NEMA EI 21.2 91st Edition, January 1, 1991
Instrument Transformers for Revenue Metering (125 kV BIL Through 350 kV BIL)
Includes all amendments and changes through Reaffirmation Notice , 2002
Additional Comments: W/D NO S/S
Published By:National Electrical Manufacturers Association (NEMA)
These standards cover general requirements, ratings, accuracy classifications, burdens and pertinent dimensions applicable to instrument current and voltage transformers for revenue metering rated 125 kV BIL through 350 kV BIL.
The values stated in U.S. customary units shall be regarded as the standard. For purposes of this Standards Publication, metric values of length (in millimeters) shall be determined by multiplying the U.S. customary units (in inches) by 25.4 and rounding off to the nearest .02 millimeter.