An AC charging device for a motor vehicle has a neutral conductor, at least one phase conductor, and at least one rectifier. The neutral conductor and the phase conductor are connected to the rectifier and the rectifier is furthermore electrically connected to at least one smoothing capacitor. The AC charging device includes a precharge circuit arranged between a mains connection of the AC charging device and the smoothing capacitor. The precharge circuit is designed to precharge the smoothing capacitor. The phase conductor, in a connection section, is connected to at least one further phase conductor of the AC charging device by way of a cross-connection line, which has a cross-connection switch for disconnecting the phase conductor and the further phase conductor. The precharge circuit is arranged between a mains connection of a first phase conductor of the phase conductors and the connection section.