TEFC

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 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, 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. "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.

References

• Siemens Basics of AC Motors