Lightning protection of buildings and structures without explosive zones. Do you need lightning protection? In what cases is lightning protection of buildings not required?

How to prevent lightning from striking an object?

Lightning protection systems can solve this problem. They “attract” the discharge to themselves and redirect it to the grounding system. While there are no technologies yet that would prevent the elements themselves, lightning protection equipment helps by directing overvoltage pulses into the circuit of the grounding system.

What is the difference between an internal lightning protection system and an external one?

Systems that protect buildings and industrial facilities from atmospheric electricity strikes are called external lightning protection systems. Such systems consist of a lightning conductor, a lightning rod and grounding conductors. In general, this design performs the functions of intercepting an incoming discharge and subsequently discharging electricity into the ground.
Internal lightning protection structures protect electrical wiring in a building, as well as electrical equipment installed indoors, from additional, secondary effects of a lightning strike (for example, pickup or current carryover through grounding or from other sources). The most important component internal systems lightning protection - SPD. It limits surge voltages.

What types and/or classes are SPDs divided into?

According to the three most common classifications - GOST, IEC (valid in the Russian Federation), as well as the DIM specification used in Germany, protective devices are divided into categories according to their testing methods and the location where the device is installed.
The first class of SPD test operations is equivalent to the class of technical requirements under the letter “B” and Type 1; The second class of tests is identical to the class of requirements with the letter “C” and, accordingly, Type 2, the third class of tests corresponds to the class of requirements with the letter “D” and Type 3.

What is the difference between SPDs of the first type and protective devices of the second type?

Protective devices of the first type are usually installed at the entrance to the protected building if the power supply is carried out over the air or if an external lightning protection system is used. In such situations, an SPD is used to divert some of the forward discharge current. According to the GOST R-514352-2008 specification, protective devices of the first type (and, accordingly, the first test class) are tested with current pulses having a waveform of 10/350 μs.
Protective devices of the second type are used to protect structures from secondary, induced impulses. They are installed either near an SPD of the first type or at the entrance to the building (if the risk of part of the discharge entering the building is completely eliminated). When testing SPDs of the second type (and, accordingly, test class 2), current pulses of 8/20 μs are used.

Does the surge protector need to be replaced or inspected in any way after the storm has passed?

The design of any SPD provides for its automatic recovery. It can be turned on and off many times, providing constant protection against electrical surges in the network. Each device is equipped with a status indicator, which signals the need for replacement or any repair of the SPD.

Is the installation of an SPD required in cases where lightning protection equipment in a building or structure is installed in accordance with the standard and grounding is connected to it?

Yes, installation of an SPD is required. An external lightning protection system is designed to remove direct lightning strikes, but it is not able to protect equipment and wiring from the secondary effects of lightning and induced strikes. An external protection system cannot prevent the occurrence of sudden changes in potential differences in the grounding system. A protective system installed outside the facility is not capable of protecting the electrical network from induced pulses, which usually appear in metal structures located near the site of a lightning strike.

Where is the SPD installed: before the meter or after it?

If you need to protect electrical equipment and the meter from secondary surges, protective devices should be installed in front of the meter. The most important thing is to adhere to the main requirement: according to the standards protective device must have no leakage current. Therefore, it is best to choose surge protectors with VG technology developed by CITEL. Such meters, firstly, do not waste electricity when in standby mode, and, secondly, are able to reduce the voltage in the network to an acceptable level in accordance with the third class of protective devices. The specific connection diagram for protective equipment in front of the meter should be agreed upon with any branch of the MZK-Electro company.

Is it necessary to install a grounding system on site (in a cottage) if there is a functional SPD at the entrance?

According to the rules for electrical installations, it is necessary to install grounding at the entrance to the facility. Moreover, without connecting the grounding conductor, the protection device will not work.

Is it necessary to connect the grounding loop of the cottage to the grounding of the lightning rod?

Yes, it's necessary. All documents defining the installation of a facility’s lightning protection system, as well as the organization of power supply to industrial structures, require the creation of a circuit of grounding elements covering all the facility’s protective systems. As a result, the risk of sparking or perforation of the protective system is reduced, and, accordingly, the level of safety at the facility increases. To ensure adequate protection of devices located indoors from secondary effects following a lightning strike, protective devices must be used. When an external lightning protection system is installed in the protected building, the use of a class 1 SPD is mandatory.

What are active lightning rods intended for?

Such devices are mounted on a high metal match. They are used to ionize the surrounding air before being struck by atmospheric electricity. The conductivity of the air increases, and lightning, which follows the path with the least resistance of the medium, is “attracted” to the receiver. Active devices - this is one of the differences from passive ones - have a much larger radius of the protective zone.

