Abstract: A method and device for connecting a load to an AC power source is arranged to ensure that the volt-second ratings of magnetic devices in the load are not exceeded, in order to limit in-rush currents resulting from saturation of the magnetic devices. In the case where the load is being disconnected from a first AC source and connected to a second AC source, the volt-seconds of the load can be measured and/or calculated during disconnect, in order to delay connection of the load to the second AC source by an amount sufficient to prevent saturation of magnetic devices and thereby ensure volt-second synchronization of the sources.