Load losses of alternating current generators

The load losses of well designed generators are relatively small and their accurate determination is difficult. When duplicate machines are available the circulating energy method is recommended. In this method the losses of the two machines are the quantities measured, and variations of any magnitude are readily determined. Careful tests were made on three machines to select some method of determining load losses when but one machine was available. The indications were that the load losses were approximately the same as the short circuit core loss. The few machines tested and the small load losses of these do not warrant a recommendation that the load losses be considered as equal to the short circuit core loss. It is hoped that additional data will be brought forth to establish a rule to cover this case.