Overview
The Cooper Bussmann FRS-R-25 is a Class RK5 dual-element, time-delay fuse designed for industrial electrical systems requiring reliable overcurrent protection. This cartridge fuse delivers precise coordination and current limitation across a wide range of load conditions, making it a standard choice for branch circuit and feeder protection in manufacturing, process control, and machinery applications.
Key Features
- Dual-Element Time-Delay Design: Delivers 10 seconds (minimum) of time-delay at 500% of rated current (8 seconds for 1/10-30A sizes), preventing nuisance trips from harmless inrush currents
- Current-Limiting: Interrupting rating of 200 kA at 600 Vac and 20 kA at 300 Vdc protects downstream equipment from damage
- Class RK5 Coordination: 2:1 selective coordination ratio (within RK5 fuse family) prevents electrical shutdowns from extending beyond the failed circuit
- Ferrule Terminals: Clip-mount design for secure holder installation in standard fuse blocks
- Compact Cartridge Body: Dimensions 0.81 x 5 inches for standard fuse holder compatibility
Technical Specifications
- Rated Current: 25 A
- Voltage Rating: 600 VAC / 300 VDC
- Fuse Class: RK5
- Type: Dual-Element, Time-Delay
- Interrupting Rating: 200 kA @ 600 VAC; 20 kA @ 300 VDC
- Time-Delay: 10 seconds minimum @ 500% rated current
- Body Style: Cartridge (Ferrule Terminal)
- Mounting: Holder Clip
- Dimensions: 0.81″ diameter × 5″ length
- Weight: 0.5 lbs
- Standards/Certifications: UL 248-12, CSA C22.2 No. 248.12, CE
- Brand: Fusetron (Cooper Bussmann)
Typical Applications
The FRS-R-25 is widely used in:
- Motor circuit and branch circuit protection in industrial control panels
- Transformer primary and secondary protection
- Distribution equipment and feeder lines
- HVAC systems, pump stations, and process machinery
- Machine tool and automation equipment power distribution
Compatibility & Replacements
Compatible With
- Standard RK5 fuse holders rated 600V
- Industrial power distribution panels and electrical enclosures
- Machinery and equipment designed for Class RK5 fuses
- Disconnect switches and motor control centers with clip-terminal fuse blocks
Replaces / Drop-In Replacement For
- Cooper Bussmann FRS-R-25 (original part number)
- Eaton Bussmann FRS-R-25 (current manufacturer designation)
- Fusetron FRS-R-25 (Bussmann brand line)
Works With
- RK5 Class fuse applications requiring dual-element time-delay characteristics
- Standard 600V industrial electrical systems and equipment
- Current-limiting circuit protection schemes in machinery and automation
