How to properly perform a lightning rod in the country. We protect the house from lightning - we make a lightning rod with our own hands. Lightning protection - external protection
A private house and country cottages are often located in open space, where the buildings themselves are the only elevation. Because of what, during the thunderstorm period, there is a significant threat of lightning hitting buildings. Such a situation threatens not only electric shock to all people in it, but also the possibility of fire, which will lead to a fire and significant damage to property. Since no one can foresee the place where the discharge will strike, the most effective way to prevent its negative consequences is a lightning rod.
That is why it is important for most owners of private houses and summer cottages to install a lightning rod with their own hands. An exception may be buildings located in a lowland, the roof of which is below the top of the ground or falling into the protection zone of a neighboring building and its lightning rod.
The device and principle of operation of a typical lightning rod
Figure 1: lightning rod deviceThe whole design of the lightning rod is represented by three elements: a lightning rod, a down conductor and a ground electrode. Depending on local conditions and your preferences, each of them may have a different design. Now we will analyze why each of them is needed, and which option to choose in a given situation.
Lightning rod
Its purpose comes from the very name of this element; in fact, it acts as an electrode that receives an electric lightning discharge. The main criterion for it is good conductivity and thermal stability, since the current value can reach 100 - 200 kA, which can easily burn through thin conductors. As a lightning rod can be installed:
- bar structures;
- lattice;
- cable;
- the roof surface itself.
Rod lightning rods can be installed either directly on the roof itself or on a special metal mast. At the same time, their height should provide the necessary protection zone for all structures of the building. Therefore, such a lightning rod is relevant for buildings with a small area and height.
Rice. 2: lightning rod Such rod devices can be copper, aluminum or steel. The first two have good resistance to corrosion damage, due to which such a lightning rod practically does not lose conductivity and cross section even during long-term operation. The metal pin made of steel, unlike the previous two, is much less prone to melting from the flow of high currents, which is why it is much better suited for areas with frequent lightning strikes.
Rice. 3: mesh lightning rod The grid as a lightning rod is used for a large area, for example, multi-storey buildings or shopping centers. Unlike the previous version, it does not affect the design of the building, so it can be used in any modern exteriors. Such a lightning rod must have a given cross section and cell size, as a rule, reinforcement of at least 6 mm 2 is selected. Its installation is carried out at a safe distance from the roof (at least 15 cm) through thermally insulating load-bearing structures.
Fig 4: wire lightning rod A lightning rod is a flexible wire that is stretched over a protected area or building. Allows you to protect a long section at a lower cost of materials for a lightning rod. It is carried out both on free-standing supports and on the roof of a country house. In the first case, the supports are installed at the beginning and end of the section, and in the second, at the beginning and end of the roof.
If conductive options are used as roofing material (corrugated board, metal tiles and others), they can be used as a lightning rod for a lightning rod. However, the following conditions must be met:
- the thickness of the metal layer is at least 4 mm for steel, 5 mm for copper or 7 mm for aluminum;
- there are no flammable materials under the roofing material (insulation, rafters, etc.);
- the outside of the metal is not coated with a dielectric material.
Making a lightning rod from a metal roof allows you to save money on a lightning rod.
Down conductor
It is a conductor that diverts electric current from the lightning rod to the ground electrode. It can be made of metal wire or tire. Must have a cross section of at least 16 mm 2 if made of copper, 25 mm 2 of aluminum, 50 mm 2 of steel. The following requirements are imposed on the current collector:
- Must be isolated from walls and other structures of the house;
- For him, the shortest path for the flow of current is selected;
- Absence of bends and coils, on which breakdown of the air gap can occur;
- Sufficient conductivity at electrical connections.
If necessary, the down conductor is isolated from the surface of the house using a cable channel or in any other way. This procedure is especially relevant for buildings with conductive finishes or combustible surfaces.
grounding conductor
It is made in the form that is buried in the ground. The material used is steel or copper elements that are buried in the ground. It is formed from reinforcement or tires, the requirements for which are established by clause 1.7.111 of the PUE and are given in Table 1
Table 1
| Material | Section profile | Diameter, mm |
Cross-sectional area, mm | Thickness walls, mm |
| Steel | Round: | |||
| black | 16 | — | — | |
| 10 | — | — | ||
| Rectangular | — | 100 | 4 | |
| Angular | — | 100 | 4 | |
| Trubny | 32 | — | 3,5 | |
| Steel | Round: | |||
| galvanized | for vertical grounding; | 12 | — | — |
| for horizontal earthing | 10 | — | — | |
| Rectangular | — | 75 | 3 | |
| Trubny | 25 | — | 2 | |
| Copper | Round: | 12 | — | — |
| Rectangular | — | 50 | 2 | |
| Trubny | 20 | — | 2 | |
| Multiwire rope | 1,8* | 35 |
All parts of the ground loop can either loop and form a closed circuit, or line up in a continuous line. Of course, the closed version is considered more reliable. The dimensions of the contour are selected depending on local conditions.
Rice. 5: earthing switch installation example The main requirement for the ground loop is to provide the specified value of the metal-to-earth transient resistance, therefore it is better to place it in a wet layer, periodically water it or treat it with materials that reduce the transient resistance and increase the spreading current area (charcoal and salt). According to clause 1.7.103 of the PUE, the resistance should be no more than 5, 10 and 20 Ohms for networks with a phase voltage of 380, 220 and 127 V, respectively.
