No one is safe from money or prison, and even more so from a lightning strike. After a blinding flash and a deafening roar, the most pleasant thing is to get away with a slight fright and delight from the impressions you experienced. It's not good if the electronics in the house burn out. It's even worse when there's a fire. It is completely unacceptable for a person to be struck by lightning. The conclusion is simple: we make a lightning rod!
A lightning strike to a house cannot be called beautifulWhere does lightning come from?
The reason for this is cheerful clouds, which, as a thunderstorm approaches, gradually grow and turn into dark cumulus-type masses. The upper layers of moisture in the air turn into small ice crystals, while the lower layers remain as water droplets. This is how we got two plates of a giant capacitor.
Huge structures move in the air and are charged as a result of friction: the upper layers accumulate positive ions, the lower ones – negative electrons. There is a limit to everything, and the accumulated potential turns into an electrical discharge. As a result, it “breaks through” where there is the least resistance: tall trees, roofs of houses and... lightning rods!
How does lightning protection work?
From the above, the strategy for a lightning protection device follows: to direct a possible electric discharge along a path that is safe for us and thus insure ourselves against troubles. For this purpose, an lightning rod is installed at a sufficient height, which is designed to capture a lightning discharge.
Lightning rod device diagram Next, an electric current of about 100,000A passes through the down conductor to the ground electrode. The latter ensures the connection of the protective system with the ground. Thus, the lightning strike bypasses the protected objects and is absorbed by the ground.
This protection system is widespread and is called passive. There are active lightning rods that have an ionizer that provokes a lightning strike. This increases the likelihood of protecting the target from damage. This type of lightning rod costs a lot, and its installation is difficult to do with your own hands.
Lightning rod options for a private house
There are three main types of lightning rods based on the type of design:
- rod lightning rod;
- in the form of a grid;
- cable lightning rod;
- roof covering as a lightning rod.
You can purchase a pin lightning rod or make it yourself An air terminal in the form of a rod is the most famous and widespread. There are industrial products with ready-made fasteners. For those who like to create with their own hands, it is possible to make an elegant structure that decorates a building. In any case, a steel pin must have a cross-section of at least 70mm2, and for a copper product 35mm2 is sufficient. Thus, its diameter can be 7-10mm.
The length of the rod can vary between 0.5-2 m, and it must protrude at least half a meter above all objects surrounding the building. The lightning rod accepts the charge at one point and is especially effective in protecting small buildings.
Lightning rod in the form of a mesh is convenient for a large roof An air terminal in the form of a mesh is made of wire with a diameter of about 6 mm. In the photo you can see what a structure of this kind looks like in practice. There are already ready-made structures with a cell size of 3-12 m. This type of lightning protection is convenient for use on the roof large area. To prevent the fire of the sheathing, the lightning rod is mounted at a distance of 0.15 m from the roof surface.
The cable lightning rod can be conveniently placed on the ridge In a private home, it is more convenient to use an lightning rod in the form of a cable. It is mounted on the roof ridge, secured to two supports on opposite gables. It is also possible combined option, when pin lightning rods are installed on the mentioned supports in addition to the cable.
The cable must have a diameter of more than 5 mm and be mounted at a safe height from the roof. This type of construction is usually used on a roof with a non-metallic covering.
Seam roofing as a lightning rod Metal roofing roof, with certain conditions, can also act as a lightning rod. In this case, the thickness of metal tiles, corrugated sheets or galvanized sheets must be at least 0.4 mm. It is tempting to provide lightning protection without using additional materials.
In practice, this is not easy to do, since there should be no flammable materials under the decking, while the sheathing is most often made of wood.
Moreover, it will be necessary to connect the down conductor to each individual sheet of coating, which is labor-intensive. This option is suitable for seam roofing, where the metal sheets are already securely connected. In this case, ignition of the sheathing is impossible if the coating is laid on a metal sheathing.
How does a down conductor work?
Ideally, for a self-made structure, the material of the lightning rod, down conductor and grounding conductor should be the same and connected by welding, that is, steel. This solution ensures reliability and durability of protection. In practice, it is possible to use galvanized and copper-plated elements, as well as various materials. Their connection is ensured by using clamps with bolts and nuts.
Down conductor on the roof, wall and basement of the house A steel conductor in the form of a rod or strip must have a cross-section of at least 50mm2, an aluminum conductor allows a size of 25mm2, and a copper wire can be used with a cross-sectional area of 16mm2, which approximately corresponds to a diameter of 8.6 and 5mm, respectively.
The down conductor is placed so that it connects the lightning rod and the ground electrode along the shortest path.
In this case, sharp bends are not allowed, which can lead to a spark discharge and ignition in this area. For the same purpose, the conductor is placed at a distance of at least 100 mm from the surfaces of combustible materials of walls and other elements of the building.
Requirements for the ground electrode
This is what a ground loop ready for testing looks like: Please note that it is not recommended to use a protective ground loop to connect a lightning rod. If a common grounding conductor is used during a lightning discharge, dangerous voltage may arise on the surfaces of household appliances. To protect electrical wiring and household appliances in a private house from lightning strikes, surge protection devices (SPDs) are installed on the input switchboard.
Grounding for the lightning rod is placed no closer than 5 m from the porch and paths and the horizontal connector is buried at least 0.8 m. This is necessary to reduce the likelihood of injury to people in the event of a lightning discharge.