A lightning strike directly into a building causes a fire due to the deformation of materials and a sharp and strong increase in their temperature. Therefore, lightning protection of buildings and structures is a necessary element in the equipment of any civil, administrative or industrial facility. This is a set of technical measures to ensure the safety of the structure, equipment, property and people in the building. And this is far from a far-fetched problem, since on average more than 40 thousand thunderstorms occur on the planet per day. But there is another aspect to modern world is damage or complete failure of electronic equipment as a result of overload caused by even remote lightning discharges. And this is a very significant problem in the times of computers and the Internet.

To prevent this from happening, a comprehensive system of lightning protection for buildings and structures has been developed. A lightning strike, even at a distance of several hundred meters from an object, causes a powerful impulse that can travel to nearby buildings, damage it and create a fire. Due to the different nature of the threats, two systems have been developed: external lightning protection of buildings and structures and internal. Each of them is designed to solve specific problems.

The external system must catch lightning heading into the building, transport it through a special outlet into the ground, while completely blocking the possibility of causing damage to the structure and the people in it. Internal lightning protection can reduce electromagnetic effects on communication systems located at the facility. Such systems are mandatory regulatory documents both at the stages of project development, construction or reconstruction, and for the operational period of all types of objects and industrial communications, regardless of ownership and But the situation is far from being so simple, since there are two documents: lightning protection of buildings and structures SO 153-34.21.122-2003 and RD 34.21.122-87. These instructions are not equivalent.

Fundamentally, the design of lightning protection for buildings and structures depends on the functions that it must perform. The external system consists of an lightning rod, a down conductor and a grounding element. The internal one is more complex - these are lightning arresters, protection devices against sparks and gas, barriers for lightning protection. In America and Europe, the requirements for these systems are much higher than in our country. Lightning protection devices there activate their functions already in the event of a threat of discharge due to special sensors capable of detecting an increase in voltage in the atmosphere. These are so-called rod lightning rods. They are able to protect a much larger area.

People have long understood that high-quality lightning protection of buildings and structures means ensuring the safety of people and property from the threat of fire and death. This is primarily a guarantee of your own well-being.

Lightning protection is a set of measures aimed at reducing material damage and injuries to people from lightning strikes.

Lightning protection device on the roof

Dangers from lightning strike:

• complete or partial destruction of structures and buildings, utility networks;
• failure of electrical appliances located in the lightning strike zone;
• injuries and death of living organisms caught inside or near a structure struck by lightning.

What is lightning?

Lightning poses a great danger both to humans and to buildings and structures. Lightning is a high-power electrical discharge that, if hit, can destroy structures and disable electrical appliances and power lines. When constructing high-quality lightning rods, the number of injuries and destruction of structures and utility networks is reduced. The nature of lightning is such that upon reaching the lower layers of the atmosphere, the strike occurs at the highest point within the radius of the danger zone.

The main condition for the formation of thunderclouds is rapid temperature changes and high humidity. Under such conditions, negatively charged clusters of clouds appear in the atmosphere. Due to electrostatic induction on a moving charged cloud, discharges are formed in the atmosphere. Those. Conventionally, it is a capacitor, and the distance between the cloud and the surface of the earth is the gap between the plates. Over time, the electric field strength increases, and tall structures (trees), ionizing the air, reduce the resistivity and provoke lightning strikes to the ground.

Thanks to this property, structures have been developed that are capable of taking a blow and discharging dangerous potential into the ground without damage or fires. Standards for the design and installation of lightning protection: PUE, instruction RD 34.21.122-87, GOST R IEC 62561.2-2014, SNiP 3.05.06-85. Lightning rods are a mandatory measure of protection against lightning strikes if the building is not located in an urban high-rise building, if there is a pond nearby, etc.

Damaging factors of lightning

1. Primary. Characterized by thermal and mechanical effects. A direct lightning strike on a building or power line, resulting in the possibility of a fire. Without additional equipment, protect against primary factor impossible. A lightning protection device is required.

Effect of lightning: melting of metal structures (less than 4 mm thick), partial or complete destruction of buildings made of concrete, brick and stone (due to mechanical impact). Rapid heating of structures causes stress in them, provoking explosions (instruction RD 34.21.122-87).

1. Secondary. When a discharge hits nearby structures, electromagnetic induction appears in the electrical network, which can damage electrical appliances. To protect against a secondary factor, it is enough to disconnect everything from the network electronic devices. This factor is impossible without the manifestation of a primary influence (instruction RD 21.122-87).

Appears as:

• electrostatic induction, expressed by sparks between metal surfaces of structures and electrical appliances. Caused by static charges from clouds onto ground structures;
• electromagnetic induction. Occurs during a lightning discharge due to a changing magnetic field. Induction causes heating of closed circuits and is accompanied by heating that is not dangerous for equipment and people.

Because Lightning is an electric charge, its movement occurs along the path of least resistance. Lightning protection must effectively conduct charges to the ground. When lightning strikes lightning rods, the current goes into the ground without causing damage to buildings inside and outside the protection zone.

