Bussmann Time Delay Fuse FRN-R Series 350A 250VAC/125VDC Class RK5 Dual Element Blade End

Bussmann Time Delay Fuse FRN-R Series 350A 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 350A 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 Protection

• 350A Current 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 damage during fault conditions
• 10 Second Time Delay at 500% - Allows motor starting while protecting against sustained overloads

Safety & Standards Compliance

• Class RK5 Rating - Meets NEC requirements for motor protection and power distribution circuits
• 200 kAIC at 250V Interrupt Rating - Safely clears high fault currents in industrial electrical systems
• CE Marked Compliance - Meets international electrical safety standards for global installations

Technical Specifications

350A amperage rating, 250VAC/125VDC voltage rating, 200 kAIC at 250V interrupt rating, 0.81" x 0.81" x 3" dimensions, Class RK5 fuse classification, blade end x blade end connection, 10 second time delay at 500% rated current, dual element construction, non-indicating design, 0.11 lb weight.

Installation & Setup

1. Turn off power and verify zero energy state using proper lockout/tagout procedures
2. Remove existing fuse using appropriate fuse pullers and safety equipment
3. Inspect fuse holder contacts for proper alignment and clean connections
4. Insert new fuse ensuring proper blade end orientation and secure contact
5. Verify fuse rating matches circuit requirements and NEC specifications
6. Restore power and test circuit operation following electrical safety protocols

Professional Applications

Ideal for:

• Motor Protection Circuits - Large industrial motors, compressors, and high-horsepower equipment requiring time delay protection
• Power Distribution Systems - Main distribution panels, switchgear, and electrical substations handling high current loads
• Industrial Machinery - Manufacturing equipment, conveyor systems, and automated production lines
• Commercial Buildings - HVAC systems, elevator controls, and large facility electrical distribution
• Transformer Circuits - Primary protection for power transformers and distribution transformers
• Control Panels - Motor control centers and industrial control systems requiring selective coordination
• Electrical Panels - Main breaker panels and distribution boards in industrial facilities
• Lighting Circuits - High-intensity discharge lighting and large commercial lighting systems

Dual Element Current Limiting Advantage

Bussmann dual element technology provides superior motor protection by allowing harmless starting currents while quickly clearing dangerous fault currents. The current limiting design reduces arc energy and system stress, while the time delay element prevents nuisance tripping during normal motor acceleration, ensuring reliable operation and extended equipment life.

Why Choose Bussmann Quality?

Bussmann commitment to electrical safety includes rigorous testing for NEC compliance, reliable overcurrent protection, and professional-grade construction. Each fuse undergoes comprehensive quality control to ensure consistent performance in critical electrical installations, providing the dependable circuit protection that electrical contractors and facility managers trust for industrial applications.