Lightning protection of a private house.
This article expresses only the subjective opinion of the author and cannot serve as a basis for making a decision. The presented material is intended only for reasonable consideration before making a decision on installing lightning protection (lightning rod) for a private house on a limited budget. The article will not be about industrial facilities or large apartment buildings. The article is based not only on a professional value judgment, but also on practical experience in eliminating the consequences various kinds Emergency situations caused by increased voltage.
The material is not teaching aid and is specially written in accessible language.
Is this topic relevant for the Moscow region?
Definitely yes. Lightning - This is a powerful spark discharge, reaching a length of 321 km and having not only colossal voltage, but also enormous current. A lightning strike in a house can pose a huge danger not only of destruction and fire, but also of fatal electric shock to people in the house. And thunderstorms are not uncommon for the Moscow region. To carefully assess the risk and make a decision about installation or refuse - there must be smart choice everyone. The most pressing topic is protecting your home from lightning damage in regions where the intensity of thunderstorms exceeds more than 80 hours per year.
The topic is controversial and controversial
Installing a lightning rod (lightning protection) when your neighbors do not have one is turning your own home into an artificial lightning rod. But more voices are inclined to install such devices. It's up to you to decide.
Is lightning protection necessary? country house?
It is not customary to discuss this topic on forums, since there is no single point of view on this matter in the professional community. A definite answer is given only by manufacturers of special lightning protection installation kits or sales agents country houses, selling lightning protection as an additional option.
The likelihood of lightning striking the house.
There is no exact formula that can be used to estimate the likelihood of your home being hit. Lightning is a phenomenon characterized by unpredictable behavior, and where it will strike is unknown. You need to know that according to some data, 30% of lightning reaches the ground.
The risk of a building being struck by lightning can be significantly affected by:
- Geographical location (high or low)
- Humidity
- The height of the building itself relative to its neighbors
- Presence of tall trees in the immediate vicinity.
What can “attract” lightning?
Towers cellular communication, tall antennas, tall trees, etc.
Important!
Lightning protection is a special installation (homemade) kit designed to protect (mitigate) the consequences of a lightning strike in your home, but you need to know that not every house burns when struck by lightning. An artificial lightning rod can be taller buildings nearby, electrified poles or lighting masts, and lightning rods from neighbors. The thicker all the elements of lightning protection, the more reliable it is. It is impossible to calculate the force of a lightning strike.
It is important to know that there are no legal conflicts in terms of prohibiting the installation of a lightning protection system in private ( country house). There is no fine under the Code of Administrative Offenses for the absence/presence of lightning protection. This means that you can freely install such protection yourself or hire an installation team. There is no point in having the illusion that any team will do a good job. Often, such types of work are seasonal (summer, autumn) and teams are recruited by advertisement. Such workers receive a small percentage from the organizer, and the quality of installation is sometimes depressing. As a rule, the warranty for installation of lightning protection is 1 year.
What is the simplest lightning protection (lightning rod).
Any lightning protection kit consists of:
— grounding (where the lightning discharge “goes”, hence the corresponding name)
— lightning rod (thick steel pin receiving discharge)
— a special current conductor (a current conductor through which the discharge instantly moves from the lightning receiver to the ground)
A thick metal rod is installed on the highest part of the roof, a steel wire with a thickness of at least 6 mm is attached to it and connected to grounding.
Grounding is done from metal pins or corners according to the principle, the deeper, the better. The pins (corners) are scalded with a 40 mm metal strip. Coloring the grounding is prohibited; only the coloring of welding areas is allowed, since such places rot quickly. Once every few years, the grounding needs to be checked with a special device, a megaohmmeter, to check its performance. Remember that metal in the ground tends to rot and do not forget to monitor the condition, your own safety may depend on it.
Grounding for the lightning rod is done separately from the grounding loop of the house. There are standard ready-made grounding loops available for sale.
If the house is wooden, it cannot be installed close to the house. Use special clamps. There is a high risk of fire, so keep your distance.
Active lightning protection.
It differs from the simplest in its ability to ionize air and due to this, the highest protective effect is achieved. I won’t talk about it - it’s not for pleasure an ordinary dacha due to high cost.
Internal lightning protection.
It is necessary to understand that a lightning strike nearby can cause a significant voltage surge, which can damage all modern electrical appliances. This is a more widespread phenomenon than a direct lightning strike on a country house. Most effective way It's just cutting off power to the house. Those who have the financial resources to install an SPD (surge protection system).
