Discussion on “the effect of delta and star connections upon transformer wave forms” (Curtis), Spokane, Wash., September 10, 1914. (see proceedings for August, 1914)

P. M. Lincoln: We may represent a three-phase system as in this diagram, in which the figure ABC may be assumed to rotate around its center O. The instantaneous voltages will then be proportional to the lengths of the projections upon a line, as XX. For instance, at the instant represented in the figure the instantaneous voltage of leg AO is zero, that of phase CB is a maximum, and those of phases AB and AC are each one-half of the maximum, one increasing and the other decreasing.