FRN-R-300 - 300Amp Fuse

FRN-R-300 - 300Amp Fuse

The Eaton Bussmann FRN‑R‑300 Fusetron Class RK5 Fuse delivers high‑performance circuit protection in industrial settings, engineered to guard your equipment against overloads and short circuits. With a hefty 300‑amp rating for 250 VAC and 125 VDC systems, this dual‑element, time‑delay cartridge fuse is built for scenarios with extreme current inrushes—think motors, transformers, and heavy‑duty panelboards. Its current‑limiting design keeps “let‑through” energy low when faults occur, while the blade‑end design ensures secure connection and easy installation.

Key Features and Benefits

• Dual‑element time‑delay construction: Gives you two‑fold protection: it handles sustained overloads while still reacting fast to short circuits.
• Current‑limiting performance: Significantly reduces the energy that passes during fault conditions, helping safeguard downstream machinery and wiring.
• High interrupting ratings: Up to 200 kA at 250 VAC and 20 kA at 125 VDC provide dependable protection even in heavy‑duty applications.
• Time‑delay characteristic: (10 seconds minimum at 500% of rated current) makes it ideal for motor control circuits where high starting currents occur.
• Non‑indicating fuse: Allows for clean, functional integration while minimizing false trips — giving you reliability without unnecessary indication features.

Technical Specifications

• Amperage Rating: 300 A
  
• Voltage Rating: 250 VAC / 125 VDC
  
• Interrupting Rating:
  • 200 kA RMS at 250 VAC
  • 20 kA at 125 VDC
• Response Time: Minimum 10 seconds at 500% of rated current
  
• Fuse Class: RK5 (cartridge, blade‑end × blade‑end)
  
• Dimensions:
  • Length: 8.63 in
  • Diameter: 2.38 in
• Weight: approx. 1.95 lbs
  
• Connection Type: Blade end × blade end – designed for holder mount applications.
  

Material Compliance and Certifications

• UL Listed: to Standard 248‑12, Guide JDDZ, File E4273.
• CSA Certified: (C22.2 No. 248.12, Class 1422‑01, File 53787).
• CE Marked: indicating conformity with applicable health, safety, and environmental standards.

Where It Works Best

• This fuse fits best in industrial control and power distribution panels: motor control centers, disconnects servicing heavy motors or transformer loads, and power‑panelboards where high inrush is common. Its time‑delay nature makes it especially valuable in circuits where devices startup draw large current spikes (for example, large compressors, industrial HVAC, or manufacturing machinery). If you’re managing equipment that demands both overload and short‑circuit protection without unnecessary nuisance trips, this is the solution.