Overview
The Bussmann LPS-RK-100SP is a Class RK1 Low-Peak time-delay fuse designed for industrial and commercial circuit protection. This dual-element, current-limiting fuse delivers 100A capacity at 600VAC (300VDC) with a 300kA interrupting rating at 600VAC and 100kA at 300VDC. The Low-Peak design offers both overload and short-circuit elements, enabling fast response to faults while allowing inrush loads typical of motors and transformers to pass through during startup.
Key Features
- Dual-Element Design: Separate overload and short-circuit elements provide time delay and current limitation in one package.
- Class RK1 Current Limitation: Reduces peak fault currents and arc flash hazard; 300kA Vac interrupting rating exceeds requirements for virtually all applications.
- Time-Delay Rating: 10 seconds minimum at 500% of rated current allows 130% FLA sizing for motor overload protection without nuisance trips.
- Selective Coordination: Simple 2:1 ampacity ratio within the Low-Peak fuse family enables easy selective coordination and reduces inventory complexity.
- UL Listed & CSA Certified: Meets UL Standard 248-12 for Class RK1 fuses with CE compliance for European applications.
- Non-Indicating Design: Electrically isolated end cap; optional open-fuse indication available with suffix “I”.
Technical Specifications
- Rated Current: 100A
- Voltage Rating: 600VAC / 300VDC
- Interrupting Rating: 300 kA at 600VAC; 100 kA at 300VDC
- Fuse Class: RK1 (current-limiting)
- Type: Dual-element, time-delay
- Response Time: 10 seconds minimum at 500% rated current
- Body Dimensions: 1.11 in. diameter × 7.88 in. length
- Terminal Style: Blade end × blade end
- Indicating Type: Non-indicating (indication available with -I suffix)
- Certifications: UL 248-12, CSA C22.2 No. 248.12, CE, RoHS compliant
Typical Applications
- Feeder and branch circuits in industrial and commercial panels
- Motor circuits and protection (130% FLA sizing capability)
- Transformer circuits with inrush protection
- Solenoid and general-purpose circuits requiring selective coordination
- Backup overload protection for NEMA and IEC motor starters (Type 2 “no damage” capability when properly sized)
Compatibility & Replacements
Compatible With
- Class RK1 fuse holders rated for 600VAC / 300VDC
- NEMA and IEC motor control centers
- Industrial electrical distribution panels and circuit protection systems
- Selective coordination networks using standard 2:1 ampacity ratios
Replaces / Drop-In Replacement For
- Bussmann LPS-RK-100 (without “SP” suffix, where available in legacy inventory)
- Older current-limiting Class RK1 fuses of equivalent 100A rating
- Compatible as a direct replacement within the LPS-RK series (70–600A range)
Works With
- All Class RK1 fuse blocks and cutout holders
- Bussmann Low-Peak fuse family for coordinated selective protection
- Standard industrial electrical systems requiring UL 248-12 Class RK1 compliance
- Systems designed for 130% FLA motor overload sizing and time-delay coordination
