The Bussmann Fusetron FRN-R-45 is a 45-amp, 250-volt, Class RK5 dual-element time-delay fuse designed to provide reliable protection for electrical circuits.
Key Features
- Dual-Element Design: Incorporates separate overload and short-circuit elements, allowing for precise sizing up to 125% of motor full-load amperes (FLA).
- Time-Delay Capability: Offers a minimum of 10 seconds delay at 500% of rated current, accommodating temporary motor overloads and surge currents.
- High Interrupting Rating: Rated at 200,000 amperes interrupting capacity (AIC) at 250 VAC and 20,000 AIC at 125 VDC, ensuring robust protection against high fault currents.
- Energy Efficiency: Engineered to be approximately 23% more energy-efficient compared to leading competitors.
- Selective Coordination: Maintains a 2:1 amp ratio within the Bussmann RK5 fuse family, preventing upstream fuses from opening during overcurrent events.
Specifications
- Amperage Rating: 45 A
- Voltage Rating: 250 VAC / 125 VDC
- Interrupting Rating: 200 kA at 250 VAC; 20 kA at 125 VDC
- Response Time: 10 seconds at 500% of rated current
- Body Dimensions: 0.81 inches in diameter x 3 inches in length
- Terminal Type: Ferrule
- Material: Fiberglass
- Certifications: UL Listed (Guide JDDZ, File E4273), CSA Certified (Class 1422-01, File 53787), CE Marked
Applications
The FRN-R-45 fuse is suitable for various applications, including:
- Combination starters
- Machinery disconnects
- Motor control centers
- Power panelboards
Its design ensures protection against motor overloads, ground faults, and short circuits, helping to prevent equipment damage and enhance system reliability.




















