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Electrical Holy Shit > Chapter 30 powerpoints > Flashcards

Chapter 30 powerpoints Flashcards

1
Q

Commercial buildings require high levels of power for:

A

Lighting
Motors
Heating elements
Other loads

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2
Q

Different size _______________ are used depending on the amount of power required and the type of loads.

A

power distribution systems

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3
Q

Relatively low voltage levels:
Used for small commercial applications by the local utility.
Like gas stations, restaurants.

A

208 V to 240 V

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4
Q

Medium voltage levels:

  1. Used for mid-sized commercial applications.
  2. Like small office buildings.
A

460 V to 480 V

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5
Q

Used for large commercial applications
Like colleges, small businesses, hotels
Voltages must be delivered and distributed to different transformer banks throughout a building

A

High levels: 1000 V and up

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6
Q

an assemblage of equipment installed for switching, changing, or regulating the voltage of electricity. Where high voltage is reduced.

A

Substation

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7
Q

The exact voltage level used to operate different loads in commercial applications depends on:

A

The loads
The given application
The NEC

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8
Q

NEC limits the voltage level to 120 V between conductors that supply:

A

Lighting fixtures, cords, and plugs that connect loads up to 1440 VA (volt-amperes)

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9
Q

Motors up to ¼ HP in dwelling units and guest rooms of:

A

Hotels
Motels
Similar rooms of occupancies

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10
Q

Commercial power needs include the same needs as residential _______________.

A

(1Φ) and industrial (3Φ) systems

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11
Q

Commercial customers use low-voltage _______ and ______.

A

3Φ and 1Φ power

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12
Q

Power companies use _________ to deliver power to customers through different distribution systems.

A

transformers

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13
Q

Primarily use________ connected in different combinations to deliver the correct power.

A

1Φ transformers

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14
Q

The distribution system used varies based on the _________.

A

application

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15
Q

Common commercial distribution systems include:

A

120/240 V, 1Φ, 3-wire
120/208 V, 3Φ, 4-wire
120/240 V, 3Φ , 4-wire
277/480 V, 3Φ, 4-wire

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16
Q

All ________________ read a voltage between the conductor and a ground point (grounded conduit, green ground wire, et c.)

A

ungrounded (hot) conductors

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17
Q

The voltage on the ___________ of a transformer begins to drop if the transformer is overloaded. The higher the overload, the greater the voltage drop

A

secondary side

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18
Q

This is the primary serviced used to supply most residential buildings.

A

Distribution Systems: 120/240 V, 1Φ, 3-Wire Service

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19
Q

In commercial wiring, small appliance usage includes more than typical _____________.

A

residential small appliance usage

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20
Q

Three-phase circuits include three individual __________________.

A

ungrounded (hot) powerlines

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21
Q
  1. Is used to supply customers that require:
  2. A large amount of 120 V, 1Φ power
  3. Low-voltage 3Φ power
  4. Includes three ungrounded (hot) lines and one grounded (neutral) line.
  5. Each hot line has 120 V to ground when connected to the neutral line
A

Distribution Systems: 120/208 V, 3Φ, 4-Wire Service

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22
Q

Is used to supply customers that require large amounts of:
3 Φ power with some 120 V
240 V, 1 Φ power

A

Distribution Systems: 120/240 V, 3 Φ, 4-Wire Service

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23
Q

Is the same as the 120/208 V, 3Φ, 4-wire service except the voltage levels are higher. Includes three ungrounded (hot) lines and one grounded (neutral) line.

A

277/480 V, 3Φ , 4-Wire Service

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24
Q

Voltage Variation Effects on AC Motors are?

A

All motors are designed to operate at the given voltage. A motor operates if the voltage varies below or above the rated voltage. Is a change in the motor’s performance.

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25
Q

Any variation in applied ________ to a heating element increases or decreases the amount of heat produced.

A

voltage

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26
Q

The voltage on incandescent lamps can vary from _____________ than the lamp’s rated voltage.

A

0V to 10% higher

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27
Q

Conductors are covered with insulating material. Available in ____________
The function of each conductor can by easily determined.

A

different colors

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28
Q

Never assume that conductors are properly marked or color-coded. Take _____________ to ensure that voltage is off before working on a circuit.

A

voltage measurements

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29
Q

Conductor Identification- Color Coding

A

Always use standard colors

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30
Q

always indicates a conductor used for grounding in the electrical field

A

Green

31
Q

may be used to indicate a hot wire in a 230 V circuit or switched wire in a 115 V circuit.

A

Red

32
Q

is used for the neutral conductor

A

White or natural gray

33
Q

a current-carrying conductor that is intentionally grounded

A

Neutral conductor

34
Q

Hot conductors in a ______ may be identified with other types of markings in addition to color coding.

A

3Φ system

35
Q

a preprinted peel-off marker designed to adhere when wrapped around a conductor. May be used in place of tape bands.

A

Wire marker:

36
Q

may be used in commercial rooms to automatically turn OFF lights when no one is present and automatically turn ON lights when a person enters the room.

