How is grounded in a private house
Electricity has long perceived by us asgranted. This is the benefit of civilization, familiar from childhood opens a lot of opportunities, and we are willing to accept the good. Most of us do not care about everything and principles of power, we are quite satisfied with the role of a mere consumer. If a citizen high-rise buildings such understanding of the issue can get away with, the holder of a private home must take into account all the features of arrangement of wiring and grounding in particular. Consider now how is grounded in a private home.
- Earthing natural or artificial
- The order of execution of works
- Basic device regulations
Grounding is necessary to protect. When using certain electrical appliances in their conductive body formed electric potential, sometimes reaching 100 or more volts, exclude the possibility of formation of stress or to prevent its occurrence can not be (each case is a private, depending on the characteristics of operation of the device). If the house is connected to three-phase power supply, and a number of electrical appliances are connected to different phases, it is likely that the rate of potential difference reaches several hundred volts, which is a serious danger to life in case of contact with the body such devices. Therefore, in accordance with modern standards of safe operation, all security appliances in a private house (refrigerator, washing machine, cooker, boiler and so on. D.) Must always be connected to the protective grounding system, then the capacity will go on the ground conductor at the ground.
earthing device in a private houseIt provides for grounding and conductor laid on him to input the switchboard. Earthing is a conductive portion in electrical contact with the ground directly.
Earthing natural or artificial
Natural grounding can be anymetal constructions, which are in contact with the ground, such as metal pipes underground water pipe, metal (except aluminum) shell armored cables laid in the ground, concrete structures of the foundation.
It is forbidden to be used as a grounding pipelines, central heating pipes and sewage pipes as any explosive and flammable substances.
In accordance with the SAE, groundingelectrical installations up to 1 kV can be performed with the use of natural earth electrodes, if resistance or contact voltage installation housing does not exceed the permissible values. The possibility of using these earth electrodes must be determined by appropriate calculations. In the absence or inability to use the natural grounding grounding device in a private house by means of artificial earth electrodes, which can be made independently. Permitted use of steel, galvanized or copper ground electrodes with a circular, rectangular, angular, tubular-section profile, the main thing - they should not be painted or have any other insulating coating.
Grounding conductors may be located in the groundvertically or horizontally at a depth below the level of soil freezing, the connection between the grounding electrodes are carried out only by means of welding, bolting is prohibited because of the possibility of oxidation. Choosing the best method of grounding devices depends on the nature of the soil at the site, discussed below grounding scheme private home is the most simple and reliableoption. Before starting the work necessary to carry out measurements, calculations of soil resistivity, make the project work, and then on the basis of the data obtained to calculate the length of the grounding electrodes and the amount of materials used.
The order of execution of works
At a distance of 5-10 m from the house, close to the entranceswitchboard should dig a trench, about a half-meter depth (the depth of the trench can be longer, depending on the performance of soil freezing), repeating the form of an equilateral triangle at each vertex of which are driven ground electrodes 1.5-3 m (the length of the electrodes depends on the ground resistance ), and the electrodes can be placed linearly, but in any case the distance between them should not be smaller than their length. The electrodes can be used steel rods (minimum round rod diameter - 16 mm), metal angles and profiles (minimum allowable cross sectional area of the rectangular and angular profile - 100 mm, a wall thickness of 4 mm) and the steel pipe (minimum diameter of 32 mm with a wall thickness of 3.5 mm).
To facilitate the necessary driving electrodessharpen their ends in hard soils require drilling. After driving the electrodes they are connected together by welding the metal strip (cross-sectional area of 48 mm2, thickness 4 mm). The same band is used as a conductor leading from the earth electrode to the main ground bus input distribution, the place of his entry into the building is designated as such.
After exiting the strip of land by means ofbolting secure the wire connecting it to the main earthing bar of the electrical input. As such a copper conductor (cross-section of at least 10 mm2), aluminum (not less than 16 mm2) or steel (not less than 75 mm2) wire. The main ground bus shall be copper or steel (using an aluminum rail is not allowed), may be inside the electrical panel or separate from it in an easily accessible location for service.
In case of placement inside the inserter toas it used tire PE, with a separate placement-section ground bus should not be less than the cross section PE conductor supply line. It is also necessary to provide for disconnection of the conductors connected to the bus.
After finishing the work, all the trenches should beuniform fill soil, preferably with a low content of stones. It is necessary to carry out a resistance measurement of grounding circuit, the rate should not exceed 4 ohms. Grounding wiring in the house lay with chains electrical outlets and power appliances, lighting network does not need grounding.
Basic device regulations
- In the case where the probability of occurrence of corrosion, it is desirable to use a large cross section with a grounding or earthing conductors applied with plated.
- It is important to take into account due to the increase in corrosion resistance grounding materials.
- It is not allowed location of earth in a place where the land allowed to dry under the influence of heat pipes.
- Electrode placement depth should be below the frost level ground.
- The distance between the electrodes must be greater than their length.
- The diameter or cross-sectional area of the electrodes must comply with Buyeo.
- The connection between the electrodes should be carried out only a welding method.
- The resistance of the entire ground system should be less than 4 ohms.
Information on how to make the groundingprivate house, of course, tell only a general idea of a serious and responsible process. In any case, the performance of work requires an appropriate qualification.