The location of the ground electrode is made no closer than 1 m from the walls and 8 m from the footpaths. Since at this point a step voltage arises that can inflict an electric shock on anyone who is within the radius of the affected area, therefore it is strictly forbidden to approach the circuit during a thunderstorm, as well as to touch its current-carrying elements.
Training
At the preparatory stage, before installing lightning protection, it is necessary to calculate the parameters of the future lightning rod and select all the elements. This will allow you to determine whether the buildings will fall into the protection zone and what parameters need to be changed in case of shortcomings.
Protection zone calculation
If the lightning protection device provides a grid or a roof surface as a receiver, then the protection zone will completely cover the building. But for wire and rod lightning rods, it is necessary to calculate the protective zone.
Rice. 6: lightning rod protection zone Look at the figure, the protection zone is a cone in space, where the probability of a lightning strike is significantly reduced. To determine the parameters of this cone in relation to the lightning rod itself and the building, a calculation is made. Methods for calculating the lightning rod zone for each type are performed on the basis of SO 153-34.21.122-2003.
Rice. 7: parameters of the protection zone of the lightning rod Look at the figure, the following parameters are shown here:
- x and y are the distance from the installation site of the lightning rod to the contour of the building boundary.
Depending on the installation height of the lightning rod and the required reliability, a formula for determining the zone it protects is selected. To do this, use the data from table 2
table 2
| Reliability of protection | Lightning rod height h, m | Cone height h 0, m | Cone radius r0, m |
| 0.9 | 0 to 100 | 0,85h | 1,2h |
| 100 to 150 | 0,85h | (1,2-10 -3 (h-100))h | |
| 0,99 | 0 to 30 | 0,8h | 0,8h |
| 30 to 100 | 0,8h | (0.8-1.43 10 -3 ( h-30))h | |
| 100 to 150 | (0,8-10 -3 (h-100))h | 0,7h | |
| 0,999 | 0 to 30 | 0,7h | 0,6h |
| 30 to 100 | (0.7-7.14 10 -4 ( h-30))h | (0.6-1.43 10 -3 ( h-30))h | |
| 100 to 150 | (0,65-10 -3 (h-100))h | (0.5-2 10 -3 ( h-100))h |
To determine the radius of the lightning rod zone at a certain height, the formula is used: r x \u003d r 0 × (h 0 -h x) / h 0
Rice. 8: lightning wire protection zone The figure shows a schematic diagram of the protection zone for a cable lightning rod with its small length. At large distances, due to poor tension at the midpoint, sagging may occur, which will slightly distort the boundaries of the area protected by the lightning rod.
Rice. 9: Parameters of the protection zone of the lightning rod Look at the figure, here the lightning rod zone is characterized by the following parameters:
- h is the height of the lightning rod itself;
- h 0 - the height of the protection zone of the lightning rod;
- h x - height at a certain point (set at the level of the roof of the building);
- r 0 is the radius of the lightning rod protection zone on the ground;
- r x is the radius of the protection zone of the lightning rod at the selected point;
- L is the length of the lightning rod.
According to the required reliability, depending on the height of the lightning rod, the parameters of the protection zone are calculated using the formulas from Table 3.
Table 3
| Reliability of protection | Lightning rod height h, m | Cone height h 0, m | Cone radius r0, m |
| 0.9 | 0 to 150 | 0,87h | 1,5h |
| 0,99 | 0 to 30 | 0,8h | 0,95h |
| 30 to 100 | 0,8h | (0.95-7.14 10 -4 ( h-30))h | |
| 100 to 150 | 0,8h | (0,9-10 -3 (h-100))h | |
| 0,999 | 0 to 30 | 0,75h | 0,7h |
| 30 to 100 | (0.75-4.28 10 -4 ( h-30))h | (0.7-1.43 10 -3 ( h-30))h | |
| 100 to 150 | (0,72-10 -3 (h-100))h | (0,6-10 -3 (h-100))h |
The radius of the lightning rod zone at the height of the building is calculated by the formula: r x \u003d r 0 × (h 0 -h x) / h 0
The choice of material for the lightning rod
As a material for a lightning rod, it is customary to use three options: copper, aluminum and steel. Copper lightning rods are characterized by a long service life and are distinguished by the ability to maintain their parameters throughout the entire installation period, even in underground areas. But the main disadvantage of a copper lightning rod is its high cost.
Aluminum is characterized by much less weight, therefore, it creates an insignificant load on the supporting structures of the building. It also has good electrical conductivity. But, over time, it is subject to destruction from atmospheric factors and is easily amenable to mechanical deformation.
Steel is the most durable, they easily withstand wind loads, and the elements of such a lightning rod can be connected by welding, unlike copper and aluminum. It is also characterized by low cost. The disadvantages of a steel lightning rod are high resistivity and susceptibility to corrosion.
Installation location
To install a lightning rod, the highest point should be selected. Therefore, it is placed on the roof of the building, if its height is not enough to get the entire building into the protection zone, special supports or nearby trees can be used. To determine the actual installation location of the lightning rod, it is necessary to plot the protection zone obtained during the calculation on the site plan.
