2006 Volume 47 Issue 9 Pages 2413-2420
The distribution of the temperature was estimated by combination of electrical and thermal calculations on the basis of Ohm’s and Fourier’s laws in the fuse element-connector-electric wire system in order to design Pb-free Sn-9Zn fuse elements used in electric power line. The temperature distributions in fuses were obtained on the basis of the amount of Joule’s heat generation and heat transfer depending on the ratio of the length and diameter of fuse elements. Main requirements for AC-low voltage fuses were satisfied on the promising fuse element with the size designed on the basis of the heat generation and transfer calculations. The promising size was the diameter of 2.5 mm and length of 10 mm in the smaller diameter part of two step cylindrical fuse elements. In contrast, the electrical potential and temperature distributions can be also estimated by this calculation method, regardless of a kind and shape of the fuse elements, connectors and electric wires.