The eGauge Core is a 15 channel energy meter with 0.5% revenue grade accuracy compliance and the ability to measure residential or commercial circuit panels, up to 3-phase 277/480VAC and 6900A. The meter has HomePlug AV powerline communication, an Ethernet port, and 2 USB ports for additional options, like WiFi and serial. The user can access meter data using the free user interface, or with other systems using a published XML API, Modbus, or BACnet IP. The embedded web server allows the user to connect to the interface over the internet or on a local area network. Each unit has a data logger that stores up to 64 data points for the lifetime of the hardware, and the user can access data as granular as 1-second averages for the most recent hour of recording. Taken together, the eGauge Core is an accurate and flexible solution for monitoring multiple circuits in any residential or commercial energy monitoring application.