Bussmann FRN-R-30 30A 250V Fusetron RK5 Cartridge Fuse — Dual-Element Time-Delay, Brass End Caps

The Bussmann FRN-R-30 is a 30-amp, 250-volt dual-element, time-delay Fusetron cartridge fuse designed to protect motors and branch circuits from overloads and short circuits.

This RK5-class cartridge fuse combines a time-delay overload element with a fast-acting short-circuit element to give reliable protection in commercial, industrial, agricultural and residential electrical systems. Its construction — fiberglass tube with brass end caps — and UL/CSA listings make it suitable for motor control centers, panelboards, combination starters and machinery disconnects. The time-delay lets harmless startup surges pass while the dual-element design interrupts dangerous faults quickly.

How does the FRN-R-30 protect motors during startup and faults?

The FRN-R-30 uses a time-delay (dual-element) design so short, harmless inrush currents at motor startup do not cause nuisance opens, while sustained overloads are cleared before motor damage occurs. For severe short circuits the short-circuit element reacts very quickly to limit energy and reduce equipment stress.

• Time-delay element tolerates momentary startup surges without blowing.
• Overload element clears prolonged, low-level overcurrents to prevent burnout.
• Fast-acting short-circuit response opens in as little as 0.004 seconds under extreme fault.
• Current-limiting behavior reduces available fault energy and arc damage.

What ratings and certifications does this fuse carry?

The FRN-R-30 is rated for 30 amps at 250 volts AC and is a Class RK5 cartridge fuse with a current-limiting characteristic. It is UL Listed and CSA Certified, meeting industry standards for motor and branch-circuit protection in a wide range of applications.

• Catalog rating: 30 A, 250 V AC.
• Class RK5 with current-limiting capability (minimum 10 seconds at 500% rated amps).
• UL Listed and CSA Certified for safety and compliance.
• Grooved brass end caps for compatibility with Class H, K, and R fuse blocks.

Where should I install this cartridge fuse and what equipment does it suit?

This fuse is intended for use in motor protection and branch-circuit locations requiring higher amp or voltage capacity than cartridge fuses typically provide. Typical installations include motor control centers, industrial panelboards, HVAC equipment, pumps, and combination motor starters.

• Motor control centers and combination starters to prevent motor burnout.
• Panelboards and branch circuits in commercial and industrial settings.
• Air conditioning units, pumps, and agricultural machinery that experience inrush currents.
• Residential systems where cartridge-style protection is specified.

How do I size and replace an FRN-R-30 safely?

Select fuse ampacity to match motor and circuit design, accounting for inrush and locked-rotor current per equipment specifications and applicable codes. Always de-energize the circuit, verify voltage is off, and use compatible fuse holders or blocks when replacing fuses; follow lockout/tagout and manufacturer instructions.

• Confirm nameplate and circuit requirements before choosing ampacity.
• De-energize and lock out the circuit prior to replacement.
• Use proper Class H/K/R rated fuse blocks or holders with grooved end caps.
• Replace with identical Bussmann FRN-R-30 or approved equivalent for ratings and class.

Who is this for: The Bussmann FRN-R-30 is ideal for electricians, facilities managers, OEMs and maintenance technicians who specify reliable motor and branch-circuit protection that tolerates startup surges but responds quickly to faults. It suits industrial and commercial sites, HVAC and pump systems, agricultural equipment, and any installation where a UL/CSA-listed RK5 time-delay, current-limiting cartridge fuse is required. If you need a single, robust 30A, 250V fuse that balances inrush tolerance with fast fault interruption, the FRN-R-30 is engineered for those needs.

Features:

• FRN Series Fusetron Dual Element Time-Delay Class RK5 Cartridge Fuse by Cooper Bussmann
• 30 Amps, 250 Volts
• Current Limiting, Class RK5, UL Listed, CSA Certified
• Pack of 1 FRN-R-30A Cartridge Fuse by Cooper Bussmann