How to calculate the cross section

If you decide to independently replace or repair the wiring, laid throughout the house, first need to answer the question: the wire of which section will be needed for the qualitative performance of this work. The correctly chosen cable will not only serve you for many years, but also keeps the mass of the problem, the main of which can become overheating and, as a result, short circuit or fire.

The choice of material and sections of the conductor can be carried out in two ways. The first - "on the eye", which is used by the majority of home electricians, and boils down to an arbitrary choice of electroproduction without taking into account the intended load, current consumption and other factors. The second is scientific, based on mathematical calculations based on electrical engineering data.

Each metal used as a core of the electric pipe, its own specific characteristics, and to produce high-quality calculations, you need to know them. Thus, in a copper wire section 1 millimeter, the current density varies in the range of 6-10 amps, and in aluminum - 4-6 amps. With an increase in cross-section area, bandwidth increases. It is extremely recommended to exceed these indicators, since the wires are not calculated for a large current strength and may not withstand the load.

So, to determine the cable cross section, calculate the total total power of all electrical appliances that will be included in the network on the same line. The calculation should be carried out with a margin, for this the resulting amount multiply on the so-called simultaneity ratio - 1.2. Then it is necessary to calculate the current strength sufficient for the operation of the instruments. To do this, divide the resulting total power to your network voltage (usually 220 volts). Having received the desired value, you can easily choose the key of the desired section according to the table of the rules of the electrical installations below.

The calculation of the cable cross section is much simpler. You only need to look at the special table in order to make the right choice. But it should be remembered that this method has its own feature - the cable cross section in the hidden wiring should be a little more than in the open. This is due to the fact that, while under load without air access, the cable will be stronger.

Despite the fact that you calculated the cross section of the wire mathematically, taking into account all the nuances and the laws of electrophysics, do not forget to install the circuit breaker on the line, which in case of excessive excess of the load turns off the electricity and keeps you and your home safe. In addition, due to small bandwidth and exposure to breaking, it is recommended to refrain from using aluminum wires and replace them with copper.

At the end, I would like to note that, as a general rule, the use of a three-core wire is recommended, one of which will be used for grounding. Owing this and outlined information, you without any problems choose a cable capable of withstanding the load of all electrical appliances used in your home.