Overview
The FRN-R-40 Class RK5 fuse is a dual-element, time-delay cartridge fuse from Cooper Bussmann (Eaton Bussmann Series). Rated for 40 amperes at 250Vac/125Vdc, it provides reliable overload and short-circuit protection across motor control centers, combination starters, disconnect switches, and panelboards in industrial automation environments. The time-delay characteristic prevents nuisance trips caused by motor inrush currents, while the dual-element design separates overload and short-circuit protection for precise coordination with upstream protection devices.
Key Features
- Dual-Element, Time-Delay Design: 10-second delay at 500% rated load prevents false trips on motor startup and transient overcurrents.
- 2:1 Selective Coordination Ratio: Within the Fusetron RK5 fuse family, promotes coordination with upstream protection and reduces unwanted cascading outages.
- Current-Limiting Performance: Reduces let-through current and minimizes equipment damage during short-circuit events.
- Ferrule Terminals: Standard 0.81-inch diameter, 3.00-inch length for compatibility with Class RK5 standard fuse holders.
- UL, CSA, and CE Certified: Meets UL 248-12 Guide JDDZ, CSA Class 1422-01, and European safety standards.
Technical Specifications
- Current Rating: 40 Amperes
- Voltage Rating: 250Vac / 125Vdc
- Interrupting Rating (AC): 200,000 amperes (200 kA) at 250Vac symmetrical
- Interrupting Rating (DC): 20,000 amperes (20 kA) at 125Vdc
- Fuse Class: RK5
- Type: Dual-Element, Current-Limiting, Time-Delay
- Time-Delay Characteristic: 10 seconds at 500% rated load
- Terminal Type: Ferrule (0.81″ diameter × 3.00″ length)
- Approvals: UL 248-12, CSA C22.2 No. 1422-01, CE Certified
- Package Quantity: Box of 10 fuses
- Country of Origin: Mexico
Typical Applications
- Motor branch circuits and motor control centers (MCC)
- Combination motor starters and soft starters
- Industrial machinery disconnects and safety switches
- Power distribution panelboards and feeder circuits
- Transformers and inductive load protection
- AC power mains, feeders, and branch circuits in manufacturing facilities
Compatibility & Replacements
Compatible With
- Class RK5-rated fuse holders and receptacles (cartridge style)
- Allen-Bradley combination starters and motor control centers
- Siemens and other industrial control equipment using Class R fusing
- Standard 600-volt rated disconnect switches and safety switches
- Industrial automation panelboards and distribution equipment rated for Class R protection
Replaces / Drop-In Replacement For
- Legacy Fusetron RK5 40-amp time-delay fuses (same footprint and electrical characteristics)
- Verify compatibility with your system integrator before ordering for critical motor control applications.
Works With
- Industrial PLCs and motor control logic (Rockwell, Siemens, Mitsubishi, Omron, Schneider)
- Drive protection and energy management systems that require Class RK5 cartridge fuses
- Backup and selective coordination schemes within multi-level fuse hierarchies
- EtherNet/IP and PROFINET-enabled motor control networks (via associated control equipment)
