jeet29

 Profile Answers by jeet29 

• Jun 8th, 2009

 

For the starting of a single phase motor we need two different fields and the resultant of both the fields works as the operating field revolving the motor
in the direction of strong field (for more refer double field revolving theory).

For the starting of the three phase motors we are using the resultant fields of all the phase which is the sum of all the fields and this is responsible for the motor operation.

If we will use two phase supply for the starting of three phase motor then due to insufficient magnitude of the field, rotor will put extra effort to catch up the stator field which will turn in the form of overheating and may be the rotor winding will damage or motor burns out.