A lightning conductor in a private house: required for construction! Do I need to arrange lightning protection in a private house? Do I need a lightning rod in a private house

How to prevent a lightning strike from hitting 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 that would allow to prevent the disaster itself, lightning protection equipment helps directing overvoltage impulses to the grounding system circuit.

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 prayer rod, a lightning rod and grounding conductors. In general, such a structure performs the functions of intercepting the incoming discharge and the subsequent discharge of electricity into the ground.
Internal lightning protection structures protect the electrical wiring in the building, as well as electrical equipment installed inside the premises from additional, secondary effects of a lightning strike (for example, pickup or current drift through the ground or from other sources). The most important component of internal lightning protection systems is an SPD. It limits surge voltages.

What types and / or classes are SPDs subdivided 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 the methods of their testing and the place where the device is installed.
The first class of SPD test operations is equivalent to the class of technical requirements under the letter "B" and Type 1; The second test class is identical to the class of requirements under the letter "C" and, accordingly, Type 2, the third class of tests corresponds to the class of requirements under the letter "D" and Type 3.

What is the difference between type 1 SPDs and type 2 SPDs?

Protective devices of the first type, as a rule, are installed at the entrance to the protected building if the power is supplied by air or if an external lightning protection system is used. In such situations, an SPD is used to divert a certain fraction of the forward discharge current. According to the specification GOST R-514352-2008, protective devices of the first type (and, accordingly, the first class of tests) are tested with current pulses having a waveform of 10 / 350μs.
Protective devices of the second type are used to protect structures from secondary, induced impulses. They are installed either near the SPD of the first type or at the entrance to the building (if the risk of a 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.

Do I need to replace the SPD or in any way check it after the end of the thunderstorm?

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

Is it necessary to install an SPD in cases where lightning protection equipment in a building or structure is installed in accordance with the standard and ground is connected to it?

Yes, it is necessary to install an SPD. An external lightning protection system is designed to discharge direct lightning strikes, but it is not able to protect equipment and wiring from the secondary effects of lightning and induced discharges. An external protection system cannot prevent the occurrence of sudden potential differences in the grounding system. A protective system installed outside the facility is not able to protect the power grid from induced impulses, which usually appear in metal structures located near the site of a lightning strike.

Where is the SPD installed: in front of the meter or after it?

If you need to protect electrical equipment and the meter from secondary overvoltages, 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 a leakage current. Therefore, it is best to choose SPDs with VG technology developed by CITEL. Such meters, firstly, do not waste electricity while in standby mode, and, secondly, they are able to reduce the voltage in the network to an acceptable level according to the third class of protective devices. The specific scheme for connecting protective equipment in front of the meter should be agreed with any department of the MZK-Electro company.

Is it necessary to install an earthing system at the facility (in a cottage) if there is a working SPD at the entrance?

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

Do I need to connect the ground loop of the cottage to the grounding of the air terminal?

Yes, it is necessary. All documents defining the installation of a lightning protection system for an object, as well as the organization of power supply for industrial facilities, require the creation of a grounding circuit that covers all protective systems of the facility. As a result, the risk of sparking or perforation of the protective system is reduced, and, accordingly, the level of safety at the facility is increased. Protective devices must be used to ensure that indoor devices are adequately protected against secondary effects following a lightning strike. When an external lightning protection system is installed in the protected building, it is mandatory to use a class 1 SPD.

What are active lightning rods intended for?

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

Country houses are usually built from combustible materials, and the fire station is far away. Yes, and you can not drive up to every building, and you should not expect anything good from a strong wind that accompanies any thunderstorm.

Sometimes from a lightning strike whole summer cottages burn out.

Let's talk about how to make an effective lightning rod on our own and minimize the risk of a direct “heavenly discharge” hitting a house.

Simplistically, the physics of the process can be described as follows: source lightning are cumulonimbus.

During a thunderstorm, they turn into a kind giant capacitors... A huge positively charged potential of ions accumulates on the upper plus part in the form of ice crystals, and negative electrons in the form of water droplets are collected in the lower minus area.

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

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

The idea of a lightning rod is to arrange it next to the house. minimum resistance area so that the lightning strike 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 its construction. 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 device (lightning protection), ensuring the safety of the building and people's lives located in it, from the destructive effects that can occur in a thunderstorm with a direct lightning strike.

it corrosion protected, a bare conductor - that is, a material that conducts electric current well with as large an area and a large 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, corners, strips, and so on.

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

What lightning protection consists of: device

A lightning rod (lightning rod) of the simplest design consists of 3 parts:

(descent).

Let's talk about each element in more detail.

A metal conductor attached to the roof of the building or to a separate support (tower). Structurally divided into three kind: pin, cable and mesh.

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

1. Pin(or rod) air termination device is a metal vertical rod that rises above the house (see the figure below).

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

Materials for making:

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

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

Any steel profile(for example, angle or flat steel at least 4 mm in thickness and 25 mm wide).

