NEMA reaffirmed NEMA CS 3.1-2009 Guide for the Application, Handling, Storage, Installation, and Maintenance of Medium-Voltage AC Contactors, Controllers, and Control Centers. Guide applies to AC medium voltage contactors and Class E controllers rated 1,501-15,000 volts, installed in accordance with the National Electrical Code, NFPA 70, and manufacturer’s instructions. Publication is useful to architects, electrical engineers, electrical contractors, maintenance engineers.