A 460-V, 25-hp, 60-Hz, four pole, Y-connected induction motor has the following impedances in ohms per phase referred to the stator circuit: R₁ = 0.641Ω R₂ = 0.3320 X₁ = 1.106Ω X₂ = 0.464Ω RM = 26.3Ω The total rotational losses are 1100 W and are assumed to be constant. The core loss is lumped in with the rotational losses. For a rotor slip of 2.2 % at the rated voltage and rated frequency, find the motor's a) Speed d) Pconv and Pout b) Stator current e) Tind and Tload c) Power factor f) Efficiency Activate

A 3-0, 50-Hz induction motor with its rotor star-connected gives 500 V (r.m.s.) at standstill between slip-rings on open circuit. Calculate the current and power factor in each phase of the rotor windings at standstill when joined to a star-connected circuit, each limb of which has a resistance of 10 Q and an inductance of 0.03 H. The resistance per phase of the rotor windings is 0.2 Q and inductance 0.03 H. Calculate also the current and power factor in each rotor phase when the rings are short- circuited and the motor is running with a slip of 4 per cent. [13.6 A, 0.48; 27.0 A, 0.47] (London University) A 4-pole, 50-Hz, 3-phase induction motor has a slip-ring rotor with a resistance and standstill reactance of 0.04 2 and 0.2 2 per phase respectively. Find the amount of resistance to be inserted in each rotor phase to obtain full-load torque at starting. What will be the approximate power factor in the rotor at this instant ? The slip at full-load is 3 per cent. [0.084 2, 0.516 p.f.]…

List 3 differences between how 3 phase induction motors and single phase induction motors work.

how does the rotor of a 3-phase induction motor get power a-  through brushes and commutador segments b- through brushes and slip ring c- indution from the stator d- none of the above