or short circuits that occur in electrical networks. Properly selected internal protection will protect equipment from overvoltages, regardless of the cause of their occurrence. It must be installed both in the case when the house is equipped with an external lightning protection system, and in the case of its absence.

Overvoltage protection must be comprehensive and consist of equalizing connections, as well as equipment that provides zonal protection.

A Class B surge arrester protects equipment from nearby lightning strikes. It is installed at the entrance of the main distribution board Class C surge suppressor – protection that is sufficient for most electrical appliances Class C surge suppressor with fault indication Main equipotential busbar with cover
Class D surge suppressor – installed for additional protection of electronic equipment Class D socket surge suppressor is installed directly into the socket for connecting particularly sensitive electronic equipment

Equalization connections

Making equalization connections requires installing the so-called main equipotential bus and connecting to it:

• Main electrical distribution board grounding points;
• Metal braided cables, as well as metal pipes, laid in the house;
• Equalization connections in bathrooms;
• Ground electrode of the external lightning protection system (if the house is equipped with such a system).

The main equipotential busbar can be installed in the basement of the house or next to the main electrical distribution panel (in a niche or in a lockable box). In rooms with an increased risk of electric shock, for example, in the laundry room and bathroom, additional busbars are also installed.

To ensure adequate safety against electric shock, equalizing connections are one of the required elements.

Zoned home protection against lightning

It consists of installing protective devices in the house, the task of which is to safely absorb pulse overvoltages and divert the overvoltage current to the ground electrode. This prevents an overvoltage pulse from entering the power supply system. These may be standard Class B, C and D protective devices or the new generation Class C protective devices, which reduce overvoltage up to 1500 V. This is usually sufficient to protect household appliances.

First stage class B arresters (lightning arresters). Installed in the input device or near the main electrical distribution panel, they protect the home's electrical system from the effects of direct lightning strikes or lightning striking nearby objects.

Class C second stage arresters (limiters). They are placed next to the main distribution board of the house. They may have an indication (indicating damage), so they can be quickly restored by replacing the protective insert.

Class D third stage limiters. They can be installed in a distribution board, in a mounting box for sockets, as well as in extension cords, that is, in close proximity to the protected devices.

Other arresters. Recently, arresters have appeared on the market for comprehensive protection of the electrical system of a home. One such device contains arresters of two or three degrees of protection. There is also a separate group installed there, designed to protect telephone lines entering the house.

Comprehensive lightning protection device for a home

In our country, thunderstorms occur more often in the southern and western regions, seasonally - in late spring and early autumn. Every owner of a private home should remember the danger posed by natural atmospheric disasters and choose a suitable lightning rod to protect the house.

Why is it needed? lightning protection? Changes in atmospheric pressure and air temperature lead to the movement of air masses. As a result, an electrical voltage is formed between the clouds and the ground, the power of which sometimes reaches a million volts. This high voltage often penetrates the insulating layers of the atmosphere in the form of lightning. Usually this is a very short electric shock of enormous power (tens of thousands of amperes), which leads to fires and the death of people and animals.

Lightning is accompanied by gigantic radiation of electromagnetic waves. The danger arises from a direct impact on a house or person, on ground power lines, or on isolated tall trees.

Overvoltage, which occurs, for example, between a tree and a house, can lead to a fire or death of people in the house. If lightning strikes a high-voltage power line, then a huge current of current passes through its wires. It rushes to the ground in places with weakened insulation, mainly to household electrical appliances that are on the network. Most often, the discharge affects sockets, switches or fuse panels of the electrical network. That's why lightning rod in the house is necessary and should be thought about in advance.

Lightning protection

Make sure your home is protected

Home protection from lightning This is the task that needs to be given priority attention. Lightning entering a house can cause a fire and great destruction, since its discharge instantly releases a huge amount of energy. What protective measures can you use to feel safe during a thunderstorm?

Regulations help assess risk and identify buildings that are at risk from lightning, but do not guarantee that other buildings will be completely safe. Therefore, it is possible and worthwhile to equip a house with an external lightning protection system even if regulatory documents do not require it.

