Bussmann BP/FRN-R-40 40 Amp Fusetron Dual Element Time-Delay Current Limiting Class RK5 Fuse, 250V Carded UL Listed, 2-Pack Quantity: 2 Pack 40A Type FRN-R Cartridge Fuse Fusetron Time Delay, 250V Provides motor overload, ground fault and short-circuit protection Helps protect motors against burnout from overloads and from single phasing on three phase systems Simplifies and improves blackout prevention (selective coordination) Can be applied in circuits subject to temporary motor overloads and surge currents to provide high performance short-circuit and overload protection Protects against low level overcurrent of overloads and will hold on inrush current 5 times greater than the amp rating of fuse for a min of 8 sec