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4th Year, Week 4 (Motors 1&2) > Motors Lvl 1 > Flashcards

Motors Lvl 1 Flashcards

1
Q

INDUCTORS store energy in the form of a(n) ____ field.

A

Electromagnetic

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2
Q

CAPACITORS store energy in the form of a(n) ____ field.

A

Electrostatic

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3
Q

____ is a force by which materials exert an attraction or repulsion to other materials.

A

Magnetism

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4
Q

Magnets are created or magnetized by aligning the ____ within a material.

A

Domains.

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5
Q

A(n) ____ magnet holds all magnetic domains aligned whether it is conducting current or not, near another magnet or not.

A

Permanent

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6
Q

A magnet that loses most magnetic properties when current/lines of flux are removed from it would be a(n) ____ magnet.

A

Temporary

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7
Q

Magnetic lines of flux flow from the ____ pole to the ____ pole.

A

North to South.

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8
Q

Magnetic lines of flux are strongest at the ____,

A

Magnetic Poles

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9
Q

Permeability is the ability of a material to ____

A

Conduct Magnetic Flux

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10
Q

Permanence is the ability of a material to ____.

A

Hold Residual Magnetism

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11
Q

A ferromagnetic material is easily ____ and has high ____.

A

Easily Magnetized and has High Permeability

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12
Q

A ____ material weakly aligns in the SAME direction as the applied field.

A

Paramagnetic

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13
Q

A ____ material weakly aligns in the OPPOSITE direction as the applied field.

A

Diamagnetic

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14
Q

A ____ is a temporary magnet produced when current flows through a conductor such as a coil.

A

Electromagnet

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15
Q

A magnetic material has reached ____ when all magnetic domains are aligned and any additional current would no longer affect magnetic properties.

A

Saturation

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16
Q

____ is the ability of an inductor to induce a voltage into another circuit or conductor.

A

Mutual Induction

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17
Q

What 3 things are needed to create electricity?

A
  1. ) Conductor
  2. ) Magnetic Field
  3. ) Relative Motion
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18
Q

The ____ rule explains the relationship between the direction of applied current, direction of magnetic field, and direction of the induced conductor motion, within a motor.

A

The Right-Hand motor rule.

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19
Q

____ are used to concentrate magnetic lines of flux inside a coil.

A

Cores.

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20
Q

Commutators are used for ____ current motors.

A

Direct (DC)

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21
Q

____ are used to reverse direction of current in DC motors.

A

Commutators.

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22
Q

What are the 4 ELECTRICAL ratings listed on a motor nameplate?

A

Voltage, Current, Frequency, and Phase

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23
Q

Voltage listed on the nameplate represents the ____ operating voltage of the motor.

A

Optimal.

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24
Q

1 Horsepower is equal to ___ watts.

A

746 Watts

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25
Q

What are the two usage ratings for motors?

A
  1. ) General Purpose

2. ) Definite Purpose

26
Q

____ is a multiplier that represents the amount of load beyond the rated load that can be placed on a motor without damaging it. (Is for accommodating starting current)

A

Service Factor.

27
Q

How is speed rated for a motor?

A

Rounds per minute (RPM)

28
Q

Operating Time Rating is either one of which two ratings?

A
  1. ) Continuous Duty

2. ) Intermittent Duty

29
Q

The measure of how effective a motor is at outputting mechanical energy from the electrical energy it receives.

A

Motor Efficiency Rating

30
Q

Insulation Class of a motor signifies the maximum ____ rating of the insulation used in the motor.

A

Temperature.

31
Q

Where is the table in the NEC providing information for Locked-Rotor indicating code letters?

A

430.7(B)

32
Q

When it comes to fractional hp motors, frame size is given in 1/__ of an inch, but in Integral motors, frame size is given in 1/__ of an inch.

A 
Fractional = 1/16"
Integral = 1/4"
33
Q

In the chart for Integral motor frame sizes, the second set of numbers is your “F” measurement and it gives you the measurement between what two points?

A

The center to center of the mounting holes.

You would half the value for the distance between one hole and the center of the motor

34
Q

What two things does the motor enclosure protect?

A
  1. ) Protects the motor from the environment and damage

2. ) Protects personnel from coming in contact with the energized and rotating interior parts of the motor.

35
Q

A(n) ____ is a synchronous machine that produces Alternating Current.

A

Alternator

36
Q

The ____ is the fixed part of a generator that includes a core and windings.

A

Stator

37
Q

The ____ is the moving/spinning part of a generator.

A

Rotor.

38
Q

What are the two types of alternators?

A
  1. ) Revolving Field

2. ) Revolving Rotor.

39
Q

What type of rotor is most common for utility power generation?

A

Revolving Field

40
Q

Brushes and slip rings allow you to make electric contact with ____.

A

Rotating Objects

41
Q

A small three-phase generator that is sometimes mounted on the shaft that supplies current to the alternator rotor is called a(n) ____.

A

Exciter

42
Q

How does an exciter regulate voltage in an alternator?

A

It changes the strength (or flux density) of the magnetic field on the rotor.

43
Q

What is the formula for calculating Alternator and Motor Rotor Speed.

A

RPM = (120xFrequency)/PolesPerPhase

44
Q

How does the ‘lights out’ method determine if alternators/generators are out-of-phase?

A

If the voltages are out of phase, there will be a difference in potential, causing the light bulbs to light up. When voltages are in phase, the light bulbs will stay off.

45
Q

A device that indicates whether two alternators are in a correct phase relationship is called a(n) ____.

A

Synchroscope

46
Q

The more poles a motor has, the ____ it will turn.

A

Slower

47
Q

T/F: Motors can be single or dual voltage.

A

True.

48
Q

In ____-connected motors, all three phase windings are connected at a single point.

A

Wye

49
Q

In ____-connected motors, the phase windings are wired end-to-end to create a closed circuit.

A

Delta

50
Q

How a motor is to be wired to a specific voltage should be shown on ____.

A

The motor nameplate.

51
Q

T/F: The higher voltage option of a dual voltage motor is often selected, because the current draw of the motor is less.

A

True.

52
Q

T/F: Current and Voltage are Directly Proportional.

A

False. They are Inversely Proportional

53
Q

How is motor torque measured?

A

Pound-Feet (lb-ft). Which is different from ft-lbs.

54
Q

How are Squirrel Cage and Wire-Wound motors different?

A

They both have conductive material (Copper or Aluminum) on the rotor, but Squirrel Cage has a cage like set of bars, while wire wound has wraps of wire around the rotor.

55
Q

T/F: The stator is different between Squirrel Cage and Wire-Wound Motors.

A

False.

56
Q

A(n) ____ is a metal piece on the end of squirrel cage rotor to connect all the bars.

A

Shorting-Ring

57
Q

Why are thin insulated laminated sheets of iron used in motor stators instead of a large blocks?

A

To eliminate Eddy-Currents.

58
Q

Which NEMA motor design is most common? (Often selected because of its normal starting torque and low-starting current.)

A

Motor Design B

59
Q

What gives motors the means to turn? (torque)

A

Like magnetic poles in the rotor and stator repelling each other.

60
Q

An Exciter that is mounted on the shaft is called a(n) ____.

A

Brushless Exciter

61
Q

What two things must be brought into a correct phase relationship before an alternator can be paralleled with another?

A

Voltage and Frequency

4th Year, Week 4 (Motors 1&2) (2 decks)

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