Abstract: In a power grid capable of electrical power delivery and power line communications, a distribution transformer and at least one smart meter is connected to the power grid. In one embodiment, the distribution transformer is configured to map the smart meters on the power grid to a virtual grid based upon measurements of signal metrics received from the various smart meters on the power grid, and the virtual grid is used to determine if a failure has occurred on the physical grid. A communications failure between nodes on the grid suggests a possible power failure, and the failure can be located using mapping information obtained from the virtual grid. A drop in power consumption on the power grid corroborates outages detected via the communications failure. In one embodiment, a cross phase delta value is computed to adjust the signal strength metrics measured between nodes having differing phases of electrical distribution.