⚡ Introduction Starting large three-phase induction motors directly on line (DOL) often leads to very high inrush current (6–8 times the full load current). This can cause voltage dips, overheating, and mechanical stress . To overcome this, industries use reduced-voltage starters such as the Auto Transformer Starter , which provides a controlled and smooth motor start. The auto transformer starter is especially useful in industries with heavy-duty motors (above 15 kW) that require high starting torque but must limit current to avoid disturbing the power supply. 👉 Related: Advantages and Disadvantages of Star Delta Starter Infographic: Advantages and Disadvantages of Auto Transformer Starter in Motor Starting 🔧 Working Principle of Auto Transformer Starter An auto transformer with tap settings (typically 50%, 65%, 80%) is connected between the motor and supply. During starting: Reduced voltage is applied through the selected tap. Mo...