When a three-phase motor is running using its direct start, a significant increase in the current level occurs, which is called the peak current (Ip). For the reduction of this current, methods are applied that make the indirect start, being the star star / triangle starter, autotransformer compensation and the use of a soft starter.
Soft-starter is an electronic equipment mrosupply that is very versatile and eliminates the application of the first forms mentioned, because its electronic circuits play the role of both methods. The operation of a soft starter is by a thyristorized bridge or semiconductor components, which switch the voltage so that it can be reversed to the motor incrementally, that is, it will increase gradually, guaranteeing a smooth start and without the presence of the peak current. This bridge switching is controlled by the control and tripping system, which is a module where it is possible to carry out the desired settings by means of parameters, which are identified one by one by the manufacturer and are included in a manual. In addition to the reduction of the Ip, this equipment guarantees several other benefits regarding the work of the three-phase motor.