Lightning in a wooden house. Protecting a private home from lightning - an overview of a good lightning rod. Mandatory grounding work
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Lightning is a natural phenomenon with great destructive power. The electric charge that lightning contains tends to reach the highest point, most often the roof of a house, an antenna, or a tree. The consequences of such a hit are a fire, a power surge, which can result in the death of people, damage to the building, household appliances, and electronics. Therefore, during construction it is necessary to pay Special attention home protection.
There are two types of lightning protection for a private home – internal and external.
The work of internal lightning protection is aimed at protecting equipment and wiring of the house from overvoltage. External protection directly conducts the lightning charge to the ground.
lightning protection of a private house photo
Structure of external lightning protection
External protection consists of a lightning rod (lightning rod), a down conductor and a grounding conductor.
Important: the grounding of the lightning rod must be separate from the general grounding loop of the house.
A lightning rod directly catches lightning, this happens primarily due to the material from which it is made, after which, with the help of a down conductor, the energy goes into the ground.
Depending on the principle of operation, the external lightning protection system is divided into passive and active.
Passive system
The most commonly used is a passive lightning protection system. Due to the simplicity of the design, you can install it yourself without the help of specialists. But with all this, several nuances should be taken into account - roofing material, type of roof, type of soil. When installing such a system, the cost of an annual operational inspection should be taken into account.
Highlight following types passive protection:
pin - the lightning rod is installed on the roof and, using a down conductor (wire with a cross-section of at least 6 mm), which is attached to the ground electrode, the charge is discharged into the ground. The system is simple in design and is most often used on metal roofs ah, inexpensive, but has a small area of action.
Important: lightning rods for metal roofs are made from round steel and installed 1.5 - 2 m above the highest point of the house.
cable - here a cable stretched between two supports is used as a lightning rod, which is connected to a down conductor and a grounding conductor. This design is preferable for temporary structures, pavilions, as well as for roofs covered with slate.
Important: the cable or wire is stretched at a height of up to 50 cm from the roof.
mesh – most a complex system for installation, it is used on roofs covered with metal tiles and is a mesh.
Active system
The operating principle of active lightning protection is that the lightning rod ionizes the air around it, thereby intercepting the lightning charge. Such a system costs much more than a passive one, but its range of action is about 100 meters, which will allow you to protect not only your home, but also nearby buildings. The main advantages include: compactness, non-obtrusiveness, and autonomy of operation.
Construction of internal lightning protection of a private house
Internal protection of the house consists of installing special equipment that will be directly connected to the electrical panel. Surge suppressors will save your home from losses, not only when lightning strikes your home, but also from all kinds of power surges. Also for these purposes, a surge protection device (SPD) is used, which is installed at the entrance to the house. The principle of their operation is to remove excess impulse through grounding.
SPD connection diagram
Grounding a private house
Grounding a house plays a big role in protecting the house from various incidents, including a lightning strike, a power surge in the network due to an accident. There are several types of grounding, among which are fundamental, deep and ring. Before installing grounding, it is necessary to make a calculation taking into account soil resistance and ground freezing. You can make a grounding circuit yourself; for this you will need grounding conductors made of copper or steel, as well as a metal structure that will connect them to each other. Grounding conductors with metal bonds must create a rigid contour in the form of an equilateral triangle. Equal angles, fittings or pipes, which are connected to each other by metal strips, can be used as vertical grounding conductors. It is best to use welding as fastening. To produce correct installation grounding, it is necessary to dig a trench from the house, 0.5 - 0.7 m deep, which will end in a triangular hole. Vertical grounding conductors are driven at the same distance from each other, with a depth of at least 2 meters. They are connected by horizontal strips to each other, the length of the strips is 1.2 m. A bus is attached to one vertex of the triangle, which is laid to the foundation of the house. Using a copper wire with a cross-section of at least 6 mm, the bus is connected to the electrical panel of the house.
Grounding for lightning protection can be done in the same way or in a linear way. In which the grounding conductors are connected to each other on the same line. At least three ground electrodes are used. The disadvantage of such a system is a decrease in its efficiency due to the influence of the electrodes on each other. It should also be taken into account that if the first ground electrode fails, the entire system stops working.
