3 phase motor

Three phase motors I: The rotating magnetic field

The rotating magnetic field  RMF is the basis of the three-phase motors - whether synchronous or asynchronous / induction motor. This video explains how a rotating field is generated, how the number of pole pairs influences the synchronous speed, how the synchronous speed can be calculated, etc..

 

Example 1:  A 6-pole synchronous motor has a rotational speed of n = 1200 min-1. At which mains frequency is it operated?

Example 2: In the USA the frequency of the power supply has 60 Hz, in Europe 50 Hz. How much does a synchronous motor with 8 poles, that means a pole pair number of 4, run faster in the USA than in Europe?    Note: 6 poles  Δ pole pair number = 3