FLNR400 - 400 Amp Fuse

FLNR400 - 400 Amp Fuse

When your electrical system calls for a 400-amp Class RK5 fuse that can tolerate normal startup currents without sacrificing dependable overcurrent protection, the FLNR400 is designed to meet the requirement. This dual-element, time-delay fuse carries a 400A continuous current rating and is rated for applications up to 250VAC and 125VDC. Its Slo-Blo/time-delay operating characteristics make it particularly useful in circuits where motors, transformers, and other electrical equipment may experience temporary inrush current during startup.

Key Features and Benefits

• 400A continuous current rating supports high-current commercial and industrial electrical applications.
• Class RK5 fuse design provides the specific fuse classification required by compatible equipment and systems.
• Dual-element construction combines time-delay performance with overcurrent protection.
• Slo-Blo / time-delay operation helps accommodate brief, normal inrush currents that can occur when equipment starts.
• A 250 VAC maximum voltage rating supports compatible AC electrical systems.
• A 125 VDC maximum voltage rating provides versatility for qualifying DC applications.
• Knife-blade construction provides a secure physical form factor for compatible fuse-mounting equipment.
• Fuse block, clip, or holder mounting allows installation in equipment designed for this fuse type.
  

Technical Specifications

• Catalog Number: FLNR400
  
• Series: FLNR
  
• Current Rating: 400A
  
• Fuse Class: Class RK5
  
• Family Style: Dual Element Fuse
  
• Opening Characteristic: Slo-Blo / Time Lag (T) / Time Delay
  
• Maximum AC Voltage: 250VAC
  
• Maximum DC Voltage: 125VDC
  
• AC Interrupting Rating: Up to 300 kA
  
• DC Interrupting Rating: 20 kA
  
• Size / Construction: Knife-Blade
  
• Indicating: No
  
• Mounting Method: Fuse Block / Clip / Holder
  
• Specified Holder: LFR25400 Series
  

Material Compliance and Certifications

The FLNR400 is part of the FLNR Class RK5 fuse family. Because certification, agency approval, and material-compliance requirements can vary by installation and may be updated over time, users should confirm the applicable documentation for the specific project or electrical system. This is especially important in installations governed by facility standards, engineering specifications, or local electrical codes.

Where It Works Best

The FLNR400 is a practical choice for commercial and industrial electrical systems that specifically require a 400A, Class RK5, dual-element time-delay fuse. Its time-delay characteristics are particularly valuable around equipment that can draw considerably more than its normal operating current for a short period when starting. Rather than reacting unnecessarily to an expected temporary surge, the fuse is designed to accommodate normal inrush while protecting sustained overcurrent conditions.

That makes the FLNR400 well suited to appropriately engineered motor circuits, transformer circuits, machinery, industrial equipment, and electrical distribution applications where its ratings match the system requirements. The combination of a 400A rating, 250VAC/125VDC capability, and high AC interrupting capacity makes it especially relevant for demanding electrical environments.