Input of the cable to the building by air
The electric power supply to the house is one of the most important factors of emergency risk now.
For the whole decades the supply and input in private households was made according to one knurled scheme. Two separate wires from the support brought on the insulators installed on the house wall. Section of the wire was chosen small, 4-6 sq. mm that quite was enough for the available loadings (the electroiron was the most heavy load). But time does not stand still, and on "yard" the 21st century.
Now load of input from electrical household appliances grew many times. It is possible to tell with confidence: there is real "electrification" of all family on precepts of the leader of the world proletariat.
And the list of electrical household appliances and electric tools in many families pretty solid. And it means, and the bringing power supply system has to conform to modern requirements.
Let's consider one of possible options of the supply of the electric power to the house, the vozdushka. As it was told above, earlier "vozdushka" represented two in parallel going wires, often uninsulated as the technology of isolation of cables at that time of time was not perfect. Besides, trees, wind, snow and icicles always constitute danger to input. It is good if the owner young and healthy, can cut off trees in time, upholster icicles. And if pensioner and old age?
Other ways of input of the cable to the building were for this purpose thought up:
- input by the cable on the trosovka to insulators on the wall and the same cable without gap to the counter;
- input "torsady" and also to the counter;
- input by the underground cable.
At once I want to make a reservation that these options have no relation to amateur performance. All works on the supply and input have to be carried out by professional electricians. Your task is only in that being defined what option will suit you better, and to prepare money. That for your money did not palm off on you "hack-work", learn as as it has to be made.
- At distance from the house to the support of "power supply networks" more than 20 meters it is necessary to put the suspension tower. These are additional expenses. It is connected with the fact that at bigger distance the wire can break when sticking snow and ice in the winter.
- If the cable passes over the carriageway, then height of the support has to be not less than 6 m if over the walking path - not less than 3,5 m, and the place of fastening on the wall has to be not lower than 2,75 m. It is necessary to adhere to these norms.
- Between the wall and the support the steel galvanized (soft) wire of 3-4 sq. mm to which by means of collars the cable fastens stretches. The cable aluminum, two-core, in double isolation, section 6-10 of sq. mm. Do not use plastic collars for these works. Under the influence of solar ultraviolet they collapse in half a year.
Why cable aluminum?
It would seem, copper is more reliable, though is more expensive. But the matter is that overhead power transmission lines are conducted by aluminum, and according to modern requirements wiring in the house needs to be executed the copper wire. However copper and aluminum on the joint is the problem. Perhaps, you had to observe at night where there is the connection of input on houses, krasnenky points? These sparks signal that in this house will remain soon "without electricity". So the overheating joint of twist of the copper and aluminum wires representing the fine galvanopara which products of corrosion reduce conductivity of the joint "shines" and because of it increase its temperature.
Another matter if you conduct "vozdushka" copper to insulators on the wall and the exit from the house copper, then the joint can be connected normal twist as it became earlier, but over time such connection will cause all the same problems. And this rupture of integrity of input is not allowed by modern rules in order to avoid plunder of the electric power.
To avoid these problems for many years, it is necessary to join wires from different metals (and homogeneous too) special clips and to pressurize them the thermoshrinkable coupling. Therefore it is desirable that from the junction on the support of power supply networks to the power meter there was the aluminum wire, of course, of the corresponding section from simple calculation 5 A loads of 1 sq. mm of section of the aluminum wire (for copper use calculation 7,5 A loads of 1 sq. mm of section).
The unique option (on norms) is to lay the integral cable from the support of power supply networks to the counter without gap. Each gap by the same rules has to be in the separate sealed-up box. It concerns the cable supply to insulators of power supply networks and to your power meter.
For those who have higher requests on loading use the cable of the torsad SSIC (self-supported insulated conductor) intended for air-lines. Its isolation is expected big differences of temperatures, and it well resists to solar radiation. It has no temperature dip, the cable can be laid without "trossovka".
The VULTURE is two-core and four-core. The most widespread versions — the VULTURE 4/16/25 and VULTURE 2/16/25.
In the wall special clips are mounted, and the torsada is brought to the input automatic machine installed in the power meter guard, and already from it be connected by the copper wire with a section up to 10 quarter of mm to the power meter entrance. The introduction automatic machine without fail is also sealed up to prevent access.
Pass through the wall - it is obligatory through the inserted pipe, with the small blousing. If "cartridge" metal, it it is necessary to ground. If you use the VULTURE cable which has no double isolation, then it is necessary to insert into the cartridge also plastic to the corrugation or the thermoshrinkable coupling. Places of the exit from the boss need to be pressurized for prevention of hit of moisture. It is possible polyurethane foam, but it is better to use silicone. If height of the entrance to the house is not included into norms, it is necessary to establish the metal strut with "gander". For laying of the cable on the wall it is possible to use brackets.
In conclusion there is a wish to note that alteration or mounting of input by the cable does not mean that now trees and bushes are ignored. No, it is all the same necessary to watch the condition of these hindrances.Top