Electrical Standards for Motors Rated Above 600 Volts

Large motors rated above 600 volts are classified according to type, mechanical protection, and application. This paper discusses USASI (formerly ASA) and NEMA Standards for horsepower rating, speed, temperature rise, torques, load inertia, frequency of starting, variations from rated voltage and frequency, routine, and over-potential tests. IEEE Test Procedures are used to determine whether motors do conform to these standards. The National Electrical Code (NEC) includes design and installation procedures necessary for providing safety to personnel and equipment.