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Electrical Engineering Utilities > Chapter 3.5, 3.6, 3.7, 3.8 > Flashcards

Chapter 3.5, 3.6, 3.7, 3.8 Flashcards

From System and Circuit Grounding to Cable, Raceway, and Enclosure

1
Q

3.5 Title

A

System and Circuit Grounding

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2
Q

___________ offers excess electricity the most effective and safest route from an appliance back to the ground by way of an _________________.

A

Grounding, electrical panel

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3
Q

____________________ is a backup pathway that is generally only used if a fault in the wiring system.

A

Electrical grounding

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4
Q

It is a continuous conductor that connects the ground to the neutral bus bar and the grounding conducting bus bar in the service equipment/ main panelboard.

A

Grounding Conductor

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5
Q

It safely carry current to ground in the event of a lightning strike or in cases of damage or defect in the circuiting, appliances, devices, or equipment. It also provide safety feature to the wiring system.

A

Grounding Conductor

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6
Q

Is the part of a building electrical system that provides protection against electrical shock, lightning, and fires.

A

System Grounding

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7
Q

It also relates to bonding (connecting) all building electrical system components at the service entrance equipment at the neutral bus of the main panelboard or switchboard.

A

System Grounding

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8
Q

It refers to a grounding conductor or grounding path that connects the non-current carrying metal components of equipment.

A

Equipment Grounding

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9
Q

Both Equipment and System grounding must be bonded. It accomplished by installing an additional grounding conductor or by permanently joining metal components in a circuit.

A

Bonding

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10
Q

The ________________ is a bare conductor or a green- colored, insulated conductor that connects (bonds) the outlet boxes, metallic raceways, other enclosures and frames on motors, appliances, and other electrical equipment

A

equipment- grounding conductor

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11
Q

_____________ of an appliance or power tool protects the user from electric shock by creating a nonconducting barrier between the user and the electric components inside the appliance or tool.

A

Double insulation

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12
Q

____________ and ______________ with double insulation are not required to have a ___________- that is, they are allowed to have a two prong plug.

A

Small appliance, power tools,grounding conductor,

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13
Q

The primary difference between an appliance with a three prong plug and an appliance with a two prong plug is the _________________.

A

appliance casing

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14
Q

If an ____________ is a good conductor, then it must have a ______________ and ____________.

A

appliance casing, grounding conductor, three- prong plug

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15
Q

3.6 Title

A

The Building Electrical System

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16
Q

There are many possible ___________ that can be used to distribute _______ in a building.

A

electrical systems, power

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17
Q

Typically, __________ begins with selection of a building system ______, which is dependent on _______ and ____ of the connected loads, utilities near the building, local codes and ordinances, economics, and safety.

A

system design, voltage, sizes, types

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18
Q
  • means a ground- mounted or roof top distributed solar generation system designed and installed for residential applications, which is leased by, or subject to a power purchase agreement with, the owner of a residence for the purpose of generating Electricity for that residence.
A

Residential Systems

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19
Q
  • is a single building that is set up to accommodate more than one family living separately. That can range from a duplex, which has two dwellings within a single building, to homes or small apartment building with up to four units.
A

Multifamily dwelling

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20
Q

Multifamily dwelling units, _____ is brought from a ____________ to the ______________. It is then divided at a _____________, passes through ___________, and is distributed to the individual dwelling units through _________.

A

power, utility transformer, building service equipment, main distribution panel, individual meters, feeders

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21
Q

Each __________ is served by a separate ________ located in the dwelling unit. _____________ extend from a panelboard to feed outlets within the unit. A ____________ has branch circuits that serve common areas.

A

dwelling unit, panelboard, Branch circuits, house panelboard

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22
Q

Large commercial and industrial facilities have large and varied power requirements that necessitate different types of systems for different building occupancies.

A

T

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23
Q

Essentially, there are so many variations that there is no standard type of system. In a typical large building, electrical power is provided to a ___________ located outside the building or it enters a ___________ located at the service level in the building.

A

transformer, transformer vault

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24
Q
  • lines serving a residential development being buried in a trench.
A

Underground Electrical Distribution

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25
Q

-lines readied for connection to exterior transformer.

A

Underground Distribution Lines

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26
Q

A 120/240 V- 150A, underground service entrance for a single family residence.

A

Electric Meter

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27
Q

Underground service entrance for a multifamily dwelling unit.

A

Electrical Meter for Multifamily dwelling unit

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28
Q

A ____________ with the electrical meter and main disconnect (below meter and above circuit breakers). ____________ are properly marked on the panelboard face.

