Overview
The Bussmann LPJ-25SP is a Low-Peakâ„¢ Class J dual-element, time-delay (slow-blow) fuse rated 25A at 600VAC/300VDC. This lot includes five units of this current-limiting cartridge fuse, designed for industrial and commercial electrical systems requiring selective coordination and protection against transient overloads. The LPJ-25SP combines thermal overload sensitivity with fast short-circuit response, making it suitable for motor branch circuits, control transformers, and general equipment protection.
Key Features
- Dual-element design: Time-delay minimizes needless fuse openings due to temporary overloads and transient surges, while current-limitation protects downstream components against damaging thermal and magnetic effects of short-circuit currents.
- Low-Peak construction: Dual-element fuses have lower resistance than ordinary fuses so they run cooler and can often be sized for backup protection against motor burnout from overload or single phasing.
- Superior interrupting rating: 300,000 amp interrupting rating at 600Vac RMS Sym and 100kA Vdc while delivering a minimum of 10 seconds of 500% rated current ride-through performance.
- Selective coordination: Consistent 2:1 ampacity ratios make selective coordination easy.
- Compact cartridge format: Non-indicating cylinder design compatible with standard Class J fuseholders and rejecting footprints.
- UL/CSA certified: cULus Listed, UL 248-8 – Class J Fuses, CSA C22.2 No. 248.8 – Class J Fuses with RoHS compliance.
Technical Specifications
- Manufacturer: Eaton Bussmann (Cooper Bussmann)
- Part Number: LPJ-25SP
- Fuse Class: J
- Current Rating: 25A
- Voltage Rating (AC): 600VAC
- Voltage Rating (DC): 300VDC
- Interrupting Rating: 300kA @ 600VAC RMS Sym.; 100kA @ 300VDC
- Fuse Type: Dual-element, time-delay (slow-blow)
- Dimensions: 0.81″ Dia. × 2.25″ L (20.6mm × 57.2mm)
- Weight (per unit): Approximately 0.18 lbs
- Time-Delay Performance: Minimum 10 seconds at 500% rated current
- Quantity Per Lot: 5 units
- Condition: New, no original box
Typical Applications
The Bussmann LPJ-25SP is widely used in:
- Motor branch circuits: Single and polyphase induction motors with high starting inrush currents requiring time-delay coordination.
- Control transformers: Secondary circuit protection in industrial control panels and motor control centers.
- Equipment feeders: Main or branch protection for machinery, HVAC systems, and industrial power distribution.
- NEMA/IEC motor controllers: Provides no damage type-2 coordinated protection for NEMA and IEC motor controllers when properly sized.
- High-inrush applications: Lighting circuits, solenoid valve banks, and other transient-heavy loads.
Compatibility & Replacements
Compatible With
- Standard Class J cartridge fuseholders (UL 248-8 compliant)
- Industrial motor control centers (MCCs) with J-class provisions
- Disconnect switches rated for Class J fuses
- NEMA and IEC motor starters with Class J fuse protection
- 600VAC power distribution systems and branch circuits
- 300VDC systems where specified
Replaces / Drop-In Replacement For
- Other Bussmann Low-Peak LPJ series fuses rated at 25A (LPJ-25, LPJ-25A, etc.)
- Cooper Bussmann LPJ-25SP
- Note: Always verify dimensional and electrical compatibility before replacing. While the LPJ-25SP is a standard Class J form factor, consult equipment documentation to ensure suitability in your specific application.
Works With
- Class J fuseholders and rejecting clips (standard across manufacturers)
- Eaton Bussmann complete Low-Peak product line (1A–600A)
- Industrial control systems requiring UL 248-8 Class J compliance
- Power system coordination software (selective coordination design)
- All standard industrial electrical test and diagnostic equipment