A

Passive infrared wall switch sensors

37
Q

Outdoor commercial lighting systems may use what type of lamps?

A

Low or high-pressure sodium, metal-halide, or mercury-vapor lamps

38
Q

Outdoor commercial lighting systems have voltages of:

A

In voltages of 120V, 280V, 240V, 277V or 480V.

39
Q

Outdoor commercial lighting systems have power ratings of……

A

35W to above 1500W.

40
Q

Indoor commercial lighting systems are required for:

A
  1. All general rooms of occupancy
  2. Halls
  3. Restrooms
  4. Work areas
41
Q

Indoor commercial lighting systems my use hat types of lamps?

A

Incandescent, halogen, or fluorescent lamps

42
Q

What are the typical voltages for indoor commercial lighting?

A

In voltages of 120V, 208V, 220V, 240V, or 277V

43
Q

Power rating for indoor commercial lighting range from what?

A

Any size up to 300 W for incandescent

15W to 215 for fluorescent

44
Q

the unit used to measure the total amount of light produced by a light source

A

Lumen (lm)

45
Q

the effect that occurs when light falls on a surface

A

Illumination

46
Q

the amount of light produced by a lamp (lumens) divided by the area that is illuminated.

A

Footcandle (fc)

47
Q

the perceived amount of light reflecting from an object

A

Brightness

48
Q

an electric lamp that produces light by the flow of current through a tungsten filament inside a sealed glass bulb sometimes filled with gas. The most widely used lamps in the world

A

Incandescent lamp

49
Q

a conductor with a resistance high enough to cause the conductor to heat.

A

Filament

50
Q

should be used in environments that contain corrosive materials (salt water, oil, sulfuric acid, steam, sodium hydroxide, hydrochloric acid, et c.)

A

Fiberglass-reinforced lamp fixtures

51
Q

The ____ of an incandescent lamp holds the lamp firmly in the socket and connects electricity from the outside circuit to the filament.

A

base

52
Q

Bulb sizes and shapes are determined by the end use of the lamp.

A

Incandescent bulb size/shape

53
Q

The size of an incandescent lamp is determined by the ________ of the lamp’s bulb.

A

diameter

54
Q

With incandescent bulbs the diameter of a bulb is expressed in _______________.

A

eighths of an inch (1/8”)

55
Q

a unit of power equal to the power produced by a current of 1 A across a potential difference of 1V.

A

Watt (W):

56
Q

Incandescent Lamps: Lamps Sizes and Ratings. To calculate power, apply the following formula:

A 
P = E x I
Where
P = power (in W)
E= voltage (in V)
I = current (in A)
57
Q

an incandescent lamp filled with a halogen gas (iodine or bromine). The gas combines with tungsten evaporated from the filament as the lamp burns.

A

Tungsten-halogen lamp:

58
Q

In Tungsten-halogen lamps wattages range from.

A

15W to 1500W

59
Q 
a low-pressure discharge lamp in which ionization of mercury vapor transforms ultraviolet energy generated by the discharge into light.
Consists of a cylindrical class tube (bulb) sealed at both ends.
A

Fluorescent Lamps

60
Q

tungsten coil coated with electron-emissive material that releases electrons when heated.

A

Cathode

61
Q

a fluorescent lamp that has a smaller diameter than a conventional fluorescent lamp and a folded bulb configuration.

A

Compact fluorescent lamp

62
Q

Cool white or light white fluorescent bulbs produce a ___________.

A

pale blue-green whiteness

63
Q

White fluorescent bulbs produce a very ___________. May also be labeled as natural or daylight.

A

pale yellow-whiteness

64
Q

produce a more yellow-whiteness.
Are used to give a warm feeling and enhance brighter colors.
Suggested for low lighting levels.

A

Warm, white fluorescent bulbs

65
Q

a fluorescent lamp-starting circuit that heats the cathode before an arc is created. Used in some low-wattage lamps (4W to 20W). Common in desk lamps.

A

Fluorescent lamps Pre-heat circuit.

66
Q

a fluorescent lamp-starting circuit that provides sufficient voltage to strike an arc instantly.

A

Instant-start circuit

67
Q

a fluorescent lamp-starting circuit that has separate windings to provide continuous heating voltage on the lamp cathodes.

A

Rapid-start circuits

68
Q

a lamp that produces light from an arc tube.

A

High-intensity discharge lamps

69
Q

the light-producing element of an HID lamp.

A

Arc tube

70
Q

the appearance of a color when illuminated by a light source.

A

Color Rendering

71
Q

Low-pressure sodium lamps are good for outdoor lighting installations

A

High-Intensity Discharge Lamps: Selection

72
Q

an HID lamp that operates at a low vapor pressure and uses sodium as the vapor.

A

Low-pressure sodium lamp:

73
Q

an HID lamp that produces light by an electrical discharge through mercury vapor.

A

Mercury-vapor lamp:

74
Q

an HID lamp that produces light by an electrical discharge through mercury vapor and metal halide in the arc tube.

A

Metal-halide lamp

Electrical Holy Shit (13 decks)

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