S45 — Motors, Motor Controls, and Variable-Frequency Drives (I-P)

Many types of alternating-current (AC) motors are available; direct-current (DC) motors are also used, but to a more limited degree. National Electrical Manufacturers Association (NEMA) Standard MG 1 provides technical information on most types of AC and DC motors. MOTORS Alternating-Current Power Supply Codes and Standards Motor Efficiency General-Purpose Motors Permanent-Magnet AC Motors Hermetic Motors Integral Thermal Protection Motor Protection and Control AIR VOLUME CONTROL Variable-Frequency Drives Power Distribution System Effects Performance Testing and Rating Standards