Application of fuse autopsy methodology to estimate protected element type of failure

Abstract

The fuse is one of the overcurrent protection devices most used in medium and low voltage distribution systems, which usually has excellent reliability. Therefore, when the fuse operates it is certain that there is a fault or disturbance that puts the protected equipment at risk, having been safeguarded by the fuse. This study of the state of the fuse is known as "autopsy". The study is divided between the analysis of fuses of high and of low breaking capacity, since their constructive characteristics differ significantly. The estimations made based on the operation of fuses in the field, are verified with that observed in tests under controlled conditions, carried out in a power laboratory, where the parameters involved are adjusted and measured. A guide is presented that allows to estimate the type and location of the disturbance. It concludes in the utility of knowing the state of the operated fuse by performing its autopsy, as a tool to reduce the cost of the damage and delay in the supply restoration, and therefore the cost of the disturbance.