Induction Motor Resistance Ring Width

The effect which the width of resistance rings has on the secondary resistance of squirrel cage induction motors has been subjected to a mathematical analysis. It is found that the width, in a radial direction, of these rings which connect the conductors of a squirrel cage rotor, need never exceed the pole pitch, and probably half of that value is sufficient. Methods for determining the current distribution in the resistance ring, and for determining the the effective width and resistance are demonstrated.