Lightning rod protection zone
You should not be under the illusion that a lightning rod on a neighboring house or a metal tower located nearby will completely protect your home from a lightning strike. The lightning rod's protective zone has very specific boundaries. In any case, the dacha will have to arrange its own lightning protection.
The size of the protected zone is determined by the height of the lightning rod placement The safety cone created by the rod lightning rod has an angle of 45-50°. This rule is valid for lightning protection installation heights of up to 15 m. The above sketch shows that at an angle of 45°, the radius of the protective zone is equal to the height of the top point of the rod above ground level. At a value of 50° the protection zone will be slightly larger.
Thus, the higher we place the lightning rod, the larger the area of the protected surface will be.
Anyway, a private house must fall completely within the protection cone area.It is highly desirable that all buildings in the yard be protected according to the same rule. Thus, it is convenient to place a lightning rod on the roof of the house. It can be easier to fix the pin on one side of the building than in the center, and the likelihood of lightning hitting the roof is reduced.In the case of a large area, it may be necessary to install another lightning rod. It can be mounted on a special mast.
We install lightning protection with our own hands
First of all, you need to select an air terminal in accordance with the above recommendations and the materials at hand. The easiest way to install an ordinary steel pin on the roof of a country house. Galvanized pipe or aluminum rod will work even better. When using a pipe, its upper end should be plugged.
If you have a piece of cable of the required length and diameter, it will not be difficult to stretch it along the ridge. On a large roof area it is more effective to use a grid option. An air terminal of any design should be secured so that it is not disturbed by the wind.
Please note: it is easier to ensure electrical contact of the entire system by making all three components of the lightning rod from the same material.
If you do not have welding in mind, it is easier to make a down conductor from thick copper wire in accordance with the recommendations above. A reliable connection to the lightning rod can be ensured using galvanized clamps with bolts and nuts. It is practical to secure the conductor to the drainpipe supports.
Dimensions of the ground loop in the form of a triangle It is best to install a grounding loop where there is the least likelihood of people being present. It is also beneficial to place it in a place where moisture is always present. This will improve the contact of the ground electrode with the ground. It wouldn't hurt to install a warning sign next to it. It is better to make a bolted connection to the ground electrode above the ground on the base of the building, and provide contact in the ground by welding.
After installing the entire system, the electrical connection from the lightning rod to the ground can be checked with a multimeter. The resistance of the ground loop can only be checked with a special device. Its value should be no more than 10 Ohms if there may be people nearby. For a separate lightning rod installed far from the house, the grounding resistance should not exceed 50 Ohms.
Standard device for measuring ground resistance At least once a year, it makes sense to check the integrity of the entire system visually. Once every few years, you should dig up the grounding and assess the degree of metal corrosion. If the rods in the ground become noticeably thinner, they need to be replaced.
The tall tree will help us
To set up a lightning rod in your dacha, you can use a tall tree growing nearby as a mast. The lightning rod should be fixed to its crown so that it protrudes at least 0.5 m above the crown. It should not be forgotten that the tree grows and changes its size.
Pyramid poplar will protect the house from thunderstorms This means that the lightning rod and down conductor should be secured with plastic clamps that will not damage the barrel. It is better to use flexible stranded copper wire and it should be laid with a spare length. In addition, once every few years you will have to climb up and move the lightning rod above the top of your head.
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Lightning protection project Lightning protection project is one of the steps for quality and correct execution complex of works on lightning protection of buildings and structures. This type of documentation requires correct and meticulous calculation and execution for the safety of the building as a whole. Of course, for the...
Measuring the resistance of the grounding loop Measuring the resistance of the grounding loop is one of the components of the entire complex of works on organizing a lightning protection and grounding system. Our company carries out measurements of ground loop resistance in Moscow and the Moscow region with on-site...
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Active lightning rod Gromostar 25 (protection radius 25 meters)
Active lightning rod Gromostar 25 (protection radius 25 meters). The new technology company Gromostar - Gromostar, develops active lightning rods based on own technology and has significant success both in the Russian and European markets. This lightning rod has its own successful design and has proven itself as high-quality and proven equipment. Easy to install and has a thread for mounting on an M16 mast. This company has its own laboratory for conducting tests and is also quite popular all over the world. All products of this Gromostar company have patents for all products and also all quality certificates and warranties. This type of product has proven itself quite widely in the field of private and industrial construction due to its affordable price and constant technical support. Based on the installation height of the lightning rod, you can achieve greater safety results from lightning damage to your structure. This concept allows you to significantly save on installation work and significantly speeds up the execution of all work on installing lightning protection. If necessary, you can equip your lightning rod with a lightning strike counter, which will additionally allow you to monitor the health of the equipment. Our specialists will promptly and free of charge, according to your project, help you calculate and recommend the required model suitable for your building and will also be happy to select all the necessary components for installing the entire system and provide all the necessary installation recommendations. Also, by contacting us, we can provide you with all additional equipment for quality work the entire building or structure. Gromostar provides comprehensive technical support and assistance to all clients, both with advice and additional equipment in the field of security of buildings and structures.
Below are special tables for studying the radius of the lightning rod depending on the height. In any case, we recommend that you contact our specialist for quality advice and the correct choice of appropriate equipment.
Gromostar 25 m Can be supplied in either steel or a special copper alloy.