Do-it-yourself lightning protection in a private house.
As a lightning rod, you can use a metal pin, a pipe closed at the top, or any cone made of copper, aluminum or galvanized steel. The lightning rod is installed so that it is 1.5 m above the highest point of the roof. You can attach it directly to the roof, antenna, or chimney.
Important: the lightning rod cannot be painted or insulated.
The lightning conductor is connected to a down conductor, which uses a wire with a cross-section of at least 6 mm. To connect the lightning rod and lightning rod, welding or bolting is used. The down conductor is lowered from the roof and directed to the ground electrode into the ground. The wire is lowered so that it is away from windows and doors. The down conductor is strengthened along the wall using special fasteners.
Important: avoid turning the down conductor at an acute angle - this can cause a spark charge.
Fastening the down conductor wire with a grounding conductor.
Lightning protection requires annual maintenance, checking the integrity of connections and fastenings, and if necessary, we clean and tighten the bolts.
Rod lightning rod at home:
lightning rod;
wooden mast;
current lead;
ground electrode;
the connection point between the end of the down conductor and the ground electrode; 6 - foundation;
soil level.
Lightning protection for a private house with a metal tile roof is made in the form of a mesh, which is made of wire and attached directly to the tiles.
Important: when installing lightning protection, the roof must have a fireproof backing.
Video
The need to install a lightning protection system for a private home is determined by the owner of the building based on the likelihood of the object being struck by lightning and 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 home rectangular shape 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.
The external lightning protection system protects directly from direct hit lightning into an object. This impact is dangerous primarily due to the high temperature of the 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 vertical axis masts. 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:
Protection zone of a single 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 gable roof(roof slope angle is at least 35°) for reliable protection it is necessary to install two masts 2 meters high along the edges of the roof ridge. For home 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 using bitumen and bitumen-latex coatings as waterproofing. Epoxy and other polymer coatings prevent electrical contact foundation with 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 minimum 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 of the 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 rubber grommet clamp 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 40 meters, ensures low grounding resistance at no large area. Installation is carried out by one person without the use of construction and specialized equipment.
Modular grounding can also be purchased in the form ready-made kits, and in the form of separate components.
Acquainted with detailed information about technology modular grounding possible 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 complete system external lightning protection. All offered products comply with national requirements regulatory documents to minimum dimensions, 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 do not come with anchor bolts. Their type and length must be selected depending on the base material.
It is also possible to attach the down conductors to the drainage system of the house (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.
Private house and country dachas often located on open space, where the only elevation is the buildings themselves. Because of this, during a thunderstorm there is a significant threat of lightning striking buildings. This 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 where the discharge will hit, most effective way prevent it negative consequences is a lightning rod.
That is why for most owners of private houses and summer cottages It is important to install a lightning rod with your own hands. An exception may be buildings located in a lowland, the roof of which is below the top point of the ground or falling within the protection zone of a neighboring building and its lightning rod.
Design and principle of operation of a typical lightning rod
Figure 1: lightning rod deviceThe entire design of a lightning rod is represented by three elements: a lightning rod, a down conductor and a grounding conductor. Depending on local conditions and your preferences, each of them may have various designs. Now let’s look at why each of them is needed, and which option to choose in a given situation.
Lightning rod
From the title itself of this element its purpose occurs; in fact, it acts as an electrode that receives an electrical discharge from lightning. 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. The following can be installed as a lightning rod:
- core 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 must provide the necessary protection zone for all structures of the building. Therefore, such a lightning rod is relevant for buildings with 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 destruction, due to which such a lightning rod practically does not lose conductivity and cross-section even during long-term operation. A metal pin made of steel, unlike the previous two, is much less susceptible 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 grating is used as a lightning rod for a large area, for example, multi-storey buildings or shopping centers. Unlike previous version, it does not affect the design of the building, so it can be used in any modern exterior. 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 on safe distance from the roof (at least 15 cm) through thermal insulation bearing structures.
