How to make a lightning rod correctly in the country. How to protect your home from lightning? The smallest allowable distance

How to properly protect a house from a thunderstorm - lightning? 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, in our house, a "blue dragon" named lightning can "fly" through external wires, untamed by anyone, and not so desirable, but so destructive for our home electrical appliances, and destroy the property they have earned - electrical equipment. That is why, it is necessary to take seriously and responsibly to protect a house from lightning and does not skimp on material costs for installing a lightning rod, as well as protection automation.

Lightning protection is of two types: internal and external protection. In the complex, two security 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

External protection includes 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 diverts the discharge to the ground. There was a time when the lightning rod was connected to the grounding of the house circuit. As it turned out, it is better to use independent grounding to drain the lightning discharge. The characteristics of the lightning rod grounding conductor must be the same as those of the ground loop of the house. It must also be deepened into the ground with pins at least 3 meters.

For private houses, a lightning rod is often installed on the roof of the house. Lightning rods are:

• a) a catenary wire lightning rod, fixed on the racks of the end parts of the house and stretched along the ridge, or a high metal lightning rod is used, which is vertically installed and fastened with guy wires or a special mount designed to withstand wind loads.

lightning protection at home - lightning rods

• b) another option, when a metal mesh of rods is laid on the roof, welded with a cell pitch of 2–5 m, with a cross section of 8–10 mm² of rods.

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 structures. It is only required to ground the roof with a conductor and lead to the ground.

It is better to use a steel conductor with a cross section of at least 16 mm², or a copper wire with a cross section of at least 10 mm², through which the lightning lightning energy will go to the ground electrode.

This is just the case when you cannot spoil the porridge with butter: the thicker the wire, the safer. The metal conductor is usually connected to the air terminal by welding or by bolting in the case of a copper conductor. The conductor goes down along outer wall a house to which it is attached with special clamps on non-combustible materials. It is advisable to lay the lightning rod conductor on a blank wall, away from front door and windows. The air-termination conductor must not run over metal elements (metal stair railings, plumbing and drainpipes) and at a distance of these structures no closer than 30 cm.

Lightning protection - internal protection

Surge arrester - protection of the house from lightning

Internal lightning protection is provided by special modular devices that are installed in switchboard circuits. Even if lightning does not directly hit our home, it can “jump” in the form of a pulse overcurrent along external street wires. A conductor that has received the impulse can be disastrous for home appliances connected to electrical network... You will have to pay for the fatal outcome of expensive equipment yourself, there will be no one to blame for this. Just to protect against such situations, there are special modular devices - surge suppressors. Inside the switchboard (ASU), you can install surge arresters that differ in classification. These devices are appearance resemble conventional modular circuit breakers (VA), only without a trip lever.

modular surge arresters - lightning protection

All you need to know about surge arresters is that they are installed between phase and earth or neutral wire and grounding.

How surge arresters work

What surge suppressors do I need to install for lightning protection?

As can be seen from the class assignments of surge arresters, surge suppression occurs in stages. It is not enough to install only a class D surge arrester and calm down on that. The last stage is able to extinguish the residues that slipped through B and C. So, alone, he is unable to withdraw hundreds, or even thousands of amperes. What conclusion suggests itself from all that has been said - it is necessary to install all three classes of surge arresters - B, C, and D.

Active lightning protection for a private house

Active lightning protection differs from passive - its predecessor, in that it is built into electronic device, which generates high-voltage impulses at the end of the air terminal. Artificial leader on great distance with the help of high-voltage pulses, it will attract a lightning discharge to itself, and take it to the ground.

