Discussion on experimental determination of losses from alternators

E. Roth : Very interesting remarks have been made by Messrs W. F. Dawson, B. L. Barns, P. A. Borden, and C. J. Fechheimer concerning the application of the method which H. M. Hobart demonstrated in 19132 for the determination of the losses in totally enclosed and ventilated electric machines, by the calibration of the air circuit which permits elimination of the measurement of rate in flow of the cooling air. These remarks have shown the high merit of the various alternatives of this method, which ought to be generalized owing to its great usefulness in industrial practise. For this reason, two alternatives, of which one corresponds to that referred to by Mr. Dawson and the other to the one I have developed in the paper mentioned by Mr. Barns, have been submitted by the French National Committee to the International Electrotechnical Commission to be introduced in the rules concerning the tests of electrical machines. It may be of interest to quote this text which is being brought to the knowledge of American engineers: