A changeover apparatus for uninterrupted changeover between two energy supply systems (17, 18), wherein the changeover apparatus has at least a first external conductor section and a second external conductor section, wherein a first mechanical bypass switch is arranged in the first external conductor section, wherein a first semiconductor circuit arrangement of the changeover apparatus is connected in parallel with the first bypass switch, wherein the changeover apparatus has a first measuring device for recording a first voltage and/or a first network frequency, which first measuring device is connected to the first external conductor section, wherein a second mechanical bypass switch is arranged in the second external conductor section, wherein a second semiconductor circuit arrangement of the changeover apparatus is connected in parallel with the second bypass switch, wherein an electronic control unit of the changeover apparatus is designed to actuate the first bypass switch, the first semiconductor circuit arrangement, the second bypass switch and the second semiconductor circuit arrangement in a predeterminable manner, wherein the first measuring device is connected for communication to the control unit for transmitting first voltage measurement signals and/or first network frequency measurement signals, wherein the control unit is designed to compare the first voltage measurement signals and/or the first network frequency measurement signals with at least one first energy supply system change criterion, wherein the control unit is further designed to first deactivate the first external conductor section and immediately thereafter activate the second external conductor section when the first energy supply system change criterion is satisfied, wherein a first current-measuring arrangement is arranged in the first external conductor section, wherein a second current-measuring arrangement is arranged in the second external conductor section, wherein the first current-measuring arrangement is connected for communication to the control unit for transmitting first current measurement signals, and wherein the second current-measuring arrangement is connected for communication to the control unit for transmitting second current measurement signals, characterized in that at least one first mechanical isolating switch is arranged between the first bypass switch and the second bypass switch and an output of the changeover apparatus to ensure galvanic isolation, and that the control unit is designed to compare the first and/or second current signals with at least one overcurrent and/or short-circuit criterion, wherein the control unit is further designed - to deactivate the first external conductor section when the first current signal satisfies the overcurrent and/or short-circuit criterion, and/or - to deactivate the second external conductor section when the second current signal satisfies the overcurrent and/or short-circuit criterion, and that the control unit is designed, in order to limit an inrush current of a downstream load, when the bypass switch is open, to activate/deactivate the first semiconductor circuit arrangement in a predetermined clocked manner according to a measured load current, in particular as a result of pulse width modulation. - to deactivate the first external conductor section when the first current signal satisfies the overcurrent and/or short-circuit criterion, and/or - to deactivate the second external conductor section when the second current signal satisfies the overcurrent and/or short-circuit criterion,