Overview
The Bussmann LPJ-80SP is a Class J low-peak dual-element time-delay fuse designed for industrial motor control and branch circuit protection. This 80A fuse features a 600V AC / 300V DC voltage rating and delivers an industry-leading 300kA interrupting rating at 600V AC and 100kA at 300V DC. The LPJ-80SP is non-indicating and manufactured to UL and CSA standards, providing reliable overcurrent protection in applications subject to high inrush currents and temporary overloads.
Key Features
- Dual-element design — Separate overload and short-circuit elements enable time delay for motor starting without nuisance trips.
- 300kA interrupting rating — Highest in its class; handles short-circuit protection in demanding industrial environments.
- 10-second time delay — Minimum 10-second response at 500% rated current ride-through, ideal for high inrush loads and soft starters.
- Current limiting — Protects downstream components against thermal and magnetic damage from short circuits.
- Selective coordination — 2:1 ratio within Low-Peak family prevents unnecessary circuit shutdowns beyond the failed circuit.
- Cartridge body — Melamine construction, 1.13″ diameter x 4.63″ length; mounts in standard Class J fuse blocks.
Technical Specifications
- Amperage: 80A
- Voltage Rating: 600V AC / 300V DC
- Interrupting Rating: 300kA @ 600V AC; 100kA @ 300V DC
- Fuse Class: Class J
- Type: Dual-element, time-delay (slow-blow)
- Time-Delay: 10 seconds minimum at 500% rated current
- Body Style: Cartridge (cylindrical)
- Dimensions: 1.13 inch diameter x 4.63 inch length
- Material: Melamine
- Indication: Non-indicating
- Terminal Type: Bolted blade
- Standards: UL listed, CSA certified
- Weight: 0.35 lbs
Typical Applications
- AC and DC motor branch circuits with high inrush starting currents.
- Industrial control circuits and machinery with soft starters or variable frequency drives.
- Power distribution and feeder protection in manufacturing plants and data centers.
- Transformer primary protection where coordinated backup is required.
- Marine, mining, and petrochemical installations requiring current-limiting coordination.
Compatibility & Replacements
Compatible With
- Standard Class J fuse holders and blocks (cartridge-style mounting).
- Low-voltage branch circuit systems rated 600V AC or 300V DC.
- Motor soft starters, frequency drives, and programmable controllers requiring time-delay protection.
- Systems requiring selective coordination with other Low-Peak fuses (2:1 ampacity ratios).
Replaces / Drop-In Replacement For
- Earlier non-low-peak Class J fuses of equivalent amperage (verify coordination with system integrator).
- Some Mersen Amp-Trap fast-acting fuses in equivalent Class J applications (consult application tables).
- Direct fit upgrade within LPJ-SP series (LPJ-70SP, LPJ-100SP, etc. for different amperage requirements).
Works With
- Class J fuse blocks and rejection-style holders.
- Series-combination ratings with NEMA and IEC motor controllers.
- Power systems requiring type 2 coordinated protection for motor overload protection.
- Coordination with other Low-Peak fuses for selective trip sequencing and inventory reduction.
