FLSR300 - 300Amp Fuse

FLSR300 - 300Amp Fuse

Looking for the FLSR300 because that's the exact fuse specified for your equipment? Then the details matter. This 300A Class RK5 time-delay fuse combines a 300-amp continuous current rating with ratings up to 600V AC and 300V DC, dual-element construction, and a knife-blade configuration. The FLSR300 is also a non-indicating fuse, so if you're matching an existing component, check more than the 300A marking. Fuse class, voltage, time-delay characteristics, interrupting capacity, blade configuration, and holder compatibility all need to line up with the application.

Key Features and Benefits

• 300A continuous current rating – Built for equipment requiring a 300-amp fuse.
• Class RK5 – Makes it easier to match the correct fuse class when replacing an existing component.
• Time-delay operation – Helps accommodate appropriate short-duration startup and inrush currents.
• Dual-element design – Provides the operating characteristics associated with this time-delay fuse family.
• Up to 600V AC – Suitable for properly specified AC applications within its ratings.
• Up to 300V DC – Also supports correctly matched DC applications.
• Knife-blade construction – Installs in a compatible fuse block, clip, or holder.
• Non-indicating model – Useful for matching the exact configuration of an existing FLSR300.
  

Technical Specifications

• Catalog Number: FLSR300
  
• Series: FLSR
  
• Fuse Type: Dual-Element Time-Delay Fuse
  
• Fuse Class: Class RK5
  
• Continuous Current Rating: 300A
  
• Maximum AC Voltage: 600V AC
  
• Maximum DC Voltage: 300V DC
  
• Opening: Slo-Blo / Time Lag (T) / Time Delay
  
• Construction: Knife-Blade
  
• Family Style: Dual Element Fuse
  
• 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

When certifications are part of the job specification, it's worth checking the paperwork rather than making assumptions. The supplied information confirms that the FLSR300 is a Class RK5 fuse. Still, it does not provide enough catalog-specific information to accurately list individual UL, CSA, RoHS, or other certification and material-compliance declarations.

Where It Works Best

The FLSR300 makes sense when the equipment specification calls for a 300A Class RK5 time-delay fuse and brief startup or inrush current is expected during normal operation. That's where its time-delay characteristic becomes particularly useful: it can tolerate appropriate temporary increases in current without operating like a fast-acting fuse.

For replacement jobs, 300 amps is only the starting point. A fuse with the same current rating isn't automatically interchangeable. Check the required Class RK5 designation, 600V AC or 300V DC rating as applicable, time-delay operation, interrupting requirements, knife-blade configuration, and mounting arrangement before making the match.