TEFC motor
A Totally Enclosed, Fan-Cooled (TEFC) electric motor is a type of industrial electric motor with an enclosure that does not permit outside air to freely circulate through the interior of the motor. An external fan blows outside air over the frame of the motor to cool it. This motor is arguably the most commonly used motor in ordinary industrial environments. TEFC enclosed motors usually cost more than open motors, but offer increased protection against weather, dirt, and moisture. TEFC motors are 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, and cools the motor. The enclosure is "Totally Enclosed". This 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. They are also not explosion proof without additional modifications. Compare to the ODP (Open Drip Proof) motor design, which has ventilation openings which are guarded to prevent falling water from entering the motor windings.