Squirrel cage induction motor cast rotor defect detection with magnetic field analysis

Testing of squirrel cage induction motor rotors for rotor cage defects while the motor is in an unassembled state is an important quality control check in the manufacturing and repair process. A new testing method using magnetic field analysis capable of identifying defects in squirrel cage inductor motor rotors is described. The rotor field analysis, RFA, testing technique is explained with finite element analysis used to demonstrate the magnetic field detection process. A guideline for test procedures and result interpretation is provided along with testing examples. A case study for a cast aluminum rotor with rotor cage defects is presented.