Parameters of heating curves of electrical machinery

G. E. Luke: As mentioned in this paper, Professor Kennelly derived the heating characteristics of an electric machine by considering it as one “chunk” of metal
²
. This paper gives the thermal equations on the basis of two “chunks” of metal (core and windings). An approximate solution of this problem based on three “chunks” of metal (core, windings, and frame) was given in another previous Institute paper
³
. As a matter of fact, a correct solution of this problem would have to be based upon an infinite number of “chunks.”