A

Electric Meter and Main Disconnect/ service entrance, Circuit breakers

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29
Q

A close-up view of the inside of the panelboard.

A

Panelboard

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30
Q

________________ can pass through floor and ceiling joists.

A

Circuit cables

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31
Q

exposed lighting fixture

A

Exposed lighting

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32
Q

A ____________ in finished drywall

A

Exposed box

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33
Q

Unattached receptacle and faceplate

A

Receptacle and Faceplate

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34
Q

Covered convenience receptacle

A

Outlet

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35
Q

3.7 title

A

Conductor Requirements

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36
Q

__________ and ___________ are the most common conductor materials used in building electrical wiring, although other materials can be used.

A

Copper and aluminum

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37
Q

As a general rule, ____________ conductors are used in small conductor sizes (up to about 8 AWG) because safety issues associated with aluminum are avoided and weight and cost are not significantly affected.

A

solid copper

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38
Q

______________ conductors are widely used on larger (above 30 A) circuits serving large motors, equipment, and appliances

A

Stranded aluminum

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39
Q

Electronic circuits and phone extensions

A

No. 20 AWG and smaller

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40
Q

Light gauge extension cords, door chime wiring, small appliance cords

A

No. 16 to 18 AWG

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41
Q

Normal 15 A and 20 A branch circuits serving small appliances, convenience (receptacle) outlets, and luminaires

A

No.12 to 14 AWG

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42
Q

Larger branch circuits at 30A and above serving electrical appliances such as electric water heaters, clothes dryers, air conditioning equipment, and water pumps

A

No. 4 to 10 AWG

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43
Q

Residential and light commercial service entrance conductors and feeders to panelboards.

A

No. 2 to 4/0 AWG

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44
Q

Heavy commercial and industrial service entrance conductors, large feeders to closet transformers, and panelboards

A

250 kcmil and larger

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45
Q

__________ are covered with insulation to provide electrical isolation and physical protection of the conductor material.

A

Conductors

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46
Q

The _________ of insulation material determines the environment in which a wire or cable can be used safely.

A

type

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47
Q

__________ like ______ and ______ are used as a covering for electric wires.

A

Insulators, plastic, rubber

48
Q

This makes electric wires safer to handle because the insulator protects you from the current

A

Insulators/ Conductor insulation

49
Q

In building electrical systems, the ___________ of a conductor may need to be adjusted with correction factors when conditions related to the temperature of the surroundings and the number of conductors in a raceway fall outside normal operating ranges.

A

ampacity

50
Q

_______________ typically applied are addressed in the following sections.

A

Correction factors

51
Q

Ampacities provided in these tables are values based on a normal operating temperature of ____________________.

A

86 degrees F (30 degrees C)

52
Q

___________ values for each conductor size are for different equipment terminal (where connections of wiring are made) temperatures.

A

Ampacity

53
Q

______ generated at the equipment terminals can damage the conductors if it is not properly dissipated.

A

Heat

54
Q

_____________ is the temperature of a surrounding medium.

A

Ambient temperature

55
Q

In the case of electrical wiring, it is the _________ of the medium surrounding.

A

temperature

56
Q

As ______________ rises, __________ generated heat is needed to reach the temperature rating of the insulation. Therefore, _________ is governed by contribution of ambient heat.

A

ambient temperature, less current, ampacity

57
Q

The ________________ of a conductor refers to the normal temperature range in the environment in which that conductor is to be used (eg. the temperature of the surrounding air, water, or earth).

A

ambient temperature rating

58
Q

_____________ is adjusted for changes in ambient temperature, including temperatures below 78 degrees F (26 degrees C) and above 86 degrees F (30 degrees C_

A

Conductor ampacity

59
Q

A _______________________ for conductors is applied based on the ambient temperature of the conductor.

A

temperature correction factor

60
Q

When several current carrying conductors are contained in a raceway or cable, the temperature of the conductors will increase under normal loading conditions.

A

T

61
Q

A ___________________ must be applied for four or more conductors in a raceway or cable installed in the same raceway or conduit or any bundled cables that are more than 24 in (0.63m) long.

A

bundling correction factor

62
Q

In addition to ampacity requirements, ________ and _______ should be analyzed for voltage drop because of the adverse effect it can have on performance and operating life of appliances and equipment.

A

branch circuits and feeders

63
Q

______________ in the feeders and branch circuits should nit exceed ____.

A

Total voltage drop, 5%

64
Q

The ___________________ is determined by the ration of voltage drop and system voltage.