Figure 4: cable lightning rod A cable lightning rod is a flexible wire that stretches over the protected area or building. Allows you to protect a long area with less material consumption for a lightning rod. Performed both on free-standing supports and on the roof country house building. 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 sheeting, metal tiles and others), they can be used as a lightning rod for a lightning rod. But 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 covered with dielectric material.
Making a lightning rod from a metal roof allows you to save money on lightning rods.
Down conductor
It is a conductor that leads electricity from the lightning rod to the ground electrode. 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 apply to the down conductor:
- Must be insulated from walls and other structures of the house;
- Selected for him shortest path current flow;
- The absence of bends and turns where 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 any other method. This procedure is especially relevant for buildings with conductive finishes or flammable surfaces.
Ground electrode
It is made in a 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 | |
| Pipe | 32 | — | 3,5 | |
| Steel | Round: | |||
| galvanized | for vertical grounding conductors; | 12 | — | — |
| for horizontal grounding conductors | 10 | — | — | |
| Rectangular | — | 75 | 3 | |
| Pipe | 25 | — | 2 | |
| Copper | Round: | 12 | — | — |
| Rectangular | — | 50 | 2 | |
| Pipe | 20 | — | 2 | |
| Multi-wire rope | 1,8* | 35 |
All parts of the grounding loop can either be looped and form a closed circuit, or line up in a continuous line. Of course, the closed version is considered more reliable. The contour dimensions are selected depending on local conditions.
Rice. 5: example of installation of ground electrode The main requirement for the grounding circuit is to ensure the established value of the metal-to-earth transition resistance, so it is better to place it in a damp layer, periodically water it with water or treat it with materials that reduce the transition resistance and increase the area of the spreading current ( 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 phase voltages of 380, 220 and 127 V, respectively.
The location of the ground electrode should be no closer than 1 m from the walls and 8 m from the pedestrian paths. Since at this point a step voltage arises that can cause an electric shock to anyone within the radius of the affected area, therefore it is strictly prohibited to approach the circuit during a thunderstorm, as well as to touch its current-carrying elements.
Preparation
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 determine whether buildings will fall into protective zone and what parameters need to be changed in case of defects.
Calculation of the protective zone
If the lightning protection device provides a grille or roof surface as a receiver, then the protection zone will completely cover the building. But for cable and rod lightning rods it is necessary to calculate the protective zone.
Rice. 6: lightning rod protection zone Look at the picture, the protection zone is a cone in space where the likelihood of being struck by lightning 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 area for each type are carried out on the basis of SO 153-34.21.122-2003.
Rice. 7: parameters of the lightning rod protection zone Look at the picture, the following parameters are shown here:
- x and y - the distance from the installation site of the lightning rod to the building boundary contour.
Depending on the installation height of the lightning rod and the required reliability, a formula is selected for determining the zone that it protects. For this purpose, data from Table 2 is used
table 2
| Reliability of protection | Lightning rod height h, m | Cone height h 0, m | Cone radius r 0, m |
| 0.9 | From 0 to 100 | 0,85h | 1,2h |
| From 100 to 150 | 0,85h | (1,2-10 -3 (h-100))h | |
| 0,99 | From 0 to 30 | 0,8h | 0,8h |
| From 30 to 100 | 0,8h | (0.8-1.43·10 -3 ( h-30))h | |
| From 100 to 150 | (0,8-10 -3 (h-100))h | 0,7h | |
| 0,999 | From 0 to 30 | 0,7h | 0,6h |
| From 30 to 100 | (0.7-7.14·10 -4 ( h-30))h | (0.6-1.43·10 -3 ( h-30))h | |
| From 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 =r 0 ×(h 0 -h x)/h 0
Rice. 8: cable lightning rod protection zone The figure shows a schematic diagram of the protection zone for a cable lightning rod with its short length. At long distances, due to poor tension, sagging may occur at the midpoint, which will slightly distort the boundaries of the area protected by the lightning rod.
Rice. 9: Parameters of the protection zone of the cable lightning rod Look at the figure, here the lightning rod area is characterized by the following parameters:
- h – the height of the lightning rod itself;
- h 0 – height of the lightning rod protection zone;
- h x – height at a certain point (set at the level of the roof of the building);
- r 0 – radius of the lightning rod protection zone on the ground;
- r x – radius of the lightning rod protection zone at the selected point;
- L – length of the lightning rod cable.
