ANSI C12.20

ANSI C12.20 is an ANSI standard that describes an American National Standard for Electricity Meters - accuracy and performance.

The C12.20 standard established the physical aspects and performance criteria for a meter's accuracy class. It refines certain details in ANSI C12.1 and ANSI C12.10.

The existing ANSI accuracy classes for electric meters are:
 * Class .5 - having ± 0.5% accuracy.
 * Class .2 - having ± 0.2% accuracy.
 * Class .1 - having ± 0.1% accuracy.

Outside North America, IEC standards are used for electric meters.