Overview
The Bussmann FRN-R-5 Fusetron is a time-delay, dual-element, current-limiting Class RK5 fuse engineered for branch circuit and motor protection in industrial electrical systems. This cartridge-style fuse combines an overload element for low-level overcurrent sensitivity with a short-circuit element for high-current interruption, making it ideal for circuits subject to temporary inrush or surge currents. The FRN-R-5 is UL listed and CSA certified for use in panelboards, motor control centers, combination starters, and machinery disconnects.
Key Features
- Dual-element construction provides separate overload and short-circuit protection
- Time-delay characteristic delivers 10 seconds (minimum) at 500% rated current, preventing nuisance trips during motor startup
- Current-limiting design restricts let-through current during faults
- 2:1 selective coordination ratio within the FRN-R family prevents upstream fuse blowing on downstream events
- 200kA interrupting rating at 250Vac / 20kA at 125Vdc ensures reliable fault clearing
- Ferrule-end construction allows snap-in mounting in standard fuse holders and blocks
Technical Specifications
- Amperage Rating: 5A
- Voltage Rating: 250Vac / 125Vdc
- Interrupting Capacity: 200kA @ 250Vac RMS Sym; 20kA @ 125Vdc
- Fuse Class: UL Class RK5 (branch circuit rated)
- Type: Dual-element, time-delay, current-limiting, non-indicating
- Time-Delay Response: 10 seconds (minimum) at 500% rated current
- Body Diameter: 0.56″ +/- 0.008″
- Body Length: 2.00″
- Terminal Style: Ferrule end x ferrule end
- Material: Fiberglass body with copper ferrule ends
- Certifications: UL Listed (Standard 248-12, Guide JDDZ, File E4273); CSA Certified (C22.2 No. 248.12, Class 1422-02, File 53787)
Typical Applications
- Motor control centers and combination motor starters
- Power distribution panelboards and branch circuits
- Machinery disconnects and industrial equipment protection
- HVAC and refrigeration control circuits
- Equipment requiring low-level overload sensitivity with high short-circuit interruption
Compatibility & Replacements
Compatible With
- Standard Class RK5 fuse blocks and holders (ferrule-end style)
- Motor control centers (MCC) with RK5 rejection slots
- Panelboards equipped with Class RK5 fuse mounting
- Industrial machinery disconnect switches rated for RK5 fuses
- Circuits designed for 250Vac / 125Vdc dual-voltage protection
Replaces / Drop-In Replacement For
- Other Class RK5 dual-element fuses in the same amperage rating (FRN-R-5, FRS-R-5 where RK5 class is specified)
- Verify compatibility with your motor control system manufacturer before ordering to ensure identical envelope and rejection characteristics
Works With
- All standard Class RK5 fuse holders and fuse blocks
- Motor starters and combination starters rated for RK5 class protection
- Industrial distribution panels and branch circuit protection devices
- Systems requiring UL 248-12 Class RK5 listed protection devices