A

percentage of voltage drop

65
Q

The insulation on small and medium size conductors is __________or identification.

A

color coded

66
Q

________________ requiring color identification are marked at the terminal ends with a hand-painted stripe or colored tape wrapped around the conductor insulation.

A

Larger conductors

67
Q

The _________________ must be color coded green, green with one or more yellow stripes, or may be a bare conductor on small conductors in cables.

A

grounding (ground) conductor

68
Q

3.8 title

A

Cable, raceway, and enclosure requirements

69
Q

CABLE AND RACEWAY REQ
All building _______ must be enclosed in a cable, conduit, wireway, or raceway.

A

wiring

70
Q

CABLE AND RACEWAY REQ
During installation:
________ are snaked through conduit or tubing, are laid in a wireway, or are contained in cables, and
secured to structural framing.

A

conductors

71
Q

CABLE AND RACEWAY REQ
______ must be exercised in placing conductors, as conductors and insulation can be easily damaged.

A

Care

72
Q

CABLE AND RACEWAY REQ
Example: if a conductor is pulled through a tight conduit, it can stretch. ( ___________ caused by stretching reduces the ______________ of the wire, thereby reducing its _________. This creates an unsafe condition because the conductor can overheat.

A

Deformation, cross- sectional area, ampacity

73
Q

CABLE AND RACEWAY REQ
_________ that are run through a raceway must have sufficient open air space to prevent overheating.

A

Conductors

74
Q

CABLE AND RACEWAY REQ
The number of current carrying conductors that can run through a raceway is limited by ______.

A

code

75
Q

CABLE AND RACEWAY REQ
A ___________ conductor found in a raceway is any ungrounded conductor or grounded conductor.

A

current carrying

76
Q

CABLE AND RACEWAY REQ
_____________ (bare or green colored) and _________________ are not current carrying and are not counted.

A

Equipment grounding, shared neutral conductors

77
Q

CABLE AND RACEWAY REQ
- rigid metal and nonmetallic conduit
- IMC
- EMT
- ENT

A

Rigid conduit and tubing

78
Q

CABLE AND RACEWAY REQ
are favorite raceway materials used to protect conductors in all types of building.

A

Rigid conduit and tubing

79
Q

CABLE AND RACEWAY REQ
it is available in straight lengths, therefore, must be bent to accommodate changes in direction.
- bends must be made no smaller than the minimum radius specified by code, about _______ times the conduit diameter.
- conduit and tubing can have up to four _________ bends or the equivalent 360 degrees total in one run.
- In runs requiring more bends, a _________ is added in the run to assist in pulling conductors and to allow access.
- _______ can be made at the factory or at the job site for small to medium conduits.

A

Rigid conduit and tubing, 6 to 8, 90 degrees, pull box, bends

80
Q

CABLE AND RACEWAY REQ
- flexible metal conduit
- liquid tight flexible metal
- nonmetallic conduit

A

Flexible conduit

81
Q

CABLE AND RACEWAY REQ
- offers the advantage of easier installation and can be salvaged easily when circuits are rearranged.

A

Flexible conduit

82
Q

CABLE AND RACEWAY REQ
It is used where mechanical protection is needed and easy relocation of equipment is desired

A

Flexible conduit

83
Q

CABLE AND RACEWAY REQ
It can have up to four 90 degrees bends or the equivalent 360 degrees total in one run.

A

Flexible conduit

84
Q

CABLE AND RACEWAY REQ
__________ should be supported to prevent wearing away against structure and to avoid stressing its end fittings.

A

Conduit

85
Q

CABLE AND RACEWAY REQ
_______________________ must be supported within 3ft of a box or other connection and at intervals of 10 ft (about 3m)

A

Rigid conduit and tubing

86
Q

CABLE AND RACEWAY REQ
Continuous, ___________ can be used as the grounding conductor.

A

metal conduit

87
Q

CABLE AND RACEWAY REQ
__________ must be supported every 4 to 6 in (1.35m and within 12 in (300mm/0 of a box, except up to 36 in (about 1m is allowed at usage points where flexibility is required (e.g.. a pump motor or air conditioner condensing unit) and 6ft ( about 2m) between a recessed light fixture and a box.

A

Flexible conduit

88
Q

CABLE AND RACEWAY REQ
_______ and _________ can be used as
grounding conductor if it is continuous and properly bonded.

