This standard applies to premium-efficiency totally enclosed fan-cooled (TEFC) and totally enclosed nonventilated (TENV), horizontal and vertical, single-speed, squirrel cage polyphase induction motors, 0.75 kW to 370 kW (1 hp to 500 hp), and up to 4000 V nominal, in National Electrical Manufacturers Association (NEMA) frame sizes 143T and larger, for petroleum, chemical, and other severe-duty applications (commonly referred to as premium-efficiency severe-duty motors). Excluded from the scope of this standard are motors with sleeve bearings and additional specific features required for explosion-proof motors.

This standard applies to premium-efficiency totally enclosed fan-cooled (TEFC) and totally enclosed nonventilated (TENV), horizontal and vertical, single-speed, squirrel cage polyphase induction motors, 0.75 kW to 370 kW (1 hp to 500 hp), and up to 4000 V nominal, in National Electrical Manufacturers Association (NEMA) frame sizes 143T and larger, for petroleum, chemical, and other severe-duty applications (commonly referred to as premium-efficiency severe-duty motors). Excluded from the scope of this standard are motors with sleeve bearings and additional specific features required for explosion-proof motors.

The purpose of this standard is to define a specification that deals with mechanical and electrical performance, electrical insulation systems, corrosion protection, and electrical and mechanical testing for severe-duty totally enclosed squirrel cage polyphase induction motors, 0.75 kW to 370 kW (1 hp to 500 hp), for petroleum, chemical, and other severe-duty applications (commonly referred to as premium-efficiency severe-duty motors). Many of the specified materials and components in this standard stem from experience with severely corrosive atmospheres and the necessity for safe, quiet, reliable, premium-efficiency motors.