Energetic Considerations About the Use of Cast Copper Squirrel Cage Induction Motors

The paper compares, from energetic point of view, a standard aluminum cage induction motor with a copper cage twin one. The prototype with the copper rotor has been manufactured using investment casting technological process. The prototypes have been tested in accordance to IEEE Std. 112-B. Torque vs. current characteristics, efficiency vs. output power, starting torque and current have been used for comparison. From the energetic point of view, the copper cage adoption brings to an efficiency increase of no more than 1.5% in the rated load conditions. This improvement is in line with the results reported in literature for the same motor power size. Finally, same critical considerations about the use of copper for the cage realization are reported taking into account the material market cost trend.