NEMA C12.31G-TR-2024 ✓ Most Recent

This document establishes standard definitions for the measurement of AC, DC and AC+DC voltage, current, electrical power (active, reactive and apparent), AC electrical energy (active, reactive and apparent) and power factor in terms of sampled voltage and current measurements.  The definitions are provided to facilitate uniform comparison of the voltage, current, power, energy and power factor measurement values reported by electricity meters in comparison to equipment used as reference standards that implement these definitions for the determination of meter accuracy in the time domain and frequency domain.