Exam Question

### (a) Star-Delta Starter for an Induction Motor
A Star-Delta starter is a reduced voltage starting method used for three-phase squirrel cage induction motors. Its primary function is to reduce the high inrush current drawn by the motor during startup, thereby minimizing voltage dips in the supply network and reducing mechanical shock to the driven machinery. This is achieved by initially connecting the motor's stator windings in a 'Star' configuration and then switching them to a 'Delta' configuration once the motor has reached approximately 75-80% of its rated speed.
#### Principle of Operation
The method relies on the voltage and current relationships in Star (Y) and Delta (Δ) connections.