Numerical method for pre-arcing times: Application in HBC fuses with heavy fault-currents

This works deals with calculations of pre-arcing time prediction for fuse links used in industrial protection circuits in case of heavy faults-currents. An enthalpy method to solve heat-transfer equation included two phase-changes is presented. The mathematical model couples thermal and electrical equations based on the principle of energy conservation and the Ohm´s law respectively. In order to determine current density and temperature evolution in the fuses, three typical fuse links have been chosen for the calculations with circular, rectangular and trapezoidal reduced sections at their centre. Silver physical properties, mathematical equations and the numerical method are reported. Calculations results show that for the fuse link with rectangular reduced section a major heat-transfer mechanism took place compared to the other ones.