A conductor that is not designed for the current flowing through it can overheat and its insulation can catch fire. On the other hand, the cable should not be too thick, otherwise it will be inconvenient to lay.
Instructions
Step 1
Convert both load parameters into SI units: voltage - in volts, power - in watts. The voltage value should be taken not in amplitude, but in effect (it is this that is indicated in most cases).
Step 2
Determine the load current by dividing the power into voltages: I = P / U, where I is the current consumed by the load, A, P is the load power, W, U is the mains voltage, V.
Step 3
Follow the link at the bottom of the article and select the wire size according to the table. It should be borne in mind that cables with aluminum conductors in newly erected buildings, as well as when replacing the wiring with a new one, are not laid. Also, such cables should never be used if the load moves in space.
Step 4
Choose the type of cable (single-core or multi-core) depending on whether you need to move the load or bend the cable often in general (for example, the TV is stationary, but the cord still has to be moved by removing the plug from the outlet). Multicore cables are significantly more flexible. Each conductor of such a cable consists of several thin conductors laid under a common layer of insulation. Their cross sections are summed up. Such conductors are not aluminum.
Step 5
The cross-section of a conductor (or the total cross-section of all conductor conductors) is often indicated directly on the insulation. For this, the same units are used as in the table - square millimeters (in the jargon of electricians - squares). If you have a cable that does not have this designation, measure the diameter of the core with a vernier caliper. Since this tool is metallic, the conductor must be de-energized. Knowing the diameter, calculate the section: S = π (D / 2) ^ 2, where S is the section, sq. mm, π - number "Pi", 3, 1415926535 (dimensionless value), D - measured diameter, mm. For a stranded conductor, measure the diameter of one core, calculate its cross-section, then count the number of cores in the conductor and multiply the cross-section of one core by it …