Active lightning protection is widely used in the field of civil engineering, in particular, the construction of cottages. In our century, much attention is paid to the aesthetic appearance of the building, therefore, in order not to spoil the view with traditional lightning rods, some home owners use active lightning rods. The advantage is explained simply: fewer lightning rods and down conductors - less violation of the aesthetics of the object

Private house and country cottages often located in an open space, where the buildings themselves are the only elevation. Because of this, during a thunderstorm period, 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 the location of the discharge, the most effective way preventing 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 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 device

The entire design of a lightning rod is represented by three elements: a lightning rod, a down conductor and a ground electrode. Depending on local conditions and your preference, each may have different execution... Now let's look at why each of them is needed, and which option to choose in a given situation.

Lightning rod

From the very name of this element, its purpose occurs; in fact, it plays the role of an electrode that receives an electrical discharge of 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:

• 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. Moreover, their height should 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: rod 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 its conductivity and cross-section even during long-term operation. The metal pin made of steel, unlike the previous two, is much less susceptible to melting from high currents, which is why it is much better suited for areas with frequent lightning strikes.

Rice. 3: mesh lightning rod

The grille is used as a lightning rod 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, therefore it can be used in any modern exteriors. Such a lightning rod must have a given cross-section and mesh size, as a rule, reinforcement of at least 6 mm 2 is chosen. Its installation is carried out on safe distance from the roof (at least 15 cm) through thermal insulating bearing structures.

Figure 4: catenary wire lightning rod

Catenary wire is a flexible wire that is stretched over the protected area or building. Allows you to protect a long section at a lower cost of materials for a lightning rod. Performed both on free-standing supports and on the roof suburban buildings... 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, etc.), they can be used as a lightning rod for a lightning rod. But at the same time, the following conditions must be observed:

• the thickness of the metal layer is at least 4 mm for steel, 5 mm for copper or 7 mm for aluminum;
• under roofing material there are no flammable materials (insulation, rafters, etc.);
• outside the metal is not covered with a dielectric material.

Making a lightning rod from metal roof allows you to save money on the lightning rod.

Down conductor

It is a conductor that leads the electric current from the lightning rod to the ground electrode. Can be made of metal wire or busbars. It must have a cross-section of at least 16 mm 2 if made of copper, 25 mm 2 from aluminum, 50 mm 2 from steel. The following requirements are imposed on the down conductor:

• Should be insulated from walls and other structures of the house;
• The shortest path of current flow is chosen for it;
• The absence of bends and turns, on which a 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 a conductive finish or a combustible surface.

Earthing switch

It is made in a form that is buried in the ground. As a material, steel or copper elements are used, which are buried in the ground. 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 earthing;	12	—	—
	for horizontal earthing	10	—	—
	Rectangular	—	75	3
	Pipe	25	—	2
Copper	Round:	12	—	—
	Rectangular	—	50	2
	Pipe	20	—	2
	Multi-strand rope	1,8*	35

All parts of the grounding loop can either loop back and form a closed circuit, or line up in a solid line. Of course, the closed version is considered more reliable. The dimensions of the contour are selected according to local conditions.

Rice. 5: example of earthing switch installation

The main requirement for the grounding loop is to ensure the established value of the metal-to-earth transition resistance, therefore it is better to place it in a wet layer, periodically watered with water or treated with materials that reduce the transition 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 phase voltages of 380, 220 and 127 V, respectively.

The location of the earthing switch 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 shock 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.

Preparation

On 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 deficiencies.

Calculation of the protection zone

If the lightning protection device provides a grid or roof surface as a receiver, then the protection zone will completely cover the building. But for catenary wire and rod lightning rods, it is necessary to calculate the protective zone.

Rice. 6: protection zone of the lightning rod

Look at the picture, 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 carried out on the basis of СО 153-34.21.122-2003.

Rice. 7: parameters of the protection zone of the lightning rod

Look at the picture, 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 height of the lightning rod installation and the required reliability, a formula for determining the zone that it protects is selected. For this, the data from table 2 are used.

table 2

Reliability of protection	Lightning rod height h, m	Cone height h 0, m	Cone radius r 0, 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 = r 0 × (h 0 -h x) / h 0

Rice. 8: cable lightning protection zone

The figure shows a schematic diagram of the protection zone for a catenary wire lightning rod with its short length. At large distances, due to poor tension at the midpoint, sagging can occur, which slightly distorts the boundaries of the area protected by the lightning rod.

