Transactions of the American Institute of Electrical Engineers

High-voltage oil circuit breakers for high-speed operation generally use some form of multibreak contact arrangement. These breakers perform satisfactorily but lack the simplicity of the conventional slower-speed two-break construction. The development of an unusually effective multi-orifice oil-flow interrupting unit now makes it possible to reduce the required number of breaks to the point where... View full abstract»

Although much has been written in recent years regarding allowable over-loading of transformers, the practical matter of matching existing load curves with such allowable limits has continued to present some difficulties. The interim report of the AIEE transformer subcommittee gives one approach to the problem, taking into account the ambient temperature and the duration of the overload. However, ... View full abstract»

The paper presents a method of determining approximately the maximum continuous current-carrying capacity of conductors in overhead lines, as fixed by certain operating limits of temperature and time, beyond which it is expected that the physical characteristics of copper conductors might be materially impaired. The paper deals illustratively with conditions in the Philadelphia area, but the metho... View full abstract»