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

2. Rope the air termination 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 commonly used. This type of 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 ram clamps.

3. Mesh the device of the air termination system is a mesh laid over the roof with a thickness 6 -8 mm. This design is the most difficult to execute. Suitable for roofs, tiled.

4. Well, very rarely used covering device Lightning protection is when metal structural elements of the house itself (roof, trusses, roof fencing, drainpipe) act as lightning rods.

All considered designs of lightning rods securely connected by welding with a down conductor and through a down conductor with one- or two-side earthing 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.

The main purpose down conductor - this is to ensure the passage of the discharge current from the lightning rod to the ground electrode.

Ideal path for electric current- the shortest straight line directed strictly downward. When installing the lightning rod, avoid sharp turns. This is fraught with the occurrence of a spark discharge between closely spaced sections of the down conductor, which will lead to inevitable ignition.

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

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

It is necessary to lay it so that there were no points of contact with such elements of the house as a porch, an entrance door, a window, a metal garage door.

We know that it is better to connect parts of the lightning rod by welding, but if this is not possible, it is allowed to pair the down conductor with the ground electrode and the lightning rod using three rivets or two bolts... The length of the overlap of the down conductor on other parts of the system with a riveted connection is 150 , and with bolted - 120 mm.

The end of the non-galvanized wire rod and the place where the down conductor is attached to steel parts to ensure reliable contact need to clean up, 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 all this is tightened with a bolt as much as possible.

In addition, the joints (if this is not welding) must be wrapped in several layers with electrical tape, then with a coarse cloth, twisted on top with a thick thread and cover everything with paint.

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

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

How to properly equip grounding is described in GOST ah and SNIP ah, but for the simplest option, at least one meter from the edge of the foundation is enough and no closer 5 bury meters from the entrance to the building NS-shaped structure made of metal conductors.

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

it 3 electrodes driven into the ground and buried in the ground, interconnected at the same distance by horizontal earthing switches. Bury the grounding structure below the maximum level of soil freezing. From 0,5 before 0,8 meters deep.

For the ground electrode they take rolled steel cross-section 80 mm, less often copper section 5o mm squared. Vertical grounding electrodes are 2-3 meters in length, but the closer the water table, the shorter they are.

If the soil in your country house is constantly in a wet state, then a meter or half-meter pin will be enough.

On how deep to hammer and how many electrodes will need to be found in energy service at the place of residence.

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

Earthing switch for a lightning rod need a separate, the lightning rod should not be grounded to the household circuit. Categorically we do not recommend experimenting... Fraught with consequences.

We offer 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 it's up to you to decide whether it is advisable to install a lightning rod (lightning rod) at your dacha. We hope this article will help you make the right decision.

Lightning is a natural phenomenon that, with high power, can even kill a person. And since everyone cares about their safety, then probably everyone would like to protect themselves from the possibility of a lightning strike in their own home. But how to make a lightning rod in a private house - not many people know the answer to this question.

In order to make a lightning rod, you need to put a special device on the roof of the house, and best of all at the highest point of your house. In this case, it will be necessary to conduct a conductor and make grounding, otherwise the entire system will be ineffective.

The lightning rod that needs to be installed on the roof is most often used of two types - either a cable that is pulled along the entire length of the roof or a metal pin exposed with wooden posts.

The advantage of a lightning receiver, which is made with the help of a cable, is that it is much larger and, accordingly, it is better to use it with a large area of the house.

At the same time, it is inferior to a lightning receiver with a bayonet for such a parameter as aesthetics and compactness, since a lightning rod with a bayonet takes up much less space than a catenary wire lightning receiver.

If you decide to install the lightning receiver using a pin, then you need to observe a certain height, namely that the pin should be approximately 25-30 centimeters high, and to achieve great efficiency, you can use a larger pin.

Another interesting and important fact - if, for example, a lightning rod is at a height of 5 meters, then it will accordingly protect the house within a radius of 5 meters.

The wire on which you will need to make grounding is best used from metals such as copper or steel. It is these two metals that are most often used due to the fact that they have all the properties necessary for this.

Then, using welding, you need to connect this conductor to the receiver on the roof. The cable itself will need to be attached to the wall of the house with the help of fastening materials (as a rule, clamps are used).

Do you need a lightning rod in a private house?

Also, very often, residents of private houses wonder whether a lightning rod is needed in a private house? This primarily depends on what kind of area you live in and how often there are weather events involving lightning.

But it is best to make a lightning rod anyway, since, unlike multi-storey buildings that are protected from lightning, private houses, as a rule, do not have any protection and thus their residents put themselves in danger.

