Intro to Three Phase Induction Motors assignment

Question 1

Name two (2) machines designed to measure the torque of a motor.

Answer 1

Prony Brake

Dynomometer

Question 2

List 4 losses that occur in an induction motor

Answer 2

Iron
Copper
Friction
Windage

Question 3

How is the counter-torque adjusted when using a belt-and-drum type torque measuring machine?

Answer 3

Tightening or loosening the belt

Question 4

What type of loss would be found in the bearings?

Answer 4

Friction

Question 5

What method is used to prevent “cogging”?

Answer 5

Skewing

Question 6

What type of three-phase motor has conventional, insulated windings in the rotor?

Answer 6

Wound rotor motor

Question 7

What type of motor has slip rings?

Answer 7

Wound rotor motor

Question 8

What type of three-phase induction motor has end rings?

Answer 8

SCIM

Question 9

Which type of windings have varying pitch?

Concentric or Lap

Answer 9

Concentric

Question 10

Which two motor parts are constructed with laminated sheets of steel?

Answer 10

Stator core

Rotor

Question 11

In which part of the motor is the rotating magnetic field established?

Answer 11

Stator

Question 12

What is the term used to describe the movement of electric charges that creates magnetic flux?

Answer 12

Magnetomotive Flux

Question 13

The rotational frequency on a nameplate always indicates the (no load, full load) rotor speed.

Answer 13

Full load

Question 14

A motor has its power stated in watts, what does this represent?

Answer 14

Output power at full load

Question 15

What is another name for torque?

Answer 15

Moment of force

Question 16

Which rotor design has poor speed regulation, but high starting torque?

Answer 16

Design D

Question 17

When looking at the front of a NEMA motor, the shaft is opposite you.

True or False?

Answer 17

True