The electrical properties of galvanized steel conductors for overhead transmission lines

In this paper are given the results of some work which was carried out with a view to obtaining definite information as to the electrical properties of steel conductors when carrying alternating currents. The most important values measured in the tests were the ¿effective a.c. resistance¿ and ¿internal inductive reactance,¿ and it is shown that it would be impossible to calculate these in the case of iron or steel conductors. Full particulars with regard to the selected range of test samples are given, including their mechanical properties, chemical analyses and magnetic qualities. The test methods are briefly described, the method of power-factor measurement employed in the ¿internal inductive reactance¿ tests being more fully referred to in the Appendix. The effect of spacing on the values of ¿effective a.c. resistance¿ and ¿internal inductive reactance¿ is then considered. The test results show that these values do not vary with the spacing until the conductors are brought very close together and, in fact, are separated only by a thickness of paper. Some observations on the test results are given, and it is shown that the most suitable of the four grades of material tested is the ¿45-ton quality, hard-drawn¿ grade.