Underground corrosion on rural electric distribution lines

SOME studies of underground corrosion associated with the grounding of multigrounded wye-connected distribution lines are described in this paper. Underground corrosion damage, mainly of anchor rods, has been experienced in enough locations to deserve special attention, but there seems to be very little electric utility experience to draw on in deciding what to do about it. The lack of information on this subject in the literature may be explained by reasons such as the following: 1. The widespread adoption of multigrounded wye-connected distribution lines is fairly recent, having occurred mostly in the last 15 to 20 years. Compared with delta-connected lines, multigrounded lines have a greater multiplicity of ground connections and therefore offer more possibilities for undesirable corrosion reactions. 2. Some of the most severe conditions causing underground corrosion are in areas where relatively little mileage of distribution line existed prior to 1935 or 1940. As a result, comparatively little experience in dealing with these conditions has been accumulated. 3. Judging from literature on this subject (or the lack of it), the electric utility industry has not given much attention to the effects of electrical grounding on underground corrosion.