POWR-GARD® Fuse Datasheet
© 2013 Littelfuse POWR-GARD® ProductsLittelfuse.com
Rev: 040913
1 of 3
250/600VAC•DualElement•Time-Delay•1/10 -600A
Description
RK1 fuses are extremely current-limiting fuses meaning they
greatly reduce or eliminate damage to circuits and equipment under
short-circuit conditions. Replacing existing Class H, K and RK5 fuses
with RK1 fuses is one of the easiest ways to immediately improve
the protection of plant workers and equipment.
Applications
• All general purpose circuits
• Motors
• Transformers
• Safety upgrades
Features/Benefits
• POWR-PRO Performance
• Indication available
• Dual-element design
• Extremely Current-Limiting
• IEC Type 2 “No Damage” protection to IEC and NEMA
type motor starters
• Indicating and DIN mount fuse holders available
Specifications
Voltage Ratings 600 VAC/300 VDC (LLSRK/LLSRK_ID)
250 VAC/125 VDC (LLNRK)
Interrupting Ratings AC: 200 kA rms symmetrical
300 kA rms symmetrical
(Littelfuse self-certified)
DC: 20 kA
Ampere Range 1/10 – 600 A
Approvals AC: Standard 248-12, Class RK1
UL Listed (File: E81895)
CSA Certified (File: LR29862)
DC: Littelfuse self-certified
Federal Specification WF-1814
(QPL- W-F-1814 )
1/10 1 2 8/10 6 1/425 80 250
15/100 1 1/83 7 30 90 300
2/10 1 1/43 2/10 8 35 100 350
1/41 4/10 3 1/29 40 110 400
3/10 1 6/10 4 10 45 125 450
4/10 1 8/10 4 1/212 50 150 500
1/22 5 15 60 175 600
6/10 2 1/45 6/10 17 1/270 200
8/10 2 1/26 20 75* 225
Note: All LLSRK_ID fuses rated 1 amp and above are Indicator® fuses.
*75 A is only available for the 600 V.
Web Resources
TC Curves, downloadable CAD drawings and other technical
information: Littelfuse.com/llsrk
Littelfuse.com/llnrk
Recommended Fuse Holders
LFR60Series•LFR25Series
PEAK LET-THRU IN AMPERES
AVAILABLE FAULT CURRENT
SYMMETRICAL R.M.S. AMPERES
1000000
100000
10000
1000
100
200000
100000
10000
1000
100
500 A
400 A
200 A
100 A
60 A
30 A
Peak Let-Thru Curve (600 V)
Note: For more information, see Peak Let-Thru Table
Dimensions
Please refer to the Class R dimensions page 3.
Ordering Information
INDICATING LLSRK_ID 60 LLSRK060ID LSRK060.TXID
NON-INDICATING LLSRK 60 LLSRK060 LSRK060.T
600 V
250 V
NON-INDICATING LLNRK 80 LLNRK080 LNRK080.V
LLSRK
QP
L
POWR-GARD® Fuse Datasheet
© 2013 Littelfuse POWR-GARD® ProductsLittelfuse.com
Rev: 040913
2 of 3
30 A 60 A 100 A 200 A 400 A 600 A
5,000 1,060 1,600 2,100 2,600 4,100 --
10,000 1,350 2,000 2,800 3,400 5,250 8,000
15,000 1,600 2,300 3,200 3,900 6,000 9,000
20,000 1,700 2,600 3,600 4,500 6,700 10,000
25,000 1,900 2,800 3,800 4,800 7,500 11,000
30,000 2,000 3,000 4,100 5,200 8,000 12,000
35,000 2,100 3,100 4,400 5,700 8,500 12,500
40,000 2,200 3,300 4,600 6,000 9,000 13,000
50,000 2,400 3,500 4,900 6,500 9,500 14,000
60,000 2,500 3,800 5,200 7,000 10,000 15,000
80,000 2,700 4,000 5,700 7,75 0 11,000 17,000
100,000 2,900 4,200 6,200 8,500 12,000 18,000
150,000 3,200 4,600 7, 30 0 10,000 14,000 21,000
200,000 3,300 4,700 8,000 11,000 16,000 23,000
Visit www.littelfuse.com/llsrk for 600 V Current-Limiting effects
Current-Limiting Effects of LLSRK and LLSRK_ID (600 V) Fuses
30 A 60 A 100 A 200 A 400 A 600 A
5,000 900 1,400 2,000 2,700 4,800 5,000
10,000 1,100 1,900 2,700 3,500 6,200 8,500
15,000 1,250 2,100 3,100 4,200 7,000 9,500
20,000 1,400 2,400 3,500 4,600 8,000 10,800
25,000 1,500 2,600 3,900 5,000 8,300 11,500
30,000 1,600 2,800 4,000 5,250 9,000 12,000
35,000 1,700 2,850 4,300 5,500 9,500 12,500
40,000 1,800 3,000 4,600 5,800 9,800 13,500
50,000 1,900 3,200 4,800 6,300 10,200 14,000
60,000 2,000 3,500 5,200 6,700 11,000 15,000
80,000 2,200 3,900 5,700 7,2 00 12,200 16,000
100,000 2,300 4,000 6,000 8,100 12,700 17,000
150,000 2,500 4,500 6,700 9,100 14,000 19,000
200,000 2,600 4,800 7,000 9,700 15,000 20,000
*Prospective RMS Symmetrical Amperes Short-Circuit Current Visit www.littelfuse.com/llnrk for 250 V Current-Limiting effects
Note: Data derived from Peak Let-Thru Curves
Current-Limiting Effects of LLNRK (250 V) Fuses
Blown Fuse Indicator Assembly
Granular Quartz Filling
Precision Formed Short Circuit Element
Fiberglass Reinforced Pultruded Body
Elastomeric Silicone Overload Section
Plated End Caps
LLSRK_ID Fuses—Quality Construction
for performance you can rely on…
Littelfuse LLSRK_ID Fuses feature true dual-element
construction. This robust design withstands
repeated surges within rated time delay
without opening needlessly, eliminating
downtime caused by power surges
or equipment demands.
