Overview
The Eaton Bussmann FNA-4 is a 4-amp dual element time-delay fuse engineered for AC circuits requiring inductive load protection. Rated at 250 V with silver-plated ferrule end connections, the FNA-4 delivers 10 kAIC at 125 Vac and 200 kAIC at 250 Vac interrupting capacity. This proven Fusetron series component is ideal for motor control, transformer primaries, and other applications where temporary inrush currents demand time-delay characteristics.
Key Features
- Dual element (time-delay) design for inductive load and electronic circuits
- Silver-plated ferrule end contacts for corrosion resistance and reliable connection
- Non-indicating type with robust construction
- 4 amp rating—standard supplemental protection for control circuits
- Drop-in compatible with existing 250V AC fuse holders
- UL 248-14 compliant
Technical Specifications
- Part Number: FNA-4
- Manufacturer: Eaton (Bussmann Series)
- Current Rating: 4 A
- Voltage Rating: 250 V AC
- Interrupting Capacity: 10 kAIC @ 125 Vac; 200 kAIC @ 250 Vac
- Type: Dual Element (Time-Delay)
- End Connections: Ferrule end × ferrule end (silver-plated)
- Form Factor: Non-indicating cartridge
- Series: Fusetron FNA
- Standards: UL 248-14
Typical Applications
- Motor starting and soft-start circuits
- Transformer primary protection
- Inductive load circuits (solenoids, contactors, coils)
- Electronic control circuits in machinery and process automation
- General industrial AC circuit protection
Compatibility & Replacements
Compatible With
- Eaton Bussmann FNA series fuse holders and rejection-style sockets
- Standard ferrule-type 250 V AC supplemental fuse blocks
- Control panel mounted fuse holders rated 250 V AC
- Motor starters and industrial control enclosures
- Any circuit designed for 4A, 250V AC protection
Replaces / Drop-In Replacement For
- Equivalent 4A, 250V dual element fuses from competing manufacturers
- Legacy 4A supplemental fuses in industrial control systems
- Other Bussmann FNA-4 units (cross-compatible)
Works With
- Eaton/Bussmann fuse holders and clips
- Industrial control enclosures and starter cabinets
- NEMA 1, 3R, and 4X control panels
- Any AC circuit requiring UL 248-14 compliant supplemental protection
