The name plate on a 460 V 50 hp 60 Hz four pole motor indicates that its speed at rated load is 1760 r/min. Assume the motor to be operating at rated load.
a) What is the slip of the rotor?
b) What is the frequency of the rotor currents?
c) What is the angular velocity of the stator field with respect to the stator? With respect to the rotor?
d) What is the angular velocity of the rotor field with respect to the rotor? With respect to the stator?
Synchronous Speed = Ns = 120*f/p = 120*60/4 = 1800 RPM
Calculations given find slip, frequency of currents and angular velocity of the stator and rotor fields.