KLNR001 - KLNR Series

KLNR/KLSR series RK1 fuses were the earliest type of current-limiting fuse 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 inrush currents. In such applications, KLNR/KLSR series fuses may only provide short-circuit protection.

We recommend using POWR-PRO™ LLNRK/LLSRK series RK1, dual-element, time-delay fuses in all new applications requiring the current-limiting ability of UL Class RK1 fuses, or in existing applications where fast-acting RK1 or RK5 fuses have been opening on harmless system surges such as motor starting currents.

  • 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.
  • 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.
  • 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.
  • Refer to FLNR for KLNR dimensions and FLSR for KLSR dimensions.
Property (Mouseover for details) Value
Ampere Rating (A) 1
VAC (V) 250
VDC (V) 125
Interrupting Rating 20000A@125VDC
Opening Fast-Acting (F)
Package Size Industrial Cartridge