In the market there are three-phase and single-phase induction electric motors, however there are a number of motors that are in the research phase, are the asymmetrical induction motors asymmetrical fed by symmetrical biphasic voltage with return. This type of motor works without the capacitors and centrifugal switches, thus the asymmetric biphasic motor with return would have an advantage over the single phase motors, which would be the lowest cost. 17129 At first this motor would be used in the urban zone since it needs a biphasic voltage source with return.

Three-phase and single-phase induction motors are the most commonly used by consumers in general, industrial, commercial and residential sectors. In the industrial and commercial sector three-phase and single-phase motors are used, while in the residences the most influential has been the single-phase motore, due to the application and cost characteristics. Single-phase induction motors have a higher cost than the three-phase induction motor, but the cost of three-phase installation is higher than two-phase or single-phase installation. At the present time we find several models of single-phase motors, for example: single-phase induction motors with capacitor start, starting at resistance, with capacitor of two values ​​and with single-value permanent capacitor among others.