In the electric power system, low-voltage power fuses with silver fuse elements and tin solder are widely used because of their simple and cost-effective work principle. Due to new applications and technical requirements e.g. in renewable energy systems and battery storages, a more precise switching characteristic is needed. Especially at low overcurrents the time-current-characteristic has a high volatility. Therefore, specific design rules for the geo-metric parameters of the fuse element need to be developed. In this paper, different geometries of the constrictions combined with different volumes of the solder were examined. Especially the length and height of the solder and its position at the fuse element were varied. The switching behavior of the fuse element was calculated with FEM, and tested at low overcurrents with the requirements of the actual gPV standard at the nominal current In and the conventional currents Inf = 1,13 In and If = 1,35 In. Main influences on the switching time are determined in this investigation, facilitating an optimization of the fuse elements using FEM-software.