After his return Kron was employed as electrical engineer for brief periods with several companies the last of which was Warner Brothers in New York. They closed his department while he was on a continuing highly paid contract. He economized by living with his family in Romania. There he studied the mathematical tools of the general theory of relativity and conceived his method for applying tensor analysis to electrical power engineering. This was described in a paper entitled "Non-Riemannian Dynamics of Rotating Electrical Machinery" printed in Romania and distributed to friends. In 1933 Kron returned to the US where his paper had been well received. He worked at General Electric from 1934 until he retired in 1966.