Specifications
Protection zones of the Gromostar 25 active lightning rod, for various protection categories and height H
(in accordance with EN62305-2 NFC 17-102)ΔT [μs]
H 2 m
H 3 m
H 4 m
H 5 m
H 7 m
H 10 m
H 20 m
25 I 17 25 34 42 43 44 45 25 II 20 29 40 50 50 52 55 25 III 23 34 46 58 58 63 65 25 IV 26 39 50 66 66 69 75
This type of product is unique and comes with an original warranty card and, at the customer’s request, can also be equipped with all technical documentation on installation. If necessary, our specialists will carry out professional installation with an on-site visit and can also measure the resistivity of the entire system with the execution of a work report and warranty obligations. If necessary, our company can equip your entire facility with all the necessary additional materials for the entire cycle of work on lightning protection of buildings and structures.Active lightning rod SCHIRTEC S-AS (protection radius up to 30 meters)
Lightning rod SCHIRTEC S-AS (protection radius up to 30 meters)– designed for installation in buildings and structures for protection against lightning strikes and direct hits to the building. Made of high quality stainless steel and has a special contact group for testing functionality. High quality is confirmed by ISO 9001:2008 and ISO 14001:2004 certificates. These active lightning rods can be installed on almost any structure. Installed on an air-termination mast, the recommended height for installation is 5-6 meters. It has a high protection radius and can be used for several buildings at the same time.Schirtec is an Austrian research company that also has several points for studying lightning protection systems, distinguished by the use of special alloys for the manufacture of systems, very high quality execution. Decent design and control systems, lightning strike counters and testers. They occupy a fairly large market segment in the field of lightning protection in private buildings. At this stage, in our opinion, they are the most in demand in the private construction segment on the Russian market.
Active lightning rod INDELEC PREVECTRON 3 S40 (protection radius up to 80 meters)
Active lightning rod INDELEC PREVECTRON 3 S40(protection radius up to 80 meters), depending on the height of the mast.The latest generation lightning rod is distinguished by its special quality and modular system manufacturing, is one of best in the world and has a full set of certificates of all international systems, also has a certificate from RosTechNadzor (certificate RRS 00-05003). This certificate allows you to use this equipment at any facility with increased security and any protection class; these types of lightning rods are the only ones in Russia with such an issued certificate. Special alloys, special quality control, and complete control over production make this product truly unique. The lightning rod can be used both in industrial systems and in private buildings. Has additional equipment for use - a lightning strike counter and special tester for check. The company's specialists always provide technical support and installation advice. It is installed on the mast depending on the calculation and has a direct connection to the conductor.
Prevectron Indelec is a company that can safely be called a leader in the development of lightning protection systems for buildings and structures, France, has several special laboratories around the world and conducts high-quality experiments in this area. The developments of this company are in great demand all over the world. These lightning rods are installed on all best buildings world, improvements are constantly being made and this type The product has the highest level of quality. New design, the use of the best modern technologies gives this product the highest quality rating.
Specifications:
Efficiency - ΔT 40 μs (advanced when triggered)
Standard. Deviation ACT/PAS σ σPDA< 0,65 σPTS
Withstand lightning strike -(wave 10/350μs) Iimp 100kA (regulatory test)
Max. shock withstand - Imax 207 kA (Unicamp)
Net weight P 3 kg
Principle of operation
Downward Leader Detection - Continuous Electrical Field Measurement(ΔE/Δt)
Conditions for the development of ascendant streamer - Optimax® - patented technology
optimizing the conditions for streamer development -Trigger Sparking due to impulsehigh voltage
Internal circuit - 3 independent synchronized modules
Center tip - Continuous electrical conductivity315 mm² sections – nickel-plated copper
Metal body Stainless steel steel 316, electronic magnetic shielding
Performance Testing - Special Tester
Maintenance - Replaceable modules
Warranty period - 5 years
Mechanical characteristics
Mast mount - M20 thread
Connection to down conductor - Special connector included
Package
Dimensions - 438 x 228 x 220 mm
Accessories included: Down conductor connector, hex key
Weight - gross 4.75 kg
Material - 100% recyclable
Certification
NF C 17 102:2011, Annex C Certificate Bureau Veritas N°6275241/2/1/3
Qualifoudre Certificate Ineris N° N°051166662001
One of the latest achievements in this area can be considered active lightning protection. It is a system using active lightning rods. Such protection is much more economical and does not require special care. At the same time, buildings and structures retain their presentable appearance, and do not turn into an object covered with many wires.
One of the modern representatives of lightning protection systems is an active lightning rod, which has a number of advantages.
- First, it charges itself from the surrounding electrical field, meaning there is no need for an external power source.
- Secondly, he has enough simple design. To protect an object from lightning discharges, it is enough to install a lightning rod, rather than entangling the building with networks of wires. In Moscow, this fact is especially important for buildings of architectural value. In addition, the likelihood of damage to the lightning rod by snow or ice is minimized, which means you will not have to pay for constant repairs and maintenance.
- Thirdly, active lightning protection applies not only to the object itself, but also to surrounding buildings. The radius of action depends on what type and at what height the head is installed on the active lightning rod.
