Copper electric conductors are applied in the production of windings. Electric copper has a very high purity and is manufactured by the electrolysis process, acquiring a purity higher than 99%. The straight section of copper conductors to be installed in the grooves are rectangular or circular.
Normally, circular section conductors are produced in standard diameters up to a diameter of about 2.5mm to 3mm. The current density alternates between 3.5 and 15 A / mm2 depending on the ventilation system, number of starts per hour, and desired efficiency. High efficiency electric motors have lower current density characteristic.
If Acon em is higher than the straight section of the largest diameter of wire available, few conductors of smaller diameter are interconnected in parallel and coiled together. Up to 6 or 8 elementary conductors can be interconnected in this way.
If the Acon is above 30 to 40mm2 (ie 6 to 8 wires of 2.5mm2 in parallel), conductors of rectangular section are advised. In several countries, these drivers are also parameterized. Usually the height of rectangular conductors is lower compared to the width (a <3.5mm) to minimize the Skin effect.