Rice. 9: Parameters of the protection zone of a catenary wire 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 - 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 is the length of the lightning rod.

In terms of 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	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	(0.75-4.2810 -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 = r 0 × (h 0 -h x) / h 0

The choice of material for the 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 in underground areas. But the main disadvantage of a copper lightning rod is its high cost.

Aluminum is characterized by a much lower weight, therefore it creates an insignificant load on the supporting structures of the building. 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, in contrast to copper and aluminum. It is also characterized by low cost. The disadvantages of a steel lightning rod are high resistivity and susceptibility to corrosion.

Place of installation

To install the lightning rod, the highest point must be selected. Therefore, it is placed on the roof of the building, if its height is not enough for the entire structure to fall into the protection zone, special supports or nearby trees can be used. To determine the actual place of installation of the lightning rod, it is necessary to apply the protection zone obtained during the calculation to the site plan.

Rice. 10: protection zone on the building plan

The roof is the most advantageous option as the peak of the protection zone will be located above the building. A freestanding support or several allows you to shift the area protected by the lightning rod to the desired point on the site, and is great for situations where buildings are dispersed throughout the site. Using wood as a support allows you to save on the purchase and installation of metal or reinforced concrete structure, but causes a number of difficulties in the process of operation, therefore, it is considered an undesirable option.

Step-by-step instructions for making a lightning rod

Most simple options for country lightning rod is rod and cable, you can implement them with your own hands. To avoid mistakes and extra costs when installing a lightning rod, observe the following sequence.

Rod

To construct a rod-type lightning rod, perform the following manipulations:

The distance between them and their height is selected in such a way that the conductor does not sag to the surface of the roof and walls.

Rope

The 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 mounted on brackets. In the first case, the lightning rod will sag when the tension changes, therefore, it is much more profitable to mount a rigid copper or steel wire on the bracket. 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 control light is also suitable.

Video instructions

To prevent such consequences during construction works lightning protection circuit is in progress... Private houses are classified by SNiP as buildings of the third class fire safety and are subject to lightning protection in mandatory... The lightning rod is planned not when the house is shining with brand new tiles, but even at the stage of project development. Then he makes a single architectural solution with it.

Type selection

Type of planned lightning protection depends on the initial state of the house and the conditions in which it is located. Lightning usually strikes the highest point of a house or a nearby tree. Trees, antennas, poles, when struck by lightning, create a screen effect and neighboring buildings, cars can fall into the affected area.

The second condition for the protection device is soil type, different types which have unequal conductivity and resistance, which is taken into account when choosing the cross-section of the metal strip and the depth of the contour.

If your house is close to a pond or keys, then the risk of being hit by a discharge is maximum, especially if, due to climatic conditions, the number of thunderstorms exceeds 40 hours per year.

Lightning protection device for a private (country) house

Lightning rod principle simple - protecting the house from destruction by diverting an electrical discharge into the ground. Lightning protection is effective only in the case of a complex solution. A complete system includes internal protection and external.

The first protects the equipment from power surges during thunderstorms. Even if a lightning strike strikes several kilometers away, a surge suppressor is required.

It is not difficult to install a ready-made arrester, but if you do not have such protection, use the safest method - unplug electrical appliances if the lightning front is within 3 km... The time difference between thunder and lightning must be less than 10 seconds.

External lightning protection keeps your home and people safe during a thunderstorm. The device of the simplest lightning rod: a support, a lightning rod, a down conductor and a ground loop.

Lightning rod- metal conductor up to 1.5 m long, receiving lightning discharge. Roof mounted, chimney, TV antenna - any highest place in the house. This method is suitable for metal roofing.

