The U.S. uses a voluntary process for the development of nationally recognized power transformer
equipment standards. This chapter describes the U.S. standards accreditation process and provides flow
charts to show how accredited standards are approved. With the International Electrotechnical Com-
mittee (IEC) taking on increased importance, the interaction of the U.S. technical experts with IEC is
also described. Finally, relevant power transformer documents are listed for the key power transformer
equipment standards that guide the U.S. industry.