FLSR400 - 400Amp Fuse

FLSR400 - 400Amp Fuse

For electrical equipment that calls for a 400A Class RK5 time-delay fuse, getting the complete specification right matters far more than simply matching the number stamped on the fuse. The FLSR400 combines a 400-amp continuous current rating with 600V AC and 300V DC maximum voltage ratings, dual-element construction, and a knife-blade configuration. Its Slo-Blo / Time Lag (T) characteristics allow appropriate short-duration startup or inrush current without unnecessary opening, within the fuse's specified time-current characteristics. This is the non-indicating FLSR400, an important detail when you're matching an existing fuse or equipment specification.

Key Features and Benefits

• 400A continuous current rating – Intended for circuits and equipment specified for a 400-amp fuse.
• Class RK5 classification – Helps ensure you're matching the correct fuse class rather than choosing by amperage alone.
• Time-delay performance – Slo-Blo operation accommodates appropriate temporary startup and inrush currents while maintaining the fuse's intended overcurrent-protection function.
• Dual-element construction – Provides the operating characteristics associated with this time-delay fuse design.
• Knife-blade configuration – Built for compatible fuse blocks, clips, and holders.
• Non-indicating design – The FLSR400 does not include the indicating feature found on certain other configurations, making this an important point to verify during replacement.
  

Technical Specifications

• Catalog Number: FLSR400
  
• Series: FLSR
  
• Product Type: Time-Delay Fuse
  
• Family Style: Dual Element Fuse
  
• Fuse Class: Class RK5
  
• Continuous Current Rating: 400A
  
• Maximum AC Voltage: 600V AC
  
• Maximum DC Voltage: 300V DC
  
• Opening Characteristic: Slo-Blo / Time Lag (T) / Time Delay
  
• Construction / Size: Knife-Blade
  
• Indicating: No
  
• DC Interrupting Rating: 20,000A (20 kA) at 300V DC
  
• Manufacturer-Listed AC Interrupt Amperage: 200,000A and 300,000A at 600V AC*
  
• Mounting Method: Fuse Block / Clip / Holder
  
• PG Holder: LFR60400 Series
  

Material Compliance and Certifications

The available product information specifically identifies the FLSR400 as a Class RK5 fuse. Exact catalog-level UL, CSA, RoHS, or other material-compliance and certification declarations were not included in the specifications supplied for this product. Those approvals should therefore be verified for the exact FLSR400 catalog number whenever a project, facility standard, or equipment specification requires them.

Where It Works Best

The FLSR400 400A fuse is best suited to properly specified electrical systems that require Class RK5, time-delay protection and may experience brief startup or inrush currents as part of normal operation. The dual-element Slo-Blo design provides the fuse with time-delay behavior, allowing it to accommodate appropriate temporary increases in current while still performing its intended overcurrent-protection role.

It's also a practical replacement candidate when the existing specification calls for a 400A, 600V AC Class RK5 knife-blade fuse without an indicating feature. For DC applications, the FLSR400 carries a 300V DC maximum voltage rating and a 20 kA interrupting rating at 300V DC.