Overview
The Bussmann FRN-R-90 is an advanced protection, energy-efficient dual-element, current-limiting fuse engineered for Class RK5 applications. Rated for 90 amperes at 250Vac (or 125Vdc), this time-delay fuse protects circuits against overload and short-circuit faults in industrial, commercial, and facility power systems. The FRN-R-90 delivers precise coordination with circuit breakers and other protective devices while limiting fault current to reduce equipment damage.
Key Features
- Class RK5 time-delay, dual-element construction for energy-efficient protection
- Current-limiting design reduces peak fault current and thermal stress
- 250Vac / 125Vdc ratings for flexible application deployment
- 200 kA interrupting rating at 250Vac; 20 kA at 125Vdc for high fault capacity systems
- 10-second minimum delay at 500% of rated current ensures nuisance-free operation
- UL 248-12, CSA C22.2 No. 248.12, and CE certified
Technical Specifications
- Amperage Rating: 90A
- Voltage Rating: 250Vac / 125Vdc
- Interrupting Rating: 200 kA at 250Vac RMS Sym.; 20 kA at 125Vdc
- Fuse Type: Class RK5 Dual-Element Time-Delay
- Time-Delay: 10 seconds minimum at 500% rated current
- Indicating: Non-indicating (standard)
- Fuse Ends: Blade x Blade
- Certifications: UL, CSA, CE
- Series: Fusetron FRN-R
Typical Applications
The FRN-R-90 is ideal for protecting feeders, branch circuits, and motor circuits in:
- Manufacturing and process control systems requiring Class RK5 precision coordination
- HVAC and refrigeration equipment circuits
- Facility power distribution and switchgear applications
- Control transformers and low-voltage AC power circuits
- Any system requiring nuisance-free, current-limiting circuit protection
Compatibility & Replacements
Compatible With
- Class R fuse blocks and fuse clips rated 65–100A at 250V or 400A/600A with reducers
- Standard electrical enclosures and distribution panels accepting Class RK5 fuses
- Overcurrent protection coordination with circuit breakers and thermal-magnetic devices
- AC power systems rated 250Vac or 125Vdc
Replaces / Drop-In Replacement For
The FRN-R-90 directly replaces other Bussmann FRN-R 90A fuses and is cross-compatible with equivalent Class RK5 90A dual-element fuses from other manufacturers, such as Littelfuse FLN-R-90. Always verify mechanical and electrical compatibility with your specific fuse block or holder before ordering.
Works With
- RM25100, RM25200, and RM25400 Class R fuse blocks (Bussmann recommended blocks for 70–100A, 110–200A, and 225–400A ratings respectively)
- Bussmann fuse reducers (No. 2641-R, 2661-R, 2662-R) for oversized fuse blocks
- Standard Class R fuses and Class RK5 fuse applications across industrial control, HVAC, and facility power systems
