Overview
The Bussmann FRN-R-600 is a high-capacity Class RK5 dual-element time-delay fuse engineered for superior overcurrent protection in industrial distribution systems. Bussmann FRN-R-600 units deliver current-limiting performance and advanced protection with selective coordination capabilities. Manufactured by Eaton’s Bussmann Division using proven Fusetron technology, this 600-ampere fuse is ideal for equipment requiring robust, reliable circuit defense.
Key Features
- Dual-element construction: Combines fast-acting element for short-circuit protection with slow-melt element for overload tolerance, delivering time-delay response (10 seconds minimum at 500% of rated current).
- Current-limiting design: Reduces let-through current and fault damage, protecting downstream equipment from surge stress.
- Selective coordination: 2:1 selective coordination amp ratio within the Bussmann RK5 family prevents upstream fuse nuisance-opening during transient overloads.
- Non-indicating: Standard blade-end-to-blade-end cartridge form factor; optional open fuse indication available on select ratings.
- UL, CSA, and CE certified: Meets international safety standards (UL std. 248-12, CSA C22.2 No. 248.12, CE Low Voltage Directive compliance).
- Recommended fuse blocks: Compatible with RM25600-1CR, RM25600-2CR, and RM25600-3CR fuse blocks (1-, 2-, and 3-pole configurations).
Technical Specifications
Comprehensive electrical and physical ratings for the Bussmann FRN-R-600:
| Specification | Value |
| Ampere Rating | 600A |
| Voltage Rating | 250Vac, 125Vdc |
| Interrupting Rating | 200 kAIC @ 250Vac RMS Sym; 20 kAIC @ 125Vdc |
| Class | RK5 |
| Type | Dual-element, time-delay, current-limiting |
| Response Time | 10 seconds minimum at 500% of rated current |
| Indicating Type | Non-indicating |
| Contact Configuration | Blade end × blade end (cartridge) |
| Length | 10.38 inches |
| Height | 0.81 inches |
| Width | 0.81 inches |
| Weight | 3.1 lb |
| Certifications | UL Listed, CSA Certified, CE Marked |
| UPC | 051712507561 |
Typical Applications
The Bussmann FRN-R-600 serves critical protection roles in:
- Industrial power distribution: Main and feeder circuits in manufacturing plants and process facilities.
- Commercial electrical panels: Building distribution systems requiring high-amperage main protection.
- Equipment protection: Motor starters, transformers, and large machinery requiring selective coordination with branch-level fuses.
- Data centers and critical infrastructure: High-capacity circuits demanding fast, reliable fault isolation without nuisance outages.
- Renewable energy systems: PV inverter disconnect and combiner box protection in utility-scale solar installations.
Compatibility & Replacements
Compatible With
- RM25600-1CR, RM25600-2CR, RM25600-3CR fuse blocks (Bussmann-recommended 1-, 2-, and 3-pole configurations)
- Class R fuse reducers (use Nos. 2641-R, 242-R, 2661-R, 2662-R, 2664-R as applicable)
- 250Vac industrial distribution systems, switchgear, and panelboards rated 600A
- 125Vdc and 250Vdc DC circuits and power supplies (within voltage ratings)
Replaces / Drop-In Replacement For
The FRN-R-600 is a direct replacement for earlier Bussmann Fusetron 600A RK5 units and is equivalent to:
- Littelfuse FLNR 600A (Class RK5 equivalent)
- Mersen TR-R 600A (Class RK5 equivalent)
Verify compatibility with your system integrator before ordering to ensure fuse block and upstream equipment rating compatibility.
Works With
- Bussmann Fusetron RK5 product line (allows coordinated 2:1 selective protection ratios)
- Class RK5 and Class R fuse systems per NEC Article 240
- UL std. 248-12 Class RK5 approved equipment and switchgear
- ANSI/NEMA standards for industrial circuit protection
- CSA-certified equipment and installations (C22.2 No. 248.12)