Based on 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 r 0, m |
| 0.9 | From 0 to 150 | 0,87h | 1,5h |
| 0,99 | From 0 to 30 | 0,8h | 0,95h |
| From 30 to 100 | 0,8h | (0.95-7.14·10 -4 ( h-30))h | |
| From 100 to 150 | 0,8h | (0,9-10 -3 (h-100))h | |
| 0,999 | From 0 to 30 | 0,75h | 0,7h |
| From 30 to 100 | (0.75-4.28·10 -4 ( h-30))h | (0.7-1.43·10 -3 ( h-30))h | |
| From 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 =r 0 ×(h 0 -h x)/h 0
Selection of material for lightning rod
It is customary to use three options as a material for a lightning rod: copper, aluminum and steel. Copper lightning rods are characterized by a long service life and are distinguished by their ability to maintain their parameters throughout the entire installation period, even underground areas. But the main disadvantage of a copper lightning rod is its high cost.
Aluminum is characterized by much lighter weight, therefore it creates a slight 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 susceptible to mechanical deformation.
Steel is the most durable and can 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 its high resistivity and susceptibility to corrosion.
Installation location
To install the lightning rod, the highest point should be selected. Therefore, it is placed on the roof of the building; if its height is not enough for the entire building to fall 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 profitable option, since the peak of the protection zone will be located above the building. A separate support or several allow you to move the area protected by the lightning rod to desired point plot, and is great for situations where buildings are dispersed on the plot. Using 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 and is therefore considered an undesirable option.
Step-by-step instructions for making a lightning rod
Most simple options for a country lightning rod there are rod and cable, you can implement them with your own hands. To avoid mistakes and unnecessary costs when installing a lightning rod, follow the following sequence.
Rod
To construct a rod-type lightning rod, perform the following manipulations:
The distance between them and their height are selected so that the conductor does not sag to the surface of the roof and walls.
Trosovogo
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 the supports or installed on brackets. In the first case, the lightning rod will sag when the tension changes, so fastening a rigid copper or steel wire to the 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
Most owners of private houses, cottages and summer cottages try to create the most comfortable and comfortable conditions inside and outside their homes. safe conditions for accommodation. It is a completely understandable desire, but most often the owners of such real estate completely forget about such a natural phenomenon as a discharge of static atmospheric electricity, which in an instant can cause enormous harm residential buildings and people's health. By its natural essence, atmospheric lightning is a very powerful discharge of electrical energy, which is capable of accurately hitting directly a private house, destroy not only all household appliances and electrical appliances, but also the building itself as a whole.
If your private property is located next to a tall building, then you should not worry. The lightning rod system of a multi-storey building will provide reliable protection for your home from damaging factors atmospheric electrical discharge. But such an arrangement of cottages, private houses and dachas is practically never found in modern reality. Basically, such real estate objects are built far from tall buildings, therefore they must be protected from lightning by equipping them with modern lightning protection units.
Lightning most often discharges to the highest point, but even a huge tree growing next to a house is not able to protect it from the discharge. Only a lightning protection device can completely protect your home from atmospheric discharge. household appliances, as well as the people present in it. In this article we will consider all questions regarding the types of lightning protection and methods of their installation for all types of houses, cottages and cottages. We will also tell you in a concise form how to install a lightning rod with your own hands, but first we will tell you about the damaging factors of lightning.
Damaging factors of atmospheric discharges
The technology for creating protection against thunderstorms is directly related to the damaging factors of atmospheric electrical discharges. Any natural phenomenon affects environment with varying degrees of impact. Lightning is no exception and its damaging factors can be divided into the following two types.
You can protect your property from a secondary damaging factor by simply disconnecting electrical appliances from the power supply for the entire period of time the storm front passes. For effective protection from a direct lightning strike, it is necessary to install lightning protection in a cottage, private house or country house.
Installation of a lightning rod and additional protective equipment will allow you to avoid negative consequences from the impact of the discharge on your residential property and on the people living in it, regardless of the type of damaging factor. Next we will look at the types and categories of lightning protection.