Rice. 10: protection zone on the building plan The roof is the most advantageous option, since the peak of the protection zone will be located above the building. A free-standing support or several allows you to move the area protected by a lightning rod to the desired point on the site, and is great for situations where buildings are dispersed on the site. The use of wood as a support allows you to save on the purchase and installation of a metal or reinforced concrete structure, but causes a number of difficulties during operation, therefore it is considered an undesirable option.
Step-by-step instructions for making a lightning rod
The simplest options for a country lightning rod are rod and cable, you can implement them yourself. To avoid mistakes and extra costs when installing a lightning rod, follow the following sequence.
Rod
To build a rod-type lightning rod, perform the following manipulations:
The distance between them and their height is selected so that the conductor does not sag to the surface of the roof and walls.
Rope
Installation of a cable lightning rod is carried out identically. Depending on the specific situation, the cable can be stretched with a flexible cable between supports or mounted on brackets. In the first case, the lightning rod will sag when the tension changes, so mounting a rigid copper or steel wire on a bracket is much more profitable. This procedure is performed in the following sequence:
After completing the installation of any of the proposed types, be sure to check the resistance of the entire structure. Ideally, the test is performed using a bridge, but at home, a regular multimeter or test light will do.
Video instructions
Recently, we are increasingly faced with situations where lightning strikes houses and, due to the lack of appropriate protection, a fire occurs. To prevent this and protect yourself, you can make a lightning rod with your own hands.
At the same time, such a device will be quite functional and productive, if, of course, it is correctly mounted. It is worth saying that although the lightning rod has a fairly simple design and with free time and the necessary materials, anyone can make it, nevertheless, you need to take into account many factors to determine the correct installation parameters, since it is important not only to have protection for your home and electrical appliances, but also to be sure of its correct functioning.
How does a lightning rod in a country house work?
A lightning rod is a special installation that attracts an electric charge of lightning to itself and redirects it from the house through a conductor to the ground. Thus, lightning will not cause any damage or harm. The lightning rod consists of two blocks:
- outdoor;
- internal.
The outdoor unit is a current collector (lightning rod) connected to a current conductor (down conductor), which together perform the role of receiving and distributing the lightning charge, as well as a ground electrode that dissipates this charge in the ground.
The indoor unit will protect your home from power surges, and, therefore, prevent the failure of electronics. Probably, everyone has heard that if the electric charge of lightning has a large force, then all electrical appliances in the house burn out.
So there is another reason to make a lightning rod.
Lightning rod rules
For the correct choice of the scheme for the device of a country lightning rod, it is first necessary to study the structure of the building and, in accordance with the "Instruction for the installation of lightning protection for buildings and structures" (Instruction RD 34.21.122-87), determine the required level of protection. Low and small in size private houses usually belong to category III lightning protection.
An effective lightning protection is one that reliably protects the building and everything inside it from direct lightning strikes and from its secondary discharges in electrical networks. A country lightning rod is usually a lightning rod, which is connected to ground using a system of down conductors.
Lightning rod
A device that directly receives a lightning strike is called a lightning rod. This is the most noticeable and significant element of the scheme of an industrial or country lightning rod. There are rod, cable, mesh receivers.
The most popular and famous thanks to Benjamin Franklin is the lightning rod, which is a metal pin made of stainless steel, aluminum or copper. It is usually installed 2 m above the highest point of the protected building. This type of lightning rod is the simplest in execution and quite cheap.
A cable lightning rod consists of two masts installed along the perimeter of the protected object, and tensioned steel cables between them. A lightning protection network is a grid of metal rods laid on the roof of a building with a certain step.
For small private houses, a metal roof can be an excellent lightning receiver. If the roof of the house is made of a different material, then it is better to choose a lightning protection mesh for the protection device, and active protection is often used for wooden country houses.
Down conductors
The current flows to the grounding device through down conductors. In accordance with the above Instruction RD 34.21.122-87, down conductors in a residential building can be various building structures made of steel, aluminum or copper (frames, fire escapes, reinforcement of reinforced concrete slabs). Special down conductors are usually laid outside along the perimeter of the building with a step of 25 m. The efficiency of down conductors depends on the continuity of the electrical network. Usually they are connected to the lightning rod and grounding devices by welding.
grounding
The lightning charge in the soil is dissipated with the help of grounding devices. In accordance with Instruction RD 34.21.122-87, they are most often reinforced concrete foundations or vertical electrodes that go deep into the ground. The latter type of grounding is necessarily protected from corrosion (therefore, it is usually made of copper-plated or galvanized steel), and the electrodes are securely connected to the horizontal bus and to each other using special connectors.
Making a lightning rod in the country with your own hands
So, if you have come to the conclusion that you want to make a lightning rod for a country house with your own hands, then you need to know how this device is made. First you need to make a rod pantograph, to which a current conductor will then be attached, which can be made from ordinary iron wire. Just choose a wire of the largest possible cross section, for example 6-8 mm. Also, the current conductor connects the current collector with the ground loop.
The ground loop can be made from a strip of iron about 4x50 mm in size. The electrode should be made of a steel rod, choosing for this a diameter of at least 18 mm. Please note that all connections should be made only with a welding machine. If you do not have such an opportunity, then you can use bolted steel clamps, but such connections will be less effective.