A

IMC and EMT

89
Q

CABLE AND RACEWAY REQ
It is required for flexible conduit

A

Grounding conductor

90
Q

CABLE AND RACEWAY REQ
It can be bare or insulated.

A

Grounding conductor

91
Q

CABLE AND RACEWAY REQ
Cannot be use as the grounding conductor.

A

Rigid nonmetallic conduit and tubing (ENT)

92
Q

CABLE AND RACEWAY REQ
Manufactured from thermoplastics that have very high rates of thermal expansion (over 6 in for a 100 degrees F temperature change per 100 ft/over 300mm in a 50 degree C temperature change per 30 m.
- provisions must be made if it is exposed to significant temperature changes.

A

Rigid nonmetallic conduit and tubing

93
Q

CABLE AND RACEWAY REQ
Permitted in sing and multifamily dwelling units and some other buildings.

A

Nonmetallic sheathed cable (NM and NMC)

94
Q

CABLE AND RACEWAY REQ
Restriction of use in
- underground
-buildings that are more than three stories above grade or in commercial garages
- Motion picture studious
- Theaters
-Places of assembly
-Elevator hoist ways
- Other corrosive or hazardous locations

A

Nonmetallic sheathed cable (NM and NMC)

95
Q

CABLE AND RACEWAY REQ
______ and _______ must be supported every 4-6 (1.35m) and within 12 in (300mm) of a box.

A

NM and NMC

96
Q

CABLE AND RACEWAY REQ
- is for use in dry, indoor applications

A

Armored cable

97
Q

CABLE AND RACEWAY REQ
Restriction of use in
- commercial garages
-motion picture studious
-Theaters
- Places of assembly
- Elevator hoist ways
- Other corrosive or hazardous locations

A

Armored cable

98
Q

CABLE AND RACEWAY REQ
Bends are limited to no less that five times the diameter

A

Armored cable

99
Q

BOX/ ENCLOSURE REQ
All electrical connections must be made in a protective enclosure such as panelboard, junction, or device box, fixture, or appliance.

A

T

100
Q

BOX/ ENCLOSURE REQ
Every switch, outlet, and connection must be contained in an electrical box and every lighting fixture must be mounted in a box.

A

T

101
Q

BOX/ ENCLOSURE REQ
All wirings must begin or terminate at a panelboard or in a box that is housing switch, luminaire connection, receptacle, conductor junction or similar terminal fitting.

A

T

102
Q

BOX/ ENCLOSURE REQ
Junction boxes must be mounted so that the black cober plate is visible and readily accessible.

A

T

103
Q

BOX/ ENCLOSURE REQ
All electrical boxes must be made adequately secure to the t=building structure.

A

T

104
Q

BOX/ ENCLOSURE REQ
Any box can be used for any purpose

A

Jojowain

105
Q

BOX/ ENCLOSURE REQ
There are no requirements that specify that a certain type of electrical box be installed for a specific purpose

A

T

106
Q

BOX/ ENCLOSURE REQ
_______ and ______ boxes for lighting outlets
- Normally installed overhead for lightning installation

A

T

107
Q

BOX/ ENCLOSURE REQ
_________ and _______ boxes for switches and receptacle outlets.

A

Rectangular and square

108
Q

BOX/ ENCLOSURE REQ
The size and number of conductors to be installed in a box influences selection if type of box and box size

A

T

109
Q

BOX/ ENCLOSURE REQ
The more conductors and/ or the conductor size, the bigger the box must be.

A

T

110
Q

BOX/ ENCLOSURE REQ
The capacity if a box, in cubic inches, is determined by its length, width, and depth.

A

T

111
Q

BOX/ ENCLOSURE REQ
An increase in one or more of these dimensions increases box capacity.
- Some boxes are designed so they can be ganged together to increase box capacity

A

T

112
Q

BOX/ ENCLOSURE REQ
By convention, a conductor that runs through the box us counted as one conductor and each conductor that terminates in the box counts as one.

A

T

113
Q

BOX/ ENCLOSURE REQ
The size and number of conductors to be installed in a box influences selection of type of box and box size.

A

T

114
Q

BOX/ ENCLOSURE REQ
Fixture wires and conductors that do not leave the box, such as an internal grounding wire, are counted.

A

F (not counted)

115
Q

BOX/ ENCLOSURE REQ
One conductor is deducted for one or more grounding conductors that enter the box.

A

T

116
Q

BOX/ ENCLOSURE REQ
Conductors in an electrical box must have sufficient open air space to prevent overheating.

A

T

Electrical Engineering Utilities (7 decks)

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