Overview
The Bussmann FRS-R-175 is a UL Class RK5 Fusetron dual-element time-delay fuse engineered for demanding industrial motor and control circuits. The dual-element, time-delay construction provides energy efficient advanced protection, making it ideal for applications subject to temporary motor inrush currents and surge loads. This current-limiting fuse combines the overload detection advantage of time-delay operation with fast short-circuit response, enabling circuit protection sized close to motor full-load amperage.
Key Features
- 175 A rated current with 600 VAC/300 VDC voltage rating and 20/200 kA interrupt capacity
- Delivers 10 seconds (minimum) of time-delay at 500% of rated current, preventing nuisance trips on legitimate motor startup
- Insulated end caps reduce exposure to live parts and extend air gap distance between adjacent mounted fuses
- Renewable blade-terminal design for field replacement in standard cartridge holders
- Non-indicating fuse with Class RK5 rating for use in motor control centers, combination starters, and machinery disconnects
Technical Specifications
- Rated Current: 175 A
- Voltage Rating: 600 VAC / 300 VDC
- Interrupt Rating: 200 kA at 600 VAC / 20 kA at 300 VDC
- Fuse Class: RK5
- Time-Delay Response: 10 seconds (minimum) at 500% of rated current
- Body Type: Cartridge body, 1.61 in diameter × 9.63 in length
- Terminal Type: Blade terminal
- Element Construction: Dual element with fiberglass housing
- Indicating: Non-indicating
- Approvals: UL 248-12, CSA, CE
Typical Applications
- Three-phase motor circuits in combination starters requiring overload and short-circuit protection
- Motor control centers (MCCs) and power distribution panelboards
- Machinery disconnect switches with time-delay protection demands
- Industrial automation systems where motor inrush surge tolerance is essential
- Equipment protection where sized-to-motor FLA operation prevents nuisance disconnects
Compatibility & Replacements
Compatible With
- Standard RK5 Class cartridge fuse holders rated for 175 A and 600 V service
- Motor control centers (MCCs) with RK5 rejection features
- Combination motor starters accepting RK5 dual-element fuses
- Power panelboards and machinery disconnect switches rated 600 VAC
- Industrial control systems using Fusetron Class RK5 protection standards
Replaces / Drop-In Replacement For
- Other 175 A, 600 V RK5 dual-element time-delay fuses with identical cartridge geometry
- Verify dimensional compatibility (1.61″ diameter × 9.63″ length) and terminal configuration before ordering as substitute
- Consult equipment documentation or your system integrator for exact interchangeability with legacy models
Works With
- UL Class RK5-compliant fuse rejection systems
- Standard 600 VAC industrial power distribution networks
- Motor overload relay coordination in combination starter circuits
- Power quality and motor soft-start systems requiring time-delay protection integration


