2) Handicraft fastener material during the passage of lightning current with a high degree of probability can not withstand huge temperatures and simply melts. Therefore, it is always necessary to know the parameters of the materials used and perform the necessary calculations. But it is easier to buy ready-made components from lightning protection manufacturers, especially since the prices for fastening elements, especially domestic ones, are acceptable. Plus, you will receive the necessary advice from experts in competent installation.
3) There is such a rule: you either make isolated lightning protection and maintain the required breakdown distance, or connect all metal elements together and bring them to ground. Here the author uses insulators and, accordingly, the first method, which means that the air gap between the receiver/down conductor must not be less than the minimum distance R, which in this particular case should be 300-400 mm, which is not noticeable. Without grounding and also a roof, a dangerous potential difference is guaranteed to occur here.
4) The option of a grounding conductor in the form of a single pin stuck into the ground cannot be considered reliable at any soil resistance, especially since the down conductor through which the discharge from the lightning rod comes is also the only one. Even in the days of the USSR, with a complete lack of knowledge and design parameters of soil resistance, focal grounding was always made in the form of a triangle or a U-shaped contour.
The main typical schemes of country lightning rods
Once again, in more detail, we will talk about three known types of protection devices installed on the roof of building structures.
The type of lightning rod chosen for a country lightning rod determines the type and scheme of its protection. Typical schemes include the organization:
- lightning protection mesh;
- rod lightning rods;
- wire lightning rods.
For flat and gable roofs of cottages, regardless of the roofing material, experts recommend using a lightning protection mesh. For its organization, steel, copper or aluminum rods with a diameter of up to 8 mm are used. The grid is installed directly on the roof or under the insulation, if the base of the roof is not combustible (Instruction RD 34.21.122-87).
Depending on the level of protection, down conductors are mounted directly to the grid around the entire perimeter in increments of 10 to 25 cm.
The rod lightning protection scheme is a metal pin attached to the chimney or other roof structures at least 2 m above its highest point.
The installation of the rod is done correctly if the protected object completely falls into the base of the cone with the apex at the extreme point of the lightning rod. Increasing the height of the rod expands the protected area. This type of lightning rod is suitable for both private and industrial facilities with complex roofs.
For gable roofs of low buildings, a cable scheme of a country lightning rod can also be used. To do this, a steel cable is pulled between the supports mounted on the skates. Its ends are usually adjoined by one down conductor, which transmits current to the ground in the ground, which looks like a "chicken foot". If the dacha lightning rod scheme is executed correctly, lightning discharges go into the soil outside the protected house. When arranging lightning protection of this type, it is important to take into account the sagging of the cable.
The choice of a scheme for organizing a country lightning rod is influenced by many factors, parameters and conditions. Therefore, this is a rather complex and responsible event requiring certain professional knowledge and experience. Our company will help you design and install the most effective lightning protection for your home. In addition, we provide services for the arrangement of a lightning rod on a turnkey basis. In the section "Our objects" there are photos of lightning rods and a description of our completed projects.
How and where to buy a lightning rod
A lightning rod that protects against a direct lightning strike will work like clockwork if you correctly and correctly select the necessary materials to create an effective and reliable lightning protection for a building. The following parameters affect the price of a country lightning rod:
- level of protection;
- lightning rod scheme;
- technical difficulties of project implementation;
- type of materials used and scope of work.
Today, numerous online stores offer a large selection of steel, copper and stainless steel rods and cables, as well as holders and clamps, and give an excellent description of their products. However, it is difficult to make a lightning rod of impeccable quality on your own. In addition, no one will guarantee the operation of a system assembled from materials with different performance characteristics.
Our company offers to buy components for lightning rods from well-known and well-established manufacturers from Germany, Russia, France, Turkey and other countries from a warehouse in Moscow: OBO Bettermann, J. Propster, BS-Technic, DEHN+SOHNE, Voltstream, Elmashprom, Duval Messien, Citel, Forend and others.
Our services
The specialists of our company will help you choose the most reliable and efficient country lightning rod at an affordable price, taking into account all the features of your home. Our consultants will answer in detail any questions of interest and make an estimate.
We can order the necessary measurements of transient resistances, resistance of grounding devices, checking the presence of a grounding circuit and grounded elements. The company's experienced professionals can also design and install a turnkey lightning rod. We provide maintenance services for various lightning protection systems before the start of the thunderstorm season and, by agreement with the client, we repair them.
A lightning rod is a protective device in which a system of conductors conducts an electrical discharge to the ground. Lightning protection is the most important element in ensuring the safety of residents and property in the building. If you wish and have certain knowledge, it is quite possible to build a lightning rod with your own hands.
Principle of operation and device
The lightning protection system consists of three components:
- lightning rod;
- down conductor;
- ground electrode.
The device diagram is shown in the figure below.
The function of receiving a lightning discharge is assigned to the lightning rod. Through down conductors, electricity enters the ground circuit, which transmits the discharge to the ground.
Lightning rod
There are three types of lightning rods:
- rod;
- pin;
- reticulate.
Also, the roof itself can act as a receiver.
The rod receiver is a metal pin mounted on a frame (on the roof, next to the building, on a tall tree). With the help of a down conductor (conductor), the pin is connected to the ground loop. Lightning rods are made of copper, aluminum or steel. Moreover, the first one is the best option in terms of protection quality, and the cheapest receivers are made of steel.
The cross section of the rod-type lightning rod must be at least 35 sq. mm, if we are talking about copper, and 70 sq. mm - for steel devices. The length of the pin ranges from 50 to 200 cm.
