Overview
The Cooper Bussmann FRS-R-4 is an industrial-grade Class RK5 cartridge fuse engineered for motor control circuits, branch circuits, and power distribution systems. This Fusetron-brand fuse features dual-element, time-delay construction that provides 10-second time-delay protection at 500% rated load, minimizing nuisance trips while ensuring fast fault isolation.
Key Features
- Dual-Element, Time-Delay Design: Discriminates between harmless inrush currents and true faults, reducing unnecessary circuit downtime
- Class RK5 Current-Limiting: Limits fault current, protecting equipment and reducing thermal stress on switchgear
- High Interrupting Rating: 200 kA at 600VAC / 20 kA at 300VDC ensures reliable operation in high-fault-current applications
- Cartridge Design: 0.81″ diameter × 5″ length ferrule-terminal cartridge fits standard clip-mount fuse holders
- Wide Voltage Range: Rated 600VAC/300VDC for versatile industrial applications
- UL, CSA, CE Certified: Meets international safety and performance standards
Technical Specifications
- Manufacturer: Eaton Bussmann (Cooper Bussmann)
- Part Number: FRS-R-4
- Brand: Fusetron
- Amperage Rating: 4A
- Voltage Rating: 600VAC / 300VDC
- Class: RK5
- Type: Dual-Element, Time-Delay (Slow-Blow)
- Interrupting Rating: 200,000A (Symmetrical) at 600VAC; 20,000A (DC) at 300VDC
- Time Delay: 10 seconds at 500% rated load
- Body Style: Cartridge Fuse
- Dimensions: 0.81″ Diameter × 5″ Length (20.57 × 127 mm)
- Terminal Type: Ferrule Clip-Mount
- Approvals: UL 248-12, CSA, CE
- Box Quantity: 10 fuses per box
Typical Applications
- Motor control circuits and motor starters (NEMA/IEC applications)
- Machine tool branch circuits and power distribution
- Industrial automation systems and control panels
- HVAC and compressor circuit protection
- OEM equipment manufacturing and retrofit applications
- Facilities requiring selective coordination and reduced false trips
Compatibility & Replacements
Compatible With
- Standard Class RK5 fuse holders and clips rated 600V
- RM60100, RM60200, RM60400 Bussmann fuse blocks
- Any electrical system with 600VAC or 300VDC power distribution
- Motor control centers (MCCs) and industrial control panels
Replaces / Drop-In Replacement For
- Previous-generation Fusetron FRS-R-4 units
- Equivalent Class RK5 dual-element 4A fuses from other manufacturers
- Verify exact compatibility with your original equipment before ordering
Works With
- Class RK5 fuse-block systems and clip-mount holders
- Industrial power distribution networks (single-phase and three-phase)
- Standard electrical safety systems and circuit protection schemes
- UL 489 and UL 508 compliant control panels
