LLNRK/LLSRK Series POWR-PRO® Class RK1 250/600 VAC ■ Dual-Element, Time-Delay ■ 1/10 – 600 Amperes SPECIFICATIONS Voltage Ratings: AC: 250 Volts (LLNRK) 600 Volts (LLSRK) DC: 125 Volts (LLNRK) 300 Volts (LLSRK) Interrupting Ratings: AC: 200,000 amperes rms symmetrical 300,000 amperes rms symmetrical (Littelfuse self-certified) DC: 20,000 amperes Ampere Range: 1/10 – 600 amperes Approvals: AC: Standard 248-12, Class RK1 UL Listed (File No: E81895) CSA Certified (File No: LR29862) QPL: Federal Specification No.WF-1814 DC: Littelfuse self-certified AMPERE RATINGS ⁄ 1 10 ⁄ 15 100 ⁄ ⁄4 * 3 ⁄10 4 ⁄10 1 ⁄2 6 ⁄10 8 ⁄10 2 10 1 1 11⁄8 11⁄4 14⁄10 16⁄10 18⁄10 2 21⁄4 21⁄2 28⁄10 3 32⁄10 31⁄2 4 41⁄2 5 56⁄10 6 61⁄4 7 8 9 10 12 15 171⁄2 20 25 30 35 40 45 50 60 70 80 90 100 110 125 150 175 200 225 250 300 350 400 450 500 600 * LLSRK Only. Example part number (series & amperage): LLNRK 450 RECOMMENDED FUSE BLOCKS LR250 series (LLNRK Series) LR600 series (LLSRK Series) Refer to Fuse Block section of this catalog for additional information. 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 FEATURES/BENEFITS ■ 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 springloaded thermal overload element, withstands repeated surges within rated time delay without opening needlessly. Eliminates needless downtime caused by power surges or equipment demands. All general-purpose circuits Motors Transformers Solenoids Fluorescent lighting All system components with high in-rush currents 12 LLNRK/LLSRK Series POWR-PRO® Class RK1 250/600 VAC ■ Dual-Element, Time-Delay ■ 1/10 – 600 Amperes A A F K G B D F B REFER TO FIG. NO. 70-600A DIMENSIONS IN INCHES (mm in parentheses) A B C D E F G H J K LLNRK 2 (50.8) 1/2 (12.7) 1/2 (12.7) 9/16 (14.3) 5/64 (2.0) 5/32 (4.0) 3/8 (9.5) — — — LLSRK 5 (127.0) 3/4 (19.1) 5/8 (15.9) 13/16 (20.6) 3/32 (2.4) 3/16 (4.8) 5/8 (15.9) — — — LLNRK 3 (76.2) 3/4 (19.1) 5/8 (15.9) 13/16 (20.6) 3/32 (2.4) 3/16 (4.8) 5/8 (15.9) — — — LLSRK 5-1/2 (139.7) 1 (25.4) 5/8 (15.9) 1-1/16 (27.0) 3/32 (2.4) 1/4 (6.4) 7/8 (22.2) — — — LLNRK 5-7/8 (149.2) 1 (25.4) 1-1/16 (27.0) 1-1/16 (27.0) 1/8 (3.2) 3/4 (19.1) 1-1/4 (31.8) 1/4 (6.4) 9/32 (7.1) 1/2 (12.7) LLSRK 7-7/8 (200.0) 1-1/4 (31.8) 1-1/16 (27.0) 1-5/16 (33.3) 1/8 (3.2) 3/4 (19.1) 1-1/2 (38.1) 1/4 (6.4) 9/32 (7.1) 1/2 (12.7) LLNRK 7-1/8 (181.0) 1-1/2 (38.1) 1-15/32 (37.3) 1-19/32 (40.5) 3/16 (4.8) 1-1/8 (28.6) 1-27/32 (46.8) 7/16 (11.1) 9/32 (7.1) 11/16 (17.5) LLSRK 9-5/8 (244.5) 1-3/4 (44.5) 1-15/32 (37.3) 1-27/32 (46.8) 3/16 (4.8) 1-1/8 (28.6) 2-3/32 (53.2) 7/16 (11.1) 9/32 (7.1) 11/16 (17.5) LLNRK 8-5/8 (219.1) 2 (50.8) 1-15/16 (49.2) 2-3/32 (53.2) 1/4 (6.4) 1-5/8 (41.3) 2-11/32 (59.5) 5/8 (15.9) 13/32 (10.3) 15/16 (23.8) LLSRK 11-5/8 (295.3) 2-1/2 (63.5) 2 (50.8) 2-19/32 (65.9) 1/4 (6.4) 1-5/8 (41.3) 2-27/32 (72.2) 5/8 (15.9) 13/32 (10.3) 15/16 (23.8) LLNRK 10-3/8 (263.5) 2-1/2 (63.5) 2-3/8 (60.3) 2-19/32 (65.9) 1/4 (6.4) 2 (50.8) 2-27/32 (72.2) 3/4 (19.1) 17/32 (13.5) 1-1/8 (28.6) LLSRK 13-3/8 (339.7) 3 (76.2) 2-13/32 (61.1) 3-3/32 (78.6) 1/4 (6.4) 2 (50.8) 3-11/32 (84.93) 3/4 (19.1) 17/32 (13.5) 1-1/8 (28.6) 1 70 – 100 2 110 – 200 2 225 – 400 2 450 – 600 FIG. 2 SERIES 1 35 – 60 2 400 300 400 300 200 200 100 80 