Bussmann High-Speed Fuse Distributor | 170M, DFJ Series

BeiLuo supplies genuine Bussmann high-speed fuses, the current-limiting fuses that protect power semiconductors from a short circuit in a fraction of a cycle. A diode, thyristor, IGBT or SCR has a very small thermal mass and fails within milliseconds of an overcurrent, so an ordinary branch fuse is far too slow. A high-speed fuse with a low I-squared-t characteristic opens before the device junction can be damaged, and its current-limiting action cuts the fault current before it reaches its first peak, which limits the energy the semiconductor sees. Bussmann builds these fuses in ferrule, British Standard and square-body form, covering a few amps up to several thousand, at voltages from 500 V to more than 2000 V. The 170M square-body series is the workhorse of drive and inverter DC links, with size 000 to size 5 bodies and an ultra-fast aR characteristic, while the DFJ series is a UL Class J full-range drive fuse with the lowest I-squared-t of any branch circuit fuse, so it can be used with standard Class J blocks and switches. Both are used in variable-speed drives, rectifiers, UPS systems, induction heating and traction converters, where the fuse is the last line of defence for an expensive power stack. A high-speed fuse must be coordinated with the device it protects, so the voltage class, the amp rating and the clearing characteristic are chosen together from the prospective fault current. BeiLuo holds mainstream ratings in stock and ships every fuse with an import declaration, a certificate of origin and a RoHS file, and our FAE team helps with coordination and selection.