Some aspects of electric-MotorDesign — Polyphase-induction-motor design to meet fixed specifications

P. H. Trickey (Diehl Manufacturing Company, Elizabethport, N. J.): It is not to be wondered at, that Mr. Lloyd became discouraged in attempting to use the classical textbook formula for the D²L of an induction motor when he found such variations in the so-called fundamental factors. Perhaps one of the reasons for the discrepancies, is that as far as I was taught by the older engineers, and as far as I have been able to determine myself, the horsepower of an induction motor is a function of the (OD)²W where OD is the diameter of the stator lamination, and W the core stack and not of the D²L of the rotor. I have personally found that I could vary the rotor diameter and proportions of iron and copper through quite wide ranges with only small effect on the performance, but that I always had to have the same (OD)²W to equal a competitor.