A power providing device to be used in a power distribution system, the power distribution system further comprising: - a powered device (4, 5, 6) to be powered by the power providing device and adapted to indicate its power class to the power providing device, and - an electrical conductor for transferring the power from the power providing device to the powered device; the power providing device adapted to provide power to the powered device (4, 5, 6) of the power distribution system in at least a maximum power mode and a normal operation mode, wherein the power providing device is adapted to measure in the maximum power mode the amount of power consumed by the powered device (4, 5, 6), wherein the powered device (4, 5, 6) is assigned to one of at least one first power class and at least one second power class, wherein to each power class of the first and second power classes a predetermined power is assigned, wherein the power providing device is characterized in that it is adapted: - to, if the power class of the powered device (4, 5, 6) is a first power class, switch to the maximum power mode, in which the predetermined amount of power assigned to the power class of the powered device (4, 5, 6) is allocated to the powered device (4, 5, 6) and the amount of power consumed by the powered device (4, 5, 6) is measured, and thereafter switch to the normal operation mode, in which the operational amount of power, which depends on the amount of power measured in the maximum power mode, is reserved for the powered device (4, 5, 6), in order to allow the powered device (4, 5, 6) to consume in the normal operation mode an amount of power being equal to or lower than the operational amount of power, and - to, if the power class of the powered device is a second power class, switch to the normal operation mode, wherein in this case in the normal operation mode the predetermined amount of power assigned to the power class of the powered device is reserved for the powered device, in order to allow the powered device to consume in the normal operation mode an amount of power being equal to or lower than the predetermined amount of power assigned to the power class of the powered device. - a powered device (4, 5, 6) to be powered by the power providing device and adapted to indicate its power class to the power providing device, and - an electrical conductor for transferring the power from the power providing device to the powered device; - to, if the power class of the powered device (4, 5, 6) is a first power class, switch to the maximum power mode, in which the predetermined amount of power assigned to the power class of the powered device (4, 5, 6) is allocated to the powered device (4, 5, 6) and the amount of power consumed by the powered device (4, 5, 6) is measured, and thereafter switch to the normal operation mode, in which the operational amount of power, which depends on the amount of power measured in the maximum power mode, is reserved for the powered device (4, 5, 6), in order to allow the powered device (4, 5, 6) to consume in the normal operation mode an amount of power being equal to or lower than the operational amount of power, and - to, if the power class of the powered device is a second power class, switch to the normal operation mode, wherein in this case in the normal operation mode the predetermined amount of power assigned to the power class of the powered device is reserved for the powered device, in order to allow the powered device to consume in the normal operation mode an amount of power being equal to or lower than the predetermined amount of power assigned to the power class of the powered device.