LLNRK225 - 225Amp Fuse

LLNRK225 - 225Amp Fuse

Some electrical equipment draws a lot more current when it starts than it does while running. Motors and transformers are good examples. That brief surge is normal, but it can be a problem when a fuse isn't designed to handle it.

The Littelfuse LLNRK225 is a 225 Amp, Class RK1 time-delay fuse built for circuits where startup current and reliable fault protection both matter. Part of the Littelfuse POWR-PRO series, it uses a dual-element design that allows temporary inrush currents while providing protection against sustained overloads and short circuits.

The LLNRK225 is rated for 250V AC and 125V DC, making it suitable for a range of properly rated commercial and industrial electrical systems. You'll find this type of fuse used in service entrance equipment, main distribution circuits, feeders, motor circuits, and other applications where dependable overcurrent protection is essential.

Key Features and Benefits

• 225 Amp Continuous Current Rating
• Class RK1 Current-Limiting Protection
• Dual-Element Time-Delay Design
• Helps Prevent Nuisance Fuse Openings
• High Short-Circuit Interrupting Capacity
• Reduced Fault Energy Exposure
• Low-Resistance Construction
• Suitable for Equipment with High Startup Currents
• Thermally Reversible Overload Element
• POWR-PRO Series Design
• Compatible Class H Fuse Block Upgrade Capability
• Fuse Block, Clip, or Holder Mounting

Technical Specifications

• Manufacturer: Littelfuse
  
• Catalog Number: LLNRK225
  
• Series: LLNRK
  
• Product Family: POWR-PRO
  
• Fuse Type: Dual-Element, Time-Delay Fuse
  
• Fuse Class: Class RK1
  
• Continuous Current Rating: 225 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 LLNRK225 belongs to the POWR-PRO Class RK1 fuse family and is designed for current-limiting, time-delay overcurrent protection.

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

Specific environmental compliance declarations and certification listings should be verified against 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
• Equipment with High Inrush Currents
• Commercial Electrical Systems
• Industrial Machinery
• Compatible Class H Fuse Block Upgrades