Duke power tackles 600-V cable problem

摘要

The impact of 600-V URD cable failures never received a great deal of attention, mainly because a single run of cable may only serve a few customers and, therefore, contributes little to system reliability indexes. Many utilities believe dig-ins cause the majority of their failures and reason there is little they can do to prevent them. However, a close examination of 600-V systems reveals some interesting results with respect to achieving a balance among system design, installation costs and failure rates. Duke Power (Charlotte, North Carolina, U.S.) conducted a survey of 33 utilities that showed the number of failures per year varied from 47 to 7000. When the number of failures per year was based on the number of cable miles installed per year, the values converged to a range of 0.09 to 3.91 failures per mile (per 1.6 km). Assuming each failure costs US