Bussmann Fuses 40A FRN-R Cartridge Fuse, 2-Pack is a heavy-duty Fusetron dual element, time delay cartridge fuse designed specifically for motor protection. This fuse helps safeguard motors from burnout caused by overloads or single phasing. Its time delay feature allows the initial startup surge typical of motors to pass through, while opening before burnout occurs during longer, dangerous overloads. It is UL listed as a Class R fuse with a 200,000 AIR (amp interrupting rating). The fuse operates at 250V and features ferrule ends for ratings from 1/10A to 60A, with knife-blade ends for ratings from 70A to 200A. Model Number: 40A FRN-R