Categories and types of external lightning protection
Atmospheric lightning is a powerful discharge of electricity that obeys the basic laws of physics. Everyone knows that electric current moves along the path of least resistance. The main task lightning protection unit of any type to create exactly such a path for the passage of electricity, bypassing the structure of the building. When lightning strikes a private house equipped with such a block, all the power electric charge It will simply go into the surface of the earth without causing damage to buildings, electrical appliances and people.
In popular slang, this type of protection of private buildings is called differently: grounding of a country house, a system of lightning rods, and also lightning rods. The last version of the name is completely incorrect, because thunder is the sound of a lightning strike and there is no need to take it anywhere. But the term has long taken root and is used in colloquial speech. Regardless of what the home's lightning protection is called, it is designed to perform one task - to discharge the energy of an atmospheric electrical discharge into the ground. Lightning protection blocks are divided into three categories: by method and type of protection, as well as by design features.
Choose better protection The next chapter of the article will help you against a discharge of atmospheric electricity for your home, in which we will talk about the design of the most popular passive external lightning protection, in addition to which it is necessary to install internal protection against a secondary damaging factor.
Design of passive external lightning protection
The design of an external lightning rod in a country house, cottage or private house is quite simple. It consists of three components: a lightning receiver, down conductors and a grounding circuit. Down conductors and grounding conductors have standard design. In contrast, lightning rods of passive protection systems can be divided into three types, which we will discuss in detail below.
What type of lightning rod to use is up to you! It is impossible to give any strict recommendations in this regard. All three types of lightning rods are capable of reliably protecting a private home from the primary damaging factor of lightning.
The next elements in the lightning protection system are down conductors. Their main task is to transfer the energy of an atmospheric discharge from the lightning rod to the grounding device. Down conductors can be made from steel wire with a diameter of at least 6 mm, special copper or aluminum cable or steel strip with a width of 30 mm and a thickness of more than 2 mm. Any down conductor is fixed to the ends of lightning rods using threaded connection, welding or soldering. In private houses built from non-combustible materials, this lightning protection element is mounted on the walls in an inconspicuous place using metal fasteners. Down conductors should not be placed close to windows and doors.
Special requirements apply to the installation of lightning protection down conductors wooden house. When lightning hits the lightning protection system in a private home, the down conductor wires can heat up to high temperatures. To prevent the fire of the wooden walls of a building, it is necessary to correctly install the current-carrying part of the lightning protection system. Down conductors must be located at a distance of at least 10 cm from the walls of the building. For one rod lightning rod, it is necessary to install one current conductor, and for cable and mesh discharge receivers, two current conductor elements. The number of down conductors depends on the number of ends of lightning rods and the area and structure of the roof.
The last element in the system of external protection of a private house from atmospheric electrical discharges is a grounding device. The simplest ground electrode is two metal rods with a diameter of at least 30 mm, driven into the soil layer 2–3 meters and connected by a jumper made of metal tape. The distance between these grounding elements must be at least 3 meters. The down conductor is connected to this structure exclusively by welding.
We examined the design of external passive lightning protection. It can effectively protect a private home from the primary damaging factor of lightning. To protect a house, cottage or cottage from overvoltages in the network that occur when exposed to the second damaging factor of a lightning discharge, it is necessary to install optional equipment. These devices provide internal lightning protection.
Internal lightning protection
Household appliances and electrical appliances in a private home should be protected from exposure to powerful induction field, which occurs as a result of an atmospheric discharge. External lightning protection is not able to cope with this task. To protect against lightning surges, it is necessary to use special electrical devices. They are called surge protection devices (SPDs) and are installed in distribution boards at the entrance of electrical lines to a private house. Currently, there is a large assortment of such devices on the market, with different capabilities and levels of protection against surges.
Only after installing an SPD in the distribution panel and installing external lightning protection can you confidently say that your home is reliably protected from all damaging lightning factors. We examined the design of lightning protection for a private home, both external and internal. The next part of the article will answer the question: how to make a lightning rod in a country house, cottage or private house with your own hands.
