Bussmann Time Delay Fuse FRN-R Series 300A 250VAC/125VDC Class RK5 Dual Element Blade End Non-Indicating

Bussmann Time Delay Fuse FRN-R Series 300A 250VAC/125VDC Class RK5 Dual Element Blade End Non-Indicating

Heavy-Duty Electrical Protection for High-Current Industrial Applications

The Bussmann Time Delay Fuse FRN-R Series 300A delivers superior electrical protection and circuit safety for high-current industrial applications. This Class RK5 time delay fuse features dual element current limiting technology designed for electrical contractors, industrial facilities, and commercial installations, providing the reliable overcurrent protection and industry-leading safety that electrical professionals demand for motor circuits and heavy equipment protection.

Professional Features & Benefits

Advanced Current Limiting Protection

• 300 Ampere Rating - Handles high-current loads with reliable overcurrent protection for industrial equipment
• Dual Element Design - Provides time delay for motor starting currents while offering fast response to short circuits
• Current Limiting Technology - Reduces let-through energy and minimizes arc flash hazards during fault conditions
• 200 kAIC Interrupt Rating - Safely clears high fault currents up to 200,000 amperes at 250VAC

Safety & Standards Compliance

• Class RK5 Classification - Meets NEC requirements for selective coordination and electrical safety standards
• CE Marked Compliance - Certified for international electrical safety and performance standards
• Non-Indicating Design - Professional-grade construction for reliable operation without visual indication requirements

Technical Specifications

Amperage Rating: 300A | Voltage Rating: 250VAC/125VDC | Interrupt Rating: 200 kAIC at 250VAC, 20 kAIC at 125VDC | Fuse Class: RK5 | Connection Type: Blade End x Blade End | Response Time: 10 seconds at 500% rated current | Element Configuration: Dual Element | Dimensions: 0.3" H x 0.3" W x 0.4" L | Weight: 0.05 lb | Indication: Non-indicating

Installation & Setup

1. Verify power is completely disconnected and follow NFPA 70E electrical safety procedures before installation
2. Confirm fuse holder is rated for 300A capacity and Class RK5 fuse dimensions
3. Insert blade ends fully into fuse holder ensuring secure mechanical and electrical connection
4. Verify proper fuse orientation and that blade connections are properly seated
5. Test installation with appropriate electrical testing equipment before energizing circuit
6. Document installation per NEC requirements and facility electrical safety procedures

Professional Applications

Ideal for:

• Motor Protection Circuits - Large industrial motors, compressors, and heavy machinery requiring time delay characteristics
• Transformer Primary Protection - High-capacity transformers and power distribution equipment in industrial facilities
• Industrial Control Panels - Main disconnect protection for manufacturing equipment and process control systems
• Commercial Building Systems - HVAC equipment, elevator systems, and large commercial electrical loads
• Power Distribution Centers - Switchgear and distribution panels requiring selective coordination
• Manufacturing Equipment - Production machinery, conveyor systems, and automated manufacturing lines
• Electrical Service Entrances - Main electrical service protection for commercial and industrial facilities
• Emergency Power Systems - Generator transfer switches and backup power distribution systems

Dual Element Time Delay Advantage

The dual element design provides superior selective coordination by allowing temporary overcurrents during motor starting while providing fast fault clearing for short circuits. The current limiting technology reduces arc flash energy and protects downstream equipment, making it ideal for industrial applications where both motor protection and personnel safety are critical.

Why Choose Bussmann Quality?

Bussmann's commitment to electrical safety excellence ensures this fuse meets the highest standards for overcurrent protection. With CE marking compliance, Class RK5 selective coordination capability, and proven current limiting technology, this fuse provides the reliable electrical protection that professional electrical contractors and facility managers trust for critical industrial applications.