TEFC stands for Totally Enclosed, Fan-Cooled and refers to an industrial electric motor equipped with an external fan to circulate outside air to the motor. This motor is probably the most commonly used motor in ordinary industrial environments. It costs a little more than the open motor, but offers increased protection against weather, dirt, and moisture.
The motor is constructed with a small fan on the rear shaft of the motor, covered by a housing. This fan forces air over the motor frame fins, removing excess heat and cooling the motor. The enclosure is "Totally Enclosed". This ordinarily means that the motor is dust tight, and has a moderate water seal as well. TEFC motors are not secure against high pressure water nor submersible. "Wash down" enclosures are designed to withstand regular washing, such as found in a food processing facility
Compare to ODP (Open Drip Proof motor), which has ventilation openings guarded to prevent falling water from entering the motor windings.