Rod receivers usually look aesthetically pleasing, but their coverage area is not very large. To calculate the covered area, a mental line is drawn from the highest point of the pin to the ground level at an angle of 45 degrees. Protected is the entire space that is in the triangle around the perimeter. Due to the small coverage area, lightning rods are used to protect small houses, bathhouses, garages, etc.
Note! Lightning protection can be either made by hand or purchased ready-made.
Mesh lightning rods are made in the form of metal meshes and represent a reinforcing cage with cells ranging in size from 3 to 12 m. The thickness of the reinforcement is 6 mm on average. The grid is placed at a certain height above the roofing material, leaving a gap of at least 15 cm. The most suitable objects for the use of grid systems are large roofs (apartment buildings, shopping centers, industrial and warehouse buildings, etc.).
The cable receiver is located on two or four masts connected to each other by steel or aluminum wire. The cable is pulled along the roof ridge using wooden blocks that act as supports. The smallest recommended rope diameter is 5 mm.
Compared to rod devices, the described devices cover a much larger area. In terms of efficiency, cable systems are better than rod or mesh receivers in dealing with the task of lightning protection. Such systems are especially common on slate roofs.
Sometimes the roof itself is used as a lightning rod. This is possible when the roof is made of corrugated board, metal tiles and any other materials based on metal. There are requirements that disqualify the structural material of the roof if its thickness is less than 4 mm (otherwise it may be burned through by lightning). Also, any combustible materials that can easily ignite are not allowed.
Down conductor
For the manufacture of conductors, six-millimeter copper, steel or aluminum wire is used. Connections with other elements of the system - lightning rod and ground loop - are made by means of bolts or welds. The down conductor needs high-quality isolation from the environment (cable channels are suitable). Another requirement is the choice for the down conductor of the shortest path from the lightning rod to the grounding device.
grounding conductor
The ground loop is located near the building. At the same time, a place is chosen that is outside the walking area and closer to any fence. The electric charge entering the ground loop through the down conductor is discharged into the ground through metal rods. The rods are dug into the ground to a depth of about 80-100 cm. They are placed in such a way that they form a triangle when connected.
Preparatory activities
Before you make a lightning rod, you need to prepare. Moreover, in terms of importance, this stage is no different from the actual process of installing a lightning protection system. You will need to make calculations according to the formula, select materials and find the right place to install lightning protection.
Calculation formula
Lightning protection is a rather complex and responsible system due to the tasks performed. When planning it, accurate calculations and an assessment of potential risks are necessary. At the same time, there is no need for overly complicated mathematical calculations. It is only necessary to determine the coverage area of the system, based on the formulas. For a lightning rod, there are coefficients used to calculate the required height of the device. The following formula is used:
It is suitable for lightning rods up to one and a half meters high, which is quite enough to protect a private house from lightning strikes.
Lightning rod material
To create a protective system, structural materials will be needed. You will have to make a choice of steel, copper or aluminum. In this case, the area of the required cross-section will differ, which is dictated by the different resistance of each type of the listed metals. To explain what has been said more clearly, below is a table that indicates the minimum requirements for lightning protection components, based on the type of metal:
| Material | Lightning rod | Down conductor | grounding conductor | |||
|---|---|---|---|---|---|---|
| Sectional area, mm | Diameter, mm | Sectional area, mm | Diameter, mm | Sectional area, mm | Diameter, mm | |
| Copper | 35 | 7 | 16 | 5 | 50 | 8 |
| Steel | 50 | 8 | 50 | 8 | 100 | 11,5 |
| Aluminum | 70 | 9,5 | 25 | 6 | Not applicable | |
Based on the data presented in the table, the optimal choice of material is copper. However, the cheapest option for a do-it-yourself lightning rod is steel.
The down conductor has a smaller cross section compared to other components of the protective system. It is recommended to gradually increase its thickness from the receiver to the ground loop.
Advice! When creating lightning protection, it is desirable to use the same type of metal for all structural elements.
For the manufacture of lightning protection, the following materials and tools are needed:
- Lightning rod. In the case of a rod system, you will need a metal pointed pin. A TV mast or antenna for receiving radio signals is also suitable. Ready-made receivers are available for sale, for example, GALMAR or SCHIRTEC.
- Metal wire of the desired section.
- Grounding devices (metal rods, pipes or tape).
- Plastic clamps, brackets, bolts.
- Tools for performing work (welding machine, electric drill, hammer, shovel).
Installation location
The lightning rod should be located at the highest point available on the site. In this case, you need to remember about the protective cone-shaped zone. The lightning rod must be located in such a place that the building is completely covered with protection. It turns out that the more distant the lightning rod from the house, the higher it should be.
For financial reasons, it is preferable to place the lightning rod on the roof of the building. In this case, the construction of a high support will not be required, which, moreover, is unlikely to be aesthetically attractive.
Advice! It is not recommended to install a lightning rod in the central part of the roof. It is better to put the receiver on the edge of the roof and fix it to the wall. With this approach, the risk of lightning hitting any part of the roof is reduced.
A separate issue is the correct placement of the grounding device. When a lightning strikes, a high-power discharge passes into the ground and at this moment there should not be living creatures near the ground electrode. Therefore, requirements have been developed for minimum distances from grounding to the wall of the house - 1 m and to footpaths - 5 m. The grounding device should be installed in a place where there is no likelihood of people being present. In addition, a fence should be installed around the grounding conductor and a warning sign should be placed nearby.