If the roof is made of slate, a metal cable is pulled on wooden supports with a length of 1-2 m and protected with insulators.

For tiled roofs, a lightning protection mesh with down conductors extending from it is pulled along the ridge. The down conductor connects the lightning rod to the ground loop. This steel wire is laid along the wall of the house and welded to the lightning rod and the ground loop.

Lightning protection grounding- 2 electrodes connected and driven into the ground. If there is a circuit, it's already good, but according to the rules, grounding household appliances and lightning protection at home should be shared. Radius protective action the lightning rod is determined by the formula R = 1, 732 h, where h is the height of the lightning rod.

How does this device work? Electricity always leaves along the circuit of least resistance, and thunderstorm lightning is a colossal discharge of electricity with a current strength of 100,000 A.

And a properly made lightning conductor will represent this least resistance, through which the lightning discharge will go into the ground, protecting your home.

This figure shows one of the options for the lightning protection device for your home.

And this video tells about the nature of lightning and about protection against them.

DIY lightning protection of a wooden house

Having dealt with the lightning rod device, it is not so difficult to protect your house or summer cottage yourself. We decided on the type of roof, let's talk about each method of protection in detail.

Lightning protection mesh- mesh made of metal wire with a diameter of 6 mm, made by welding at the intersections. It is laid on the roof and connected by several current leads to the ground loop.

Suitable for non metal roofs when you need to protect one building, because the neighboring buildings are lower on the level. Sometimes this mesh is laid on the roof during the construction of the house.

Lightning protection wire- the cable is stretched on insulators between two metal or wooden supports. They are installed on a ridge, at a height of 0.25 m. The diameter of the wire is at least 6 mm.

A loop is made around the pipe from this wire and connected to the lightning rod. The connection is best done by welding or soldering. The down conductor is also made of the same wire. The result is a tent-shaped protective zone and is suitable for all non-metallic roofs.

Pin lightning rod is a metal pin round, square or rectangular cross-section and a length of at least 0.25 m and a cross-sectional area of ​​100 sq. mm. It takes the brunt of it and has to withstand various thermal and dynamic loads.

It is made of a material that does not lend itself to oxidation (copper, galvanized steel), since it cannot be painted. Minimum diameter section of a rod or gas pipe- 12 mm. If the pipe is hollow, the end must be welded. Installed on the ridge of the roof on a mast of the desired length.

Down conductor serves to direct the received discharge into the ground. We attach it by welding, soldering or bolting. The contact area in this case must be at least twice the cross-sectional area of ​​the parts to be joined.

This type of protection is suitable for metal roofs, and the roof itself must also be grounded. He creates a kind of protective umbrella. You can attach it with nails, staples, clamps.

And finally protective earth... The earthing switch conducts the lightning current into the ground and has a small fraction of electrical resistance. It is laid at a distance of 5 m from the porch and paths.If the soil is wet and the depth groundwater less than 1.5 m, horizontal earthing switches are used. His can be done like this:

1. Dig a ditch along the house to the width of a shovel 6 m long and up to 1 m deep.
2. Hammer three galvanized water pipes with a diameter of 20 mm and a length of 2 m to the bottom of the ditch every three meters. We leave 5 cm on the surface.
3. Lay a wire with a diameter of at least 8 mm and weld it to the pipes. The down conductor must also be welded to the middle pipe. You can weld bolts to the pipes and connect the pipes with a copper cable.
4. Lubricate the bolts with grease and bury the pipes.

If the soil is dry and underground waters are deep, you can build a vertical ground electrode from two rods 2-3 m long, which are driven into the ground to a depth of 0.5 m and a distance of 3 m from each other. They are connected by a jumper with a cross section of 100 sq. m

This grounding can also be used to protect electrical appliances, electrical panels in the house. During a thunderstorm, it is dangerous to be near the ground within a radius of 4 m(you can get under the step voltage). Lightning protection can also be arranged on trees. This is possible if the tree is 2-2.5 times higher than the house together with the antenna and is 3-10 m away from the house. It is made from a piece of wire with a diameter of 5-8 mm, has a one-way descent and one grounding in the form of a loop.

