Cooper Bussmann LPS-RK-40SP 40A RK1 Time Delay Cartridge Fuse

Product Description

The COOPER BUSSMANN LPS-RK-40SP is a Class RK1 time delay cartridge fuse rated at 40 amps. It is designed for general-purpose overcurrent protection in industrial, commercial, and residential electrical systems. The cartridge body measures 27 millimeters in diameter and 5.5 inches in overall length, housing a dual-element construction that provides time delay performance. This fuse handles an interrupting rating of 100 kA at DC and 300 kA at AC (RMS), making it suitable for circuits with high available fault current. Licensed electricians and industrial maintenance technicians are the primary installers of this fuse class.

The LPS-RK-40SP is used in fuse holders and fusible disconnects where RK1 class overcurrent protection is specified. Its time delay characteristic allows motors and other inductive loads to start without nuisance opening while still providing fast response to sustained overloads and short circuits. Typical applications include motor branch circuits, feeder panels, and control panels in commercial and light industrial facilities where a 40-amp RK1 fuse is required by design or code.

Key Features

• Class RK1 rating provides superior current-limiting performance compared to standard Class RK5 fuses
• Time delay dual-element design allows motor inrush without nuisance opening
• High interrupting rating: 100 kA at DC and 300 kA at AC (RMS)
• Cartridge body: 27 millimeters diameter, 5.5 inches overall length
• Non-indicating design for standard fusible disconnect and fuse holder installations
• Certified to UL, CSA, and CE standards for broad application compliance

Compatibility

Designed for use in fuse holders and fusible disconnect switches that accept Class RK1 cartridge fuses at 40 amps. Consult the disconnect or fuse holder manufacturer specifications to confirm fitment before installation.

Installation Notes

Installation must be performed by a licensed electrician in accordance with the NEC and any applicable local electrical codes. De-energize and lock out the circuit at the upstream disconnect before removing or installing the fuse. Use an appropriately rated fuse puller for cartridge-style fuses — do not handle energized fuses with bare hands or standard pliers. Verify that the fuse holder or disconnect is rated for Class RK1 fuses at the circuit voltage and amperage before installing.