You will need
- - computer with Internet access;
- - reference tables;
- - handle.
To make the correct choice of conductor cross-section, define first the most significant factors for electrical installation. For example, you navigate a short chain with a heavy load – so the determining factor will be the choice of the cross section in terms of heating. If, on the contrary, laid line has a greater length and small load – it is advisable to consider its mechanical strength and magnitude of the voltage losses.
Keep in mind that although aluminum wires are cheaper, but, unlike copper, have a number of disadvantages: oxidize in the air, have limited flexibility. In addition, the conductivity of aluminum cable than copper and, therefore, with the same characteristics, the latter will have a smaller cross section, which is important for outdoor wiring.
Before you make a final choice, remember to consider all the electrical appliances that will connect to the mains. Better if the cable is to have a small reserve of power. This will give you the opportunity to continue to connect additional electrical equipment.
When calculating wire size always deviate in a big way. For example, you need to find a section of copper wire to connect the appliance with a power of 4kW. Look in the reference table size is 5kW and will receive the nominal value equal to 1.5 square millimeters. But as it is always better to take the cable off, so the best sectionin your case would be 2.5 mm2.
Sometimes to select the wire size electricians equate every square millimeter to 10 amps.
Calculating the cable section, use the appropriate tables or online calculators, but consider the material of conductors rated current network, method of laying, and environmental conditions. For example, cables laid in pipes, will be stronger to heat up and, therefore, they must have a larger cross section than the wire with the open method of wiring.