60 100 80 60 40 30 40 30 20 20 10 8 6 10 8 6 200A 400A 600A 60000 80000 100000 30000 40000 20000 6000 8000 10000 3000 4000 2000 600 800 1000 300 400 5 60000 80000 100000 30000 40000 20000 6000 8000 10000 3000 4000 2000 600 800 1000 .01 300 400 .02 .01 200 .04 .03 .02 60 80 100 .04 .03 30 40 .1 .08 .06 20 .2 .1 .08 .06 5 .2 8 10 .4 .3 200 1 .8 .6 .4 .3 CURRENT IN AMPERES 100A 2 60 80 100 1 .8 .6 30 40 2 4 3 20 4 3 8 10 TIME IN SECONDS 1000 800 600 60A 15A 400A 600A 200A 100A 60A 30A 15A 1000 800 600 30A LLSRK LLNRK TIME IN SECONDS G J C FIG. 1 1/10 – 30 D H E AMPERES E C CURRENT IN AMPERES 13 LLNRK/LLSRK Series POWR-PRO® Class RK1 250/600 VAC ■ Dual-Element, Time-Delay ■ 1/10 – 600 Amperes Current-Limiting Effects of LLNRK (250V) fuses Current-Limiting Effects of LLSRK (600V) fuses * Prospective RMS Symmetrical Amperes Short-Circuit Current ** Apparent RMS Symmetrical Note: Data derived from Peak Let-Thru Curves * Prospective RMS Symmetrical Amperes Short-Circuit Current ** Apparent RMS Symmetrical Note: Data derived from Peak Let-Thru Curves Short Circuit Current* 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 50,000 60,000 80,000 100,000 150,000 200,000 30A 900 1,100 1,250 1,400 1,500 1,600 1,700 1,800 1,900 2,000 2,200 2,300 2,500 2,600 Peak Let-Thru Current** for various fuse ratings 60A 100A 200A 400A 1,400 2,000 2,700 4,800 1,900 2,700 3,500 6,200 2,100 3,100 4,200 7,000 2,400 3,500 4,600 8,000 2,600 3,900 5,000 8,300 2,800 4,000 5,250 9,000 2,850 4,300 5,500 9,500 3,000 4,600 5,800 9,800 3,200 4,800 6,300 10,200 3,500 5,200 6,700 11,000 3,900 5,700 7,200 12,200 4,000 6,000 8,100 12,700 4,500 6,700 9,100 14,000 4,800 7,000 9,700 15,000 600A 5,000 8,500 9,500 10,800 11,500 12,000 12,500 13,500 14,000 15,000 16,000 17,000 19,000 20,000 1000000 800000 600000 400000 300000 400000 300000 200000 200000 100000 80000 60000 100000 80000 60000 30A 1,060 1,350 1,600 1,700 1,900 2,000 2,100 2,200 2,400 2,500 2,700 2,900 3,200 3,300 600A — 8,000 9,000 10,000 11,000 12,000 12,500 13,000 14,000 15,000 17,000 18,000 21,000 23,000 4000 3000 AVAILABLE FAULT CURRENT SYMMETRICAL R. M. S. AMPERES 200000 60000 80000 100000 30000 40000 200000 60000 80000 100000 30000 40000 20000 100 6000 8000 10000 100 3000 4000 200 2000 200 600 800 1000 400 300 300 400 400 300 200 1000 800 600 20000 2000 1000 800 600 AVAILABLE FAULT CURRENT SYMMETRICAL R. M. S. AMPERES 30A 6000 8000 10000 2000 10000 8000 6000 3000 4000 4000 3000 100A 60A 2000 30A 20000 600 800 1000 60A 300 400 100A 10000 8000 6000 400A 200A 200 200A 20000 600A 40000 30000 100 600A 400A 40000 30000 PEAK LET-THRU IN AMPERES 1000000 800000 600000 100 PEAK LET-THRU IN AMPERES 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 50,000 60,000 80,000 100,000 150,000 200,000 Peak Let-Thru Current** for various fuse ratings 60A 100A 200A 400A 1,600 2,100 2,600 4,100 2,000 2,800 3,400 5,250 2,300 3.200 3,900 6,000 2,600 3,600 4,500 6,700 2,800 3,800 4,800 7,500 3,000 4,100 5,200 8,000 3,100 4,400 5,700 8,500 3,300 4,600 6,000 9,000 3,500 4,900 6,500 9,500 3,800 5,200 7,000 10,000 4,000 5,700 7,750 11,000 4,200 6,200 8,500 12,000 4,600 7,300 10,000 14,000 4,700 8,000 11,000 16,000 LLSRK LLNRK 14 Short Circuit Current*