Bussmann Fusetron FRN-R Series Class RK5 Time-Delay Fuse

Bussmann Fusetron FRN-R Series Class RK5 Time-Delay Fuse, 250V

The Bussmann Fusetron FRN-R series is a family of Class RK5 time-delay (TD) fuses rated for 250V circuits, engineered to deliver dependable overcurrent protection across a wide range of low- and mid-current electrical applications. This product page covers the FRN-R fuse family, available in amperage ratings from 1/4 Amp up to 17-1/2 Amp, giving electricians and facility teams a single, consistent Class RK5 time-delay platform to standardize on across control circuits, instrumentation, motor circuits, and branch-circuit protection points. Every fuse in the FRN-R family shares the same 250V voltage rating, Class RK5 construction, and dual-element Fusetron design, with the amperage rating selected to match the specific circuit being protected. The time-delay characteristic common to the entire series allows these fuses to ride through brief current surges, such as motor or transformer inrush, without unnecessary opening, while still providing fast response to genuine short-circuit and sustained overload conditions.

Key Features

• Voltage Rating: 250V rating supports standard low-voltage circuit protection applications across the entire FRN-R family.
• Fuse Class: Class RK5 construction for compatibility with RK5-rated fuse blocks, holders, and disconnect switches.
• Time-Delay (TD) Design: Time-delay characteristic allows the fuse to ride through brief current surges, such as motor or transformer inrush, without unnecessary opening.
• Amp Rating Range: Available from 1/4 Amp through 17-1/2 Amp, allowing a single family to cover both low-current control circuits and higher-current branch circuits.
• Fusetron FRN-R Series: Part of the Bussmann Fusetron FRN-R fuse family, a recognized dual-element time-delay fuse line used across commercial and industrial electrical systems.
• Dual-Element Construction: As a Fusetron-series fuse, each FRN-R fuse uses a dual-element design that separates overload sensing from short-circuit response for well-rounded circuit protection.
• RK5 Rejection Fit: Class RK5 sizing allows the fuse to seat properly in RK5 rejection-style fuse blocks and holders, supporting correct fuse coordination.
• Compact Fuse Format: Every rating in the FRN-R family fits standard Class RK5 fuse holders, simplifying fuse selection and stocking for maintenance teams standardized on the RK5 class.

Technical Specifications

• Amperage Rating: 1/4A
• Product Subgroup: Shop by Brand

Typical Applications

• Control Circuit and Instrumentation Protection
• Motor Starter and Control Transformer Circuits
• Low-Current Branch Circuit Protection
• Panelboard and Equipment Overcurrent Protection
• Replacement Fuse for Class RK5 Fuse Holders and Reducers
• Commercial and Industrial Electrical Maintenance

Why Bussmann?

Bussmann is a trusted name in circuit protection, and the Fusetron FRN-R series of Class RK5 time-delay fuses reflects that reputation with a shared 250V rating and time-delay performance designed for dependable, code-compliant operation across the full amperage range. For electricians and facility teams who need overcurrent protection that stands up to real-world motor and control-circuit demands, the Bussmann FRN-R family delivers consistent performance backed by Class RK5 construction and dual-element Fusetron design at every amp rating from 1/4 Amp to 17-1/2 Amp. With Bussmann fuses in place, facilities gain a recognized level of manufacturing quality and consistent fit within Class RK5-rated equipment, whatever amperage the circuit calls for. Choose Bussmann for electrical protection components built to keep circuits, equipment, and personnel safe.