Passive lightning rods are one of the most common materials in lightning protection. Their classification consists of height and thickness and also some design features
Lightning protection of buildings and structures is an important element of ensuring the safety of administrative, industrial and residential buildings. A negligent attitude to this issue can lead not only to serious damage to property, fires, failure of expensive electrical appliances, but also cause colossal harm to human health. This is also evidenced by statistics from the Ministry of Emergency Situations: about 30% of fires occur due to lightning strikes. Despite this, practice shows that many buildings and structures in Moscow do not have enough reliable protection from such a serious natural phenomenon as lightning. Some of the complexity comes from the fact that lightning cannot be predicted or prevented. But this should not become a reason for inaction. Modern science offers current solutions. In a certain area, lightning can be controlled using special equipment, preventing destructive consequences.
Following regulatory documents that specify the requirements for lightning protection of buildings and structures, most often elementary lightning rods and grounding are designed and installed, which can fully guarantee safety.
Designing lightning protection is a serious job that must be performed by specialists. There is a certain set of parameters that can affect efficiency. They should be taken into account when designing. First of all, this is the height of buildings, roof design, type of building materials and throughput soils. To ensure reliable protection of buildings and structures, this data is analyzed and the optimal solution is proposed.
Today there are two types of lightning protection:
- Active lightning protection. This operation is ensured by active lightning rods, which are capable of generating high-voltage pulses, creating an artificial leader. It captures lightning at a great distance from the object and directs it to the ground, providing reliable protection.
- Passive lightning protection. This traditional look, which assumes a direct hit of the discharge into the lightning rods and its safe grounding.
Thus, lightning protection of a private home always provides protection and the choice of system is always yours or, better yet, specialists based on economic conditions.
Installation of lightning protection for a private house Lightning protection and installation price directly depend on the area of the house and the type of roof. Before starting installation, of course, a routine inspection of the roof is carried out and the installation location of the lightning rod is determined, as well as the location of the installation of conductors and fastenings for non..
In this article you will learn:
- What are the dangers of thunderstorms and lightning strikes for private households?
- What types of lightning protection are there in a private home?
- What does the standard composition of a lightning protection system include?
- Passive or active lightning protection? Advantages and disadvantages
- Basics of external moniment protection for a private home
- What are the categories of structures according to the degree of lightning protection?
- Materials used and corrosion issues
- What is the smallest permissible distance (separation gap)
- What should a lightning rod be like?
- How to choose a down conductor? Types of down conductors.
- How to properly attach lightning protection elements? Roof and facade holders, holders for drainpipes, terminals and connectors, grounding fastening elements
- How to choose grounding
- How to properly connect the grounding system to the down conductor of the lightning protection system
- Features of the monie protection system for different types and roof configurations
Atmospheric electricity has enormous potential, thousands of times greater than the capacity of man-made installations. In a thundercloud, a potential difference of up to 10 million kilovolts can be created, the discharge current reaches 200,000 amperes, it is possible to protect yourself from such a force, which causes large-scale destruction, without special protective systems does not seem possible.
The danger of lightning for private homes
The saturation of homes with electronics, household appliances and means of receiving over-the-air transmission channels has sharply increased the likelihood of lightning exposure, which is explained physical features electrostatic forces. A lightning discharge entering an unprotected structure not only damages Electricity of the net and devices, the greater the risk of fires, the cause of which is lightning in every fifth case. Protection against lightning damage to private houses is entirely in the hands of the owners, which cannot be a reason for refusing a lightning protection device, given the dire consequences that befall unprotected houses.
Types of lightning protection
Currently, two types of protection against the effects of lightning discharges have been developed in detail and are used: external and internal protection.
External lightning protection
It is a well-known lightning rod in the form metal rod, towering above the roof of the house. Such protection consists of three main elements.
1. Lightning rod - a metal rod, which can be steel, copper or aluminum.
2. A down conductor, which uses a metal conductor that connects the lightning rod to grounding.
3. Grounding, consisting of steel grounding conductors buried in the ground, connected into a single circuit using metal buses.
In fact, a conductor is used for all three elements different sections, the minimum values which are selected in accordance with the material used according to the following table:
Depending on the type of roof and roof configuration, in addition to the rod receiver, a steel cable stretched over the protected object or a special mesh can be used (see pictures below), or even a combination of these elements can be used.
External protection systems are increasingly being used, using an active method of searching for and removing lightning discharges in the early stages of their development (read about this a little below).
Internal lightning protection
Currents resulting from lightning flow through resistor and inductive connections, causing overvoltages that can melt microcircuits and damage electrical equipment. To protect against such consequences, SPDs are used - devices for protecting internal networks from surge voltages. The magnitude of the impulse overvoltage depends on the location of the lightning strike, and therefore, there are overvoltages of type I (induced by a direct lightning strike) and type II (induced by an indirect strike). Type I overvoltages are especially dangerous because they are 10–20 times higher than type II overvoltages.
Standard composition of a lightning protection system
To protect a private home from the damaging effects of lightning, a standard set of means is used:
- External protection with lightning rods, down conductors and grounding;
- Protection against the introduction of high potentials by potential equalization;
- Protection against overvoltages (internal overloads) using arresters or surge protectors.
From the above list, the greatest differences are in the methods of external protection, which can be active and passive, and with passive protection they have significant differences depending on the roof configuration and the type of roofing covering.
Active lightning protection
In recent years, active lightning protection has been gaining popularity. Its spire has a special head - an ionizer, which generates a counter flow of electrons. As a result, lightning is attracted, after which the resulting discharge is discharged through a down conductor into the ground, where it is extinguished. Active protection is distinguished by a large radius of the protected zone, which is 8 times greater than the protection radius of a passive lightning rod of the same height.
