Overview
The Bussmann LPJ-150SP is a Low-Peak Class J dual-element time-delay fuse engineered for selective protection in industrial automation and control circuits. Rated 150 amps at 600 VAC / 300 VDC, the LPJ-150SP combines overload and short-circuit protection in one compact cartridge, making it ideal for sized protection of circuits with high inrush currents such as motor starters and transformers.
Key Features
- Dual-element design: separate overload and short-circuit protection elements
- Time-delay function: minimum 10-second ride-through at 500% rated current, preventing false trips on legitimate inrush
- Class J form factor: compact, non-interchangeable design that prevents accidental misinstallation
- Current-limiting performance: 300 kA interrupting rating (600 VAC RMS symmetrical)
- Selective coordination: 2:1 ratio within Low-Peak family prevents cascading shutdowns across circuits
- UL Listed and CSA Certified for North American installations
Technical Specifications
The LPJ-150SP meets NEMA and IEC standards for industrial fuse protection:
- Rated Current: 150 amps
- Voltage Rating: 600 VAC / 300 VDC
- Interrupting Rating: 300 kA (VAC RMS Sym.) / 100 kA (VDC)
- Speed Type: Time Delay (Slow Blow)
- Response Time: minimum 10 seconds at 500% rated current
- Case Size: 1.63″ diameter × 5.75″ length (41 mm × 146 mm)
- Connection Type: Bolted blade (bolt-on cartridge)
- Standards: UL Class J (File E4273), CSA C22.2 No. 248.8, RoHS 2011/65/EU compliant
Typical Applications
- Motor feeder and branch circuits in industrial plants
- Distribution panel protection for machinery with high starting currents
- Transformer primary and secondary protection
- Control system power supply circuits rated 150 A, 600 VAC service
- Series combination with branch-circuit breakers for broad coordination coverage
Compatibility & Replacements
Compatible With
- Class J fuse blocks and holders (modular open blocks, pyramid blocks, Safety J holders)
- Standard industrial electrical panels rated 600 VAC / 300 VDC service
- Motor control centers (MCCs) with Class J cartridge slots
- Equipment designed for 150 A rated-current protection circuits
- Selective coordination with upstream and downstream branch-circuit breakers
Replaces / Drop-In Replacement For
- LPJ-150 (non-SP variant)
- 150 amp Class J time-delay fuses in legacy installations
- Other 150A dual-element fuses requiring 10-second time-delay response
Works With
- Class J fuse reducers (J-63 style, 100A to 30A pairs)
- Standard fuse pullers and handling tools
- Industrial distribution systems using Class J selective coordination ratios
- Systems requiring RoHS 2011/65/EU compliance for EU installations