And also you can see video Installation of lightning protection, lightning protection of a country house

Before considering the process of calculating and installing a lightning rod in a private house, you need to find out the physical reasons for the phenomenon. This will allow you to better understand all 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 a lightning strike contact. The strength of the current in lightning can reach 500 thousand amperes, and the voltage is several million volts. Such a powerful eclectic discharge causes air to heat up to high temperatures, and its volume increases sharply. As a result, sound waves from lightning appear, 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, to build not a lightning rod, but a lightning rod.

Why do you need a lightning rod

Some not very competent developers think that a metal pin attached to the ridge of the house will attract all lightning bolts 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 bar on a ridge will not bring any benefit. Why?

Where can you find a wire that would withstand a current of 500,000 A and a voltage of 1,000,000,000 V? This is exactly the kind of discharge that lightning has when it meets the ground.
Why, in principle, attract lightning and guide them along the wire, risking igniting the structure due to overheating of the down conductor?
What to do if there are several buildings of different storeys in the summer cottage? Do you have to make a lightning rod system for everyone?

Output. It is necessary to install 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 hitting 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.

Lightning protection and grounding prices

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 unite and form step leaders. It is they who shine brightly and are rapidly heading towards the ground.

As we approach, the voltage of the eclectic field on the earth increases, all electrons in it rush upward and, at the highest point, throw out a reciprocal streamer towards it. It connects to the leader, the circuit closes, 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 the house.

If the earth in a given 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 old-timers. If they cannot remember the cases of lightning striking any objects, then there is no need to mount a lightning rod.
The house is located on lands that can accumulate a charge, lightning strikes in this area are not uncommon. 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 aims to minimize the direction of lightning step leaders into the building area. And for this there is only one condition - the electric potential of the land in this area should be minimal and necessarily much lower than on the neighboring ones. This task must 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, the lightning finds other points of energy drainage.

Important. If lightning has hit the lightning rod, it means that it is not installed correctly and instead of doing good it brings harm.

The size of the protected area depends on the number and quality of the grounding rods, they collect electrons and send them through wires to the vertical rod of the lightning rod. From there, electrons gradually pass 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 the lightning rod is clear, the tasks of each element of the system are clear, you can start installing the protection of the house.

Step-by-step installation instructions

As it 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 go to work only after calculating the number, size and location of 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. Fold back 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 the skates of various sizes, while the reliability of the fastening remains the entire period of operation, spontaneous unscrewing is completely excluded.

Step 2. Fasten the holders of the down conductors to the ridge. If you buy an industrial-made lightning protection system - great, it has all the elements you need 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, it is necessary to ensure that the wire does not touch the roof covering. Try to fasten at the same pitch, so the system looks much better and does not negatively affect the appearance of the house.

Practical advice. Always work with a safety rope on roofs, especially for metal surfaces. If it is not possible to purchase industrial equipment for climbers, then make the elementary ones yourself.

Tighten the lambs (nuts) tightly, use open-end wrenches or pliers. Remember that it is difficult to correct the mistake later, you will have to climb onto the roof again. Make sure that all vertical wire posts are in a straight 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, thereby significantly improving performance.

The wire will not rust and brown streaks will not appear on the roof. Traces of rust greatly impair 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 junction points, resistance decreases; during operation, it does not deteriorate the physical and electrical characteristics.

You should not save 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 nippers.

Step 5. Spread the threaded connections with special mastic, if it is not there, 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 metal requires protection for openings.

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

Single wave metal roof tiles. It is necessary to slightly release the screws, lift the sheet and insert the mounting bracket into the gap formed. It has a curved leg that fits 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 the tabs.
Piece tile. 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 tiles, thereby increasing the strength of the fastening. Then you should raise 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 roof 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 sheathing. 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 self-tapping washer.
Flexible bituminous shingles. This roof covering has a solid base, which greatly simplifies the technology of fixing the brackets. They are screwed to the surface with ordinary wood screws; rubber pads 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 point of 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 the down conductors.

Prices for holders for down conductors

Holders for down conductors

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

Down conductors installed on the house are connected to the ground.

Manufacturing grounding

This is the most important element of a lightning rod, as already mentioned above, only a specialist with 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 burial for each ground. Depending on the size of the house, a specific location of ground electrodes is selected.

Voltage stabilizers prices

Surge Protectors

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 oxides negatively affect the current conductivity. The cross-section and surface area of the rods must be selected with a margin, and resistance measurements should be made 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 soils; decisions are made by a specialist at the place of work.
All ground connections are best done by welding, clamps quickly lose their initial resistance values. Welding is done on both sides, the seam length is at least five centimeters.
Professionals advise using a metal strip with a thickness of at least 1 mm and a width of about 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 area of contact with the ground.

To make or not to make a lightning rod is the business of every developer. Strict requirements are established 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 lightning strikes were taken away from the building and what is the efficiency of the device.

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 need to carefully analyze all the factors that affect the likelihood of a lightning strike in 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 meet the existing building codes.