Lightning rods used to protect against linear lightning are ineffective with ball lightning. To prevent such lightning from entering the house in case of a thunderstorm, you need to tightly close windows, doors, chimneys, and ventilation blocks should have a mesh of copper or steel wire with cells of 3-4 cm and reliable grounding.

And finally some tips... To ground a metal roof, storm drains can be used as down conductors. For the convenience of clogging the pipe, you can first build a scaffold. If the dimensions are not known, then the protection zone can be determined using a conventional right-angled isosceles triangle. Aim on the long side (hypotenuse) at the air terminal. The short side (leg) is parallel to the ground.

If the aiming point is below the top of the air terminal, then you are in the protection zone. Do not place down conductor descents near doors. Everything metal constructions on the roof are also grounded. The lightning protection condition requires maintenance and systematic checking of the connections. It is best if they are welding.

You can build two down conductors for reliability. Corrosion must not be allowed, regularly descale it. Open the grounding electrodes every five years, check and replace if necessary. And your lightning rod is on long years will provide you with a safe stay.

in this video you can see an example of lightning protection installation.

The lightning rod is protective device in which a system of conductors conducts an electrical discharge to earth. Lightning protection is the most important element of ensuring the safety of residents and property in a 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;
• earthing switch.

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 loop, which transfers 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 rod mounted on the bed (on the roof, next to the building, on tall tree). With the help of a down conductor (conductor), the pin is connected to the ground loop. For the manufacture of lightning rods, copper, aluminum or steel are used. Moreover, the first one the best option in terms of quality of protection, and the cheapest receivers are made of steel.

The cross-section of a rod-type air terminal must be at least 35 sq. mm, when it comes to 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 the coverage area is not very large. To calculate the area covered, a mental line is drawn from the highest point of the pin to ground level at an angle of 45 degrees. Protected is all space that is in the perimeter triangle. Due to the small coverage area, lightning rods are used to protect small houses, bath buildings, garages, etc.

Note! Lightning protection can be 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 mesh is placed at a certain height above the roofing material, leaving a gap of at least 15 cm.The most suitable objects for using mesh 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 a steel or aluminum wire. The cable is pulled along the ridge of the roof using wooden blocks that act as supports. The smallest recommended cable diameter is 5 mm.

Compared to rod devices, the described devices cover a much larger area. From the point of view of efficiency, catenary wire systems are better than rod or mesh receivers in coping 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 roof 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 by lightning). Also, no flammable materials that can easily ignite are not allowed.

Down conductor

For the manufacture of conductors, a six-millimeter copper, steel or aluminum wire is used. Connections to other elements of the system - the lightning rod and the ground loop - are made by means of bolts or welds. The down conductor needs high-quality isolation from environment(cable channels are suitable). Another requirement is the selection for the down conductor of the shortest path from the lightning rod to the grounding device.

Earthing switch

The ground loop is located near the building. At the same time, they choose a place 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 making a lightning rod, it is necessary to prepare. Moreover, in terms of importance, this stage is no different from the actual process of installing lightning protective system... You will need to make calculations according to the formula, select materials and find right place for the installation of lightning protection.

Calculation formula

Lightning protection is a rather complex and responsible system due to its tasks. When planning it, you need accurate calculations and assessment of potential risks. At the same time, there is no need for overly complex mathematical calculations. You just need to determine the area of ​​operation of the system, based on the formulas. For a rod lightning rod, there are coefficients used to calculate the desired height devices. 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, you will need materials of construction. You will have to choose from 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 was said more clearly, below is a table that shows the minimum requirements for lightning protection components, based on the type of metal:

Material	Lightning rod		Down conductor		Earthing switch
	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, optimal choice material - copper. However, the cheapest option for a DIY 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 required:

1. 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 will also work. Ready-made receivers are available on the market, for example GALMAR or SCHIRTEC.
2. Metal wire of the required section.
3. Grounding devices (metal rods, pipes or tape).
4. Plastic clamps, staples, bolts.
5. Tools for performing work (welding machine, electric drill, hammer, shovel).