Self-installation of lightning protection
Based on the above, we can conclude that the installation of lightning protection can be done with your own hands without the involvement of hired workers. Of course, if you have basic installation skills. Otherwise, you should invite a specialist. If you decide to install a lightning rod with my own hands, then you must first perform the design and calculation of lightning protection. This process will not cause difficulties. We will briefly talk about the design of lightning protection and its self-installation using the example of installing a lightning rod with a lightning rod. This is the most popular option for protecting suburban real estate from thunderstorms.
A lightning rod with a lightning rod provides protection in the form of an imaginary cone, with the apex at the end of the lightning rod. To ensure reliable protection of the structure from lightning, the entire object must fall into the inner zone of this cone.
In the above figure we see that part of the house did not fall into the protection zone, so it is necessary to move the lightning rod to the middle of the house or increase its height. The best place To install the lightning rod, use a roof ridge or a chimney. The calculation of the height of the receiver rod is calculated using the following formula.
- Rx is the lower radius of protection of an imaginary cone, which must be measured with a tape measure on the surface of the earth;
- Ha is the height of the active lightning protection zone, which is measured from the ground to the highest point of an imaginary cone;
- Hx is the highest point of a private house, which can be located on the roof ridge, chimney or other structural elements;
- H is the height of the lightning rod.
After calculating the length of the lightning rod, you should determine its location and lay an imaginary route for installing the down conductor from the rod to the installation site of the ground electrode. At this point, the design and calculation of lightning protection is completed and you can proceed directly to the installation of the lightning rod.
Installation of ground electrode
First of all, you should install a grounding loop. To complete the work you will need the following tools and materials:
- grinder with cutting wheels, welding machine, sledgehammer, hammer and shovel;
- 40×40 steel angle for the vertical pins and 40×5 strip for the jumpers.
The ground electrode should be mounted near the wall of the house. We choose a place and dig an equilateral triangular trench 70 cm deep with sides of 1.2 meters. It is also necessary to dig a trench up to the wall of the house to lay the down conductor. In the corners of the triangle we hammer in pieces of steel angle to a depth of 2 meters.
A strip is welded to the ends of the pins. A steel strip is welded to one corner of the circuit and brought out onto the wall of the house, where a down conductor from the lightning rod will be connected to it. The trench is dug and compacted. The ground electrode is ready to connect the down conductor.
Installation of lightning receiver
The best place to attach the lightning rod is a chimney located near the ridge of the roof. The most convenient way to secure the mast is with brackets with clamps at the ends.
An alternative option for fastening the lightning rod is to install it on a special support on the ridge of the house.
On final stage After installation, the down conductor is attached to the lower end of the rod using a clamp with a threaded connection.
Installation of down conductors
A down conductor, a metal wire with a diameter of at least 6 mm, is laid directly along the roof and wall of the house, to the point where the connecting steel strip exits from the ground loop. The entire structure is attached to the roof and walls of the house using plastic or metal clamps with support.
The lower end of the down conductor wire is fixed to the metal grounding strip using a threaded connection.
At this point, the installation of external lightning protection is complete, but if you do not install an internal surge protection unit, then your lightning protection system will be incomplete.
SPD installation
The surge protection device completely de-energizes the electrical network of the house when a powerful induction field occurs, that is, the secondary damaging factor of lightning. The module is installed in the distribution panel according to the following diagram.
After installing the SPD, your lightning protection of a private home is completely complete functional view. With this system, your property and household appliances are reliably protected from atmospheric electrical discharges.
Conclusion
High-quality installation of a lightning rod will provide you with comfortable accommodation in my house. In this case, protection from all damaging factors of lightning will be provided. But it should be noted that lightning protection must be periodically checked for damage. During a preventive inspection, the main attention should be paid to all connections. Only if the lightning rod is operational will your home be reliably protected from lightning strikes.
Video on the topic
How to properly protect a house from lightning strikes? Lightning is a natural discharge of electricity. If it were possible to accumulate a powerful lightning charge, this would provide an entire area of the city with absolutely free electricity. Sometimes, a “blue dragon” called lightning can “fly” into our house via external wires, tamed by no one, and not so desirable, but so destructive for our home electrical equipment, and destroy the property we have acquired within our means—electrical equipment. That is why it is necessary to treat home protection from lightning seriously and responsibly and not skimp on material costs for installing a lightning rod, as well as automatic protection.
