Overview
Bussmann LPS-RK-45SP Low Peak Time Delay Fuse
The Bussmann LPS-RK-45SP is a 45A Class RK1 low peak dual-element current limiting time delay fuse rated at 600V AC / 300V DC. Manufactured by Eaton Bussmann, this fuse is engineered to protect electrical circuits while accommodating normal motor inrush currents. The dual-element design provides superior overload and short-circuit protection, making it a standard choice in industrial branch circuits, motor control, and general electrical distribution.
Key Features
- Dual-element time delay design — accommodates temporary inrush currents while protecting against sustained overcurrent
- Class RK1 rated — 300 kAIC interrupting capacity at 600V AC; 100 kAIC at 300V DC
- Current limiting — restricts fault current and reduces arc damage to switchgear
- 10 second response at 500% rated load — quick action on true faults, slower on transient surges
- Ferrule-end terminals — fits standard RK1 fuse holders
- Non-indicating — mechanical design without visual status window
- UL, CSA, and CE approved — meets North American and international electrical standards
Technical Specifications
- Amperage Rating: 45 A
- Voltage Rating: 600 VAC / 300 VDC
- Class: RK1
- Type: Dual-Element, Time Delay, Current Limiting
- Interrupting Rating: 300 kAIC @ 600V AC; 100 kAIC @ 300V DC
- Terminal Type: Ferrule End × Ferrule End
- Body Diameter: 1.06 inches (26.9 mm)
- Body Length: 5.5 inches (139.7 mm)
- Response Time: 10 seconds @ 500% rated load
- Body Material: Melamine
- Indicating: Non-Indicating
- Series: LPS-RK (Low Peak)
- Quantity per Box: 10
- Approvals: UL, CSA C22.2, CE
Typical Applications
The Bussmann LPS-RK-45SP is recommended for:
- Branch circuit protection — feeders, lighting, and convenience outlet circuits
- Motor and transformer protection — handles inrush without nuisance blowing
- Industrial control circuits — solenoids, contactors, and general purpose equipment
- Electrical distribution panels — main breaker backup or secondary protection
- Machinery and process equipment — where momentary overloads are expected
Compatibility & Replacements
Compatible With
- Class RK1 fuse holders and clips (ferrule-end cartridge mountings)
- Electrical panels rated for 600V AC or lower
- Motor control centers (MCCs) and distribution equipment
- Transformer primary and secondary circuits (within voltage/amperage limits)
- Industrial PLC and automation equipment control cabinets
Replaces / Drop-In Replacement For
- Cooper Bussmann LPS-RK-45SP (original OEM designation before Eaton acquisition)
- Eaton Bussmann LPS-RK-45SP (current manufacturer)
- Other Class RK1 45A low peak fuses in equivalent circuits (verify voltage and interrupting rating first)
Works With
- RK1 Fuse Holders — standard ferrule-end cartridge sockets
- Combination Motor Controllers — as integral protection device
- Panelboard Distribution — primary or backup overcurrent protection
- Load Centers — residential and light commercial panels
