Abstract: The mathematical model of the open-circuit transition wye-delta controller has been developed. Two possible delta configurations have been taken into consideration. The dynamic behavior of the motor starting using the open-circuit transition wye-delta controller with different delta configurations has been analyzed. A comparative study between the two delta configurations has been performed and a recommendation to avoid excessive undesirable inrush values of the motor current and the electromagnetic torque has been given. The inrush values of the motor current, electromagnetic torque and acceleration time have been considered as criteria in the comparative study. Curves of the phase currents and electromagnetic torque for motor starting using each of the delta configurations have been illustrated.