The type of lightning protection depends on the type of building, electrical appliances, type of grounding of the electrical network, and the frequency of thunderstorms in the selected climatic region.

Cable lightning protection of a building

Based on the need for lightning protection, buildings and structures are divided into categories:

1. Category 1. Explosive and flammable substances are not permanently stored in buildings. There is a process of processing and storage of hazardous substances openly or in unpacked containers. The occurrence of explosions in such structures is accompanied by significant destruction and human casualties (RD).
2. Category 2: In buildings, hazardous substances are stored in sealed containers. Explosive mixtures are formed only in the event of industrial accidents. The explosion is accompanied by minor destruction, without casualties (RD).
3. Category 3. A direct lightning strike causes fires, large destruction of buildings and utility networks, and injury to people and animals. Such buildings must have effective protection against direct lightning strikes (LD).

Protection options

1. Active. New look protection against lightning strikes. Artificially attracts discharges to itself using a built-in ionizer (ID).

Active lightning protection

Advantages:

• 100% performance;
• eliminating the appearance of a secondary factor of lightning damage.

Flaws:

• Price.

1. Passive lightning rods. The peculiarity of the work is that lightning does not strike it in all cases.

Flaws:

• does not work in all cases.

Advantages:

• high reliability;
• low cost of work;
• possibility of construction manually.

Type of protection (RD and GOST R IEC 62561.2-2014)

External type

Protects buildings from the primary factor of lightning - from destruction and fire. Allows you to intercept discharges and deflect the blow to the ground.

During a lightning strike, lightning rods take up the current and conduct it through the system into the ground, where the energy is completely dissipated.

External lightning protection of a building

Requirements for lightning protection - with proper design and installation of the system, complete safety is ensured outside and inside the building.

Types of external protection (instruction RD 34.21.122-87):

• mesh lightning rod;
• lightning rod;
• stretched lightning rod.

Cable structure for protection against lightning strikes

Components of lightning protection (RD and GOST R IEC 62561.2-2014):

1. Lightning rods are structures that intercept the discharge. They are made of metal, usually stainless steel, copper or aluminum.
2. Descents (down conductors) are metal outlets along which the discharge is diverted from the lightning rod to the grounding conductor.
3. Ground electrode is a protective grounding device consisting of conductive materials that are in contact with the ground. It has an external and underground part (ground loop).

Internal type

Protects homes from secondary exposure to electric current. Consists of a number of surge protection devices (SPDs). The purpose of the devices is to prevent the failure of household electrical appliances from overvoltages in the electrical network, which are caused by lightning strikes.

Overvoltages can be caused by direct (when lightning strikes a building or power line) and indirect (strikes in the immediate vicinity of structures or power lines) lightning strikes.

Based on the type of impact, there are several types of overvoltage:

• 1 type Caused by direct impacts, they pose the greatest danger.
• Type 2 Caused by indirect current shocks, the stored energy is 20 times lower than in type 1 overvoltages.

SPD types according to GOST R 50571.26-2002

• 1 type Capable of withstanding current loads completely from the resulting lightning discharge. Type 1 SPDs are recommended for installation in rural areas with overhead power lines in buildings with lightning rods, in detached buildings located in close proximity to high objects.

• Type 2 Used in conjunction with type 1. The devices are not able to withstand lightning strikes. The permissible surge voltage is 1.5..1.7 kV.
• Type 3 SPD type 3 is used after stage 1 and 2 protection. Designed for installation at the consumer's site: surge protectors, automation devices on household electrical appliances (boilers, etc.).

SPDs are installed together with automatic switches to prevent burnout and fire in the electrical panel. Long-term overvoltages can damage the SPD.

Input circuit breakers with a rated operating current of less than 25A can act as SPD protection (GOST R 50571.26-2002).

Lightning protection connection is carried out according to two schemes:

1. With safety as a priority. The SPD is not destroyed, lightning protection works uninterruptedly. In the event of a lightning strike, it completely disconnects consumers.
2. With continuity as a priority. In this case, disconnecting consumers is unacceptable; in the event of a lightning strike, lightning protection is turned off.

When installing devices, a minimum permissible distance of 10 m should be maintained, which ensures the necessary inductance for triggering the machine of a higher stage.

Surge protection device type 1

It is possible to install 1st and 2nd stage SPDs together in one housing (GOST R 50571.26-2002). For each grounding system, SPDs are designed accordingly.

Rod lightning rod

It is installed on the roof of buildings so that the structure is higher than all other points. To maintain aesthetics appearance at home, the lightning rod should be installed on a separate support (tree).

The following are used as lightning rods (according to the PUE): angle steel 50x50, round steel with a cross-section of more than 25mm 2 .

It is also permissible to use a metal pipe with a diameter of 40..50 mm with sections welded at both ends as a lightning rod.

