SEARCH PRODUCT
LLNRK/LLSRK Series POWR-PRO



Class RK1 Fuses
250/600 VAC Dual-Element, Time-Delay 1/10 600 Amperes
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/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 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.
Specifications
Ampere Ratings
Voltage Ratings:
AC: 250 Volts (LLNRK)
1 10
1
2 8 10
6 1 4
25
80
250
600 Volts (LLSRK)
15 100
1 1 8
3
7
30
90
300
DC: 125 Volts (LLNRK)
2 10
1 1 4
3 2 10
8
35
100
350
300 Volts (LLSRK)
1 4 *
1 4 10
3 1 2
9
40
110
400
Interrupting Ratings:
AC: 200,000 amperes rms symmetrical
3 10
1 6 10
4
10
45
125
450
300,000 amperes rms symmetrical
4 10
1 8 10
4 1 2
12
50
150
500
(Littelfuse self-certified)
1 2
2
5
15
60
175
600
DC: 20,000 amperes
6 10
2 1 4
5 6 10
17 1 2
70
200
Ampere Range:
1/10 600 amperes
8 10
2 1 2
6
20
75*
225
Approvals:
AC: Standard 248-12, Class RK1
* LLSRK Only.
Example part number (series & amperage): LLNRK 450.
For online ordering, use numbers LNRK and LSRK for LLNRK/LLSRK.
UL Listed (File No: E81895)
CSA Certified (File No: LR29862)
QPL: Federal Specification No. WF-1814
Recommended Fuse Blocks
DC: Littelfuse self-certified
LR250 series (LLNRK Series)
LR600 series (LLSRK Series)
Refer to the Blocks & Holders section of this catalog for additional information.