A star delta is a motor configuration with a three-part circuit operated through use of a thermal overload contact and contactor coils. Closing the circuit turns the motor, which in turn winds the springs within it, transforming electricity into latent potential kinetic energy.
Star delta motors work on fixed time scales controlled by timers. They can be left to wind themselves for fixed periods based on how much tension their springs can take and on how much electricity is available.
The motor is "connected in star" only briefly, meaning its three contactor coils are in circuit with one another. This occurs when charging ceases and when it begins.