POWR-GARD® Fuse Datasheet
© 2013 Littelfuse POWR-GARD® ProductsLittelfuse.com
Rev: 040913
3 of 3
AMPS
AC H J K
1
/
10
–30
1
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
LSRK_ID 5 (12 7.0 ) 3⁄4 (19.1) 5⁄8 (15.9) 13⁄16 (20.6) 3⁄32 (2.4) 3⁄16 (4.8) 5⁄8 (15.9) — —
—
35 – 60
1
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
LSRK_ID 51⁄2 (139.7) 1 (25.4) 5⁄8 (15.9) 11⁄16 (2 7.0 ) 3⁄32 (2.4) 1⁄4 (6.4) 7⁄8 (22.2) — — —
70 – 100
2
LLNRK 57⁄8 (149.2) 1 (25.4) 11⁄16 (2 7.0 ) 11⁄16 (2 7.0 ) 1⁄8 (3.2) 3⁄4 (19.1) —1⁄4 (6.4) 9⁄32 (7.1) 1⁄2 (12.7)
LLSRK
LSRK_ID 77⁄8 (200.0) 11⁄4 (31.8) 11⁄16 (2 7.0 ) 15⁄16 (33.3) 1⁄8 (3.2) 3⁄4 (19.1) —1⁄4 (6.4) 9⁄32 (7.1) 1⁄2 (12.7)
110 – 200
2
LLNRK 71⁄8 (181.0) 11⁄2 (38.1) 115 ⁄32 (37.3 ) 119 ⁄32 (40.5) 3⁄16 (4.8) 11⁄8 (28.6) —7⁄16 (11.1) 9⁄32 (7.1) 11 ⁄16 (17.5)
LLSRK
LLSRK_ID 95⁄8 (244.5) 13⁄4 (44.5) 115 ⁄32 (37.3 ) 127⁄32 (46.8) 3⁄16 (4.8) 11⁄8 (28.6) —7⁄16 (11.1) 9⁄32 (7.1) 11 ⁄16 (17.5)
225 – 400
2
LLNRK 85⁄8 (219.1) 2 (50.8) 115 ⁄16 (49.2) 23⁄32 (53.2) 1⁄4 (6.4) 15⁄8 (41.3) —5⁄8 (15.9) 13 ⁄32 (10.3) 15 ⁄16 (23.8)
LLSRK
LLSRK_ID 115⁄8 (295.3) 21⁄2 (63.5) 2 (50.8) 219 ⁄32 (65.9) 1⁄4 (6.4) 15⁄8 (41.3) —5⁄8 (15.9) 13 ⁄32 (10.3) 15 ⁄16 (23.8)
45 0 – 600 2
LLNRK 103⁄8 (263.5) 21⁄2 (63.5) 23⁄8 (60.3) 219 ⁄32 (65.9) 1⁄4 (6.4) 2 (50.8) —3⁄4 (19.1) 17⁄32 (13.5) 11⁄8 (28.6)
LLSRK
LLSRK_ID 133⁄8 (339.7) 3 (76.2) 213⁄32 (61.1) 33⁄32 (78.6) 1⁄4 (6.4) 2 (50.8) —3⁄4 (19.1) 17⁄32 (13.5) 11⁄8 (28.6)
A
F
EC
D
GB
A
J
K
H
B
C
FD
70-600A
FIG. 1 FIG. 2
E
Dimensions
