If you decide to independently replace or repair the electrical wiring installed around the house, you first need to answer the question: what cross-section of wire will be needed to perform this work efficiently? A properly selected cable will not only serve you for many years, but will also protect you from a lot of problems, the main one of which may be overheating of the wiring and, as a result, a short circuit or fire.
The choice of conductor material and cross-section can be done in two ways. The first is “by eye”, which is used by most home electricians, and which comes down to an arbitrary choice of electrical wire without taking into account the expected load, current consumption and other factors. The second is scientific, which is based on mathematical calculations based on electrical engineering data. Each metal used as an electrical wire has its specific characteristics, and to make high-quality calculations, you need to know them. So, in a copper wire with a cross-section of 1 millimetre, the current density varies within 6-10 amperes, and in aluminium – 4-6 amperes. As the cross-sectional area increases, the throughput also increases. load.
So, to determine the cable cross-section by power, calculate the total total power of all electrical appliances that will be connected to the network along one line. The calculation must be carried out with a reserve; to do this, multiply the resulting amount by the so-called simultaneity coefficient – 1.2. Then it is necessary to calculate the current strength sufficient to operate the devices. To do this, divide the resulting total power by your network voltage (usually 220 volts). Having received the desired value, you can easily select the wire of the required cross-section according to the table below of electrical installation rules.
