Failure Analysis of Distribution Transformers - A Case Study of Ughelli Business Unit

Analysis of Distribution Transformers failures was carried out in Ughelli Business unit in Delta State under the Benin Electricity Distribution Company (BEDC). The aim of this study was to find out the cause of Distribution Transformer failure and proffer solution to mitigate it. Data includes numbers of transformers in each of the service center and their ratings, customer population and the failures reported in the past four (10) years in the Unit. Upon our analysis, the failures were seen to be dominant in transformers with 100kVA, 200kVA, and 300kVA ratings. Personal investigation revealed that protection integrity of visually all the transformers in the unit have been violated as wire-fusing has been a common practice with almost same size of wire. In other to avoid the continuous failures as a result of over fusing, a new method for calculating the actual size of wire to be used as fuse was developed.