13 February, 2014

3-phase Ac Motors

. I was so happy to find this — Both have 3 a phase stator winding, the squirrel cage has a rotor with bars arranged around it's periphery, these bars are joined at both ends by a continuous ring. This forms a closed circuit of low resistance which is fixed. The wound rotor (slip ring motor) is similar in construction but the bars are replaced by copper windings, similar to those in the stator. They are star connected and the three ends are brought out to slip rings which allow an electrical connection to be made to the outside world. When no connection is made between these ends and the stator is energised, little current flows in the stator which does not turn, but when any resistance is inserted, current flows in the stator windings and the rotor rotates. As the rotor gains speed the resistance is taken out of circuit and the slip rings shorted together. The motor runs as a cage induction motor.

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  1. Bright Eyes X1792 February 9, 2014 at 8:38 am #
    Your question is like asking what is the difference between a red and gray squirrel. The red squirrel is smaller but eats the balls of the larger gray squirrel. Slip rings are prone to resistance problems but a squirrel cage rotor and stator are only magnetic transfer of energy and thus more efficient.
  2. TuffGirl Johnson February 9, 2014 at 10:00 am #
    The squirrel cage is the type of the induction motor. And the slip ring motor is also the type of the motor. The only difference between them is the slip ring motor use the external resisters but squirrel cage is not use the external resistance. So the starting torque of the slip ring motor is higher then the squirrel cage motor.