How is a Wound Rotor Motor usually started in terms of circuit resistance?

A wound rotor motor is typically started with all of the resistance included in the rotor circuit. This is because the primary function of the additional resistance is to limit the starting current of the motor, thereby preventing damage to the motor and the power supply due to excessive current draw at startup. By incorporating a high level of resistive material, the motor can safely start under load conditions, preventing torque spikes and allowing for a more controlled acceleration of the rotor.

As the motor gains speed, the resistive components can be gradually reduced or removed, allowing the motor to operate efficiently once it reaches a certain speed. This procedure enables more flexibility in controlling both the starting conditions and the operating characteristics of the motor, making it highly effective for applications where load and speed need to be dynamically managed.