The number of lightning rods is selected by calculation depending on the size of the structure. For houses with an area of ​​less than 200 m2, one design is sufficient. For buildings with an area of ​​more than 200 m2, it is necessary to install two rods, the distance between which should not exceed 10 m. To prevent current flow into the house, the rod is secured to the roof with insulating materials, for example, wooden blocks etc.

Excavation work for lightning protection installation

Cable lightning rods

They are used to protect long buildings and structures and high-voltage power lines, i.e. for narrow, long structures.

The main element is a metal cable that is suspended along the entire length of the roof. It is fixed on wooden supports so that there is no contact with the roof surface. At least 2 down conductors are constructed on all sides of the building.

For lightning rods, galvanized steel rope TK with the required design cross-section, but not less than 35 mm 2, is used. The design of cable lightning rods is carried out taking into account the area's icy conditions and the requirements of the PUE. The coverage area of ​​this type of lightning rod has the form of a triangular prism, the upper edge of which will be a tensioned cable on the roof of a building. If the roof has a large slope or several structures of different heights, it is necessary to install lightning rods in order to reduce financial costs.

In the case of rod and cable lightning rods, the distance from the nearest structures must be at least 15 m, or installation is supposed to be on different sides of the building.

Mesh lightning rods

They are made of steel (aluminum) wire with a cross-section of 6 mm in the form of cells with an area of ​​no more than 150 mm 2 so that the mesh does not have points of contact with the roof (6..8 cm from the surface). The mesh is stretched over the entire roof area along isolated supports, with a total size of at least 6x6 m. Down conductors are laid in the corners of the building for every 25 m of the perimeter.

All protruding parts of the structure must fall into the protective area of ​​lightning rods. All ventilation and gas exhaust pipes must be within the lightning protection zone, subject to their mandatory protection with special structures.

Free-standing lightning rods are used in the following cases:

• it is necessary to protect several buildings with one structure;
• It is impossible to install lightning rods on the roof.

Metal lightning rods are used to protect buildings with a height of more than 30 m.

Down conductors

The task of down conductors is to effectively remove the charge from the lightning rod to the grounding structure.

As down conductors, steel wire with a diameter of 6 mm and a metal strip with a wall of at least 2 mm and a width of 30 mm are used.

Provided that the walls do not contain conductive elements, down conductors are fixed along the wall anywhere, subject to the clearance of proximity to doors and windows. To secure the structure, bolting and welding are used.

The number of current collectors is taken based on the number of lightning rods. For rod rods, it is taken equal to the number of rods; for mesh and cable rods, the minimum number is at least 2.

Grounding

One circuit is constructed with a common ground electrode of the electrical network. The simplest design is a triangular ground loop. The tops are vertical electrodes driven into the ground to a depth of 3 m. The optimal distance between the peaks is 3m.

A horizontal grounding conductor (connecting the vertices of a triangle into a single structure) is laid to a depth of at least 0.5 m. The connection is made exclusively by welding.

Installation of lightning protection

For private houses, passive lightning protection rods are most often built.

Preparatory work:

• First of all, it is necessary to carry out all measurements: width, height of the house, estimated protection radius (for rod lightning rods).
• After this, it is necessary to determine the height of the lightning rod and the method of securing it.
• The length of the down conductor is calculated after determining the installation point of the lightning rod. The path from the shock receiving point to grounding must be the shortest, therefore the design of complex structures is not recommended, connections in the form of a ring are prohibited.
• The grounding element, according to PUE and SNiP, must be located at a distance of at least 1 m from the wall of the building, and must not cross pedestrian paths and porches.

After accurate calculations length and grounding design, it is necessary to proceed directly to construction and installation work.

Grounding device:

• For grounding, angle steel 50x50 (GOST 8509-93) or strip steel 40x4 (GOST 103-76) is used. Round steel can also be used.
• The grounding loop is made in the form of a polygon, into the vertices of which vertical electrodes with a length of at least 2 m are driven. The vertices of the triangle are connected by welding with strip steel into a single metal structure.

Installation of lightning rod:

• Wooden supports are installed on the roof of the building, installation on which completely eliminates contact of the rod with the roof of the building.

Down conductor installation:

• The last stage is the installation of a down conductor and the connection of all lightning protection elements. Down conductors are mounted on special structures - skates, which also prevent contact with the surface of the house.
• After completion of excavation and construction and installation work, it is necessary to measure the resistance of the lightning rod and whether the obtained values ​​correspond to the calculated values.
• For wooden houses The process of constructing a lightning rod system is similar. All elements of the lightning protection structure must be 150 mm away from the wall plane.

Lightning protection for wooden houses

Internal protection of buildings and structures

SPDs provide protection of electrical equipment from surge voltages and large inductive loads.

Sources of surge voltages during thunderstorms:

• DLM (direct lightning strikes) into a lightning protection device, strikes into nearby power lines;
• lightning strikes near objects.

SPDs are installed in residential and administrative buildings and industrial facilities. It is mandatory to include an SPD in the power supply circuit in country houses, with one- and two-story building areas (GOST R 50571.26-2002).

