The AC motors have their operation based on the principle of the rotating field and to achieve this field, it is necessary that we have several windings, 1.5 hp 56h motor notably one per phase, around magnetic cores in the stator that formed the pole pairs of an electromagnet.
It is formed of a three-phase winding, which is made up of three single-phase windings spaced apart from each other by 120 °. If this winding is fed by a three-phase system, the currents I1, I2 and I3 will likewise create their own magnetic fields H1, H2 and H3. Moreover, as they are proportional to the respective currents they will also be time lagged by 120 ° from each other and can be represented by a graph.
The resulting total field H will be identical to the graph sum of the three fields H1, H2 and H3 at that instant. Then, this graph sum represents six successive instants and when a three-phase winding is fed by three-phase currents, we create a rotating field, as if there were a single pair of rotating poles, of constant intensity. As the rotating field rotates according to the maximum and minimum current that goes through each winding, we have that the faster the current alternates the faster it will rotate.