The failure rates of underground distribution system components

Abstract

1,'iiderground distribution systems utilize a number of principal components. A list would include: Cable Distribution Transformers Switches Elbows Splices .A typical underground distribution feeder may contain of tlie orders of 100 miles of cable. 400 transformers, 100 switches, 2500 elbows and 1000 splices. A failure of any one of these components usually results in a wstained outage on the feeder which may involve hundreds of custoniers for a time duration measured in hour^..l'his papcl-provides estimates of the failure rates of underground distribution system components. The cstiiiintcs are based on information collected from a number of utility sources throughout the United States of America. They represent considerable field experiences of these sources over time spans of the order of 10 years. These data have been analyzed to produce die most comprehensive estimates of failure rates of underground components known to the authors.