Cooper Bussmann LPS-RK-6-1/4SP RK1 Time Delay Fuse 6.25A

Product Description

The COOPER BUSSMANN LPS-RK-6-1/4SP is a Class RK1 cartridge time delay fuse rated at 6.25 amps. It is designed for general-purpose overcurrent protection in industrial and commercial electrical systems. The dual-element, time delay construction allows it to ride through harmless inrush currents while still providing fast, reliable response to sustained overloads and short-circuit faults. It carries an interrupting rating of 100 kA at DC and 300 kA at AC (RMS), making it suitable for high-available-fault-current applications. Electricians and maintenance technicians install this fuse in fuse holders sized for Class RK1 cartridge fuses.

This fuse is used in branch-circuit and feeder protection for motors, transformers, and general electrical loads in residential, commercial, and light industrial settings. The RK1 classification indicates a rejection-style fuse body that prevents accidental substitution with lower-rated fuse classes. It fits standard fuse holders and fuse blocks configured for 5-inch Class RK1 cartridge fuses. Applications include motor starters, control panels, disconnect switches, and distribution boards where time delay characteristics are required to handle motor starting inrush without nuisance tripping.

Key Features

• Class RK1 rejection-style cartridge body prevents substitution with lower interrupting-rated fuses
• 6.25-amp rating with time delay characteristic suits motor and transformer protection
• Dual-element construction distinguishes between inrush and sustained overload conditions
• High interrupting capacity: 100 kA at DC and 300 kA at AC (RMS)
• Non-indicating design with standard cartridge form factor for fuse-holder mounting
• CE Certified, CSA Certified (C22.2 No. 248.12), and UL Listed (Guide JDDZ File E4273)

Compatibility

Designed as an OEM-style replacement or direct-install cartridge fuse for Class RK1 fuse holders and fuse blocks accepting a 5-inch overall length, 20.6 mm diameter cartridge body.

Installation Notes

Installation must be performed by a qualified electrician in accordance with the National Electrical Code (NEC) and all applicable local codes. Always de-energize and lock out the circuit before removing or installing fuses. Use fuse pullers rated for this fuse size to avoid contact with live components. Confirm the fuse holder is rated for Class RK1 cartridge fuses before installation to maintain the rejection-class integrity.