Motors

Question 1

Define the stator

Answer 1

The stationary part of the motor that houses the field poles and windings. When supplied with current, it creates a magnetic field that induces rotation in the rotor

Question 2

Define the rotor

Answer 2

The rotating part of the motor housed inside the stator. It contains windings, and will spin when under the influence of the magnetic field created by the stator.

Question 3

Define field poles

Answer 3

Field poles are solid iron poles built into the stator that the field windings are wrapped around.

Question 4

Define field windings

Answer 4

Field windings are rotations of copper wire wrapped around the field poles built into the stator that when supplied with current, will induce a magnetic field on the rotor

Question 5

What is a squirrel cage rotor

Answer 5

A rotor constructed out of a solid iron core, encased in metal bars that connect at the ends to form a complete circuit. Negates the need for copper windings on the rotor.

Question 6

Define motor end bells

Answer 6

End bells/plates enclose the motor on either end and provide a place for the bearings to sit inside the motor housing. When the motor shaft is mounted in the bearings, the end bells support the rotor.

Question 7

Define motor nameplate

Answer 7

Provides all necessary and relevant information on the motor including rpm, voltage, amperage, hz, hp, bearing no, frame type, and motor size.

Question 8

Define motor terminal box

Answer 8

Installed onto the exterior of the motor housing, it contains all connections used to control and power the motor.

Question 8

Explain the basic operating principles of an electric motor.

Answer 8

Go off I guess

Question 9

Explain the relationship of synchronous speed, rated full load speed, and slip.

Answer 9

Synchronous speed happens when the magnetic fields for the rotor and stator are running at the same speed. Rated full load speed is the rotation speed of the motor when under load. Slip is the difference between the two, which is usually a 4-5% difference.

Question 10

Define torque

Answer 10

The work performed by a twisting or turning action

Question 11

Define the difference between start windings and run windings

Answer 11

Run windings operate continuously throughout the entire runtime of the motor, and perform the bulk of the magnetic drive for the rotor. Start windings only operate temporarily during the motors start to add extra torque.