Advantages of using SPD:

• reliable protection against surge voltages;
• low cost of devices.

The operating principle of the devices is based on the nonlinearity of the current-voltage characteristic. With a significant increase in voltage, the varistor retains the ability to pass electric current.

The devices fail after several protection activations. The SPD must be checked after each operating cycle.

Fuses are included in the circuit in front of the SPD to protect against heavy currents.

In networks up to 1 kV, three stages of surge protection are provided:

1. SPD 1st stage. Class B. Designed for current surges up to 100 kA. Installed in prepared metal cabinets in the input distribution device or on the main electrical panel.
2. SPD 2 stages. Class C. The amplitude of pulse currents is 15..20 kA. They are used in areas completely protected from direct lightning strikes. Installation is provided in distribution panels at inputs to buildings and premises.
3. SPD 3 stages. Class D. Designed to protect equipment from residual overvoltage currents. Installation is provided directly in front of electrical appliances, the minimum permissible distance is 5 m.

SPD selection parameters according to GOST R 50571.26-2002:

• rated mains voltage;
• long-term permissible operating voltage of the protective device - the highest voltage that can be applied before the protection operates;
• Varistor leakage current;
• protection response time;
• pulse current;
• maximum voltage value when current flows through the SPD;
• classification voltage;
• maximum pulse discharge current – ​​the maximum current load during which the device remains operational.

Maintaining the distance between devices is necessary to guarantee the time delay and provide an impulse to trigger the next protection stage:

• between SPDs of 1st and 2nd degrees - at least 10 m;
• between stage 2 and 3 SPDs – at least 5 m;
• between class 3 SPDs (between each other) – at least 1 m.

Each SPD must be connected to the grounding device with a separate conductor.

A 3-stage surge protector protects devices at a distance of up to 10 m. If it is necessary to protect the network further, the installation of the next device is required.

For reliable protection buildings and structures must use internal and external lightning protection. Surge protection devices will not perform their functions if there are no effective lightning rods.

Video about lightning protection

For country houses A high-quality lightning protection system is extremely important, because helps prevent the destruction of houses and damage to property. The construction of passive lightning protection systems can be done with your own hands, in accordance with the requirements of the PUE. Active protection requires high qualifications and cannot be installed without the help of specialists.

Lightning protection is a set of measures aimed at ensuring the safe operation of buildings, structures and engineering communications when exposed to thunderstorm manifestations caused by a direct lightning strike and its secondary manifestations.

Remember:

Installing a lightning protection system ensures the safety of both the building and the people in the building.

Lightning protection of buildings and structures consists of: an lightning rod (lightning rod) and a down conductor (galvanized circle or strip).

The lightning rod receives the lightning discharge and transmits it through the down conductor to the grounding device.

The lightning protection system for a residential building differs from an industrial facility, not only in the scale of lightning protection, but also in its constituent elements.

Lightning protection of buildings

Let's consider lightning protection of buildings. Let's take .

For installation to the surface of the roof, facade, gutters and other structural elements of the building, lightning protection elements are used - clamps, clamps, etc.

The ground electrode serves as a grounding device. Grounding can be implemented various options, more information about grounding can be found in our article: grounding.

The result of high-quality grounding is the execution of an action - the discharge of the resulting charge into the ground.

It's interesting to know that active lightning protection is nothing more than a hyped myth. We will release a detailed article about this soon. Stay tuned.

Lightning protection of industrial buildings (industrial lightning protection)

Let's consider lightning protection of an industrial building, or any other large structure with a straight roof.

A significant difference is the presence of a straight roof; in this case, the method of placing the conductor is used (usually a galvanized circle Ø8 mm is used) in the form of a grid. This creates a kind of shielded barrier that prevents lightning from entering the roof of the building.

In this case, or is used.

The holders are placed over the entire roof surface at a distance of 0.8 to 1.2 meters from each other.

The main requirement, in addition to the relative position of the holders (according to TKP 366-2011), is maintaining the height. The conductor should not be closer than 110 mm. to the roof surface.

This requirement is met by the overall dimensions of the roof holder (code: 30000 or code: 30001) TerraZinc.

It is worth noting that this requirement (to maintain a height of 110 mm) is specified only in technical requirements Belarusian standards and in the requirements specified in technical documentation countries of the former CIS. And yet, knowing the requirements, Polish and German manufacturers continue to produce holders of much smaller height.

Under these conditions, when using such holders, when installing a galvanized conductor in a lightning protection system, it is necessary to use additional pads and extensions, which greatly increases the cost industrial lightning protection.

The Belarusian company TerraZinc LLC proposed a way out of this situation. The enterprise for the production of lightning protection and grounding systems began producing roofing holders in April 2015 own production, meeting all the requirements specified in the technical documentation.

