Overview
Bussmann LPN-RK-60SP is a Class RK1 low-peak dual-element time-delay fuse engineered for industrial and commercial electrical systems. Rated 60 A with an interrupting rating of 300 kA at 250 Vac and 100 kA at 125 Vdc, this current-limiting fuse combines overload and short-circuit protection in a single cartridge body, making it ideal for feeder circuits, motor protection, and branch circuit applications.
Key Features
- Dual-element design: Separate overload and short circuit elements provide time-delay response and prevent nuisance trips on inrush currents
- Class RK1 current limitation: Reduces peak let-through current, protecting downstream equipment from damage during faults
- 10-second time delay at 500% overload: Non-indicating time-delay response allows proper motor starting without unwanted interruptions
- Ferrule terminals: Ferrule end terminals ensure secure cartridge fuse holder installation
- Rejection feature: Physical size and design prevent cross-installation with incompatible fuse classes, enhancing safety and system reliability
- Certifications: UL, CSA 22.2, and CE approved
Technical Specifications
- Amperage: 60 A
- Voltage Rating: 250 VAC / 125 VDC
- Fuse Class: RK1
- Interrupt Rating: 300 kA AC / 100 kA DC (symmetrical)
- Type: Time-Delay, Dual-Element, Current-Limiting
- Time Delay Response: 10 seconds at 500% overload
- Body Style: Cartridge
- Diameter: 0.81 inches
- Length: 3 inches
- Terminal Type: Ferrule
- Non-Indicating: Blown fuse indication via visual inspection only
- Material: Melamine cartridge body with copper alloy elements
Typical Applications
Feeder and branch circuits, transformers, motors, solenoids, and general purpose circuits benefit from LPN-RK-60SP protection. The 10-second time delay is particularly suited for motor circuits requiring 130% full-load-ampere sizing capability, while the RK1 current-limiting action safeguards sensitive electronics and motor windings. Commonly used in panel boards, motor control centers, and industrial disconnect switches.
Compatibility & Replacements
Compatible With
- Cartridge fuse holders rated for Class RK1, 250V/125V systems
- Motor starter control circuits and branch circuit protection
- Industrial panelboards and distribution equipment rated 250 VAC or lower
- Single-phase and three-phase motor applications
- Equipment with 2:1 selective coordination requirements
Replaces / Drop-In Replacement For
- Bussmann LPN-RK-60 (legacy designation)
- Other Class RK1 60A fuses of equivalent voltage rating when space and fuse holder permit
- Verify existing fuse holder dimensions (0.81″ dia × 3″ length) before ordering
Works With
- Rejection-type cartridge fuse holders (Class RK fuse holders only)
- Standard AC motor starters and soft starters with appropriate fuse ratings
- Transformer primary and secondary protection circuits
- Equipment conforming to UL 248-1 and UL 1077 standards
- Systems requiring RK-class selective coordination (2:1 ratio with Class J or L fuses)