Note! Effective work of grounding is possible only in wet ground. This must be taken into account when choosing a location for the ground loop. If there is no constantly wet area, you should think about artificial irrigation.
Installation of a wire lightning rod
First of all, you need to stretch the wire along the roof ridge. It will act as a lightning receiver. If the roof is made of fire hazardous materials (wood, plastic tiles, etc.), the wire should be placed at a height of at least 15 centimeters from the material. At the same time, plastic clamps will perform the supporting function for it. The ends of the wire are fixed on metal masts (they are called horizontal receivers).
The down conductor is fixed to the receiver using a welding machine with bolted connections or rivets. Insulation is applied to adjacent areas. On the roof, the down conductor is fixed with brackets, and on the walls - with plastic clamps. It is better to place the conductor in a cable duct to avoid the harmful effects of moisture on it.
Grounding is created like this:
- Dig a trench with a depth of 80 cm.
- Metal pins are hammered into the bottom of the pit.
- Connect them with a steel pipe or tape. To do this, use a welding machine.
- The tape is taken to the area of connection with the down conductor.
- Connect the down conductor to the ground electrode.
Installation of a lightning rod
To mount the rod system, you will need a high bed. Its functions can be performed, for example, by a TV antenna mast. The receiver is fixed to it by a welded or bolted connection.
The installation of a down conductor and a grounding conductor is carried out in the same way as described above when it came to cable lightning protection. After installation is complete, the system resistance should be tested. The maximum allowable indicator is 10 ohms.
Tree as a lightning rod
To create a lightning rod with your own hands, an ordinary tree is suitable. At the same time, its height should exceed the level of the roof of the building by about 2.5 times. The distance to the house should not be less than 3 m.
One end of a five-millimeter wire is welded to a grounding device and the connection is buried in the ground. The remaining end will be the receiver. He is led to the top of a tree.
Construction care
Metal devices are sensitive to negative environmental influences. To avoid the development of corrosive processes and maintain the working properties of metals, it is necessary to regularly inspect the lightning protection system.
With the onset of spring - before the start of the thunderstorm season - it is necessary to conduct a visual study of all components of the system. During operation, the metal is so damaged that it is impossible to do without replacing parts.
Particular attention should be paid to contacts. Poor contact leads to opening of the system and fire. If necessary, they are cleaned of oxide.
The underground part of lightning protection also needs to be checked. However, due to the complexity of the process, it is allowed to do this not every year, but once every three years.
Lightning protection is such an important element of ensuring the safety of residents and the building that it is worth taking on its creation only with full confidence in one's knowledge and experience. If this feeling is not enough, it is better to entrust the work to professionals.
People living in private homes are afraid of lightning entering their homes. Some of them, in order to protect themselves from this, think about protecting the building. Their concern is understandable, since there are regions where lightning intensity can reach up to 80 hours a year. In such an area, it is necessary to install lightning rods. The device of such a structure, of course, requires certain costs. However, in some cases, they can be minimized if all the work on creating a lightning rod is done by hand.
Protection zone
At the moment, according to the degree of reliability, structures that protect against lightning are distinguished. There are two types of them:
- type A;
- type B.
Lightning rods of the first type provide 99% protection, which allows us to call them the most reliable designs against lightning. Structures of the second type provide 95% protection.
Device
If you are seriously afraid of lightning entering your house and, in order to protect yourself from this, you decide to arrange a lightning rod, then in this case, during work you will need to create the following elements this building:
- lightning rod;
- down conductor;
- ground electrode.
Lightning rod
This is a device that looks like a metal rod. After installation, it will rise above the roof of the building. It is on him that lightning strikes will fall. Thus, reliable protection of the building is ensured. In addition, such a device is able to withstand severe voltage loads that occur when lightning strikes. When creating this element, you can use various materials.
The best choice - flat or round steel, whose cross-sectional area is at least 60 square meters. m. This element has certain requirements in terms of length. This parameter must be at least 20 cm. The device must be placed strictly in a vertical position. The tallest building on the site is the perfect place to anchor it.
Down conductor
The down conductor has the form of a thick wire with a diameter of 6 millimeters. To create it, the best choice is galvanized steel. With regards to its location, it is better to choose areas where lightning strikes are most likely. For example, the edge of the gable can be a good place to place it. It can also be placed on a skate. The fastening of this element of the lightning rod is carried out close to the private house, but with a small indentation of 20 cm.
If the house is roofed with materials that are easily flammable, then in this case the gap is all the more necessary. To fix the down conductor you need to use a special fastener: nails and staples. For greater reliability of fastening of this element, clamps can be used.
grounding conductor
It is necessary to divert the current from lightning to the ground. When choosing a material to create this element of a lightning rod, it is necessary to use one that conducts an electric charge well. It is also necessary that the material has a minimum resistance. If we talk about its location, then this element of the lightning rod is placed near the porch of a private house, at least 5 m. It is not recommended to install a ground electrode in the immediate vicinity of the tracks, as well as in places where people can be. After placing it, to make sure it does no harm, you can create a fence around it.
