NEC Test 1
Mandatory rules in the NEC contain the language
"shall" or "shall not"
Holes must be bored so that the edge of the hole is at least ___ from the nearest edge of the wood member.
1 1/4 in (32 mm)
The minimum approve electrical trade size for EMT is ___ in
1/2
Volume shall be marked on all nonmetallic boxes and boxes with a volume of __ or less
100 in cubed (1650 cm cubed)
The minimum box width for U pulls must include ___
12 in between raceways plus the thickness of the two raceways
A 3- by 2-inch (75 x 50-mm) device box, 2.5 in (65 mm) deep, has a volume of
12.5 in cubed (205 cm cubed)
The weight supported by any single conduit shall not exceed __
20 pounds (9 kg)
What is the angle pull for a raceway in the vertical dimension where the trade size of the largest raceway is 4 in and the sum of the other raceways in the same row on the same wall is 5 in?
29 in
A luminaire that weighs more than ___ shall be supported independently of the outlet box, unless the outlet box is listed for note less than the weight to be supported.
50 lb (23kg)
The ___ is the organization, office, or individual responsible for enforcing the requirements of a code.
AHJ
Formal interpretations of the NEC are governed by
NFPA
Which agency is responsible for the maintenance and publication of the NEC
National Fire Protection Association (NFPA)
Flexible metal conduit (PVC) is a raceway of circular cross section made of
a helically wound, formed and interlocked metal strip
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
Electrical metal tubing (EMT) provides protection from
all but severe phsical damage
A(n) __ is a device intended to provide protection from the effects of arc faults by recognizing characteristics unique to arcing
arc-fault circuit interrupter (AFCI)
Protection is required for cables located within 6 ft (1.8 m) (measured both vertically and horizontally) of the ___.
attic entrance
A grounding electrode is a(n) __ object that establishes a direct connection to earth
conducting
An attachment plug establishes connection between
conductors of the attached flexible cord and the conductors permanently connected to the receptacle
Grounded (grounding) is defined as being
connected to ground or to a conductive body that extends the ground connection
An appliance branch circuit supplies energy to one or more outlets for the purpose of
connecting appliances
NEC identifies ___ types of rigid PVC conduit
five
___ or fewer luminaire wires (smaller than 14 AWG) and an equipment grounding conductor can be omitted from box fill calculations if they enter a box from a domed luminaire (or similar canopy) and terminate within that box
four
Cables running horizontally ( or diagonally) are considered supported and secured when passing through a(n) ___ unless the support intervals exceed those listed for the specified cable.
framing member
Overcurrent devices do not have to be readily accessible if
located adjacent to the equipment where access is achieved by the use of portable means
Local ordinances
may adopt the NEC as written or amend the Code with more or less stringent regulations
___ wire, together with strain insulators, is used to support conductors in all spans exceeding 40ft (12 m) in length
messenger
Ready access to wiring in luminaries is
not required
Liquidtight flexible metal conduit (LFMC) is a raceway of circular cross section having a(n) ___ over an inner flexible metal core.
outer liquidtight nonmetallic, sunlight-resistant jacket
Supporting screws for nonmetallic boxes must be mounted ___ unless the box is constructed in a manner that prevent contact between the conductors in the box and the supporting screws
outside of the box
A key provision found in most of the cable articles states that the cable must not be installed where subject to
physical damage
Volume in boxes can be increased by using ___ rings, domed covers, extension rings, or similar items
plaster (mud)
No requirement specifies the depth of a box, unless a __
raceway enters the rear of the box
All cut ends of IMC and RMC must be ___
reamed
A contact device installed in an outlet for the connection of an attachment plug is a(n) ___
receptacle
Conduit body support must be ___
rigid and secure
In addition to installation rules, the NEC is concerned with the
type and quality of electrical wiring system materials
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
Generally, ungrounded (hot) conductors can be any color except
white, gray, green or green with yellow stripes
What is the angle pull for a raceway in the horizontal dimension where the trade size of the largest raceway is 3 in and the sum of the other raceways in the same row on the same wall is 4 in.
22 in
Listed flexible metal conduit can serve as a grounding means if certain conditions are met. One of these conditions is that the circuit conductors contained therein must be protected by overcurrent devices rated at __
60 amperes or less ???
