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.
See also
Electricity meter
Further reading ANSI C12.1, American National Standard for Electric Meters - Code for Electricity Metering ANSI C12.10, American National Standard for Physical Aspects of Watthour Meters - Safety Standard ANSI C12.18, American National Standard for Protocol Specification for ANSI Type 2 Optical Port
External links The ANSI C12.20 standard at NEMA