How does a soft starter function?

A soft starter operates by gradually increasing the voltage supplied to an electric motor during startup. This controlled increase in voltage allows the motor to accelerate smoothly to its operating speed, thereby reducing the mechanical stress and electrical impact on the motor and associated equipment. By adjusting the voltage, the soft starter helps to limit the inrush current that would typically occur if full voltage was applied immediately. This feature minimizes wear and tear on the motor and helps in protecting the electrical components in the system.

In a correctly functioning soft starter system, the control of voltage is too critical to overlook, as it not only optimizes performance but also enhances the longevity of the motor. This contrasts with other options such as increasing initial voltage directly, which may lead to excessive currents; using capacitors to boost current, which is typically the function of a different type of device; or switching phases, which is a method used in different contexts, such as variable frequency drives.