JLLN Series UL Class T Fast-Acting Fuse. Space saving POWR-T fuses are the most compact fuses available in ratings above 30 amperes, less than one-third the size of comparable Class R fuses. When rated in accordance with the NEC, POWR-T fuses provide fast-acting overload and short circuit protection for non-inductive circuits and equipment. Used in inductive circuits, the ampere rating of POWR-T fuses must be increased to prevent opening on inrush currents. In such instances, POWR-T fuses may provide only short circuit protection. For motor and general purpose circuits where space is not critical, we recommend POWR-PRO JTD ID Indicator series, LLNRK/LLSRK series, or FLSR ID Indicator series.