Active protection characteristics provide a significant reduction in consumables for roofs with complex configurations, as well as equipment installation time. Looks aesthetically pleasing appearance masts with an ionizer, there is no need to ground individual metal structures located under the hood of the protective zone.
Among the disadvantages of the active method, one can note the short period of its use, which does not make it possible to talk about many years of positive experience. Moreover, in Lately More and more cases of lightning strikes are being recorded in objects with active lightning rods, and manufacturing companies are being sued in connection with this.
External lightning protection device for a private house
When installing lightning protection for private houses, the principles and protection designs set out in special literature must be used (“Instructions for the installation of lightning protection...” SO 153-34.21.122-2003 and RD 34.21.122-87).
The severity of the destructive effects of lightning depends on the presence on the affected object of gases, dust, vapors, or mixtures thereof that can explode upon contact electric spark. Important factors classification of buildings into classes (or lightning protection categories) are: the expected estimated number of lightning strikes into an object, its value, the threat to human life and the surrounding environment. Therefore, private residential buildings, cottages and garden houses are considered to be classified in Group III of buildings in which there are no such dangers.
Depending on the degree of reliability, 4 classes of lightning protection are adopted:
- first - reliability of more than 99% (for example, ammunition depots, gas stations, refineries);
- the second - from 95 to 99% (large enterprises that pose a threat to the environment);
- third - from 90 to 95% (retail, office and residential buildings);
- fourth - at least 85% (buildings in which there is no electrical wiring and constant presence of people).
Corrosion problems
Metal elements of external protection are constantly exposed to weather conditions, which cause corrosion. Slow down metal destruction and ensure long service life structural elements protection can be done using the following methods:
- The use of metals that are less susceptible to corrosion is stainless steel, copper or aluminum;
- The use of protective galvanic coatings, the most common of which is galvanizing;
- For bolted connections - stripping the metal at the point of contact, tightening it tightly and using conservative lubricants;
- The choice of an oversized cross-section of metal structures relative to the calculated indicators, which affects the cost of the system.
You can read more about components and materials for lightning protection and grounding of houses, the features of their use in our large review material on this page.
The rate of corrosion development is affected by the incompatibility of certain metals. Thus, copper has very poor contact with galvanized steel and aluminum, so such contacts should be avoided. To connect incompatible materials, special clamps are used, in which the ends are made of different metals.
Minimum allowable distance
Currents induced in metal conductors by lightning discharges can cause a spark discharge. Distance between down conductors and metal elements must be such as to prevent sparking, this is the smallest permissible distance, designated by the letter S.
In addition, there are also requirements for maintaining the distance between the fastening elements of the lightning protection system, the location of down conductors relative to window openings, doors and other building structures. You can get more detailed information in the material on how to properly lay down conductors.
If metal structures, fences, facade elements, pipes are located closer than 1.0 meters from down conductors and do not have a conductive connection with the structures of the protected building, such elements must be connected directly to the lightning protection system.
Requirements for lightning rods
Stage 4. We draw conclusions from lightning rods to future down conductors. Important clarification! To increase the efficiency of the system, the ends of the conductor on the skates must be 15 cm longer and bent slightly upward.
An example of a lightning protection device for a private house for a flat roof
For flat roof We use the "lightning mesh method".
Stage 1. First of all, in those areas where the probability of a lightning strike is greatest, and this is the edge or protrusions of the roof, we plan a conductor that will act as an lightning rod or the basic contour of the lightning rod mesh.
Stage 2. Similar to the previous example, we find the protection angle, transfer it to the drawing and check whether all elements of the structure are covered by the protective zone.
Stage 3. Actually, we supplement our contour with grid cells based on the fact that for buildings of class III lightning protection, this size should be no more than 15x15 meters, that is, if the perimeter of your house is no more, then it will be enough to leave only the basic contour, otherwise we recommend dividing the entire space into equal cells and lay the conductors in this way.
Stage 4. If the roof has additional protruding elements, then we supplement the lightning protection device with lightning rods for the corresponding elements according to standard rules.
Basic lightning protection schemes for typical projects
The figure below shows lightning protection options for several typical house designs (click to enlarge).
It is worth noting that in three variants the conductor on the skate is raised to a certain height. This indicates that the angle of inclination of the roof is greater than the angle of protection, and some part of the building does not fall within the protection zone. In fact, this is the simplest version of a cable lightning rod.
The shown grounding circuits should not be considered as focal ones; they are depicted only conditionally (for more details, see above).
Owners of private residential buildings constantly wonder about providing their property with various types of protection, including from lightning. The need to erect an absorbing device is usually dictated by the climate in a certain region, and if in a particular area there is high level precipitation with thunderstorms, then installing a lightning rod is considered advisable. Since purchasing and installing this device can be quite expensive, it is better to do it yourself.
The choice of the type of planned lightning protection should take place not when the construction of a private residential building has already been completed, but at the project development stage. This will allow you to make the absorbing device according to all the rules, and also save time and financial resources. The principle of operation of a lightning rod is that a powerful electric charge sent to the ground for repayment, protecting structures from destruction.
