Control of the Switching Surge Voltages Produced by the Current-Limiting Power Fuse

A new transient condition unique to fuses of the current-limiting type is described and it is recommended that these fuses be designed to inherently control switching surge voltage magnitudes to meet the following conditions: 1. The transient recovery voltage should not exceed the insulation level of rotating machines √2(2E+1,000) where E is the rated terminal-to- terminal rms voltage of the lowest rated machine involved. 2. The transient recovery voltage should preferably not exceed the 60-cycle crest spark-over voltage of associated lightning arresters. 3. If the transient recovery voltage does exceed the 60-cycle crest spark-over voltage of associated arresters, the interrupting rating of the fuse should be determined and assigned to limit the arrester current to a safe magnitude.