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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".
In TEFC motors, interior heat losses are dissipated indirectly through enclosure fins, mostly by forced air convection. Cutaway view through stator of TEFC induction motor, showing rotor with internal air circulation vanes. Many such motors have a symmetric armature, and the frame may be reversed to place the electrical connection box (not ...
Squirrel-cage induction motors are very prevalent in industry, in sizes from below 1 kilowatt (1.3 hp) up to tens of megawatts (tens-of-thousand horsepower). They are simple, rugged, and self-starting, and maintain a reasonably constant speed from light load to full load, set by the frequency of the power supply and the number of poles of the ...
The circle diagram can be drawn for alternators, synchronous motors, transformers, induction motors. The Heyland diagram is an approximate representation of a circle diagram applied to induction motors, which assumes that stator input voltage, rotor resistance and rotor reactance are constant and stator resistance and core loss are zero.
A blocked rotor test is conducted on an induction motor.It is also known as short-circuit test (because it is the mechanical analogy of a transformer short-circuit test), [1] locked rotor test or stalled torque test. [2]
A Dahlander motor (also known as a pole changing motor, dual- or two speed-motor) is a type of multispeed three-phase induction motor, in which the speed of the motor is varied by altering the number of poles; this is achieved by altering the wiring connections inside the motor.
In one arrangement, the motor has an ordinary stator. A squirrel-cage rotor connected to the output shaft rotates within the stator at slightly less than the rotating field from the stator. Within the squirrel-cage rotor is a freely rotating permanent magnet rotor, which is locked in with rotating field from the stator.
The switched reluctance motor (SRM) is a type of reluctance motor. Unlike brushed DC motors , power is delivered to windings in the stator (case) rather than the rotor . This simplifies mechanical design because power does not have to be delivered to the moving rotor, which eliminates the need for a commutator .