Place of installation

The lightning conductor 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 conductor 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 is 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 is not 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 place the receiver at the edge of the roof and fix it to the wall. This approach reduces the risk of lightning striking any part of the roof.

A separate issue is the correct placement of the grounding device. In the event of a lightning strike, a high-power discharge passes into the ground and at this moment there should be no living beings near the ground electrode. Therefore, requirements have been developed for minimum distances from grounding to the wall of the house - 1 m and to pedestrian paths - 5 m. The grounding device should be installed in a place where there is no probability of finding people. In addition, a fence should be installed around the earthing switch and a warning sign should be placed nearby.

Note! Effective work grounding is possible only in wet ground. This must be taken into account when choosing a place for the ground loop. If there is no permanently wet area, you should think about artificial irrigation.

Installation of catenary wire lightning rod

First of all, you need to stretch the wire along the ridge of the roof. It will act as a receiver for lightning. If the roof is made of flammable materials (wood, plastic shingles, etc.), the wire should be placed at a height of at least 15 centimeters from the material. In this case, the plastic retainers will perform the supporting function for it. The ends of the wire are fixed to metal masts (called horizontal receivers).

The down conductor is fixed to the receiver using welding machine 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 harmful effects of moisture on it.

Grounding is created as follows:

1. Dig a trench with a depth of 80 cm.
2. Metal pins are hammered into the bottom of the pit.
3. Connect them steel pipe or tape. For this, a welding machine is used.
4. Take the tape to the section of connection with the down conductor.
5. The down conductor is connected to the ground electrode.

Installation of a rod lightning rod

A high bed is required to mount the rod system. Its functions can be performed, for example, by a TV antenna mast. The receiver is fixed to it with a welded or bolted connection.

Installation of the down conductor and ground electrode system is carried out in the same way as described above when it comes to catenary wire lightning protection. After completing the installation, test the system resistance. The maximum allowable indicator is 10 ohms.

Wood as a lightning rod

To create a lightning rod with your own hands fit an ordinary tree. Moreover, its height should exceed the level of the building's roof by about 2.5 times. The distance to the house should not be less than 3 m.

One end of a 5 mm wire is welded to the grounding device and the connection is buried in the ground. The remaining end will be the sink. He is taken to the top of the tree.

Maintenance of the structure

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 examination of all components of the system. During operation, the metal is so damaged that it is impossible to do without replacing parts.

Pay special attention to contacts. Poor contact leads to system opening and fire. If necessary, they are cleaned of oxide.

The underground part of the lightning protection also needs to be checked. However, due to the laboriousness of the process, it is allowed to do this not every year, but once every three years.

Lightning protection - so much important element ensuring the safety of residents and the building, that it is worth taking on its creation only with full confidence in your knowledge and experience. If this feeling is not enough, it is better to entrust the work to professionals.

Lightning is a natural phenomenon with great destructive power. The electrical charge that lightning contains tends to reach the highest point, most often the roof of a house, antenna, tree. The consequences of such a hit are a fire, a power surge, as a result of which people can die, the building is damaged, Appliances, electronics. Therefore, during construction, special attention must be paid to protecting the house.

There are two types of lightning protection of a private house - internal and external.

The work of internal lightning protection is aimed at protecting equipment and house wiring from overvoltage. External protection Directly conducts the lightning charge into the ground.

lightning protection of a private house photo

External lightning protection structure

External protection consists of a lightning rod (lightning rod), a down conductor and a ground electrode.

Important: the grounding of the lightning rod must be separate from the general grounding circuit of the house.

