Characteristics of fuse opening switches in granular quenching media

Characteristics of fuse opening switches using powder or granular type quenching media, alumina, silica, and polytera-fluoroethene (PTFE), were compared with those using air. Fuses were made of a piece of copper foil of 18 /spl mu/m thick, and their width and length were varied from 10 to 30 mm, and from 120 to 500 mm, respectively. To explode the fuse, a current of 60 to 80 kA was supplied from a capacitor bank. The length of the fuse was reduced approximately by a half when any type of quenching media was used, when compared with the length showing a useful dwell time with an air medium. The capability of suppressing the current restrike was improved too. Test results showed that silica is the best quenching medium for high power generation out of materials used in this study.