Similar roof holders made in Poland:

All other lightning protection elements: lightning rods; fastening elements and clamps used for mounting the conductor to the facade of a building, etc., are similar to the lightning protection elements used for a residential building.

What effects does lightning have on unprotected objects?

Lightning is characterized by a direct strike - a powerful damaging factor that causes explosions, fires, death of people and animals, destruction (damage) building structures And engineering equipment. With a direct strike, the lightning current can reach up to 200 kA, the voltage can reach 1000 kV, and the lightning channel temperature can reach up to 30,000 0 C.

Secondary manifestations of lightning occur as a result of a direct or close (up to 1 km) lightning strike. Secondary manifestations mean carried electrical potential through the wires of power supply systems and metal pipelines, accompanied by overvoltage pulses up to 100 kV, and electromagnetic interference that interferes with the operation of highly sensitive equipment. In secondary manifestations, a person is injured by lightning current, damage and fire to the insulation of electrical wiring, failure of electrical equipment, loss of databases and failures in the operation of automated systems.

Lightning protection price

To determine the cost of a lightning protection system, we need information:

1. building design;
2. photographs of the building from 4 sides;
3. overall dimensions of the building (length, width, height of the wall to the beginning of the roof, length of the slope, length of the ridge);
4. roof covering material;
5. ridge shape (semicircular/angular);
6. the presence of elements (dormer window, chimney, ventilation pipe, antenna, etc.) protruding above the roof (specify the distance);
7. material and size of pipes on the roof (diameter or perimeter, height);
8. presence of storm drains; location and diameter of drainpipes;
9. facade material (main wall material; insulation material and thickness);
10. the presence of snow retention, roof fencing and ladders for maintenance;
11. type of soil.

Use our service for .

It is necessary to refer to the accompanying documentation to answer what the price of lightning protection depends on, or more precisely to TKR 366-2011:

For buildings of the 1st level of lightning protection, the number of elements used in the lightning protection system will be greater and, accordingly, the price of lightning protection will be higher. And for Level 4 structures, the number of elements used is smaller and the price of lightning protection is correspondingly lower.

At the same time, regardless of the level of lightning protection, a large object requires a large amount of galvanized conductor (galvanized circle or galvanized strip).

And if there is a complex roof structure ( sloping roof, the presence of a large number of output pipes and receiving antennas and other protruding elements located above the roof) the number of lightning rods increases.

All these conditions will influence the formation of the price for lightning protection.

The price of lightning protection will depend on the number of elements required to provide lightning protection and grounding of the facility.

Specialists of TerraZinc LLC will quickly and free of charge carry out calculations and draw up a list of necessary elements for your building. They will also explain why these particular elements were chosen for lightning protection of your structure. And they will answer the question: lightning protection price.

If necessary, we will refer you to a friendly design organization (with a good discount), where they will draw up a project and issue the necessary set of accompanying documentation, in accordance with the legislation of the Republic of Belarus.

A direct lightning strike into a building or structure and discharges from the electrostatic induction of clouds and from the electromagnetic induction of lightning current inside a building can injure people in it, cause fires and explosions, destruction of stone and concrete structures, split wooden supports of overhead lines and damage insulation. Protection from atmospheric electricity must be organized in accordance with the Instructions for the installation of lightning protection of buildings and structures.
Depending on the presence and class of explosive zones in a given building, one of three categories of lightning protection is required or lightning protection is not required at all.
Lightning protection category I is used for industrial buildings with explosive zones of classes B-Ia and B-II. These are all non-rural properties.
Lightning protection category II is used for industrial buildings with zones of classes V-Ga, B-Ib and B-IIa (provided that they occupy at least 30% of the volume of the entire building, and if less, then either the entire building is protected under category III, or part under category II), as well as open installations with zones class B-Ig. Lightning protection for these open installations is mandatory throughout the entire area, while category II lightning protection for buildings is required only in areas where there are at least ten hours of thunderstorms per year. Dividing the territory into districts with different number thunderstorms (thunderstorm hours) are given in the PUE and in the Instructions for the installation of lightning protection of buildings and structures. Lightning protection of category II is performed for ammonia refrigerators, mills, factories or workshops for the production of animal feed, hay flour, fuel and materials warehouses with gasoline, some fertilizers, and pesticides.
For other industrial, residential and public buildings, it is necessary to construct category III lightning protection or not at all, depending on the purpose and nature of the building, and sometimes also on the expected number of direct lightning strikes into this building per year.
This number is determined by calculation depending on the size of the building and the number of thunderstorm hours.
Regardless of the number of expected direct lightning strikes with 20 or more thunderstorm hours per year, lightning protection of category III is constructed in the following cases: for outdoor installations of classes II... III; for buildings of fire resistance levels III...IV - kindergartens, nurseries, schools and boarding schools, dormitories and canteens, children's health camps and holiday homes; for hospitals, clubs, cinemas; for vertical exhaust pipes of boiler houses or industrial enterprises, water and silo towers at a height of more than 15 m from the ground. In areas with the number of thunderstorm hours of at least 40 per year, lightning protection category III is required for livestock and poultry buildings with fire resistance degrees III...V: cowsheds, calf barns and pigsties for at least 100 heads of all ages and groups of animals, stables for 40, sheepfolds for 500 and poultry houses for 1000 animals (all ages); for residential buildings - only at a height of more than 30 m (more than five floors), if they are located further than 400 m from the general area.
Lightning protection category III protects against direct lightning strikes and against the introduction of high potentials into the building through overhead electrical lines, as well as through other overhead metal communications (overpass pipelines, overhead railways).
When entering the building and at the nearest support, these communications are connected to grounding conductors with a resistance of no more than 30 Ohms. At the input, you can use a grounding switch to protect against direct lightning strikes.
On air electrical lines voltage up to 1000 V, passing through an open area or along a street with one- or two-story buildings (if the line is not shielded by tall trees or houses), insulator hooks or pins of phase wires (including street lighting lines) and the neutral wire are grounded no less than every 200 m with thunderstorms 10...40 hours per year and no less than every 100 m with a greater number of thunderstorms (more happens, for example, to the west of Moscow). The grounding resistance should be no more than 30 Ohms; it is made on supports with branches to the entrance to a building where there may be many people (school, nursery, hospital, club), or to livestock buildings, warehouses, as well as on the terminal supports of lines, if from them an entrance is made into any building. In this case, the previous grounding should be no further than 100 m from the grounded end support during thunderstorms of 10...40 hours per year and no further than 50 m if there are more of them.
When lightning overvoltages occur on the line wires, the insulators are overlapped along the surface by an electric discharge onto the grounded hooks, and only relatively small overvoltages penetrate into the houses. Only approaching a few centimeters to the wiring during a thunderstorm can pose a danger, for example, when trying to turn on or off the light or radio. And in the absence or improper implementation of lightning protection, cases of injury to people were observed at a distance of 2 m from the wiring or more.
All of the above applies to both wooden and reinforced concrete supports. For those reinforced concrete supports where lightning is not required protective grounding, zero the fittings, insulating hooks or pins and lamps. A steel rod with a diameter of at least 6 mm is used as a grounding conductor, which is connected to the hooks with a wire bandage and to the neutral wire with a clamp. On reinforced concrete supports, support reinforcement is used, to which the upper and lower grounding outlets are welded for attaching grounding hooks and for connecting to the grounding electrode. Lightning protection groundings on the line are done more often than repeated groundings of the neutral wire.
To protect against direct lightning strikes, rod or cable lightning rods are used. A lightning rod is a vertical steel rod of any profile, mounted on a support located close to the protected object, or on a tree. The distance from the support to the building is not standardized, but it is desirable that it be at least 5 m. The cross-sectional area of ​​the rod, called an lightning rod, is usually at least 100 mm2, and the length is at least 200 mm. It is connected to the grounding conductor by a down conductor made of steel wire rod with a diameter of at least 6 mm, but can be used as down conductors for the metal structures of protected buildings and structures by welding their joints. These are metal trusses, columns, elevator guides, fire escapes.
For lightning protection, it is necessary to make maximum use of natural rod lightning rods: exhaust pipes, water towers and other high structures located close to the protected object. Trees growing closer than 5 m from buildings of III...V degrees of fire resistance can be used as a support for a lightning rod if a down conductor is laid on the wall of the building against the tree to the full height of the wall, welding it to the grounding rod of the lightning rod. However, for any category of lightning protection, it is permissible to place lightning rods directly on the protected building without any additional measures. As an lightning rod, you can use a metal roof, grounded at the corners and along the perimeter at least every 25 m, or a mesh of steel wire rod with a diameter of 6... 8 mm with a mesh size of up to 12x12 mm and nodes connected by welding, applied to a non-metallic roof, grounded in the same way as metal roof. Iron caps over chimneys or a wire ring specially placed on the pipe if there is no cap are attached to the mesh or metal roofing.
No special lightning rods are required if the roof covering consists of metal trusses or reinforced concrete, and the waterproofing and insulation are non-flammable (from slag wool, etc.). Farms are grounded.
It is possible to have one common grounding conductor for protection against direct lightning strikes and against lightning overvoltages carried over air lines or other extended communications and from damage electric shock. Chimneys of power plants and boiler houses or silos and water towers must have a lightning rod height above the pipe of at least 1 m. It is recommended that instead of installing a special artificial ground electrode, use a reinforced concrete foundation of the pipe or tower. For reinforced concrete pipes and towers, steel reinforcement serves as a down conductor, while for metal ones, lightning rods and down conductors are not required at all.
In Fig. Figure 38 shows the protection zone of a single lightning rod of height h. It is a circular cone with a top at a height of h 0 1 and with a zone boundary at ground level in the form of a circle of radius r 0 . The horizontal section of the protection zone at height h x is a circle with radius r x . There is a narrower zone in which the object is protected from a lightning strike with a probability of 99.5%, and a wider zone where the probability of protection is 95%. Rural properties generally require a wider protection zone. For it the following relations take place: h 0 = 0.92h; r 0 = 1.5h; r x = 1.5(h-h x /0.92); h = 0.67r x + h x /0.92.

