NEC 3&4
The equivalent of _____ is the maximum allowed between pull points.
four quarter bends (360 degrees total)
All cut ends of IMC and RMC must be
reamed
Volume shall be marked on all nonmetallic boxes and boxes with a volume of ___ cubic inches or less
100
Flexible metal conduit (FMC) is a raceway of circular cross section made of --------
Helically wound formed and interlocked metal strips
A multiconductor cable, optical fiber cable, or flexible cords of two or more conductors is treated as ____ for percentage conduit fill areas calculations
a single conductor
Surface nonmetallic raceways and their fittings must be designed so that sections can be mechanically coupled together and installed without subjecting the wires to ____
abrasion
Electric metal tubing (EMT) provides protection from ____
all but severe physical damage
Exposed runs of Type AC cable installed on the underside of joists must be supported at ____
every joist
Electrical installation openings that penetrate into or through fire-resistant-rated structures must be
firestopped
The maximum number of conductors applies only if the box does not contain any
fittings or devices
NEC identifies ______ types of rigid PVC conduit.
five
Type AC cable must have a bending radius at least ______ times the diameter of the cable
five
Cables running horizontally or diagonally are considered supported and secured when passing through a
framing member
Cables not installed on the face do not require
guard strips or running boards
Cable installed under a building must be _______ unless the wiring method is Type MC or Type MI cable that is identified for diret burial
in a raceway
Where a box contains both straight and angle or U pulls or straight pulls and splices calculate each type of pull ______ to find the dimension
individually
Equipment grounding conductors or equipment bonding jumpers entering a box count as ______
one conductor
Volume in boxes can be increased by using _____ rings, domed covers, extension rings, or similar items
plaster (mud)
A key provision found in most of the cable articles states that the cable must not be installed where subject to
pysical damage
No requirement specifies the depth of a box, unless a _______
raceway enters the back of the box
Box calculations for 4 AWG and larger conductors (under 600 volts) are performed based on the
size and number of raceways
Electrical metallic tubing must not be
threaded
Wireways are _______ housing and protecting electric wires ( and cables)
troughs with hinged or removable covers for
A cable assembly's ___ conductor can be used as a switch loop (leg) in single-pole three-way and four-way switch installations, even though it is an ungrounded (hot) conductor.
white or gray
Wire connectors pigtails locknuts bushings raceway connectors grounding screws and equipment bonding jumpers are not factors when calculating
box fill
Rigid metal conduit (RMC) is a thread-able raceway of ______ designed for the physical protection and routing of conductors and cables
cable abrasion
Cable connectors with a ______ outside the box are not counted when determining the number of conductors
clamping mechanism
Underfloor raceway dead ends must be
closed
Type AC cable shall have a
flexible metal tape armor
PVC bends must be made so that the conduit remains undamaged and the internal diameter of the conduit is
not reduced
Supporting screws for nonmetallic boxes must be mounted ____
outside of the box
The minimum approved electrical trade size for EMT is ____ inches
.5
Holes must be bored so that the edge of the hole is at least
1 1/4 inch
The minimum box width for U pulls must include ____
12 in. between raceways plus the thickness of the two raceways
Grounding conductors are required for circuits over ____ amperes
20
What is the angle pull for a raceway in the vertical dimension where the trade size of the largest raceway is 4 and the sum of the other raceways in the same row on the same wall is 5?
29 inches
A luminaire that weighs more than _______ pounds shall be supported independently of the outlet box, unless the outlet box is listed and marked on the interior of the box to indicate the maximum weight the box shall be permitted to support.
50
Half-round and flat-top raceways not over 4 inches in width must be covered by _____ or mor of concrete (or wood)
75 inches
A 3x2 inch device box 2.5 in deep has a volume of ___ cubic inches
12.5
Multiconductor cord or cable used to support a box must be protected in an approved manner so that the conductors are not subjected to
strain
Nonmetallic-sheathed cable not fastened to the box must be secured within ___ in. of the box.
8
________ or fewer luminaire wires (smaller than 14 AWG) and an equipment grounding conductor can be omitted fro box fill calculations where they enter a box from a domed luminaire (or similar canopy) and terminate within that box
four
____ in the ends of larger conduits (2 to 6 inches) can prevent conduit collapses or other deformities
installing PVC plugs
A group of conductors that fit into one conduit may not fit into another type because the ___ of different types of conduit vary
internal diameters
Generally ungrounded (hot) conductors can be any color except _____
white, gray, green, or green with yellow stripes
Article 100 defines raceway as a _____ designed expressly for holding wires, cable or busbars
enclosed channel of metallic (or nonmetallic) materials.
The definition for intermediate metal conduit (IMC) and rigid metal conduit (RMC) is _____
essentially the same
Contact of dissimilar metals (except for the combination of aluminum and steel) should be avoided wherever possible to lessen the potential for
galvanic action
Raceways installed within drop ceilings must
have secure support provided by the support wires and associated fittngs
Inspection of the connections between luminaire conductors and circuit conductors must be possible without ____
having to disconnect any part of the wiring
Nonmetallic sheathed cable passing through holes in metal framing must be protected by -------- covering all metal edges
listed bushings (or grommets)
Ducts used to transport dust, loose stock or flammable vapors shall not contain ___ of any type
wiring systems
The weight supported by any single conduit shall not exceed ___ pounds
20
What is the angle pull for a raceway in the horizontal dimension where the trade size of the largest raceway is 3 and the sum of the other raceways in the same row on the same wall is 4?
22 inches
_______ are permitted inside conduit bodies if the manufacturer durably and legibly marked the cubic inch capacity on the conduit body
Splices, taps, or devices
Protection is required for cables located within 6 ft (measured both vertically and horizontally) of the ________
attic entrance
Bends must be made so that the conduit or tubing remains undamaged with its internal diameter
basically undiminished
A widely accepted practice is to identify 3-phase ungrounded (hot) conductors as ____ in 208/120 volt, 4 wire, wye-connected systems.
black, red and blue
Cover measurement commences at the top surface of any direct burial wiring method and ends at the ____ of the finished grade's top surface
closest point
Raceway fill calculations are a prerequisite in _____ needed for particular circuits.
determining the size of raceway
The length of a straight pull for multiple raceways must be at least ___ times the trade size (metric designator) of the largest single raceway
eight
Snap switches (including dimmer switches) must be connected to a(n) ______ and must also provide a means to connect metal faceplates to the equipment grounding conductor, even if a metal faceplate in not installed
equipment grounding conductor
A header is a transverse raceway ____
for electric conductors, providing access to predetermined cells of a cellular metal floor
Liquidtight flexible metal conduit (LFMC) is a raceway of circular cross section having a(n) _________ over an inner flexible metal core
out liquidtight, nonmetallic sunlight resistant jacket
Conduit body support must be ________
rigid and secure
Splices and taps are permitted within surface metal raceway having a removable cover that
remains accessible after installation
Where multiple rows of raceways enter a box, calculate each row separately and use the ____
single row that provides the maximums distance
