Calculate the mechanical speed of rotar:

An asynchronous machine of 460V, 25hp, 4 poles with rotor wound in Y has the following data (of the side stator):

Resistance of the rolling-ups of the stator: R1=0.55 ?

Reactance of the rolling-ups of the stator X1=1.1 ?

Resistance of the rolling-ups of the rotor R2=0.3 ?

Reactance of the rolling-ups of the rotor X2=0.46?

Reactance of magnetizing x_Φ = 30Ω

Frequency of operation 60Hz

1-What is the mechanical speed (in tours per minute) of the rotor for the maximal led couple?

2-What is the couple led by starting up?

3-Recalculate the mechanical speed (in tours per minute) of the rotor for the maximal led couple having doubled the resistance of the rotor.

4-Recalculate the couple led by starting up having doubled the resistance of the rotor.