The Existence of Large Inter-Bar Currents in Three Phase Squirrel Cage Motors with Rotor-Bar And/Or End-Ring Faults

An analysis is developed which describes the existence of substantial inter-bar laminar currents in large three phase squirrel cage induction motors with broken bars and/or rings. Results of experimental measurements are presented which verify the theoretical model. Also the effect of these tangential currents on the production of very large axial vibrations are shown.