250V. Fusetron time-delay fuse is the industry standard for motor protection. When sized correctly it helps protect motors from burnout caused by overloads or single phasing. The time-delay feature allows the initial start-up surge for typical motors to pass, but opens prior to motor burnout when longer, dangerous overloads are present. In addition, the dual element design opens in as little as .004 seconds if the fuse experiences short circuit conditions.