The most common motors used in a vast array of applications are in fact the Ac induction motors. The reason for this is the high level of availability they comprise, running off with the help of AC voltage at every outlet and their durability that is of great importance to the user. The fundamental components of an Ac induction motor are the rotor and the stator. The stator represents the stationary coils located in the motor. This is also the place where the production of current takes place and that creates the magnetic field we’re after. The magnetic field created is accountable for the rotation of the rotor.
The most important characteristics of Ac induction motors are its running speed and the power of the starting torque.
The running speed partially depends on the power supply frequency and partially on the quantity of motor poles and amount of slip. These are the aspects that determine the speed of the motor. The term slip refers to the amount of speed that runs under the motor’s synchronous speed. In order for the Ac motor to be able to induce current within the rotor it requires exactly that – the slip. The amount of slip is forever altered as the load on the motor doesn’t remain the same. The speed of the Ac motor can only be changed if the frequency is altered as well. The one thing that can tackle this task is the VFD ( Variable Frequency Drive).
The starting torque is more of a limitation than a beneficial characteristic for the Ac induction motors. Unfortunately, the single phase motors are usually defined by the methods they rely on for starting. To name a few of these motors: the permanent split capacitor motor, the split phase motor, the shaded pole motor, the two value capacitor motor and the shaded pole motor. All of these motors share one same feature: they utilize a secondary coil that is out of phase or a capacitor for the purpose of creating secondary phase that will start the motor.
Three phase motors, on the other hand, have a much higher level of starting torque, therefore their efficiency is on a higher level too. They have the ability to start on their own and avoid the need for a capacitor.
The Ac induction motors are compatible with a large number of different applications including: conveyors, pumps and commercial products. If you are considering to buy an Ac motor, simply be mindful and ask about the two important aspects mentioned above. Knowing the specifics on those features will help you determine whether you’re investing in the right direction.
