Overview
The Bussmann FRS-R-45 is a Class RK5 dual-element, time-delay current-limiting fuse from the Fusetron product line. With a 45 A rating, 600 Vac and 250 Vdc voltage capacity, and an interrupting rating of 200 kA at 600 Vac and 20 kA at 250 Vdc, this fuse delivers energy-efficient protection for demanding industrial and commercial electrical systems. Its time-delay design makes it ideal for equipment that experiences inrush currents during startup.
Key Features
- Dual-element design provides time-delay protection for power panelboards, combination starters, motor control centers, machinery disconnects, and safety switches
- Separate overload and short-circuit elements provide short circuit protection with the added benefit of letting inrush currents pass without opening the fuse
- Time-delay construction allows temporary overload conditions without opening, necessary for equipment that regularly experiences short-term power surges such as motor or transformer startup
- Non-indicating style; ferrule-end connections for standard cartridge fuse clips
- UL listed; meets industrial electrical safety standards
Technical Specifications
- Current Rating: 45 A
- Voltage Rating: 600 V AC, 300 V DC
- Fuse Class: RK5
- Type: Dual-element, time-delay, current-limiting
- Interrupting Rating: 200 kA @ 600 V AC; 20 kA @ 250 V DC
- Response Time: 10 seconds @ 500% of rated current
- Physical Diameter: 1.06 inches (20.6 mm)
- Overall Length: 5.50 inches (127 mm)
- Weight: 0.3–0.5 lb
- Connection Type: Ferrule-end cartridge
Typical Applications
The FRS-R-45 is commonly used in:
- Electrical power distribution panelboards and sub-panels
- Motor control centers and combination starters
- Industrial machinery disconnects and safety switches
- Transformer protection circuits
- AC and DC-powered control and lighting circuits
- Equipment experiencing regular inrush currents (motors, solenoids, transformers)
Compatibility & Replacements
Compatible With
- Standard cartridge fuse holders and clips rated for 20.6 mm × 127 mm cartridges
- 600 V AC electrical distribution systems
- Industrial control panels and machinery power supplies
- Any circuit requiring Class RK5 fuse protection up to 600 V
Replaces / Drop-In Replacement For
Verify compatibility with your system integrator before ordering. The FRS-R-45 is a direct replacement for existing Bussmann FRS-R-45 and FRSR-45 installations. For 250 V applications, consider the FRN-R-45 (250 V AC, 125 V DC rated equivalent).
Works With
- Eaton Bussmann fuse blocks and holders designed for RK5 cartridge fuses
- Allen-Bradley, Siemens, Schneider Electric, and other industrial control panel manufacturers
- Dual-element fuse applications where time-delay is required
- Electrical systems requiring UL-listed Class RK5 protection
