Protect Critical Power Electronics with High-Speed Fuses
Littelfuse high-speed (semiconductor) fuses protect critical power electronics from overcurrents that may cause damage to your equipment. High-speed fuses are reliable, very fast-acting products that can reduce the amount of short circuit current and improve the life of your power semiconductor devices.







POWR-SPEED fuses with an innovative bridge design, arc-quenching material and a robust element to provide fast, extreme current limitation exactly where you need it.





Square Body PSR Series

POWR-SPEED fuses specifically designed for protection of power semiconductor devices such as diodes, triacs, IGBTs, SCRs, MOSFETs and other solid state devices that are typically designed into power conversion and power conditioning equipment. Variable frequency drives, inverters, UPS, rectifiers and soft-starters are examples of typical equipment designed with sensitive power semiconductor devices that cannot withstand any line surge or overcurrent conditions and require high-speed protection.

Littelfuse POWR-SPEED PSR Series products offer optimized circuit protection at the extremely fast speed required to protect modern day power conversion devices. Such products are commonly found in numerous applications including pulp and paper industries, cranes and heavy-lifting equipment, processing industries, wastewater treatment plants and various large factories and MRO facilities.


  • Best in Class DC performance
  • Extremely current limiting
  • Superior cycling capability
  • Global certification cURus, CCC, IEC
  • Direct bus-bar mount flush-end and blade designs
  • Visual and optional microswitch fuse blown indication
  • Low watt-loss design
  • Compliance with US and Canadian requirements
  • Class AR performance according to IEC60269-4

Round Body QS Series

Our new high-speed QS Series fuses have reduced the energy let-through by up to 70% over previous generation high-speed semiconductor fuses. Our experts have designed high-performance silver fuse elements that combine with a hardened silica filler to provide enhanced system protection.

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POWR-Speed Product Catalog - Mandarin
POWR-Speed Fuse Overview Guide
POWR-Speed Application Guide
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Disclaimer Notice – Information furnished is believed to be accurate and reliable. However, users should independently evaluate the suitability of and test each product selected for their own applications. Littelfuse products are not designed for, and may not be used in, all applications.