A genset including at least one generator for generating electrical energy, which can be driven by a drive device is provided. Also provided is a detection device for detection of the presence of a grid fault in at least one phase of the power grid, a device for determining an operating state of the generator immediately before or upon detection of a grid fault, and a regulating device, to which the signals of the detection device and the device for determining an operating state of the generator can be fed. The regulating device is designed upon detection of a grid fault to reduce the power of the drive device in dependence of that operating state of the generator, which has been determined immediately before or upon detection of the grid fault.