The most important elements of a lightning protection system are:

• lightning rod – serves to absorb a lightning strike; it is installed at the highest points of the roof - on the ridge, brick chimneys, etc.;
• down conductors – connect the lightning rod(s) to grounding conductors through dismountable (control) clamps and grounding conductors; down conductors are usually mounted on the side walls of the house;
• grounding conductor - connects the control terminal to the ground electrode;
• ground electrode – diverts the lightning discharge current into the ground; this part of the system is laid in the ground

The lightning rod serves to absorb a lightning strike; it is mounted at the highest points of the roof - on the ridge

Natural grounding

The cost of implementing a lightning protection system can be significantly reduced by resorting to reinforcing walls and reinforced concrete foundations to use them as elements of a lightning protection system. For this purpose, the wall reinforcement is connected to lightning rods installed on the roof, as well as to the reinforcement of the foundation bases. In this case, the base of the foundation is a natural grounding conductor. Metal pipelines laid in the ground next to the house can also be used as natural grounding conductors.

In order for the reinforcement of a house to provide protection against lightning damage, its elements must be galvanically continuous, that is, correctly connected. According to the norm, at least half of the vertical and horizontal rods must be welded along their entire length or securely connected with soft wire. The ends of the rods should overlap each other to a length equal to the sum of their diameters. It is also necessary to ensure continuity of connections between individual finished elements.

Lightning protection

Artificial ground electrodes

If natural grounding conductors do not provide sufficient protection, artificial grounding conductors are additionally installed - point horizontal and vertical, as well as ring ones, laid around the house at a depth of at least 0.5 m, no closer than 1 m from the external walls. The type of grounding conductor must be matched to the ground conditions. For example, vertical ground electrodes should be used in soils whose electrical resistance decreases with increasing depth.

The ring ground electrode can be replaced with a foundation one, which is laid after digging a pit, during the foundation work. It will be cheaper than doing it separately.

Lightning rods

To make lightning rods, you can also use building elements - in in this case metal coating roofs. But a metal coating can be used as an lightning rod if it has the appropriate thickness (see table). All metal elements of the building, such as deflectors, gutters and stairs, are connected to lightning rods.

Horizontal lightning rods should be firmly fixed at a distance of 2 cm from the roof covered with non-flammable or difficult to ignite materials. They can even be laid on its surface, provided that the flow of lightning current into the lightning rods does not lead to thermal damage to the roofing. Unfortunately, it is not possible to accurately determine the magnitude of the lightning current.

The size of the cells of mesh lightning rods laid on the roofs of residential buildings, as a rule, does not exceed 20 x 20 m, but if a higher degree of protection is needed, the cell size can be even 5 x 5 m.

Elements of external lightning protection

1. Lightning rod, which is mounted on a steep roof covered with tiles 2. Ridge bracket for tiled roof

Down conductors

They must be positioned so that they are a direct continuation of lightning rods. Down conductors should be laid in a straight line, ensuring the shortest possible distance to grounding conductors. For residential buildings, the distance between down conductors laid along the perimeter of the building should be no more than 25 m. It is always necessary to install at least two down conductors. The distances between them should be the same, and if possible, there should be one down conductor near each corner of the house.

If the walls of the house are made of non-combustible material, down conductors can be laid along the surface of the wall or inside it. If the walls are made of flammable materials, down conductors must be laid at a distance of at least 10 cm from the wall surface and attached to brackets (metal brackets can be attached to the wall).

The following can be used as natural down conductors:

• metal house structures;
• steel elements of the house connected to each other;
• facade elements, profile rails, etc.

The connection of down conductors to the grounding conductor must be made using a removable clamp (this does not apply to natural down conductors).

Two mounting methods

Lightning rods and down conductors can be fastened using a tension system or using appropriate brackets installed at least every 1 m.