The SPDs themselves can be different types, but any SPD consists of a varistor (nonlinear resistor). A necessary thing in everyday life, the resistance of a varistor is nonlinear and depends on voltage. During an abnormal voltage surge, the resistance of the varistor drops to zero and the surge current goes to ground. Installing an SPD without a ground loop is pointless. We will talk about the SPDs themselves in the next article; In any case, it is necessary for a summer resident to have an understanding of surge protectors and varistors.
In what cases should you first take care of protecting the roof?
Few people know that roofs made of newfangled metal tiles and corrugated sheets (or simply galvanized) can pose a danger to humans if they are not grounded. It's about wooden houses. Such roofs are capable of accumulating an electric charge as a container, and if a person touches them, they can be electrocuted. Any charge is a spark that can ignite roofing felt or wood. In such cases, it is necessary to ground the roof. All available metal elements on the roof (vane) must be connected to the roof with a conductor.
Lightning rod and safe area.
Each lightning rod has its own safety zone. According to the generally accepted rule, it is calculated using the formula:
1.5*H, where H is the height of the lightning rod. This is a reasonable safety zone. It's not worth checking for yourself. In the event of a thunderstorm, seek shelter and stay out of open areas.
Besides, lightning rod can be done not on a house, but on a tree under the following conditions -
a) Grows no closer than 3 meters to the house,
A private house is always a sea of troubles and worries, especially in terms of its arrangement. For example, when we build our own housing, we try to make it the most reliable and durable, so that trouble does not happen to it, like with the houses of Nif-Nif and Nuf-Nuf. Therefore, everything is important: the choice of construction technology, the selection of materials, and design features future building. A lightning rod also plays an important role in a private house.
Protection from natural disasters
Today's news is simply full of various events related to disasters. And one of the most dangerous things for humans is lightning. If it gets into the house, it can lead to a fire, and therefore there must be a lightning rod in a private house. According to the laws of physics, lightning is a spark of electrical origin. To reach the ground, it looks for a metal conductor. And elements such as antennas, metal chimney, zinc roofing can cause lightning to strike them. And this can lead to trouble.
It is to protect the house from such dangerous consequences that a lightning rod is installed in a private house. Ideally, it should be built on a separate tower, so that in the event of a lightning strike, the strike would fall not on the house, but on the tower itself. But before you build a lightning rod, you need to do certain calculations. First, you need to find a place for this structure. As a rule, for this purpose they choose the piece of land that is most distant from the residential property. Secondly, the height of the lightning rod plays an important role: it should be at least two meters higher than the building, but not too high.
Tower installation
To install a lightning rod in a private house, you need to build the tower itself. Its design can be any, the main thing is that there is space in the middle of the tower - the grounding conductor will be laid here. Clamps are installed at the tops of the tower, a copper or aluminum rod is attached to them, which is connected to the ground. The finished tower must be dug into the ground to a depth of at least two meters. After strengthening the structure, lightning protection and grounding are connected. To arrange grounding around the tower, you need to draw a triangle with equal sides. Reinforcement is dug into its tops to a depth of about two meters - it serves as Then they should be connected to each other with metal rods. The last stage of work is connecting the lightning rod conductor to grounding.
In order to correctly and competently build a lightning rod in a private house, a diagram is simply mandatory: it will help to avoid possible errors. In addition, it is important to carry out all connections carefully and responsibly - only in this case will it be possible to protect your home. It is best to cover the conductor with corrugation - this will help prevent oxidation, which will reduce the conductive properties. The tower also needs to be painted to protect it from corrosion.
A lightning rod in a private house is an important component of the safety of living there. This structure is especially relevant for open areas or areas located on hills. It is worth thinking about a lightning rod for a country house - this will allow you to timely protect your home from one of the most dangerous elements.
Lightning is natural phenomenon, which at high power can even kill a person. And since every person cares about his own safety, probably everyone would like to protect themselves from the possibility of lightning striking 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 place 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 in two types - it is either a cable that is pulled along the entire length of the roof or a metal pin exposed using wooden posts.
The advantage of a lightning rod made using 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 an air terminal using a bayonet due to such parameters as aesthetics and compactness, since an air terminal using a bayonet takes up much less space than a cable lightning rod.
