LPN-RK-40SP is a Class RK1 dual element, current-limiting, time-delay fuse designed for ultimate circuit protection. It is rated for 40 amperes at 250 Vac or 125 Vdc, with an interrupting rating of 300 kA AC RMS symmetrical and 100 kA DC. The fuse provides time-delay performance of 10 seconds minimum at 500% of rated current, allowing for motor inrush currents while providing fast short-circuit protection. This fuse is UL Listed and CSA Certified, and an optional open fuse indication version (LPN-RK-40SPI) is available requiring 75 Vac minimum voltage. Common applications include motor protection, industrial control circuits, and general electrical distribution systems where current-limiting and selective coordination are required.