Temperature distributions in electrical machinery

The paper deals with certain fundamental principles governing heat distribution and temperature in electrical apparatus. The general problems of heat generation, heat flow and heat dissipation, upon which the resultant temperatures depend, are discussed at some length. The various paths of heat flow and the effects of the heat resistance of such paths are discussed. The effects of rapid heat flow on the equalization of the temperatures, and on their measurement, are considered briefly. Some of the fallacies in temperature guarantees and in temperature indications are pointed out. Some of the more common errors in the methods of measurement are described. In conclusion it is stated that no hard and fast rules can be made to cover the facts, except in a very general way, and that commercial temperature measurements should be considered as approximate, this being permissible because there is no sharply defined line between good and bad.