There should be at least 150 cm to balconies and window openings from power lines. The distance is measured in the horizontal plane at the maximum deviation of the wires and is calculated in accordance with the established SanPiN and SNiP standards. It is important to fully comply with these standards, since the fire safety of residential premises depends on their implementation.
Field with power line supports Source asutpp.ru
What is a power line
High-voltage power transmission lines are the main element of the country's energy system. Most often, the wires are placed above the ground on special supports.
Experts have long noticed the negative consequences of constantly being near power lines, so standards for a safe distance from residential buildings were determined, which take into account the voltage of the lines. The result of the calculation was the emergence of special sanitary zones - areas located next to high-voltage supports. Such areas are also called “encumbrance zones,” where it is prohibited to erect buildings or sell plots for individual housing construction and gardening non-profit partnerships.
Sunset and power line supports Source rusenergetics.ru
The influence of power line radiation on humans
Electrons pass through the wires, resulting in an electric field. Different types of current can have a constant or variable value. If the current constantly changes from plus to minus, then the field strength changes more frequently.
At the end of the 20th century, research began on the influence of electric fields on the human body, vegetation and wildlife. As a result, WHO determined the maximum permissible radiation doses in Hertz. In many states, documentation has appeared prohibiting the construction of industrial and residential facilities in close proximity to high-voltage cables.
Wires on power transmission towers Source ntc-retec.ru
Voltage danger
High-voltage lines differ in dangerous and safe voltages. The higher the power of the line, the greater the distance the electric field operates.
There is a direct relationship between these values. To accurately calculate the voltage, it is necessary to take into account that the connecting phase of one phase may have a different number of wires. For example, 2 wires typically correspond to a voltage of 330 kV, 3 wires to 500 kV, and 4 wires to 750 kV.
Power line supports and pond Source energybase.ru
Harm to technology and means of communication
The increase in the length of electricity transmission routes across the country has led to the fact that the electromagnetic field of power lines began to affect the reception of television signals and radio communications.
What are the causes of radio interference from overhead lines, and why do they affect TV reception? As a result of a corona discharge in space, electromagnetic disturbances arise near the wires, which cause interference for radio receiving devices.
How does weather affect radio interference? Depending on meteorological conditions, interference may decrease, increase, or disappear temporarily. For example, when rain washes away contaminants from wires, the level of interference on radio channels and communication lines also decreases. They do not increase during fog or dew. But in rainy weather, the increase in interference on terrestrial television occurs in proportion to the intensity of the rain.
When using overhead line supports for the installation of fiber-optic communication lines, it is necessary to take into account that the fiber-optic line will be subject to an electromagnetic field. The potential induced in this case will cause its premature failure. To avoid this moment, you need to find the point of zero potential and attach the optical cable to it.
High-voltage power lines have an unsafe effect on steel main pipelines, including gas pipelines in the following cases:
- parallel running of the pipeline and power lines;
- at the places of their intersection;
- in places of approaching and moving away from each other.
The danger lies in the fact that the alternating electromagnetic field created by the overhead electric line affects the pipeline located in the ground. The induction that appears in this case leads to the formation of a longitudinal EMF in the pipeline. The health and life of service personnel is at risk.
How does this process affect the pipeline itself? Due to alternating current, electrolytic corrosion of the metal occurs. Electrical devices associated with the pipeline may fail. In addition, if a power line breaks, the pipeline may be under high voltage.
To ensure safety, pipeline protection devices (PPD) are used:
Does the magnetic field of overhead lines affect mobile communications and phones? Much depends on the operator, on the technical capabilities of the phone, on the distance to the power lines. At high humidity, when corona discharges are clearly audible, the connection at the support may be weak or even absent. But, in general, overhead lines do not have a significant impact on cellular communications.
The same can be said about the effect of overhead lines on drones and other radio-controlled models. Interference occurring on power lines can interfere with the control of these devices. But, basically, nothing interferes with the movement of quadcopters. They are even planned to be used for technological inspections of overhead electrical routes.
Definition of remoteness
The size of sanitary zones along power lines depends on the voltage level. To determine their boundaries, draw a conditional line along the projection of the wires onto the earth's surface. For even greater security, these values should be multiplied by 10.
Power lines against the backdrop of sunset Source elektrovesti.net
A distance of 100 meters from power lines can be considered completely safe for humans. During rainy weather, a large number of oppositely charged ions are released into the atmosphere, which leads to an increase in the area of electric fields and their spread to adjacent areas.
Not only residential and industrial buildings, but also garages, fences and other structures cannot be located on the territory of the sanitary zone. It is also prohibited to plant trees in these areas.
Residential buildings, children's and educational institutions should not be located under the wires. In this case, it is allowed to build production structures of the first and second levels of fire resistance in accordance with fire safety standards.
Wires with birds Source birdsandpowerlines.blogspot.com
The distance from power lines is a conditional value that provides for the safe functioning of people at a sufficient distance from wires and supports. Such a distance cannot guarantee the complete absence of any exposure to the residents of the house.
Underground installation significantly reduces the size of the danger zone, which is no more than 1 meter on each side of the electrical cable. At the same time, moving power lines underground requires investing a significant amount of money. Compared to the air type, the cost of underground installation increases several times. Therefore, this solution is still rarely used in practice.
For large urban settlements, underground cable laying is more typical. In this case, the wires are placed in special trenches, which are laid in blocks or tunnels. The depth of installation is about 1 meter. In this case, it is necessary to organize quick access to the lines during an emergency.
Harm to human health
It should be noted that all electrical devices can have harmful magnetic and electrical effects on the human body, which can lead to both deterioration of health and exacerbation of chronic diseases. Some of the recent studies by Kosov A.A. and Barabanov A.A. , the role of electromagnetic fields and radiation in the human security system confirmed the direct dependence of most biochemical reactions on the level of externally induced voltage. In turn, powerful power lines have a much greater impact, so a standard for approaching the source has been established.
