A node in a power distribution system is described. The node includes an electrical connection to a single-phase power signal from an AC mains power source, a wireless communication interface configured to receive a first phase synchronization message, and a controller. The controller is configured to determine whether the first phase synchronization message is acceptable and detect a zero-crossing event on the single phase power signal subsequent to the receipt of the first phase synchronization message in response to determining that the first phase synchronization message is acceptable. The controller is further configured to calculate a time difference between the receipt of the first phase synchronization signal and the detected zero-crossing event, determine a local phase angle based on the time difference, and establish an identity of the single phase power signal based on the local phase angle.