Open drip proof motors are just that – open. It’s like an open door from whatever is outside, to your bearings and windings on the inside. … The ventilating openings permit passage of external cooling air over and around the windings of the motor.
What is totally enclosed 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. … This means that the motor is dust tight, and has a moderate water seal as well.