When constructing a fence from the ground electrode, it is necessary to make an indent of 4 meters, and arrange the fence itself along the radius. If the weather is good outside, then it will not do any harm. But if it is cloudy, and even more so a thunderstorm has begun, then standing in close proximity to it can be dangerous to health. The ground electrode is installed in the ground. The decision regarding the depth of this element is made by the owner of the house. In doing so, the following points must be taken into account:
- soil type;
- availability of groundwater.
For example, if dry soil prevails on the site, and the groundwater level is low, a ground electrode system consisting of two rods is arranged. The length of each of them should not exceed 3 meters. The components of this element must be fixed to the jumper, whose cross-sectional area should be 100 square meters. m.
When this is done, the ground electrode is fixed to the down conductor by welding. After that, it plunges into the ground to a depth of 0.5 meters. In the event that the soil on the site is peat and has high humidity, and groundwater is located close to the surface, then there is no possibility of grounding half a meter. Therefore, in such a case metal corners must be used, which will act as a ground electrode. They are immersed to a depth of 80 cm.
If a multi-storey building is being built, then in this case, work on the installation of a lightning rod is carried out by specialists. These structures have their own radius of protection zone, which makes it possible to place them on each building. Before installing this structure, they check whether the already installed lightning rods are able to provide lightning protection for the erected building or whether it is necessary to erect a new one.
In the case of individual houses, the issue of a lightning rod is decided by the owner himself. There are a number of building placement factors that minimize the risk of lightning entering a home:
- if a house is located in the lowest place on the site, the probability of being hit by lightning during a thunderstorm is small;
- if a high-rise building is located next to the dwelling, then when a lightning strikes, it is more likely to be struck by lightning. Thus, your home will be safe;
- if a lightning rod is installed on a neighboring house, then its protective zone of action may extend to your house. And in this case, there is no great need for a lightning rod device.
Thus, it cannot be said that a house that does not have a lightning rod is at high risk of being struck by lightning.
Options for creating a lightning rod
If you have inspected your own and neighboring houses and as a result found that there is no such protection as a lightning rod on nearby buildings, then in this case the most reasonable thing is to do the work on creating it yourself. Of particular danger are buildings whose roofs are covered with metal tiles or steel sheets. Although such a roof looks attractive, the lack of grounding increases the risk of lightning hitting such a house.
In most cases, the installation of this roofing is carried out on a crate, which is made of wood. This provides charge storage. The discharge of such a device can only occur after a thunderstorm. A person, touching it, can receive a current discharge of several thousand volts. In addition, do not forget that after a lightning strike, a spark can occur, from which a wooden house can easily ignite.
If you want to avoid such unpleasant situations, then need to think about grounding, which should be located every 20 cm. If your home has a metal roof, then in this case you can refuse to create a lightning rod. The roof material itself will become an excellent lightning rod.
To save your home from lightning strikes, you can install a lightning rod on its roof. However, other options are also possible. If there is a tall tree near your dwelling, then you can install a lightning rod on it with your own hands, but on condition that it is located at a distance of three meters from the building, and its height is 2.5 times greater than that of your house.
If this option of a lightning rod seemed attractive to you and you decided to arrange it, then you will need a 5 mm wire. First you need to prepare it, then one end must be buried in the ground, having previously welded it to the ground electrode. The other end will act as a lightning rod. It must be placed at the very top of the tree.
In the event that there is no tall tree in your area, you can use a lightning rod mast with two metal rods instead. Their installation is carried out at opposite ends of the roof. The drain in this case will act as a down conductor. Of great importance is the material of its manufacture. It must be metal. In this case, you should also not forget about the grounding device.
Conclusion
Regardless of which method you have chosen to install a lightning rod, you must remember that, having completed the installation of this structure with high quality, you will ensure a comfortable stay in your wooden house. But it is necessary to periodically check the condition of the lightning rod handmade. Particular attention must be paid to its connections. There should be no violations in them. Only in this case you can not be afraid of lightning strikes into the house.
Lightning is one of the most terrible enemies for a private house. Its destructive power is so great that you can lose your shelter in a matter of seconds. Of course, the case of a lightning strike in a house is not the most common cause of property loss. Many are just lucky to have a home near lightning rods, power lines or high towers. However, as long as there is a danger of sudden and complete destruction of all property, it is hardly possible to live in peace.
The probability of lightning hitting a house increases many times if it is located on a hill or near water bodies. In such cases, the implementation of a lightning protection circuit necessary during construction work. According to SNiP, all private buildings are classified as buildings with a third fire safety class, which means that they are subject to lightning protection without fail. As a rule, lightning protection is designed together with the house and installed during its construction.
How much lightning protection is needed for a private house
To properly build lightning protection, you need to know the nature of the occurrence of lightning. Due to the accumulation of a large electric charge in rain clouds, an impulse of enormous force occurs, in other words, an electric current is discharged through the highest point on the ground.
The current strength of an electric discharge during a lightning strike reaches 100 thousand amperes, and in some cases up to 200 thousand amperes. About 200 lightning strikes occur every second on the planet. Even if we take into account that the probability of it getting into a particular house is not so great, it is still better to secure your home in advance and install a structure that protects the house from a lightning strike.
During the passage of an electrical discharge colossal thermal energy is released through the materials of the house, which causes fires and destruction. As you know, most suburban buildings are built from wooden materials, namely, they are most at risk of rapid ignition.