Tension system. This is a fastening to a rigid base on anchors, between which a wire or cable is pulled using turnbuckles (Roman bolts). This method does not require the use large quantity holders - anchors are placed at large intervals. The lightning rod, stretched in this way on a flat roof, must be fixed at a certain distance from the roof. This can be done using, for example, plastic brackets mounted on concrete cubes weighing about 1 kg. On a roof covered with roofing felt, the brackets can be glued with mastic.

Standard method. On small houses or those with wide roofs, the use of tension lightning rods may not be possible. Then the down conductors or cables are secured in the usual way - using remote brackets. The type of bracket is selected according to the type of base:

• For flat roofs and walls, brackets are used that are driven into expansion dowels, as well as corner brackets that are fastened using breakaway rivets or screws and expansion dowels. Fastening the brackets involves making holes in the roof covering and therefore requires sealing around the fastening. Therefore, on flat roofs covered with roofing iron, roofing felt, built-up roofing felt, etc., the best solution is to use brackets that are glued with mastic or silicone glue or secured with strips of built-up roofing felt. On flat roofs, the brackets can also be fixed to specially laid small concrete blocks. Thanks to this, they hold firmly even without gluing the blocks to the coating;
• On roofs covered with ceramic tiles or similar materials, a different type of bracket must be used. Skates use ridge brackets, the dimensions of which correspond to the width of the skate. They are also suitable for ridges made of roofing iron. On a steep roof slope, you can use brackets that are placed underneath the tiles and attached to the slats. There are also brackets with a hole for attaching a wire or cable of a lightning protection system, having a ceramic base that matches the color of the tiles. Using glue, they can be glued to a base of any shape (flat, concave or convex), for example, to a tile or ridge. Of course, for this you need to use water- and frost-resistant glue.

Connections

Lightning rods, down conductors and grounding conductors must be connected to each other, as well as to individual elements of the house. Various types of connectors (clamps) are used for this. Cross connectors are used to connect system elements: wire to wire, wire to sheet metal, or two sheet metal elements to each other. Special connectors - for connecting the lightning rod to the gutter; collapsible control connections - for connecting down conductors with grounding conductors. The latter make it possible (after disconnection) to measure the electrical resistance of the ground electrodes.

Brackets and connecting elements are made of galvanized steel, copper or brass. Steel brackets have galvanized bolts and nuts, while copper and brass brackets have brass.

Special solutions

Thatched roof. The distance of horizontal lightning rods from the roof covering must be at least 10 cm, provided that special protection for flammable coatings is used. Therefore, lightning rods must be mounted on high brackets.

Small chimneys and deflectors made of plastic. To protect them, short vertical lightning rods are used, which are attached to the side wall of the chimney or to the deflector pipe using a clamp.

Superstructures with air conditioning. Small superstructures can be protected by one or more vertical lightning rods. Large ones require the use of a horizontal (one or more) lightning rod, which is stretched above the superstructure.

Solar panels on the roof. They must be equipped with separate protection in the form of a high horizontal lightning rod stretched above them.

High antennas. If the house is not equipped with an external lightning protection system, the steel antenna mast must be connected using a grounding conductor to a natural or artificial grounding conductor made specifically for grounding the antenna. The down conductor must be laid on outside walls of the house and is equipped with a control connection.

How to operate a lightning protection system at home

After completing the lightning protection system, it is necessary to draw up a passport for it - with a description of the solutions that were used, a layout plan protective elements and the first protocol of control measurements. Protocols of periodic control measurements of grounding resistances are attached to it.

It must be remembered: for the lightning protection system to perform its functions, it must be in good working order. Even minor damage must be repaired in a timely manner, since in the event of a direct lightning strike, it can cause damage to the house, and even fire. Therefore, during the operation of the system, it is necessary to carry out periodic inspections, based on the results of which protocols must be drawn up; This is especially true for external lightning protection systems.

Inspections. The simplest one is done twice a year (minimum), including once in the spring before the onset of spring thunderstorms. It should include:

• inspection of the condition of connections of the ground part of the system (lightning rods, down conductors and grounding conductors);
• inspection of fastenings of remote brackets and down conductors in these brackets;
• assessment of the degree of corrosion damage to down conductors and brackets, as well as detachable connections.

