LLNRK250 - 250Amp Fuse

LLNRK250 - 250Amp Fuse

A motor starting up or a transformer being energized can draw a lot more current than it normally uses. That's expected. You don't want a fuse opening every time equipment experiences one of those brief surges.

The Littelfuse LLNRK250 is a 250 Amp, Class RK1 time-delay fuse designed to handle that challenge while protecting electrical circuits against overloads and short circuits. As part of the Littelfuse POWR-PRO series, it combines a dual-element design with current-limiting protection, making it a practical choice for commercial and industrial electrical systems.

If you're maintaining a distribution system or protecting equipment with demanding startup characteristics, the Littelfuse LLNRK250 250A time-delay fuse offers a useful combination of inrush tolerance, high interrupting capacity, and current-limiting performance.

Key Features and Benefits

• 250 Amp Continuous Current Rating
• Class RK1 Current-Limiting Protection
• Dual-Element Time-Delay Design
• Tolerance for Temporary Startup Surges
• Reduced Nuisance Fuse Openings
• High Short-Circuit Interrupting Capacity
• Reduced Fault Energy Exposure
• Low-Resistance Construction
• Thermally Reversible Overload Element
• POWR-PRO Series Performance

Technical Specifications

• Manufacturer: Littelfuse
  
• Catalog Number: LLNRK250
  
• Series: LLNRK
  
• Product Family: POWR-PRO
  
• Fuse Type: Dual-Element, Time-Delay Fuse
  
• Fuse Class: Class RK1
  
• Continuous Current Rating: 250 Amps
  
• Maximum AC Voltage: 250V AC
  
• Maximum DC Voltage: 125V DC
  
• AC Interrupting Ratings: 200,000A and 300,000A at 250V AC, as listed by Littelfuse
  
• DC Interrupting Rating: 20,000A at 125V DC
  
• Opening Characteristic: Slo-Blo / Time Lag / Time Delay
  
• Current-Limiting: Yes
  
• Overload Element: Thermally Reversible, Spring-Loaded
  
• Indicating: No
  
• Mounting Method: Fuse Block / Clip / Holder
  
• Compatible Holder Series: LFR25400
  
• Class H Fuse Block Compatibility: Suitable for compatible existing installations, subject to equipment ratings
  

Material Compliance and Certifications

The Littelfuse LLNRK250 is part of the POWR-PRO Class RK1 fuse family, designed for time-delay overcurrent protection in appropriately rated electrical systems.

• Material Compliance: Refer to current Littelfuse documentation for RoHS and REACH status
• Safety Certifications: Verify applicable UL, CSA, and other certification listings in current manufacturer documentation

Confirm certification listings and environmental compliance declarations using the manufacturer's latest product records.

Where It Works Best

• Service Entrance Equipment
• Main Distribution Circuits
• Feeder Circuits
• General-Purpose Branch Circuits
• Industrial Motors
• Transformers
• Solenoids
• Fluorescent Lighting Circuits
• High-Inrush Electrical Equipment
• Commercial Electrical Distribution
• Industrial Machinery
• Compatible Class H Fuse Block Upgrades