A power adapter assembly and an electrical system. The power adapter assembly is operable to supply power to an electrical device. The power adapter assembly includes a power box including a housing, an electrical circuit supported by the housing, the electrical circuit being operable to receive as input AC power and to output DC power, an adapter controller operable to control the adapter assembly; and an adapter electrically connected to the power box, the adapter including an adapter engagement portion connectable to a device engagement portion to connect the adapter to the electrical device, DC power being output from the electrical circuit through the adapter to the electrical device to power the load, when the adapter engagement portion is connected to the device engagement portion, a communication interface between the adapter assembly and the electrical device being active even when power is not being output to power the load.