KLNR/KLSR series RK1 fuses were the earliest type of current-limiting fuse developed. Their single-element, silver link design enables them to provide fast-acting overload and short-circuit protection. When used to protect inductive loads such as motors, solenoids, and transformers, KLNR/KLSR series fuses must be greatly oversized to prevent opening the fuses on harmless inrush currents. In such applications, KLNR/KLSR series fuses may only provide short-circuit protection. We recommend using POWR-PRO™ LLNRK/LLSRK series RK1, dual-element, time-delay fuses in all new applications requiring the current-limiting ability of UL Class RK1 fuses, or in existing applications where fast-acting RK1 or RK5 fuses have been opening on harmless system surges such as motor starting currents.Safety: 200,000 A.I.R. — Reliable interruption of all overcurrents up to 200,000 amperes. Extremely current limiting — Stops damaging short-circuit current faster than any mechanical protective device. Fast-acting — Provides fast-acting protection to equipment such as variable speed drives, rectifiers and other equipment containing surge-sensitive components. Longer Equipment Life: Current-limiting design reduces damage to equipment caused by heating and magnetic effects of short-circuit currents. Economical: Extremely current-limiting — often permits use of readily available, less costly equipment. Used as input or output fuses for surge-sensitive components, such as variable speed drives and rectifiers, fast acting KLNR/KLSR fuses may prevent opening of expensive semiconductor fuses protecting individual components. Easy to Use: 200,000 A.I.R. rating minimizes need for short circuit calculations. Dimensions: Refer to FLNR for KLNR dimensions and FLSR for KLSR dimensions.