If a private house is located in an open area far from neighboring structures, if it is located on a hill, or if there is even a small body of water nearby, then a lightning rod must be installed. At the same time, the device itself must be reliable, taking into account all factors that may affect the absorption of a high electrical discharge. IN in this case You can opt for a lightning rod tower. This type of lightning protection will have its highest point high enough to prevent lightning from striking the house itself. This type of device is more expensive, but there is no doubt about its reliability.
If the house is located near tall towers, buildings or near power lines, then this place is less susceptible to such natural influences. In this case, lightning protection can be done on the house with a special circuit and grounding under the house. Both types of structures can be made with your own hands. To do this, you need to obtain special knowledge about performing this type of work, purchase consumables for the construction of a lightning protection device, make a diagram of its location and grounding location.
When choosing the type of device to protect a building from lightning, you should take into account the type of soil on which the house stands. Different types of soil have different electrical conductivity as well as resistance levels. Depending on the soil resistance, the cross section is selected metal sheet for grounding and the size of the buried circuit. Also, the type of lightning protection will depend on the initial condition of the building. Typically, lightning strikes the highest point of the house or the nearest tall tree. Antennas, poles, trees serve as a shield during a lightning strike. In this case, people, cars or other objects may fall into this affected area.
Video “Pros and cons of a lightning rod”
How to do it yourself
A complete home protection system against high discharge consists of external and internal protection. The internal one is needed to prevent a sharp surge in voltage in the electrical network. A surge suppressor can work even if lightning strikes several kilometers from the house. External protection will ensure the safety of the residential building itself and the people in it. In order to make lightning protection with your own hands, you need to know that an effective device must consist of the required elements - a lightning rod, a down conductor, and a grounding loop. If necessary, you can use a support.
Lightning rod. This part is a regular metal rod. Its length can be from 25 cm to 1.5 meters. It is usually installed on the roof, forming the highest point on the house and surrounding area. Also, the lightning rod can be installed on a chimney or on a television antenna. Any highest point of the building is suitable for attaching a metal rod. This method is suitable for houses with metal roofing. Suitable material is strip steel or 60 mm 2 at round section rod. When installing an air terminal with your own hands, you should know that it should only be placed in a vertical position.
If the roof is made of slate or fired tiles, then such a receiver can be made with your own hands from metal flexible cable 6-7 mm thick. He's being pulled over wooden supports 1.5-2 meters high, and then protected with insulators.
Down conductor. This part of the lightning protection structure can be a thick wire of 5 mm in diameter. Galvanized steel is well suited for wire, as it has good characteristics. The down conductor is placed in the place where lightning is most likely to strike. For example, this could be the pediment of a private house. It should not be attached close to the wall, but at a distance of 15 to 20 centimeters. You need to be especially careful if the roof or other parts of the building are made of flammable materials. For fastening, you can use nails, clamps or staples.
Grounding. The last element of lightning protection is necessary to conduct a powerful electric charge into the ground. The choice of material should be made in favor of a metal that has good electrical conductivity with a low resistance value. The grounding is located at a distance of about 5 meters from the walls of the house or porch, no less. It is not recommended to install it near paths or other places where people may be. This place can be fenced off for greater security (at least 3 meters from the ground electrode).
Then you need to determine the depth to which the ground will be placed. This value is usually more individual than other indicators. This may be influenced by the type of soil, as well as the presence of groundwater. Groundwater makes grounding more effective. In dry soil, grounding should be done to a depth of 2 to 4 meters. You can make 2 rods with your own hands, connect them with a wide jumper, and secure the workpiece by welding to the down conductor. Then bury the ground electrode into the ground.
In wet or peaty soil, grounding can be done at a depth of 80 cm.
The decision to build a separate tower to protect a building from lightning strikes is usually made if there is space for this on the territory and there are no such devices in the surrounding area. This method may be more expensive, but no less effective. It is also quite easy to understand the design.
Choosing a place for a lightning rod
Experts recommend erecting a lightning rod at a distance of several meters from the house. For example, the outskirts land plot. In this place it will not interfere, but will not lose its purpose. You should not place this type of lightning protection at a distance of more than 100 meters. A similar problem can be solved by cooperating with the owners of neighboring plots, since a lightning rod can provide lightning protection to several houses at the same time, or even a dozen at once.
The lightning rod must be placed so that its highest point rises above the houses by at least 2 meters. In this situation, there is a directly proportional relationship - the higher, the better. But in order not to attract extra charges, you should not make it too high.
Installing a tower
The material for mounting the tower can be metal corners that can be welded together. If you make a structure with your own hands, then its appearance is an individual decision. The most important thing is that there is a void in the core where the grounding conductor will be placed.
Clamps for attaching copper and aluminum rods are welded to the lightning rod. They are then connected by a separate conductor, which will subsequently need to be connected to the ground loop. Then a hole 2-2.5 meters deep is dug and the tower itself is dug in. If the height of the house is about 5 meters, then the tower with the receiver rod should be at least 7 meters.
Grounding
When installing a tower, grounding is done in a slightly different way. On the ground you can draw a conventional equilateral triangle (side 1.2-1.5 m). At the corners of the triangle, vertical grounding conductors should enter the ground, the lower end should enter the ground 2.5 meters or deeper, and the upper end half a meter from the surface of the earth. Grounding electrodes can be made of reinforcement or copper rods with a flat surface (which is very expensive). Vertical grounding elements are connected to each other by horizontal ones underground. The tower itself is installed in the center of this triangle.
