Analysis Of Drop-out Fuses In Power Systems

For medium-voltage lines, the drop out fuse set fuse should be installed at critical nodes on branch or main lines of distribution networks with voltage levels of 10 kV and below, providing a response mechanism for short-circuit and overload conditions. The common operating voltage levels of drop out fuse unit cover 10 kV, 12 kV and even higher, and medium voltage network personnel can often perform on-site operations through insulated operating rods.

The drop out type fuse is composed of core components such as a fusible tube, a fusible wire, and contacts. The material and geometry of the fuse wire enable it to respond according to predetermined characteristics when the rated current exceeds its limit. An internal arc is formed and quickly extinguished by the dielectric and structural design. Simultaneously, the tensioned contacts release, and the dropout fuse of transformer device falls due to gravity or spring force, thus visually indicating the circuit disconnection status.

For power system designers and operators, selecting the expulsion drop out fuse fuse requires parameter matching based on the system's voltage level, rated current range, and installation environment conditions. These parameter specifications typically refer to national and industry standards, such as the GB/T 15166 series and relevant IEC standards, to ensure compliance with system technical requirements and safety regulations.