Bussmann Time Delay Fuse FRN-R Series 400A 250VAC/125VDC Class RK5 Dual Element Blade End

Bussmann Time Delay Fuse FRN-R Series 400A 250VAC/125VDC Class RK5 Dual Element Blade End

Heavy-Duty Electrical Protection for High-Current Industrial Applications

The Bussmann Time Delay Fuse FRN-R Series 400A 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 power distribution systems.

Professional Features & Benefits

Advanced Current Limiting Protection

• 400A Current Rating - Handles high-current loads with reliable overcurrent protection for industrial equipment
• Dual Element Design - Provides time delay for motor starting while offering fast fault clearing capability
• 200 kAIC Interrupt Rating - Superior fault current interruption at 250VAC for maximum electrical safety
• 10 Second Time Delay at 500% - Allows motor starting currents while protecting against sustained overloads

Safety & Standards Compliance

• Class RK5 Current Limiting - Reduces let-through energy and arc flash hazards in electrical panels
• CE Marked Compliance - Meets international electrical safety standards for global installations
• Non-Indicating Design - Professional-grade construction for reliable operation without visual indication

Technical Specifications

400A amperage rating, 250VAC/125VDC voltage rating, 200 kAIC interrupt rating at 250VAC, 2.06" x 2.06" x 8.63" dimensions, Class RK5 current limiting, blade end x blade end connection, 10 second response time at 500% rated current, dual element time delay design, 1.6 lb weight, non-indicating operation.

Installation & Setup

1. Verify power is OFF and use proper lockout/tagout procedures before installation
2. Inspect fuse holder and blade connections for proper alignment and cleanliness
3. Insert fuse ensuring blade ends are fully seated in fuse holder connections
4. Verify proper fuse class and amperage rating matches circuit protection requirements
5. Test installation with appropriate electrical testing equipment before energizing
6. Document installation per NEC requirements and facility electrical safety procedures

Professional Applications

Ideal for:

• Motor Protection Circuits - Large industrial motors, pumps, compressors, and HVAC equipment requiring time delay protection
• Power Distribution Systems - Main electrical panels, switchgear, and distribution boards in industrial facilities
• Transformer Protection - Primary and secondary protection for power and control transformers
• Industrial Machinery - Manufacturing equipment, conveyor systems, and automated production lines
• Commercial Buildings - Office complexes, retail facilities, and institutional electrical systems
• Control Panel Applications - Motor control centers, variable frequency drives, and electrical control systems
• Lighting Circuits - High-current lighting systems and electrical distribution for large facilities
• Electrical Panels - Main breaker panels, sub-panels, and electrical distribution equipment

Current Limiting Technology Advantage

Bussmann's advanced current limiting technology in the FRN-R series provides superior arc fault suppression and reduces let-through energy during fault conditions. The dual element design offers selective coordination with downstream protective devices while the 200 kAIC interrupt rating ensures reliable fault clearing capability in high-fault current applications, making it ideal for industrial electrical systems requiring both motor starting capability and fast fault protection.

Why Choose Bussmann Quality?

Bussmann's commitment to electrical safety excellence is demonstrated through rigorous testing, CE marking compliance, and proven performance in demanding industrial applications. The FRN-R series delivers reliable overcurrent protection with current limiting technology that reduces arc flash hazards and provides selective coordination for professional electrical installations, ensuring maximum safety and system reliability for electrical contractors and facility managers.