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Cylindrical fiberglass fuse, 4 amp, RK5 time-delay

Littelfuse

Littelfuse FLNR004 RK5 Time-Delay Fuse 4A 250V AC 125V DC

SKU CH-CTTP-H0XKJ

A time-delay RK5 fuse rated 4 A at 250 V AC and 125 V DC with a 200 kA interrupt rating

  • TypeFuses & Accessories
  • Time-delay operation protects against nuisance trips from inrush currents
  • 200 kA interrupt rating at 250 V AC handles high fault currents safely
  • RK5 current-limiting class reduces let-through energy to downstream equipment
  • Dual-element construction provides both overload and short-circuit protection
  • 4 A rating at 250 V AC and 125 V DC suits a range of control circuits

Littelfuse FLNR004 RK5 Time-Delay Fuse 4A

This Littelfuse FLNR004 is a UL Class RK5 time-delay fuse rated at 4 amps for 250 volts AC and 125 volts DC. It features a cylindrical fiberglass body measuring 2 inches long by 9/16 inch diameter. The dual-element design provides overload and short-circuit protection with a 200kA interrupt rating at 250V AC. It fits rejection-style fuse blocks for secure installation.

For industrial power circuits needing Class RK5

Suitable for maintenance teams replacing FLNR, FRN-R, ECNR, or TR-R series fuses in existing rejection blocks. The time-delay characteristic handles temporary motor-starting surges without nuisance opening. Not for buyers who need indicating fuses that show visual blown status. Not for circuits requiring higher ampere ratings or different voltage classes than the 4A 250V AC specification provides.

200kA interrupt rating at 250V AC

The 200kA interrupt rating at 250V AC is the critical specification determining if this fuse safely clears the maximum available fault current in your panel. Verify your system's available short-circuit current does not exceed this value before installation. The 20kA rating at 125V DC applies for DC circuit applications. Matching this rating to your equipment ensures proper coordination and safety compliance.

Highlights

  • Time-delay operation protects against nuisance trips from inrush currents
  • 200 kA interrupt rating at 250 V AC handles high fault currents safely
  • RK5 current-limiting class reduces let-through energy to downstream equipment
  • Dual-element construction provides both overload and short-circuit protection
  • 4 A rating at 250 V AC and 125 V DC suits a range of control circuits

Specifications

BrandLITTELFUSE
TypeFuses & Accessories

Questions about this item

What comes in the box and do I need to buy a fuse block separately?

The fuse is sold individually and fits rejection-style fuse blocks such as the LFR series; a compatible block must be purchased separately if one is not already installed.

Which ampere rating and voltage class should I select for my circuit?

This model is a 4 A RK5 fuse rated for 250 V AC and 125 V DC; choose it only when the circuit requires exactly those ratings.

What does the 200 kA interrupt rating mean when the fuse is installed?

It means the fuse can safely interrupt fault currents up to 200 kA at 250 V AC, protecting downstream equipment during a short-circuit event.

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