Overview
The Bussmann JKS-125 is a fast-acting Class J Limitron fuse engineered for high-fault-current circuit protection in industrial and commercial systems. Manufactured by Eaton (formerly Cooper Bussmann), the JKS-125 combines rapid response time with advanced current limitation to prevent equipment damage during short-circuit events. With a 200 kA interrupting rating and rejection-style blade terminals, this fuse is ideal for branch circuit protection in power distribution cabinets, motor control centers, and automated machinery.
Key Features
- Fast-acting response: Quick-blow characteristics protect sensitive equipment and reduce arc energy
- Current-limiting design: Provides 10X better current limitation to help prevent equipment damage during short circuits
- Class J standard compliance: UL Listed (Std. 248-8, Guide JDDZ, File E4273) and CSA certified
- High interrupting rating: 200 kA RMS symmetrical at 600V ensures protection across all circuit locations
- Blade terminal: Rejection-style design ensures proper fit and prevents incorrect installation
- Global certifications: UL, CSA, and CE approved for broad regional compliance
Technical Specifications
- Rated Current: 125 A
- Voltage Rating: 600 VAC
- Interrupting Rating: 200 kA RMS (symmetrical)
- Speed: Fast-acting (quick-blow)
- Fuse Class: Class J
- Terminal Type: Blade terminal, rejection style
- Form Factor: Cartridge fuse
- Dimensions: Diameter 1.63 in. (41.4 mm) × Length 5.75 in. (146 mm)
- Weight: 12.8 oz (363 g)
- Agency Approvals: UL Listed Std. 248-8, CSA Class 1422-02, CE
Typical Applications
The JKS-125 fuse is ideal for:
- Branch circuit protection in medium to large industrial control systems
- Power distribution in manufacturing facilities and automated production lines
- Motor control center (MCC) feeder protection
- High-fault-current circuits requiring NEC® Section 110.9 compliance
- Commercial HVAC and refrigeration systems
- Critical industrial equipment with sensitive electronics
Compatibility & Replacements
Compatible With
- Class J fuse holders and fusible disconnect switches
- Power distribution cabinets and motor control centers (MCC)
- Industrial electrical systems rated 600V or less
- NEC® Article 240 compliant branch circuit protection
- Systems requiring UL 248-8 Class J fuses
Replaces / Drop-In Replacement For
- JKS125 (alternate designation)
- JKS 125A (alternate designation)
- Applications previously using slower-acting Class J fuses (verify current-limiting compatibility)
Works With
- Class J fuse clips and rejection-style holders
- Industrial automation control systems (Allen-Bradley, Siemens, Mitsubishi, Omron)
- Power management and protection relays
- Arc flash reduction systems (due to current limitation)
