A DC-voltage vehicle electrical system for a motor vehicle, having a current source and a user. The DC-voltage vehicle electrical system is preferably developed as a 42V multi-voltage vehicle electrical system. A device for the cyclical interruption of the current is provided in the DC-voltage vehicle electrical system, in order to prevent the formation of arcs during switching and plugging procedures under a load at the DC-voltage vehicle electrical system or to end rapidly the formation of arcs, in a simple manner and without expensive constructive or switching technology measures.