The last stage of installing a lightning rod in a private house is connecting the circuit to grounding. This point is very important. To prevent the conductor itself from oxidizing, it must be covered with corrugation. This will reduce the charge permeability. The receiver rod can be regularly cleaned with your own hands when signs of oxidation of its surface are noticeable.
The need to install a lightning protection system for a private house is determined by the owner of the building based on the likelihood of the object being struck by lightning and the possible material damage. National regulatory documents do not impose requirements for the mandatory implementation of the MH system for individual residential buildings.
The likelihood of a lightning strike on an object depends primarily on the duration of thunderstorms in the area where it is located.
Increase
For a rectangular house with dimensions of 10x12 m and a height at the ridge of 8 m, this relationship is shown in the table:
| Average annual duration thunderstorms in hours | Probability of a lightning strike to a house 10x12x8 m* |
| 10-20 | 1 stroke in 332 years |
| 20-40 | 1 stroke in 166 years |
| 40-60 (Moscow and region) | 1 stroke at 83 years old |
| 60-80 | 1 stroke at 60 years |
| 80-100 | 1 stroke at 47 years old |
| 100 or more | 1 stroke at 39 years old |
The complex of lightning protection means for buildings includes devices for protection against direct lightning strikes (external lightning protection system) and devices for protection against secondary effects of lightning (internal lightning protection system). In particular cases, lightning protection may contain only external or only internal devices.
System external lightning protection protects directly from direct lightning strikes on an object. This exposure is primarily dangerous high temperature lightning channel, which can lead to fire of combustible building structures.
You can learn more about the dangers posed by a lightning strike in the series of articles “Lightning Protection for Beginners” by Professor E. M. Bazelyan.
Composition and design of components of an external lightning protection system
The external lightning protection system consists of three components: lightning rods that absorb a direct lightning strike; a grounding device that ensures the flow of current in the ground, and down conductors that communicate between the first two elements.
Lightning rods
The choice of the number and height of lightning rods should be made by calculating protection zones. The design protection zone of installed masts must include the entire volume of the protected object.
The protection zone of a rod lightning rod is a cone, the top of which coincides with the vertical axis of the mast. The dimensions of this cone depend on the required reliability.
The dimensions of the protection cone in accordance with SO 153-34.21.122-2003 “Instructions for the installation of lightning protection of buildings, structures and industrial communications” for a reliability of 0.9 are determined by the formulas:
Single protection zone rod lightning rod:1 - border of the protection zone at level h x, 2 - the same at ground level
Installing a free-standing mast to protect a house will not be advisable, due to the fact that its height must be substantial (up to 30 meters). This is not only expensive and labor-intensive, but also increases the total number of lightning strikes to the area of land in question. It would be optimal to place masts directly on the protected object.
Installing one mast may only be sufficient for a house with a hip (pyramid) roof when placing the mast at the top of the roof.
For a rectangular house with a gable roof (roof slope angle of at least 35°), for reliable protection it is necessary to install two masts 2 meters high along the edges of the roof ridge. For a house of a more complex shape, it is necessary to carry out calculations taking into account the structurally possible locations for installing lightning rods.
Lightning rods must be made of materials and dimensions (sectional area, thickness) corresponding to GOST R IEC 62561.2-2014.
Down conductors
The diameter of down conductors made of round steel must be at least 8 mm. Down conductors must be positioned in such a way that between the point of damage and the ground, the current spreads along several parallel paths, and the length of these paths is minimal. It is recommended to lay down conductors at the maximum distance from doors and windows.
Direct contact of a down conductor of the required cross-section with the material of the walls and roof cannot lead to fires, due to the fact that the increase in the temperature of the down conductor under the influence of lightning current is not enough even to begin the process of charring wood, not to mention other low-flammable materials. In addition, the thermal effect is very short-lived.
Grounding device
In all possible cases, it is necessary to use metal foundation piles or interconnected reinforcement as a grounding device reinforced concrete foundations building. This decision applicable if connection is possible (presence of fittings outlets) and when bitumen and bitumen-latex coatings are used as waterproofing. Epoxy and other polymer coatings prevent electrical contact between the foundation and the ground, and, therefore, this foundation cannot be used as a natural ground electrode.
Artificial ground electrodes should be located under asphalt pavement or in rarely visited places away from pedestrian roads.
The grounding device to which the lightning rod is connected must have the following minimal design:
Three or more vertical electrodes with a length of at least 3 meters, united by a horizontal electrode, with a distance between the vertical electrodes of at least 5 meters.
Grounding electrodes should be located outside the protected object and be as distributed as possible. The preferred depth of electrodes is at least 0.5 m, the distance from the walls of the object is 1 meter.
The dimensions of grounding conductors must meet the requirements of corrosion and mechanical resistance. Regulatory documents (GOST R 50571.5.54-2011) provide the minimum dimensions of electrodes depending on the material from which they are made.
Notes
* The probable number of lightning strikes per year for an object is calculated using following formula:
Where:
A - building length, m
B - building width, m
H - building height, m
n - average annual number of lightning strikes per 1 km 2 earth's surface, 1/(km 2 *year)
Specific Gravity n is determined based on the average annual duration of thunderstorms in hours as follows:
| Average annual duration | Specific density of lightning strikes into the ground n, 1/(km 2 *year) |
| 10-20 | 1 |
| 20-40 | 2 |
| 40-60 | 4 |
| 60-80 | 5,5 |
| 80-100 | 7 |
| 100 or more | 8,5 |
Lightning strike period:
External lightning protection components
Traditional vertical lightning rod in the form of a two-meter (GL-21101G) or four meter (GL-21103G) mast, comes with a screw-on sharp tip.
