Axial electric-field measurements of d.c. arcs in current-limiting fuses

The design of current-limiting fuses to meet the modern system requirements needs a thorough understanding of the fuse aic characteristics. In high-voltage fuse designs, a knowledge of the axial electric field and the speed of burn-back of the element will be useful to designers. This paper describes a method for measuring the axial electric field in the low overcurrent region of direct current arcs in current-limiting fuses. An arc model has been presented for the notched elements which shows that the electric field is inversely proportional to the thickness of lumen dimension.