Overview
The Bussmann FRS-R-70 is an Eaton Bussmann Series Class RK5 fuse featuring time-delay, dual-element, current-limiting design with a 70A rating and interrupting rating of 200 kA at 600 Vac and 20 kA at 300 Vdc. This cartridge-style fuse is engineered for industrial applications requiring motor overload protection combined with short-circuit performance.
Key Features
- Dual-element time-delay design provides protection for motor overload, ground fault and short-circuit
- Can be sized close to full-load amperes in circuits subject to surge currents from motors and transformers, with higher short-circuit protection capability
- 10-second minimum response time at 500% of rated current
- Non-indicating rejection cartridge with knife blade terminal and dual-element fiberglass design
- Approved to CE, UL, and CSA standards
Technical Specifications
- Current Rating: 70A
- Voltage Rating: 600 VAC / 300 VDC
- Class: RK5
- Type: Dual-Element, Time-Delay (Slow-Blow)
- Interrupting Rating: 200 kA @ 600V; 20 kA @ 300V
- Response Time: 10 seconds minimum @ 500% rated current
- Body Style: Cartridge with Knife Blade Terminals
- Dimensions: 1.11″ Dia × 7.88″ Length
- Weight: 10.88 oz
- Certifications: UL 248-12, CSA C22.2 No. 248.12, CE
Typical Applications
The FRS-R-70 is ideal for:
- AC motor branch circuits requiring time-delay fusing
- Equipment with temporary inrush currents (transformers, compressors, pumps)
- Industrial control systems and machinery
- HVAC systems and refrigeration compressor protection
- Power distribution systems requiring Class RK5 current-limiting performance
Compatibility & Replacements
Compatible With
- Standard Class RK5 fuse holders and blocks rated 70A
- Industrial motor control centers (MCCs)
- Disconnect switches and distribution panels rated 600 VAC
- Bussmann RM25 series fuse blocks (1-pole, 2-pole, 3-pole configurations)
Replaces / Drop-In Replacement For
- Bussmann FRN-R-70 (250V/125V rated variant)
- Littelfuse FLS-R-70 (equivalent current-limiting time-delay fuse)
- Mersen TRS-R-70 cartridge fuse
Works With
- Class RK5 rated fuse blocks and holders
- Renewable-element fuse clips and terminals
- Industrial electrical distribution equipment certified for 600V class fusing