The lightning rod directly catches the lightning, this is primarily due to the material from which it is made, after which, with the help of the down conductor, the energy goes into the ground.

Depending on the principle of operation, the system external lightning protection subdivided into passive and active.

Passive system

Most often used passive system lightning protection. 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 - the material of the roof, the type of roof, the type of soil. When installing such a system, the costs of an annual operational check should be taken into account.

The following types of passive protection are distinguished:

pin - the lightning rod is installed on the roof and with the help of a down conductor (wire with a cross section of at least 6 mm), which is attached to the ground electrode, the charge is discharged to the ground. The system is simple in design, most often used on metal roofs, inexpensive, but has small area actions.

Important: the lightning rod for metal roofs is made of round steel and installed 1.5 - 2 m above the highest point of the house.

catenary wire - here a wire is used as a lightning rod, stretched between two supports, which is connected to the down conductor and the ground electrode. This design is preferable for temporary structures, pavilions, as well as roofs covered with slate.

Important: the cable or wire is stretched at a height of up to 50 cm from the roof.

mesh - the most complex installation system, it is used on roofs covered with metal tiles, and is a mesh.

Active system

The principle of active lightning protection is that the air terminal ionizes the air around it, thereby intercepting the lightning charge. Such a system is much more expensive than a passive one, but its radius of action is about 100 meters, which will allow you to protect not only the house, but also the nearest buildings. The main advantages include - compactness, not flashiness, autonomy of work.

The structure of the internal lightning protection of a private house

The internal protection of the house is to install special equipment, which will be directly connected to the switchboard. 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. Their principle of operation is to drain the excess impulse through the ground.

SPD connection diagram

Grounding a private house

Grounding the house plays a big role in protecting the house from various accidents, including a lightning strike, a power surge in the network due to an accident. There are several types of grounding, among which there are fundamental, deep and ring grounding. Before installing grounding, it is necessary to make a calculation taking into account the resistance of the soil, freezing of the earth. You can make a ground loop yourself, for this you need ground electrodes made of copper or steel, as well as a metal structure that will connect them to each other. Earthing switches with metal connections must create a rigid contour in the form of an equilateral triangle. Equal angles, fittings or pipes, which are connected with metal strips, can be used as vertical ground electrodes. It is best to use welding as an attachment. 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 pit. Vertical ground electrodes are driven at the same distance from each other, at least 2 meters deep. They connect horizontal stripes between themselves, the length of the strips is 1.2 m. A bus is connected to one vertex of the triangle, which is laid to the foundation of the house. By using 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 performed in the same way, or in a linear way. In which the ground electrodes are connected to each other on the same line. Use at least three ground electrodes. 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 borne in mind that when the first earthing switch fails, the entire system stops working.

Lightning protection in a private house with your own hands.

As a lightning rod, you can use a metal rod, 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 higher than the highest point of the roof. You can fix it directly to the roof, antenna, chimney.

Important: the lightning rod must not be painted or insulated.

The lightning rod is connected to a down conductor, which is a wire with a cross section of at least 6 mm. Welding or bolted connection is used to connect the lightning rod and the lightning rod. The down conductor is lowered from the roof and directed to the ground electrode in the ground. The wire is lowered in such a way that it is away from windows and doors. The down conductor is reinforced along the wall using special fasteners.

Important: to avoid turns of the down conductor at an acute angle - it is fraught with the appearance of a spark charge.

Fastening the down conductor wire with a ground electrode.

Lightning protection requires annual maintenance, checking the integrity of connections, fasteners, if necessary, we carry out stripping and tightening of bolts.

Rod lightning rod at home:

lightning rod;

wooden mast;

conductive wire;

earthing switch;

the junction of the end of the down conductor and the ground electrode; 6 - foundation;

soil level.

Lightning protection of a private house with a roof made of metal tiles is made in the form of a mesh, which is made of wire and is attached directly to the tiles.

Important: when installing lightning protection, the roof must have a fireproof backing.

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