Purpose and design
Three-phase autotransformers are designed for starting electric motors using the autotransformer method. Compared to transformers at the same power, autotransformers are lighter but have a much lower short circuit impedance. Starting autotransformers are used to adjust the voltage supplied to the motor during start-up. The winding of an autotransformer usually has several voltage tap changers. The design of the device provides fixing by means of angle brackets screwed to the core. Upon agreement, autotransformers can be supplied in enclosures with the required protection class.