The mast is made of stainless steel in the form of a pipe with a wall thickness of 2 mm.
GL-21101G GL-21103G Weight: 5 kg 10 kg Height: 2000 mm 4000 mm Lightning rod diameter: 35 mm 35 mm Wall thickness: 2 mm 2 mm
The clamp allows you to quickly attach a down conductor wire with a diameter of 8 mm to the façade/wall of a building.
The clamp with rubber grommet allows you to quickly secure an 8mm diameter down conductor wire to a roof covered with metal profile/ corrugated sheet.
There is NO screw included (example in the photo).
A clamp with the ability to disconnect the external lightning protection system (down conductors) from the grounding device (for example, for taking measurements). Allows you to connect down conductors made of D8 wire in a straight line.
ZANDZ and GALMAR
GALMAR and ZANDZ grounding rods are made of steel coated with a protective copper coating with a thickness of at least 0.250 mm, which ensures a guaranteed service life of the device of up to 100 years.
The design of the rods, which can be interconnected and immersed in the soil to a depth of up to 40 meters, ensures the achievement of low resistance grounding to small area. Installation is carried out by one person without the use of construction and specialized equipment.
Modular grounding can be purchased both in the form of ready-made kits and in the form of separate components.
You can find detailed information about modular grounding technology on a separate page.
An example of lightning protection for a private house based on GALMAR and ZANDZ products
On the right side of the page there is a list of products, using which you can organize a complete system of external lightning protection. All offered products comply with the requirements of national regulations for minimum sizes, quality of contact connection, mechanical strength, service life, etc.
Lightning rods are mounted on vertical surfaces of walls or chimneys, ventilation shafts. When placing masts, you should take into account the size of the overhang of the roof slope over the walls and check the possibility of using holders 21101G/21102G.
Most of the clamps for down conductors are available in two versions: galvanized painted steel and copper. The current conductor is fastened using clamps in increments of 1 meter. The type of clamps is selected based on the surface of placement (roof: flat, slope, ridge; facade, etc.) and its material (metal profile, natural tiles etc.). Please note that façade and roofing clamps are not included anchor bolts. Their type and length must be selected depending on the base material.
It is also possible to attach down conductors to drainage system at home (attachment to gutter, pipe).
The grounding device is assembled from components of a modular grounding system.
An example of a complete set of products for lightning protection of a rectangular house with dimensions 8x10 m, height at the ridge of 8 m, roof slope angle 35°. The roofing material is metal tiles, the wall material is wooden beams.
A=10 m; B=8 m; H=8 m; α=35°;
Nkr=3.5 m; Nst=4.5 m; Lsk=6.1 m
Lightning rods are connected to each other to organize two down conductors from each lightning rod.
| Lightning rod | ||
| GL-21101G | GALMAR Vertical lightning rod (lightning rod-mast) | 2 pcs. |
| GL-21202 | GALMAR Holder for lightning rod - mast GL-21101G to the wall ( stainless steel) | 2 pcs. |
| GL-20022 | GALMAR Clamp for lightning rod - mast GL-21101G for down conductors (stainless steel) | 2 pcs. |
| Down conductor | ||
| GL-11149-10/20/50 | GALMAR Copper-coated wire (D 8 mm / S 50 mm²; coil 10/20/50 meters) | 40 m |
| GL-11551A | GALMAR Clamp for connecting down conductors (painted galvanized steel) | 6 pcs. |
| Clamps for fastening down conductors on the roof | ||
| GL-11564A | GALMAR Ridge clamp for down conductor with its elevation above the clamp by 15 mm (painted galvanized steel) | 11 pcs. |
| GL-11747A | GALMAR Clamp for a roof covered with a metal profile / corrugated sheet, for down conductor (painted galvanized steel) | 12 pcs. |
| Clamps for fastening down conductor outlets | ||
| GL-11703A | GALMAR Facade clamp for down conductor with a rise of 15 mm (painted galvanized steel) | 10 pieces. |
| GL-11562A | GALMAR Control clamp for connecting down conductors wire + strip (painted galvanized steel) | 2 pcs. |
| Grounding device | ||
| GL-11075-10/20/50 | GALMAR Copper-plated strip (30*4 mm / S 120 mm²; coil 10/20/50 meters) | 20 m |
| ZZ-001-065 | ZANDZ Copper-plated threaded grounding pin (D14; 1.5 m) | 6 pcs. |
| ZZ-002-061 | ZANDZ Threaded coupling | 4 things. |
| ZZ-003-061 | ZANDZ Starter tip | 3 pcs. |
| ZZ-004-060 | ZANDZ Guide head for jackhammer attachment | 1 PC. |
| ZZ-005-064 | ZANDZ Clamp for connecting conductor | 5 pieces. |
| ZZ-006-000 | ZANDZ Conductive lubricant | 1 PC. |
| ZZ-008-000 | ZANDZ Jackhammer attachment (SDS max) | 1 PC. |
If you have any difficulties in calculating or selecting components, you can always contact our technical center for help.