Historical
NEMA ANSI C37.58:2003
For switchgear - - indoor ac medium-voltage switches for use in metal-enclosed switchgear -- conformance test procedures
Applies to the conformance test procedure for ac medium-voltage switches rated above 1000 V as designed, manufactured and tested in accordance with ANSI/IEEE C37.20.4.
NEMA: National Electrical Manufacturers Association [nema]