Bussmann FRN-R-40 Fuse

The Bussmann FRN-R-40 Fuse is a professional-grade 40A Fusetron dual-element time-delay fuse designed for critical motor protection and branch circuit applications. Engineering for a 250V AC voltage rating, this Class RK5 fuse provides essential current-limiting performance that prevents downstream equipment damage. Its dual-element construction offers a 10-second minimum time delay at 500% of the rated current, effectively eliminating nuisance tripping caused by high inrush currents during the startup of HVACR compressors, motors, and transformers. As a current-limiting electrical fuse, it features an impressive 200 kAIC interrupting rating, ensuring reliable arc suppression and system safety during massive overcurrent events. This 40-amp cartridge is the standard for motor control centers and machinery disconnects where precision timing and high-capacity fault protection are non-negotiable for operational uptime.

• Minimizes Nuisance Outages: The dual-element design allows for temporary surges during motor starts without opening the circuit prematurely.
• Advanced Motor Protection: Provides superior overload protection to help prevent motor burnout from single-phasing on three-phase systems.
• High Interrupting Capacity: Safely handles faults up to 200,000 Amps, making it suitable for high-fault current environments like industrial power panelboards.
• Class RK5 Identification: Easy to integrate into existing Class R fuse blocks to maintain UL/CSA code compliance.
• Enhanced Coordination: Features a 2:1 selective coordination ratio within the Fusetron family to prevent upstream fuses from blowing unnecessarily.

Is the FRN-R-40 interchangeable with a standard FRN fuse?
While they share footprints, the "R" designation signifies a Class RK5 rating with a rejection feature. You can install an FRN-R-40 into a standard H-class block, but a standard FRN cannot be used in a rejection-style Class R block. Always verify your fuse holder type before installation.

How does this fuse handle high-heat environments common in HVACR?
These fuses are built with a robust ferrule-to-ferrule connection and internal elements that maintain stability in varying ambient temperatures, though derating should be calculated according to the Eaton Bussmann technical data sheets for extreme conditions.

Can I use this for DC applications?
Yes, the Bussmann FRN-R-40 is typically rated for 125V DC in addition to its 250V AC rating, making it versatile for diverse machinery control circuits.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.