Overview
The Bussmann FRS-R-70 is a Fusetronâ„¢ dual-element, time-delay Class RK5 cartridge fuse designed for industrial electrical protection. Rated at 70 amperes, 600 VAC / 300 VDC, with a 200 kA interrupting rating, this fuse is engineered to handle the temporary surge currents common in motor circuits, transformers, and other inductive equipment while providing dependable overcurrent protection. The current-limiting design and renewable cartridge element make it a cost-effective choice for facilities requiring frequent fuse replacement.
Key Features
- Dual-element, time-delay construction: Delivers 10 seconds (minimum) of time-delay at 500% of rated current, allowing safe accommodation of motor inrush currents without nuisance blowing.
- Class RK5 rating: UL-recognized rejection-type design compatible with Class RK5 fuse holders.
- Current-limiting cartridge: Fiberglass-reinforced body with knife-blade terminals for secure holder mounting.
- High interrupt capacity: 200 kA at 600 VAC and 20 kA at 300 VDC for superior fault protection.
- Applications: Motor overload, ground fault, and short-circuit protection in motors, transformers, and similar inductive loads.
Technical Specifications
- Rated Current: 70 amperes
- Voltage Rating: 600 VAC / 300 VDC
- Class: RK5
- Type: Dual-element, time-delay
- Interrupting Rating: 200 kA @ 600 VAC; 20 kA @ 300 VDC
- Time-Delay Response: 10 seconds minimum at 500% rated current
- Body Material: Fiberglass-reinforced cartridge
- Terminal Type: Knife-blade
- Mounting: Class RK5 fuse holder
- Dimensions: 1.34″ diameter × 7.88″ length
- Manufacturer: Eaton Bussmann Series
Typical Applications
The FRS-R-70 is widely used in:
- Three-phase motor branch circuits requiring 70A capacity
- Industrial machinery and equipment with inductive loads
- HVAC systems and compressor circuits
- Transformer protection in commercial and industrial settings
- Any application where temporary surge currents necessitate time-delay fuse characteristics
Compatibility & Replacements
Compatible With
- Class RK5 fuse holders and cartridge fuse blocks
- Panelboards and motor control centers equipped for RK5 rejection fuses
- Industrial electrical distribution systems rated 600 VAC
- UPS systems, generators, and backup power equipment (300 VDC rating)
Replaces / Drop-In Replacement For
The FRS-R-70 is a direct replacement for other 70A Class RK5 time-delay fuses when the same voltage and interrupting rating are required. Similar 70A cartridge fuses from other manufacturers (such as Littelfuse FLS-R-70) may provide equivalent performance; however, always verify compatibility with your specific equipment and application before substitution. Consult your system integrator or equipment manufacturer to confirm suitability.
Works With
- Motor-rated switches and disconnect equipment
- Thermal-magnetic overcurrent protection devices in coordination with fuses
- Industrial control systems and motor starter circuits
- Standard UL/NEC-compliant electrical distribution equipment
