Bussmann Series Fusetron cartridge fuses are 23% more energy efficient and offer the best time delay performance. Their dual element feature allows closer sizing to load for superior protection of motors and transformers. These Class RK5 fuses with a 200 kA interrupting rating can be used in a broad range of applications. When sized correctly, they help protect motors from burnout caused by overloads or single phasing. The time delay feature allows the initial startup current surge for typical motors to pass, but opens prior to motor burnout when longer, dangerous overloads are present.