Deck 16: Three-Phase Induction Motors

Question 1

The stator leads of a three-phase, wound-rotor induction motor are marked M₁, M₂, and M₃.

Answer 1

False

Question 2

At start-up, all of the resistance of the wye-connected speed controller is inserted in the rotor circuit.

Answer 2

True

Question 3

The ____________________ is a three-phase winding that is placed in the slots of a laminated steel core.

Answer 3

stator

Question 4

List the disadvantages of a wound-rotor induction motor.

Question 5

Describe a three-phase, squirrel-cage induction motor.

Question 6

What are the three factors that cause the magnetic field to rotate in a three-phase motor.

Question 7

The basic structure of a three-phase, squirrel-cage induction motor consists of a(n) ____________________, a rotor, and two end shields that house the bearings supporting the rotor shaft.

Question 8

The wound-rotor motor and the squirrel-cage motor have the same percent efficiency, power factor, percent slip, speed, and torque characteristics.

Question 9

Discuss how the direction of a wound-rotor induction motor can be reversed.

Question 10

The ____________________ induction motor is used when a strong starting torque and a range of speed control are required.

Question 11

Some types of squirrel-cage induction motors are smaller than others and have aluminum end rings that are cast in one piece.

Question 12

The winding of a three-phase, squirrel-cage induction motor is made of formed coils that are connected to give three single-phase windings spaced 60 electrical degrees apart.

Question 13

The basic squirrel-cage induction motor is a(n) ____________________ speed motor.

Question 14

List the advantages of a wound-rotor induction motor.

Question 15

The torque produced by an induction motor results from the interaction between the stator flux and the ____________________.