If you decide to install a lightning rod using a pin, then you need to maintain a certain height, namely that the pin should be approximately 25 - 30 centimeters in height, and to achieve greater efficiency, you can use a larger pin. 
Another interesting and important fact is that if, for example, a lightning rod is located at a height of 5 meters, then it will accordingly protect the house within a radius of 5 meters.
The wire through 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 located on the roof. The cable itself will need to be attached to the wall of the house quite firmly using fastening materials (usually 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 area you live in and how often weather events involving lightning occur there.
But it is best to make a lightning rod, since unlike multi-storey buildings, which are protected from lightning, private houses, as a rule, do not have any protection and thus their residents expose themselves to danger.
And you can also look video Installation of lightning protection, lightning protection of a country house
Reliable lightning rod for summer cottage will not only protect a person from lightning, but also a house from fire, especially if it is wooden. Consists of good system lightning protection consisting of a grounding conductor, down conductor and lightning rod. Next, we will tell readers what all the elements of the system should be like and how to make a lightning rod in a private house with your own hands!
How the system works
First, let's figure out how lightning protection for a private home works and what is needed to create it. You can clearly see all the components of the system in this diagram:
As you already understood, the metal rods on the roof are lightning rods that discharge a dangerous discharge to the ground through a down conductor and a special one.
There is an opinion that if a telephone tower is installed near the house, there is no need to install a lightning rod in a private house. This is wrong, because... It’s better to spend a little time and ensure yourself complete protection from lightning strikes. So that you know what a lightning rod should be like and how to make it correctly with your own hands, below we will separately consider the features of choosing each of the system elements.
Brief overview of lightning protection installation
Components of protection
Lightning rod
The main task is to choose the right lightning rod, which should provide complete protection country house in its coverage area. Today, a pin, mesh, cable, or the roof itself can act as a lightning receiver. Let's take a closer look at the features of using each option in a private home.
As for the pin, there are ready-made products from manufacturers that have suitable shape and convenient fastening. As a rule, the metal used to make the lightning rod is copper, aluminum or steel. The most suitable and effective is the first option. In order for the receiver to cope well with its task, its cross-section must be at least 35 mm 2 (if copper) or 70 mm 2 (steel rod). As for the length of the rod, in domestic conditions it is recommended to use receivers with a length of 0.5 to 2 meters. The pins are convenient to use to make a lightning rod on garden house, bathhouse or other small building. 
Metal mesh can also be sold in already finished form. As a rule, a mesh lightning rod is a cellular frame made of reinforcement, 6 mm thick. The cell size can range from 3 to 12 meters. Most often, this type of lightning protection is used in apartment buildings and large buildings, for example, shopping centers. 
The cable is more practical at home and does the job better than the mesh. To make a lightning rod in a private house using a cable, you need to stretch it along the roof (along the ridge) by wooden blocks, as shown in the photo below. The minimum diameter of the cable for lightning protection of a building must be 5 mm. As a rule, this option is used if you want to make a lightning rod on a house with a slate roof with your own hands. 
Well, the last option - the roof as a receiver, can be used if the roof of a residential building is covered with corrugated sheets, metal tiles or other metal roofing material. With this type of lightning rod, two important requirements are imposed on the roof. Firstly, the thickness of the metal must be at least 0.4 mm. Secondly, there should be no flammable materials under the roof. Make a lightning rod in a private house with metal roof can be done much faster and at the same time saving on the purchase of special lightning rods.
Please note that if you use a mesh, it must be installed at a height of at least 15 cm above the roof itself!
Down conductor
Ground electrode
Well, the last element of the lightning rod is the grounding circuit. In order not to make the material too voluminous, we have dedicated a separate article to this issue -. We recommend that you read the information so that you know all the intricacies of this stage.
In short, we can say that the grounding loop should be located next to the house, but not in the walking part of the site, but, on the contrary, closer to the fence. The charge is discharged to the ground by metal rods buried in the soil to a depth of 0.8 meters. It is better to place all the rods according to the diagram, which is exactly shown in the photo: 
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 protecting 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 the building, as well as electrical equipment, installed indoors from additional, secondary effects of a lightning strike (for example, interference or current drift through grounding or from other sources). The most important component internal systems lightning protection - 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 through the air or if it is used external system lightning protection. 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 that usually appear in metal structures located near the lightning strike site.
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. Specific connection diagram protective equipment before the meter should be agreed 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 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 - they have a much larger radius of the protective zone.
