Understanding solid-state starters - Part 1

Solid-state starters are the modern version of the traditional electromechanical reduced-voltage starters that have been used for many years to start ac induction motors. The primary function of a solid-state starter, in most instances, is to reduce motor starting current to a level that results in the least disturbance to the power distribution system. However,it also has the capability to significantly reduce shock to the motor and load. In some applications, a solid-state starter is used to reduce severe start-up (or stopping) mechanical shock to the motor and drive components. Such start-up 'jolting' may damage components and reduce reliability. The paper describes how solid-state starters work.