Figure 2: Electric field strength differences with distance
So, depending on the location, it is allowed:
- In populated areas, the voltage is no more than 5 kV/m;
- At intersections of highways and pedestrian roads up to 10 kV/m;
- Outside populated areas no more than 15 kV/m;
- In hard-to-reach places (mountains, forest belts, etc.) up to 20 kV/m.
If the above values are not observed during the construction or operation phase, power transmission lines may be relocated. In other cases, prolonged exposure to magnetic radiation of 0.5 kV/m is allowed.
However, there are a number of situations when, when performing technological processes or operations, a person may come close to or be directly in powerful electromagnetic fields. In this case, a restriction on the time spent near overhead line wires or supports is introduced for different voltage levels:
- At 5 kV/m – the duration of stay during the shift is not regulated;
- At 10 kV/m - the residence time should be no more than 3 hours;
- At 15 kV/m – no longer than 1.5 hours;
- At 20 kV/m – no more than 10 minutes;
- At 25 kV/m – no longer than 5 minutes.
If such standards are observed for staying near power lines, the human body recovers naturally within 24 hours, the chemical composition of the blood and the condition of the internal organs return to normal. If the duration of exposure to magnetic lines is longer, then shielding and special protective equipment are used.
Rice. 3. An example of human protection from electromagnetic radiation
Voltage in residential areas
Within cities, there are numerous power lines on the streets, the voltage of which usually does not exceed 10 kV. Such values do not pose a risk to human health. The wires provide electricity to homes; they pass over residential areas and fenced areas.
Mountain and power line supports Source neftegaz.ru
Standards for safe use are also taken into account here. Buildings and structures are located at a distance from power lines of at least 5 meters. This line is the front boundary along which all communications pass. All wires are within this zone, except for the cable connected to the house itself.
An insulator with a fixed wire is placed at a height of 275 cm on the wall of the building. It should not enter the building in the areas of bedrooms, children's rooms and living rooms. The use of storage rooms, utility rooms and corridors is allowed.
City and power line pylons Source fadedead.org
The wires can hang over the tracks no more than 350 cm. Moreover, this distance should be more than 6 meters above the tracks for cars.
In single-story residential areas, power lines are usually located on one side of the road. On the plan this place is marked with a red line. The distance from the power line support to residential buildings must fully comply with PUE standards. To connect the building from the opposite side to the wire, it is necessary to use additional poles. Insulators should be located at a height of 620 cm. The shortest distance from a 6 kV line to vegetation is 2 meters.
Sanitary protection zones
Security zones near power lines are fixed in accordance with the requirements of Rostechnadzor. The boundaries of protected areas are marked in the State Cadastre. When purchasing land or housing, you need to carefully study the cadastral documentation in order to subsequently avoid unpleasant factors.
Marking of the territory is carried out using signs installed on the supporting structures of the power line at a distance of 250 meters from each other. The signs indicate the size of the zone, the power of the line in kW and the contact information of the owner of the power line.
Pole options
On the territory of the sanitary protection zone it is prohibited:
- launch foreign objects, for example, kites or flying objects towards power lines;
- climb onto supporting structures;
- block the passage and access to supporting structures;
- drain corrosive liquids or substances that promote corrosion into the ground, since they negatively affect the supports;
- organize landfills;
- plant or cut down bushes and trees;
- carry out blasting operations;
- use agricultural machinery higher than 4.5 meters;
- make fires.
In these territories it is prohibited to organize events requiring the participation of a large number of people.
Scheme of a security zone along an overhead power line
Sports and children's playgrounds cannot be installed there either. Thus, the sanitary protection zone cannot be used to its maximum. Compliance with all rules is mandatory.
Electromagnetic radiation protection
As you move away from the power line, the electric field has less and less influence. The standards specify the values when this indicator becomes acceptable, but the radiation does not completely disappear. For greater safety, it is necessary to take into account a distance of 10 times the recommended values.
Various cables and electrical equipment are also located inside the home. During their operation, electromagnetic radiation is created, which can spread over a distance of up to 2 meters.
Some of the most dangerous devices are irons and refrigerators, and a person can receive the greatest amount of radiation from a TV because they stay near it for a long time. As a result, the total radiation rate often exceeds all permissible standards.
Buildings that are located at a distance not exceeding 100 meters from wires with household voltage, as well as 200 meters from high-voltage cables, must be additionally protected from possible radiation.
During the construction of a house, you should carefully study the placement of power lines and, if necessary, immediately shield the facade of the building. If the home has already been built, it is necessary to organize repairs and carry out work to protect against electromagnetic radiation. The roof must be covered with a metal covering. A steel mesh is laid around the perimeter of the walls, which is hidden under the interior decoration.
The new building should be constructed from cinder block. This material has the ability to reflect and absorb radiation well. The roof and mesh in the walls must be grounded.
What additional methods of protection are there?
To increase protection from the harmful effects of fields generated by power lines, additional protection options are provided. These include:
- Shielding devices for voltages from 10 kV.
- Roofs made from metal tiles or corrugated sheets should be grounded. The roof is grounded only if the distance from it to the power lines is small.
- The presence of reinforcing mesh - the kind that is laid in reinforced concrete walls.
At present, the harmful effects of power lines on human health have not been officially confirmed. Such studies have not been conducted in Russia. But this does not mean that the problem does not exist.
Possible damage zone in an accident
According to the observations of foreign scientists, a huge number of people who live or work in close proximity to high-voltage structures experience their negative influence, they often feel unwell. In addition, the risk of nervous ailments and the development of cancer increases.
