Power meter with current and phase sensor

A method for measuring power provided by a feeder line of an electrical system to a load, the electrical system receiving AC power from an AC source on an input line, the method comprising acts of:

• measuring, with a voltage sensor coupled to the input line, an input voltage on the input line;
• measuring, with a current sensor coupled to the feeder line, a current of the feeder line;
• calculating, with a voltage phase sensor coupled to the feeder line, a voltage phase shift between a voltage on the feeder line and the input voltage on the input line;
• and
• calculating, based on the current of the feeder line, the voltage phase shift, and the input voltage on the input line, a power level being provided to the load via the feeder line.

A system for measuring power provided by a feeder line of an electrical system to a load, the electrical system receiving AC power from an AC source on an input line, the system:

• a voltage sensor configured to be coupled to the input line and to measure voltage on the input line;
• a central metering unit coupled to the voltage sensor and configured to receive, from the voltage sensor, a signal related to the voltage on the input line;
• and
• means for measuring current of the feeder line and calculating a voltage phase shift between a voltage on the feeder line and the voltage on the input line at substantially a same location and without direct connection to a conductor within the feeder line,
• wherein the central metering unit is configured to calculate power provided to the load via the feeder line based on the measured current and voltage phase shift of the feeder line.