Nonmetallic-sheathed cable not fastened to the box must be secured within ___ of the box
8 in (204 mm)
Bends must be made so that the conduit or tubing remains undamaged with its internal diameter
basically undiminished
A feeder consists of all circuit conductors located
between the service equipment, the source of separately derived system, or other power supply source and the final branch-circuit overcurrent device
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
Wire connectors, pigtails, locknuts bushings, raceway connectors and grounding screws are not factors when calculating ___
box fill
Cables entering or exiting conduit used for support or protection against physical damage require fittings on the conduit ends to prevent ___
cable abrasion
Rigid metal conduit (RMC) is a threadable raceway of ___ designed for the physical protection and routing of conductors and cables.
circular cross section
Cable connector(s) with a ___ outside the box are not counted when determining the number of conductors
clamping mechanism
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
The NEC arose as a consensus of more than 1200 individuals primarily to
combat a growing epidemic of electrical fires
Conductors in concealed raceways, even though they may become accessible by withdrawing them, are still considered
concealed
A load having the maximum level of current sustained for three hours or more is referred to as a ____ load.
continuous
A multiwire circuit must consist of conductors connected to
different phases
"Equipment" is a general term, including fittings, devices appliances, luminaires, apparatus, machinery, etc used ___ in an electrical installation
directly or indirectly
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
Article 100 defines raceway as a(n) ___ designed expressly for holding wires, cables, or busbars
enclosed channel of metallic (or nonmetallic) materials
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 is not installed.
equipment grounding conductor
The term " labeled" means that
equipment/material must continue to comply with the appropriate standards (or performance) under which the labeling was granted
The term "listed" means that
equipment/materials/services meet appropriate designated standards or have been tested and found suitable for a specified purpose
The definition for intermediate metal conduit (IMC) and rigid metal conduit (RMC) is ___
essentially the same
Exposed runs of Type AC cable installed on the underside of joists must be supported at ___
every joist
Electrical installation opening that penetrate into or through fire-resistant-rated structures must be ___
firestopped
A(n) __ is an accessory, such as a locknut or bushing, whose function is primarily mechanical, rather than electrical in nature
fitting
The maximum number of conductors applies only if the box does not contain any __
fittings or devices
The AC cable must have a bending radius at least ___ times the diameter of the cable.
five
Type AC cable shall have a(n)
flexible metal tape armor
The equivalent of ___ is the maximum allowed between pull points.
for quarter bends (360 degree total)
Contact of dissimilar metals (except for the combination of aluminum and steel) should be avoided wherever possible to lessen the potential for ___
galvanic action
Cables running across the top of the floor joists must be protected by
guard strips
Panelboards having doors or covers are considered
guarded
Raceways installed within drop ceilings must ___.
have secure support provided by the support wires and associated fittings
Inspection of the connections between luminaire conductors and circuit conductors must be possible without ___
having to disconnect any part of the wiring
Cable installed under a building must be ___ unless the wiring method is Type MC or Type MI cable that is identified for direct burial
in a raceway
Where a box contains both straight and angle (for U) pulls, or straight pulls and splices, you should calculate each type of pull ___ to find the dimensions
individually
___ in the ends of larger conduits (2 to 6 in) 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
Nonmetallic-sheathed cable passing through holes (for slots) in metal framing must be protected by ___ covering all metal edges.
listed bushings (grommets)
NEC tables such as 210.21(B)(3) present a requirements
multiple application possibilities
A neutral conductor is defined as the conductor connected to the __ that is intended to carry current under normal conditions
neutral point of a system
A separately derived system is an electrical source, other than a service, having ___ connection to circuit conductors of any other electrical source other than those established by grounding and bonding connections.
no direct
Wiring components are considered accessible with (1) access can be gained without damaging the structure or finish of the building or (2) they are
not permanently closed in by the structure or finish of the building
PVC bends must be made so that the conduit remains undamaged and the internal diameter of the conduit is ___
not reduced
Equipment grounding conductors(s) or equipment bonding jumpers entering a box count as ___ unless there are more than four equipment grounding conductors.
one conductor
A point in a wiring system from which current is taken to supply utilization equipment is known as a(n) ___
outelet
The NRTL program specified in the regulation "OSHA Recognition Process for nationally Recognized Laboratories"
regulates training standards
When metal parts are required to be electrically connected a(n) is installed, thereby guaranteeing the required electrical connectivity
reliable conductor (bonding jumper)
A service point can be described as the point of demarcation between where the __ ends and the premise wiring begins
serving utlity
Where multiple rows of raceways enter a box, you should calculate each row separately and use the ___
single row that provides the maximum distance
Box calculations for 4 AWG and larger conductors (1000 volts or less) are performed based on the ___
size and number of raceways
__ are permitted inside conduit bodies, if the manufacturer durably and legibly marked the cubic capacity on the conduit body
splices, taps, or devices
Multiconductor cord or cable used to support a box must be protected in an approved manner so that the conducgtors are not subjected to ___
strain
The Illustrated Guide to the NEC should be used as a(n)
supplement to the NEC
The word luminaire refers to
the complete lighting unit
The UL logo indicates that
the listed product complies with UL standards
All conductors of a multiwire branch circuit must originate from
the same panelboard or similar distribution equipment
Raceway fill calculations are a prerequisite in determining ___ needed for particular circuits.
the size of raceway
Electrical metallic tubing must not be ___
threaded
Ducts used to transport dust, loose stock, or flammable vapors shall not contain ___ of any type.
wiring system
The neutral point is the common point on a ___ in a polyphase system
wye-connection