Overview
The Bussmann LPS-RK-40SP is a Class RK1 dual-element, time-delay fuse designed for reliable protection of industrial electrical circuits. Rated at 40A for 600VAC and 300VDC applications, this cartridge fuse combines current-limiting capability with time-delay performance to prevent nuisance trips while protecting downstream equipment from short-circuit damage.
Key Features
- Dual-element, time-delay design: Permits sizing as close as 130% of motor full-load amperage (FLA) for back-up overload protection
- Current-limiting technology: Reduces thermal and magnetic stress on downstream components during fault conditions
- Class RK1 rating: High interrupting capacity of 300 kA at 600VAC and 100 kA at 300VDC
- Selective coordination: 2:1 ampacity ratios enable easy coordination with other protective devices
- No-damage motor protection: Provides Type 2 coordination for NEMA motor controllers
- Cartridge form factor: Fits standard clip-terminal holders for simple replacement
Technical Specifications
- Current Rating: 40A
- Voltage AC: 600VAC
- Voltage DC: 300VDC
- Class: RK1
- Type: Time-Delay (Slow-Blow)
- Interrupting Rating: 300 kA @ 600VAC; 100 kA @ 300VDC
- Body Style: Cylindrical cartridge
- Terminal Style: Centered tag (clip terminals)
- Indicator: Non-indicating
- Time-Delay: ≥10 seconds at 500% rated current
- Body Dimensions: 1.06″ diameter × 5.5″ length (26.92 × 139.7 mm)
- Weight: 5.44 oz per unit
- Approvals: UL, CSA, CE
- Series: LPS-RK (Low-Peak)
- Quantity per Lot: 2
Typical Applications
The Bussmann LPS-RK-40SP is suitable for:
- Feeder and branch circuits in industrial control panels
- Motor branch protection with selective coordination
- Transformer primary and secondary protection
- Solenoid and general-purpose circuit protection
- Equipment requiring dual-voltage (AC and DC) rated protection
Compatibility & Replacements
Compatible With
- Standard RK1 class fuse holders (clip-terminal cartridge style)
- NEMA motor control centers and disconnect switches
- Industrial power distribution equipment rated for 600VAC/300VDC
- Equipment requiring Class RK1 fuse protection
Replaces / Drop-In Replacement For
- Other 40A Class RK1 fuses with 600VAC/300VDC rating
- Legacy Cooper Bussmann LPS-RK-40SP units
- Verify compatibility with your equipment before ordering for critical applications
Works With
- Eaton/Bussmann fuse holder systems (Low-Peak compatible)
- Standard industrial fuse blocks and disconnect switches
- Motor starters and overload protection devices using coordinated fuse protection
