A control apparatus (30, 30.1) for an electrical device (18, 20, 22, 24, 26, 32) arranged in a power supply network (8, 10, 12, 14, 14.1, 14.2) for controlling the restarting of the electrical device (18, 20, 22, 24, 26, 32) upon a blackout in the power supply network (8, 10, 12, 14, 14.1, 14.2), comprising at least one detection unit configured to detect at least one first switch-on condition, wherein the control device (30, 30.1) further comprises: - at least one control unit configured to determine a first switch-on delay period upon a detection of the first switch-on condition, - wherein the first switch-on delay time period is a random time period, and - wherein the control unit is configured to cause an establishment of an electrical connection between the electrical device (18, 20, 22, 24, 26, 32) and the power supply network (8, 10, 12, 14, 14.1, 14.2) at the earliest after the first switch-on delay time period has elapsed, characterized in that - the random first switch-on delay time period is between a minimum time limit value and a maximum time limit value, - the control unit is configured to determine the minimum time limit value and the maximum time limit value in response to at least one parameter selected from the group comprising: - system class of the electrical device (18, 20, 22, 24, 26, 32), - controllable network load or non-controllable network load of the electrical device (18, 20, 22, 24, 26, 32), - type of network load of the electrical device (18, 20, 22, 24, 26, 32), - level of rated power of the network load of the electrical device (18, 20, 22, 24, 26, 32), - historical data of the electrical device (18, 20, 22, 24, 26, 32), - local time of the electrical device (18, 20, 22, 24, 26, 32), - duration of the blackout. - at least one control unit configured to determine a first switch-on delay period upon a detection of the first switch-on condition, - wherein the first switch-on delay time period is a random time period, and - wherein the control unit is configured to cause an establishment of an electrical connection between the electrical device (18, 20, 22, 24, 26, 32) and the power supply network (8, 10, 12, 14, 14.1, 14.2) at the earliest after the first switch-on delay time period has elapsed, - the random first switch-on delay time period is between a minimum time limit value and a maximum time limit value, - the control unit is configured to determine the minimum time limit value and the maximum time limit value in response to at least one parameter selected from the group comprising: - system class of the electrical device (18, 20, 22, 24, 26, 32), - controllable network load or non-controllable network load of the electrical device (18, 20, 22, 24, 26, 32), - type of network load of the electrical device (18, 20, 22, 24, 26, 32), - level of rated power of the network load of the electrical device (18, 20, 22, 24, 26, 32), - historical data of the electrical device (18, 20, 22, 24, 26, 32), - local time of the electrical device (18, 20, 22, 24, 26, 32), - duration of the blackout. - system class of the electrical device (18, 20, 22, 24, 26, 32), - controllable network load or non-controllable network load of the electrical device (18, 20, 22, 24, 26, 32), - type of network load of the electrical device (18, 20, 22, 24, 26, 32), - level of rated power of the network load of the electrical device (18, 20, 22, 24, 26, 32), - historical data of the electrical device (18, 20, 22, 24, 26, 32), - local time of the electrical device (18, 20, 22, 24, 26, 32), - duration of the blackout.