FLNR400-ID - 400 Amp Fuse

FLNR400-ID - 400 Amp Fuse

When your circuit calls for a 400A Class RK5 time-delay fuse, the FLNR400-ID combines the electrical ratings and practical features required for demanding commercial and industrial applications. This 400-amp dual-element fuse is rated for up to 250VAC and 125VDC and uses a time-delay (Slo-Blo) design. That matters in equipment that can experience a temporary surge when it starts up—the fuse is designed to accommodate normal short-duration inrush current while still providing overcurrent protection. The FLNR400-ID also includes an indicating feature, which can make a real difference during maintenance.

Key Features and Benefits

• 400A current rating – Built for circuits and equipment requiring a 400-amp fuse.
• Class RK5 fuse – Designed for applications specified for Class RK5 protection.
• Time-delay performance – Helps accommodate normal temporary inrush currents that can occur when certain equipment starts.
• Dual-element construction – Provides the operating characteristics expected from this type of time-delay fuse.
• Indicating design – Gives maintenance personnel a more convenient way to check fuse status during inspections and troubleshooting.
• 250VAC and 125VDC ratings – Suitable for compatible AC and DC applications within the fuse's specified limits.
  

Technical Specifications

• Catalog Number: FLNR400-ID / FLNR400ID
  
• Series: FLNR_ID
  
• Fuse Type: Dual-Element Time-Delay Fuse
  
• Fuse Class: Class RK5
  
• Current Rating: 400A
  
• Maximum AC Voltage: 250VAC
  
• Maximum DC Voltage: 125VDC
  
• Opening Characteristic: Slo-Blo / Time Lag / Time Delay
  
• AC Interrupting Rating: Up to 300 kA
  
• DC Interrupting Rating: 20 kA
  
• Indicating: Yes
  
• Construction: Knife-Blade
  
• Mounting Method: Fuse Block / Clip / Holder
  
• Specified Holder Series: LFR25400 Series
  

Material Compliance and Certifications

The FLNR400-ID is identified as a Class RK5 fuse. Because certification, approval, and material-compliance requirements can vary by application, project, and jurisdiction, the appropriate documentation should be confirmed for the specific installation.

It's also worth checking more than amperage when replacing an existing fuse. Voltage rating, fuse class, interrupting capacity, time-delay characteristics, and physical style must all meet the requirements of the circuit and equipment.

Where It Works Best

The FLNR400-ID makes sense in applications where startup current is part of normal operation. Motors, transformers, industrial machinery, manufacturing equipment, and compatible electrical distribution systems are examples where a time-delay fuse may be specified. Rather than reacting unnecessarily to an acceptable momentary inrush, its time-delay characteristic is designed for applications where those brief current increases are expected.

The indicating feature is especially handy in facilities where maintenance speed matters. When a piece of equipment goes down, anything that makes troubleshooting more straightforward is useful. Technicians can more readily check fuse status and move on to the next step in diagnosing the circuit.