Temperature Rise and Losses in Solid Structural Steel Exposed to the Magnetic Fields from A-C. Conductors

Experimental investigations were made for the determination of the temperature rise and the losses occurring in structural steel members exposed to the fields from a-c. conductors. The worlz originated fromn the demand among the designing engineers of an electrical manufacturing company for practical data which would enable them to estimate, at least roughly, the temperature rise and the heat losses in the more common cases of structural steel members passing near the conductors. In the paper presented here are given the results of the investigations in question. Examples are given illustrating the method of procedure in estimating temperature rise and losses in structural steel. The method of calculation applied is, in most cases, empirical. The major factors affecting temperature rise and losses are discussed on the basis of the test data. An understanding of these factors will often permit a designer to avoid iron heating without sacrifice of space or of economy. Thus a good part of the data presented apply to cases for which the temperature rise of the steel would ordinarily be considered not seriously objectionable. Iron members passing between going and return conductors in adjacent-phase layouts may reach very high temperatures; on the other hand, iron members passing at right angles to, but outside of, a group of going and return conductors will usually heat less than an iron member crossing a single conductor, when the current and minimum spacings are the same.