Overview
The Bussmann LPJ-50SP is an Eaton/Bussmann series Low-Peak Class J time-delay fuse engineered for industrial control and automation systems. This dual-element, current-limiting fuse combines fast short-circuit protection with time-delay capability, making it ideal for circuits with motor inrush loads and sensitive equipment. Bussmann series Ultimate protection LPJ Class J dual element, current-limiting, time-delay fuses deliver reliable circuit protection while minimizing nuisance fuse openings in industrial panelboards, machinery disconnects, and branch circuit applications.
Key Features
- Industry leading 300,000 A interrupt rating at 600 VAC RMS Sym and 100 kA VDC, with minimum 10 sec of 500% rated current ride-through performance, ideal for sizing of high inrush loads
- Separate overload and short circuit elements provide time delay for sizing of high inrush loads linked with class J current limitation
- Selective coordination ratio of 2:1 (within Low-Peak fuse family) prevents electrical shutdowns from extending beyond the failed circuit
- UL Listed and CSA Certified, providing reliable protection with a minimum 10-second time delay at 500% rating, suitable for protecting circuits against overloads and short circuits
- Ferrule terminal design for easy installation in Class J fuse holders
- Non-indicating design (no visual fuse-blown indicator)
Technical Specifications
- Amperage Rating: 50A
- Voltage Rating: 600VAC / 300VDC
- Interrupt Rating: 300kA @ 600VAC, 100kA @ 300VDC
- Fuse Type: Class J, Dual-Element, Time-Delay (Slow-Blow)
- Time-delay – 10 seconds (minimum) at 500% of rated current
- Ferrule end connections and a compact size of 1.06 by 2.38 inches
- Body Material: Melamine Cartridge
- UL 248-8 – Class J Fuses, CSA C22.2 No. 248.8 – Class J Fuses, CE, RoHS Compliant
- Series: LPJ-SP (Low-Peak)
Typical Applications
- Industrial panelboards and branch circuit mains protection
- Motor control centers and machinery disconnects
- Plant automation and control systems
- High-inrush load circuits (motors, transformers, compressors)
- Power distribution and coordination with breakers and other protective devices
Compatibility & Replacements
Compatible With
- All UL Class J fuse holders and clips rated 600VAC 50A
- Industrial panelboards with Class J cavity mounting
- Coordination with NEMA and IEC motor controllers
- Series combination ratings with branch circuit breakers
- Low-Peak fuse family products (2:1 selective coordination)
Replaces / Drop-In Replacement For
- Littelfuse JTD-50 (equivalent 50A Class J time-delay)
- Mersen Amp-Trap A4J50 (alternative 50A Class J fuse)
- Verify compatibility with your system integrator before ordering
Works With
- UL 248-8 and CSA C22.2 No. 248.8 compliant systems
- Standard Class J fuse applications per NEMA and IEC standards
- Series combination ratings with Eaton/Bussmann and third-party breakers
