Question 1
A 3-phase, 2200-V, delta-connected, 12-pole 60-Hz induction motor runs at no load with
rated voltage and frequency impressed and draws a line current of 20 Amp. and an input
power of 14 Kw. The stator is Y-connected, and its resistance per phase is 0.4 Ohm. The rotor
resistance r2
’ is 0.2 Ohm per phase. Also, x1+x2'=2.0 Ω per phase. The motor runs at a slip of
2% when it is delivering power to a load. For this condition, determine
a) The developed torque.
b) The input line current and power factor.
