SEARCH PRODUCT
KLNR/KLSR Class RK1
250/600 VAC • Fast Acting • 1 – 600 Amperes
Applications
Resistance heaters
Lighting circuits
Non-inductive loads
Molded case circuit breaker load centers and panelboards have
increased interrupting ratings when series rated with Littelfuse
KLNR/KLSR Class RK1 fuses. Refer to panelboard manufacturer’s
literature for UL Listed combination of fuses and panelboards. Series
ratings up to 200,000 amperes are available.
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.
KLNR/KLSR series RK1 fuses were the earliest type of current-limiting
fuses 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 in-rush currents. In such applications, KLNR/
KLSR series fuses may only provide short-circuit protection.
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.
We recommend using POWR-PRO ® LLNRK/LLSRK series Class RK1,
dual-element, time-delay fuses in all new applications requiring the
current-limiting ability of UL Class RK1 fuses. POWR-PRO LLNRK/
LLSRK series fuses are also recommended in existing applications
where fast-acting RK1 or RK5 fuses have been opening on harmless
system surges such as motor starting currents.
Dimensions
• Refer to FLNR_ID for KLNR dimensions and FLSR_ID for KLSR
dimensions.
Specifications
Voltage Ratings:
AC: 250 Volts (KLNR); 600 Volts (KLSR)
Ampere Ratings
1
10
40
100
250
DC: 125 Volts (1 – 600A KLNR);
2
12
45
110
300
250 Volts (1 – 30A KLSR);
3
15
50
125
350
300 Volts (35 – 600A KLSR).
4
20
60
150
400
Interrupting Ratings:
AC: 200,000 a­peres r­s sy­­etrical
5
25
70
175
450
DC: 20,000 a­peres
6
30
80
200
500
Ampere Range:
1 – 600 a­peres.
8
35
90
225
600
Approvals:
AC: Standard 248-12, Class RK1
Exa­ple part nu­ber (series & a­perage): KLNR 200
UL Listed (File No: E81895)
CSA Certified (File No: LR29862)
Recommended Fuse Blocks
LR250 series (for KLNR series fuses)
LR600 series (for KLSR series fuses)
Refer to the Blocks & Holders section of this catalog for additional infor­ation.
DC: Littelfuse self-certified
General Purpose Fuses
KLNR/KLSR Class RK1 Fuses
250/600 VAC • Fast Acting • 1 – 600 Amperes
KLNR
KLSR
1000
800
600
400
300
200
1000
800
600
400
300
200
100
80
60
40
30
20
100
80
60
40
30
20
10
8
6
4
3
2
1 8
6
4
3
2
.8
.6
.4
.3
.2
.8
.6
.4
.3
.2
.1
.08
.06
.04
.03
.02
.1
.08
.06
.04
.03
.02
.01
.01
CURRENT IN AMPERES
CURRENT IN AMPERES
KLNR
KLSR
1000000
1000000
800000
800000
600000
600000
400000
400000
300000
300000
200000
200000
100000
100000
80000
80000
60000
60000
600A
400A
600A
400A
40000
40000
30000
30000
20000
200A
20000
200A
100A
60A
10000
100A
60A
10000
8000
8000
6000
6000
4000
30A
4000
3000
30A
3000
2000
2000
1000
800
1000
800
600
600
400
400
300
300
200
200
100
100
AVAILABLE FAULT CURRENT
SYMMETRICAL R. M. S. AMPERES
AVAILABLE FAULT CURRENT
SYMMETRICAL R. M. S. AMPERES