Lightning protection comes in two types: internal and external protection. In combination, two lightning protection circuits will provide one hundred percent protection of your home from lightning, which will protect both electrical equipment and human life.
Lightning protection - external protection
TO external protection refers to a lightning rod, which, as a rule, is installed at the highest point of the house; the lightning rod is connected to a conductor that discharges the discharge to the ground. There was a time when a lightning rod was connected to the grounding of the house circuit. As it turned out, it is better to use independent grounding to remove a lightning discharge. The characteristics of the lightning rod grounding conductor must be the same as that of the house grounding loop. It must also be deepened into the ground using pins by at least 3 meters.
For private houses, a lightning rod is often installed on the roof of the house. Lightning rods are:
- a) a cable lightning rod, fixed to the racks of the end parts of the house and stretched along the ridge, or a high metal lightning rod is used, which is installed vertically and secured with guy wires or a special fastening designed to withstand wind loads.
home protection from lightning - lightning rods - b) another option, when they are laid on the roof metal mesh made of rods, welded with a cell pitch of 2–5 m, with a cross-section of rods of 8–10 mm².
Lightning protection - mesh - c) the third version of the lightning rod is used if the roof is metal, then there is no need to use the two previous designs. You only need to ground the roof using a conductor and lead it into the ground.
It is better to use a steel conductor through which the thunderstorm energy of lightning will go to the ground electrode, with a cross-section of at least 16 mm², or copper wire with a cross section of at least 10 mm². 
This is exactly the case when you can’t spoil the porridge with oil: the thicker the wire, the safer it is. The metal conductor is usually connected to the lightning rod by welding or using bolted connection in the case of a copper conductor. The conductor descends along outer wall house, to which it is attached using special clamps on non-flammable materials. It is advisable to lay the lightning rod conductor on a blank wall, away from front door and windows. The lightning rod conductor must not pass through metal elements(stairs metal railings, water and drain pipes) and at a distance of these structures no closer than 30 cm.
Lightning protection - internal protection
SPD - home protection from lightning Internal lightning protection is provided by special modular devices that are installed in electrical switchboard circuits. Even if lightning does not directly hit our house, it can “jump” in the form of a pulsed overcurrent along external street wires. A conductor that receives an impulse can lead to catastrophic consequences for home equipment connected to the electrical network. You will have to pay for the fatal outcome of expensive equipment yourself; there will be no one to blame for this. It is precisely to protect against such situations that there are special modular devices - surge suppressors. Inside the switchboard (ASU), you can install surge suppressors (SPDs) of different classifications. These devices are appearance resemble ordinary modular ones circuit breakers(VA), only without shutdown lever.
modular voltage limiters - lightning protection
All you need to know about surge suppressors is that they are installed between a phase and grounding or neutral wire and grounding.
Operating principle of surge suppressors
What surge suppressors should be installed for lightning protection?
As can be seen from the class assignments of surge suppressors, suppression of impulse overvoltage occurs in stages. It is not enough to install only a Class D surge suppressor and leave it at that. The last stage is capable of extinguishing the residues that have slipped through B and C. So, alone it is unable to remove hundreds, or even thousands of amperes. What conclusion suggests itself from all that has been said is that it is necessary to install all three classes of surge suppressors - B, C, and D.
Active lightning protection for a private home
Active lightning protection differs from passive lightning protection, its predecessor, in that it has built-in electronic device, which generates high-voltage pulses at the end of the lightning rod. Artificial leader on long distance with the help of high-voltage pulses, it will attract a lightning discharge to itself and conduct it to the ground.
Active lightning protection is widely used in the field civil engineering, in particular the construction of cottages. In our century, much attention is paid to the aesthetic appearance of a building, therefore, in order not to spoil the appearance with traditional lightning rods, some home owners use active lightning rods. The advantage is explained simply: fewer lightning rods and down conductors mean less disruption to the aesthetics of the facility
