LLNRK UL CLASS RK1 ELEMENT TIME DELAY 5A. Littelfuse LLNRK and LLSRK series POWR-PRO™ fuses provide superior overload and short circuit protection for service entrance, main, feeder and general-purpose branch circuits up to 600 amperes. LLNRK/LLSRK series fuses can be installed in existing Class H fuse blocks to upgrade systems containing lower interrupting rating Class H one-time or renewable fuses. Applications: All general-purpose circuits. Motors. Transformers. Solenoids. Fluorescent lighting. All system components with high in-rush currents. Features: Extremely current limiting — Reduces damage to circuits and equipment under short-circuit conditions. Stops damaging short circuits faster than any mechanical protective device. 300kA Interrupting Rating — Littelfuse self-certified to 300,000 amperes as standard. Meets future trend towards higher available short circuit currents. Reduced costs — Current limiting design often permits use of readily available, less costly equipment. Low resistance design reduces power consumption and utility bills. Excellent time delay — True dual-element construction, with separate non-fatiguing thermally-reversible spring-loaded thermal overload element, withstands repeated surges within rated time delay without opening needlessly. Eliminates needless downtime caused by power surges or equipment demands.