Based on this, lightning protection of a house becomes an important and mandatory task during its construction. Moreover, regardless of the location of the residential building in the city or outside it and the types of building materials used for its construction, there must be lightning protection.
Principles of operation and types of lightning protection
Lightning protection for a private house can be of two types:
- Active.
- Passive.
Traditionally, the first type of protection is used - passive, which consists of a lightning rod, a current outlet and grounding. The principle of operation of such protection is very simple.. Lightning, striking the receiver, passes through the lightning rod, which directs the discharge to the ground. When designing any lightning protection system, it is necessary to take into account the characteristics of the material from which the roof is made, the roof structure and its features.
Active lightning protection works on a slightly different principle. The discharge of electric current is intercepted by a lightning rod, which creates an ionized field around itself, attracting lightning. Further, the principle of operation is identical to passive protection. At the same time, its active type acts within a radius of up to one hundred meters, while the passive one protects only the house itself.
Active lightning protection is the most preferable and it is installed in many countries to protect the house and the entire surrounding area. However, it has a high cost, which may not always be appropriate to install it.
Do-it-yourself lightning protection of a private house
You can ensure the safety of a residential building with the help of lightning protection made by yourself. The lightning rod circuit is quite simple, it's easy to do it yourself. Any such security system of a private house is based on the manufacture of a lightning rod from available building materials.
Any lightning rod has three main components, as shown in the diagram:
- Lightning rod.
- Down conductor.
- Ground loop.
Lightning rods
A conductor made of metal, the task of which is to take over the electric discharge of lightning, is called a lightning rod. It is installed at the highest point of the roof, while on the roof, which has a complex structure, several such lightning rods are installed.
According to their design features lightning rods can be of several types:
- metal pin;
- metal cable;
- metal grid.
metal pin
With this method of lightning protection at home, a metal pin is made, from 20 centimeters to one and a half meters long. It should be mounted on the highest point of the roof of a private house.
The material used is copper or galvanized steel due to its high resistance to oxidation. Such a pin can be of any shape. The cross-sectional area should not be less than 100 m2. If the pin has a round shape, then its diameter must be at least 12 millimeters. The use of a hollow pipe is allowed, but in this case its diameter should be slightly larger, and the end facing upwards must be welded. How to protect your home from lightning suitable for any type of metal roofing, including metal tiles.
metal cable
A device with a metal cable is also quite simple to do with your own hands. The whole structure consists of a cable and a pair of supports that can be made of metal. However, in this case, they will have to be isolated.
A steel cable with a diameter of at least 12 mm is pulled along the roof ridge and fixed at the edges. The cable should be at a height of 1-2 meters from the roof ridge.
Metal grid
Lightning rod with receiver metal mesh is the best protection option for a tile roof.
When installing the grid, it is fixed along the roof ridge with branches from down conductors that have reliable grounding over the entire roof area.
All lightning rods on the roof must be connected to ladders, gutters and any other metal objects.
When large and tall trees grow next to a private house in the immediate vicinity, one of them can be used as a lightning rod. To do this, the metal pin should be installed so that it is one and a half meters higher than the crown of the tree, and then connected to the down conductor. An important condition is the height of the tree- it should be 10–20 cm higher than the house.
Creation of a down conductor
Down conductor - one of the components of the lightning rod, responsible for the electric discharge wire from the lightning rod to the ground loop. It is made of steel wire with a diameter of at least 6 mm. One of its ends is welded to the base of the lightning rod, and the other to the ground loop. The quality of welding should be given special attention, in order to avoid breakage at the attachment point. The current that passes through the down conductor can reach 200,000 amperes.
It is necessary to fix the down conductor along the contour of the roof and the house with the help of insulators at a distance of 2–3 cm from the roof and walls . If there are several down conductors, then the distance between them should be at least 25 meters.
It is impossible to fix the wire near doors and doorways. When installing, avoid sharp bends and places where it can be damaged by snow or debris. The down conductor should be as short as possible, and it should be located in places where there is the greatest risk of lightning strikes: on sharp ledges, gable edges, etc.
Grounding the lightning rod
The ground loop completes any design of a lightning protection device. Its task is to ensure reliable contact of the entire device with the ground. Externally, the design looks like three large electrodes that are interconnected and recessed into the ground.
To assemble the device responsible for grounding, you will need steel with a cross section of 80 m2 or copper with a cross section of 50 m2. In a trench dug in advance, about one meter deep and 3 meters wide, two metal rods made of copper or steel should be driven in along the edges. Then they are interconnected by welding and a down conductor from the house is welded to them. The entire structure is driven to the ground into the ground.
When assembling the grounding device, remember that it must be located no closer than five meters from doors or windows, walkways, porches and paths. Distance from the walls of the house must be at least one meter.
Lightning protection care
Every year before the start of the thunderstorm season, special attention should be paid to the preventive inspection of lightning protection at home. All components of the lightning rod and attachment points must be inspected, if necessary, painted or repaired.
Every three years, a major inspection of the entire system should be carried out. Check the connection points of the down conductor and the ground loop, clean and tighten the contacts there. Faulty clamps - replace.
Every five years, the ground loop electrodes are inspected. To do this, they must be removed from the ground and carefully checked for corrosion. If, for its reason, the cross section of the electrodes has decreased by more than a third, then they should be replaced.