If construction work has been carried out in the house, especially roofing or plastering, immediately after completion it is necessary to carry out an additional inspection of the system and eliminate possible damage.

Measurements. At least once a year, preferably before the start of the thunderstorm period, during the spring inspection it is necessary to measure the resistance of the grounding conductors. They can only be carried out by a person with the appropriate qualifications, and their results must be included in the measurement report, attached to the passport and presented when performing the next measurements.

If an increase in grounding resistance is detected during measurements, it is necessary to quickly determine the cause and eliminate it. After repairing the ground electrode, measurements are taken again to check whether its resistance corresponds to the standard.

There are instructions that describe all the calculated norms and values ​​​​for the device lightning protection at home and structures. Depending on the type of structure, its size, location, and the average annual duration of thunderstorms in a given region, an appropriate home protection from lightning. In our country, the southern and western regions are particularly at risk.

Those most susceptible to lightning strikes are tall buildings, buildings with roofs made of flammable materials, single-family houses, and buildings located in mountainous areas or in natural areas with frequent thunderstorms. Such buildings need a lightning rod first of all.

Lightning protection on a wooden shingle roof

Within regulatory requirements Each building structure requires mandatory or recommended installation of a lightning rod. Each owner chooses the type and design of lightning protection at his own discretion, taking into account all the necessary parameters of his home.

External lightning protection system
External lightning protection system. Attic
Internal overvoltage protection. First floor

Compliant with regulatory requirements

Until recently, the regulatory document regulating the installation of lightning protection was “Instructions for the installation of lightning protection of buildings and structures” RD 34.21.122-87. The widespread introduction of new electronic equipment required significant changes in approaches to lightning protection. This document is outdated; it did not take into account the fact that the main reason for the failure of modern electronic equipment is not lightning itself, but its secondary manifestations in the form of overvoltage pulses and/or overcurrents in conductors, caused by introduced or induced voltage, electrostatics.

From 01/01/2009 a new state standard“Engineering equipment of buildings and structures. Lightning protection device for buildings and structures" DSTU B V.2.5-38:2008.

What's new? The new regulatory document introduces many new concepts and definitions. According to the classification of objects from the point of view of lightning protection, residential buildings belong to the so-called ordinary objects (as well as buildings for commercial, industrial, agricultural or office purposes).

Special objects include:

• Objects that pose a danger to the immediate environment (oil refineries, gas stations, enterprises for the production and storage of explosives);
• Objects that pose a danger to environment when struck by lightning (chemical plants, nuclear power plants, biochemical factories and laboratories);
• Objects with limited danger (fire hazardous enterprises, power plants, substations and power lines, communications equipment);
• Other objects (buildings over 60 m high, objects under construction).

Due to widespread use at sites different types electronic devices (computers, television, radio equipment, etc.), methods are proposed to protect them from overvoltage pulses that occur in electrical networks due to lightning discharges.

The regulatory document also distinguishes between external and internal lightning protection systems (LPS). An external MPS can be separate (isolated) from the structure being protected, for example, nearby structures that perform the function of natural lightning protection or a separate mast that protects a neighboring building. Naturally, an external MPS can be mounted directly on the structure being protected or be part of it.

In some cases, lightning protection may contain only external or only internal MPS.

The regulatory document contains a list of natural components lightning protection systems, that is, components of the house that can be used as lightning protection elements; This could be, for example, a metal roof covering used as a lightning rod. At the same time, the conditions under which this is possible are clarified. Basically, these conditions relate to the type of materials and their thickness.

Determining the degree of threat. The regulatory document defines criteria that must also be taken into account when determining the degree of threat of a direct lightning strike on a structure. An important indicator is the estimated frequency of direct lightning strikes on an object N, which is calculated using the formulas given in this document.

Taking into account all the criteria, a decision is made on the need to install an external lightning protection system.

We can draw a general conclusion that small and not very tall residential buildings (not towering above the surrounding area), surrounded by taller objects, usually do not require the installation of individual external lightning protection systems. But only a specialist can give a recommendation regarding a specific object.