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Electrical Engineering Utilities > CHAPTER 2, ENCLOSURES AND RACEWAYS > Flashcards

CHAPTER 2, ENCLOSURES AND RACEWAYS Flashcards

1
Q

• are ELECTRICAL BOXES and CABINETS that are made of metal or non-metallic materials that protect conductors, connections, controls, and other equipment

• they protect wiring, devices, and equipment from damage from accidental contact, wear, corrosive, atmospheric exposure, and sunlight

• for faulty enclosed conductors, connections, controls, and electrical equipment, enclosures contain the arc and
flaming, thereby confining damage from fire

A

enclosureS

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2
Q

• are METAL AND NONMETALLIC ENCLOSURES that hold devices such as switches or outlets and safety PERMIT wiring connections

• boxes are in four primary shapes: square, rectangular, octagonal, or round

• boxes can be joined together to accommodate multiple outlets or switches, namely; two-gang, three gangs, or four gang boxes

A

electrical boxeS

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3
Q

• special type of electrical box used to ENCLOSE CONDUCTOR CONNECTIONS

• connections are commonly called junctions in the trade

A

junction boxeS

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4
Q

kind of junction box that allows access to a raceway for

SNAKING conductors through the raceway

A

pullbox

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5
Q

in most boxes and enclosures, it can be EASILY REMOVED

to allow wiring to enter the box

A

knockout

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6
Q

• required for various single or combinations of switches, convenience outlets, blank covers, and dimmers; plastic is a commonly used material

• attached with screws to the switch or receptacles

• all the boxes should be finished with a cover plate

A

cover plateS

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7
Q

• an ENCLOSED CHANNEL such as conduit, tube, or gutter used for holding WIRES, cables, or bus bars

• in some cases, metal __________ that are fully bonded serve to provide a path for the flow of fault current to

ground

A

RACEWAY

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8
Q
  • a HEAVY GALVANIZED STEEL or aluminum tube that looks like the galvanized steel pipe used for plumbing applications, except it is much smoother and is labeled with a UL Listed stamp or label has THREADED connections much like a pipe
  • can be used in contact with the earth and embedded in concrete
A

RIGID METAL CONDUIT

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9
Q

• galvanized steel or aluminum tube that has a thinner wall than rigid metal conduit
• has threaded connections much like pipe or threadless connectors and couplings

• can be used in contact with earth and embedded in concrete

A

INTERMEDIATE METAL CONDUIT

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10
Q

• THIN _ WALLED GALVANIZED STEEL or aluminum tube in nominal diameters up to 4 in.

• CANNOT BE THREADED

• labeled with UL Listed stamp or label

• joined with threadless compression couplings, couplings that are crimped into the tubing with a special indenting tool, or fittings that are TIGHTENED WITH SCREWS

A

ELECTRICAL METALLIC TUBING

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11
Q

• a FLAME - RETARDANT corrugated plastic tube that is semi flexible such that it can be bent by hand. • must be used behind fire-rated finish materials

• permitted in damped locations and can be set in concrete above ground

• can also be solvent welded to rigid _____________

(PVC) conduit

• can be used in any building, but special precautions are required when used more than three floors above grade

A

ELECTRICAL NONMETALLIC TUBING, polyvinyl chloride

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12
Q

• THIN WALLED PIPE OF PVC

  • joined with fittings that are SOLVENT WELDED
A

RIGID NONMETALLIC CONDUIT

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13
Q

similar to armored cable yet, installed without cables or wiring in it; wiring must be pulled

A

FLEXIBLE METAL CONDUIT

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14
Q

similar to flexible metal conduit but covered with plastic, a WATERTIGHT JACKET that is sunlight resistant
• unlike flexible metal conduit, the special connectors are watertight

A

LIQUID TIGHT FLEXIBLE METAL CONDUIT

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15
Q

• a flexible plastic conduit used similarly to flexible metal conduit

cannot be used over 6 ft. in length

A

LIQUID TIGHT FLEXIBLE NONMETALLIC CONDUIT

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16
Q

are hollow voids in floors made of precast concrete slabs (core slabs) found in certain precast concrete buildings

A

cellular concrete floor racewayS

17
Q

• involves cutting, bending, and threading lengths

A

EMC, EMT, ENT

18
Q

• a run of conduit should be straight and direct

A

so true

19
Q

_________ or __________ must support the conduit in the entire run

A

strapS , hangerS

20
Q

• the number of conductors in a raceway is based on the

A

size of the conduit,
type of conductor insulation,
size of conductors

21
Q

• several conductors fed into conduit should be kept

___________, _________, and _________ and _____________.

A

parallel, straight, and kinks and bends-free

22
Q

• is of a standardized, factory assembled enclosure consisting of outer DUCT LIKE HOUSING, BUS BARS, and INSULATORS

•__________ systems are used in service equipment or as __________ because they are designed to carry a large amount of current

A

BUSWAY, feeders

23
Q

A type of busway system that used to deliver a LARGE AMOUNT OF POWER with LOW VOLTAGE DROP • available in sizes from 600 A to several thousand amps

A

FEEDER BUSWAY

24
Q

• Another type of busway system used to provide POWER TAP-OFFS at multiple points • available in 100 A- 3000 A sizes

A

PLUG-IN-BUSWAY

25
Q

make power distribution flexible

A

PLUG-IN-BUSWAY

26
Q

____________ is available anywhere along the busway without necessitating the major service interruption.

A

Power

27
Q

Connections cannot be made at any point along the busway.

A

false, pwede ra uy

28
Q

Rigid and flexible conduit or flexible _____________ extends from the busway to the equipment piece.

A

bus drop cable

29
Q

• are only used in large commercial and industrial installations where LARGE LOADS ARE CONCENTRATED (600 A and above), where large numbers of taps are required, or where superior fire and mechanical injury protection is desirable.

A

busway

30
Q

can also be salvaged and moved more easily and costeffectively than ordinary conductors.

A

BUSWAY

31
Q

___________________ are sheet metal or nonmetallic, FLAME-RESISTANT plastic throughs that serve as HOUSING that encloses and protects conductors

• access to the enclosure interior is through a hinged door or removable cover

• _________________ carry large conductors

A

wirewayS

Electrical Engineering Utilities (10 decks)

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