Rice. 38. Scheme of a single rod lightning rod and its protective zone

As grounding conductors for a lightning rod located on the roof of a protected building, you can use grounding conductors constructed for reasons of electrical safety (repeated grounding of the neutral wire), and if they are far from the lightning conductor or are absent altogether (when powering the building via cables with plastic sheaths), then reinforced concrete can be used foundation of the building, connecting the down conductor from the lightning rod to the foundation reinforcement by welding. From each lightning rod on the roof ridge, two down conductors should extend along both roof slopes to their grounding conductors. If there is no reinforced concrete foundation, a special one is built in the form of two vertical rods with a diameter of 10...20 mm and a length of 3 m, located at a distance of 5 m from each other and connected underground at a depth of at least 0.5 m with a steel strip with a cross-section of at least 40x4 mm.
When the lightning rod is in the form of a grounded metal roof or a mesh on a non-metallic roof, the ground electrode is made in the form of a grounding steel strip 25x4 mm, laid on an edge along the building at a depth of 0.5 ... 0.8 m and at a distance from the foundation of 0.8 m. K these strips must be connected to all metal structures, equipment and pipelines located inside the building.
To prevent people and animals from being struck by step voltage, concentrated lightning protection grounding conductors of all categories are recommended to be located no closer than 5 m from roads and pedestrian paths, from building entrances, in rarely visited places (lawns, shrubs). Down conductors should not be located near doors or gates of livestock buildings. If grounding conductors are forced to be placed in frequently visited places, these places must be paved. For example, when placing a ground electrode along the wall of a barn, the width of the asphalt coating must be at least 5 m from the walls.
Outdoor installations of class P-III, in which flammable liquids with a vapor flash point of more than 61 ° C are used or stored, are protected from direct lightning strikes as follows: the housings of these installations or individual containers with a roof metal thickness of less than 4 mm are protected by a lightning rod (free-standing or installed on the protected structure), and the space above the gas outlet pipes may not be included in the lightning rod protection zone. If the thickness of the roof metal is at least 4 mm or, regardless of the thickness of the roof, the volume of individual containers is less than 200 m3, then it is enough to connect them to grounding electrodes at least 50 m apart around the perimeter of the base.
Extended lightning rods (grounded cables made of multi-strand steel rope with a cross-sectional area of ​​at least 35 mm2) are used to protect long buildings from direct lightning strikes. Then the height of the cable lightning rod is considered to be the height of the cable above the ground in the place where it is closest to the ground as a result of sagging Nm, and the sag is taken equal to 2 m for a building length of up to 120 m, i.e. Nopor = Nm + 2. At the level earth Ro = = 1.7 Nt. At the height Нх (wall height) Rx = 1.7(Нт + Нх/0.92), and if Нх and Rx are given (for example, half the width of the building), then Нт = 0.6 RxHx/0.92 can be found.
Small buildings with fire resistance degree III...IV, located in rural areas with an average duration of thunderstorms per year of 20 hours or more, are allowed to be protected from a direct lightning strike in a simplified manner compared to lightning protection category III by one of the following methods.
1. A tree growing at a distance of 3...10 m from the building is used as a lightning rod support, if its height is at least 2 times the height of the building, taking into account the pipes and antennas protruding above its roof. A down conductor is laid along the tree trunk, which should protrude at least 0.2 m above its top. At the roots of the tree, a simplified grounding conductor is made in the form of a single vertical rod with a diameter of at least 10 mm and a length of 2...3 m or the same horizontal one depth of at least 0.5 m (they are also grounded in three other variants of simplified lightning protection. All connections are allowed to be bolted, not welded). The main simplification in this option is the absence of checking whether the entire structure is included in the lightning rod protection zone.
2. If the roof ridge corresponds to the maximum height of the building, a cable lightning rod is suspended above it, rising above the ridge by at least 0.25 m. The cable supports can be wooden planks attached to the ends of the roof. If the length of the building is more than 10 m, down conductors from both ends of the cable are laid along the end walls or one roof slope at each end, and if the length of the building is less than 10 m, then only one end of the cable is grounded.
3. If it rises above the ridge and other elements chimney, a rod lightning rod is mounted on it, rising at least 0.2 m above the pipe. From it, one down conductor along one roof slope is enough.
4. Metal roofing grounded at one point, and all metal objects protruding above it are connected to the roof, and can serve as a down conductor drainpipes, metal stairs, if they ensure continuity of the electrical circuit.