ForewordThis Standards Publication was prepared by a technical committee of the NEMA Industrial Automation Control Products and Systems Section. It was approved in accordance with the bylaws of NEMA and supersedes the indicated NEMA Standards Publication. This Standards Publication Parts 2 3 of ICS 3-1993: Factory Built Assemblies have been renumbered as Parts 1 and 2 and renamed Medium Voltage Controllers Rated 2001 to 7200 Volts AC.ICS 3-1993@ Part 1: Motor Control Centers Rated Not More Than 600 Volts AC was removed from the original ICS 3-1993 standard and published as ICS 18-2001.This Standards Publication provides practical information concerning ratings@ construction@ test@ performance@ and manufacture of industrial control equipment. These standards are used by the electrical industry to provide guidelines for the manufacture and proper application of reliable products and equipment and to promote the benefits of repetitive manufacturing and widespread product availability.NEMA Standards represent the result of many years of research@ investigation@ and experience by the members of NEMA@ its predecessors@ its Sections and Committees. They have been developed through continuing consultation among manufacturers@ users@ and national engineering societies and have resulted in improved serviceability of electrical products with economies to manufacturers and users.One of the primary purposes of this Standards Publication is to encourage the production of reliable control equipment which@ in itself@ functions in accordance with these accepted standards. Some portions of these standards@ such as electrical spacings and interrupting ratings@ have a direct bearing on safety; almost all of the items in this publication@ when applied properly@ contribute to safety in one way or another.?