Cooper Bussmann LPS-RK-3-1/2SP RK1 Time Delay Fuse 3.5A

Product Description

The COOPER BUSSMANN LPS-RK-3-1/2SP is a Class RK1 time delay cartridge fuse rated at 3.5 amps. It is designed for general-purpose overcurrent protection in industrial and commercial electrical systems. The fuse features a two-element design that provides time delay characteristics, allowing temporary inrush currents to pass without nuisance tripping while still protecting downstream equipment from sustained overloads and short circuits. The body measures 5 inches in overall length and 20.6 mm in diameter. Interrupting capacity is rated at 100 kA at DC and 300 kA at AC (RMS). Licensed electricians and industrial maintenance technicians are the primary installers.

This fuse is suited for use in fuse holders designed to accept Class RK1 cartridge fuses. Typical applications include motor branch circuits, control panels, and distribution equipment in residential, commercial, and light industrial settings where time delay protection is required to handle motor starting inrush or transformer magnetizing currents. The non-indicating design means no built-in visual blown indicator, so a fuse tester or multimeter is required to confirm fuse condition during troubleshooting.

Key Features

• Class RK1 time delay design allows temporary inrush without nuisance tripping
• Two-element construction for reliable overload and short-circuit protection
• High interrupting rating: 100 kA at DC, 300 kA at AC (RMS)
• Non-indicating fuse body — no visual blown indicator
• UL Listed and CSA Certified for use in rated fuse holder applications
• CE Certified meeting applicable international standards

Compatibility

Designed for use in fuse holders that accept Class RK1 cartridge fuses with a 5-inch overall length and 20.6 mm body diameter. Verify holder ratings match fuse voltage and amperage before installation.

Installation Notes

Installation must be performed by a qualified electrician in accordance with the National Electrical Code (NEC) and applicable local codes. De-energize and lock out the circuit before removing or inserting fuses. Use an appropriately rated fuse puller for cartridge fuse removal — never remove or install fuses while the circuit is energized. Confirm the fuse holder is rated for the circuit voltage and the Class RK1 fuse format before installation.