Commercial Wiring Midterm
Holes must be bored so that the edge of the hole is at least ____ inches from the nearest edge of the wood member.
1.25, 1-1/2
NEMA rated motors are designed to operate at plus or minus ____ percent of their nameplate rated voltage.
10
In three-phase motors, each phase is ____ degrees out of phase (symmetrical) with the other phases.
120
If a lighting load is considered to be continuous, as is the case in commercial buildings, a load factor of ____ percent must be applied.
125
NEC® 430.24 requires that the conductors supplying several motors, or a motor(s) and other load(s), shall have an ampacity not less than ____ percent of the full-load current rating of the highest rated motor.
125
Motors marked with Insulation Class B are suitable for use in ambient temperatures of up to ____ degrees Celsius.
130
The weight supported by any single conduit shall not exceed ____ pounds.
20
An appliance is rated at 4500 volt-ampere, 240 volts, single-phase. The maximum size fuse permitted is _______ amperes
30
Often the load is such that parallel conductors should be considered. This usually occurs with loads over ____ amperes.
400
Type AC cable must have a bending radius at least ____ times the diameter of the cable.
5, five
A luminaire that weighs more than ____ pounds shall be supported independently of the outlet box, unless the outlet box is listed for not less than the weight to be supported.
50
In the United States, ____ Hz is standard or the fundamental frequency.
60
Nonmetallic-sheathed cable not fastened to the box must be secured within ____ inches of the box.
8
The length of a straight pull for multiple raceways must be at least ____ times the trade size (metric designator) of the largest single raceway.
8
The two most popular types of PVC are Schedule 40 and Schedule ____.
80
A(n) ____ fault circuit interrupter is a device intended to provide protection from the effects of arc faults by recognizing characteristics unique to arcing.
Arc
The ____ Having Jurisdiction is the organization, office, or individual responsible for enforcing the requirements of a code.
Authority
____ fuses are designed to withstand motor-starting inrush currents and will not open needlessly.
Dual element, time delay
_____________is defined as being connected to ground or to a conductive body that extends the ground connection
Grounded, grounding
For installations where the nonlinear load is huge, most consulting engineers will specify ____-rated transformers.
K
Which agency is responsible for the maintenance and publication of the NEC®?
National Fire Protection Association, NFPA
A contact device installed at an outlet for the connection of an attachment plug is a(n) ____.
Receptacle
Wiring components are considered _______________ when (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
accessible
Where PVC conduit is connected to a box or enclosure, a box ____ is recommended.
adapter
An appliance branch circuit supplies energy to one or more outlets for the purpose of connecting ____.
appliances
Protection is required for cables located within 6 ft (1.8 m) (measured both vertically and horizontally) of the ____ entrance.
attic
A widely accepted practice is to identify 3-phase ungrounded (hot) conductors as black, red and ____ in 208/120 volt, 4-wire, wye-connected systems.
blue
Wire connectors, pigtails, locknuts, bushings, raceway connectors, and grounding screws are not factors when calculating ____ fill.
box
Cable connector(s) with a ____ mechanism outside the box are not counted when determining the number of conductors.
clamping
The word luminaire refers to the ___________ lighting unit
complete
A grounding electrode is a(n) ____ object that establishes a direct connection to earth.
conducting
When metal parts are required to be electrically connected, a reliable ______________is installed, thereby guaranteeing the required electrical conductivity.
conductor
A load having the maximum level of current sustained for three hours or more is referred to as a ____ load.
continuous
Splices, taps, or ________ are permitted inside conduit bodies, if the manufacturer durably and legibly marked the cubic inch capacity on the conduit body.
devices
The maximum number of conductors applies only if the box does not contain any fittings or ____________.
devices
A ____________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
feeder
The NEC® arose as a consensus of more than 1200 individuals primarily to combat a growing epidemic of electrical ____.
fires
Electrical installation openings that penetrate into or through fire-resistant-rated structures must be ____.
firestopped, caulked
Cables running horizontally (or diagonally) are considered supported and secured when passing through a(n) ____ member unless the support intervals exceed those listed for the specified cable.
framing
Color selection for ungrounded "hot" conductors can be just about any solid color except green, white, gray, or any color conductor (except ____) that has three continuous white stripes.
green
Nonmetallic-sheathed cable passing through holes (or slots) in metal framing must be protected by listed ____ covering all metal edges
grommets, bushings
Cables running across the top of floor joists must be protected by ________ strips.
guard
For most applications, the motor circuit switch for a motor must be ____ rated.
horsepower
Voltage drop in a circuit is calculated by multiplying the current flow times the ____.
impedance
Type MC cable is a factory assembly of one or more insulated circuit conductors with or without optical fiber members enclosed in an armor of ____ metal tape, or a smooth or corrugated metallic sheath.
interlocking
The term __________ means the equipment or material must continue to comply with the appropriate standards (or performance) under which the labeling was granted
labeled
When sizing feeder conductors, only the ____ of any noncoincident loads (loads unlikely to be operated simultaneously such as the air-conditioning and the heating) need be included.
larger, largest, biggest
The UL logo indicates that the _________ product complies with UL standards.
listed
The term _________ means that equipment, materials, or services meet appropriate designated standards or have been tested and found suitable for a specified purpose.
listed
The reason the Code uses the term motor ____ instead of motor is that, in many instances, the motor is inside an enclosure and is out of sight until an access panel is removed.
location
A neutral conductor is defined as the conductor connected to the ____ point of a system that is intended to carry current under normal conditions.
neutral
On a 3-phase, 4-wire, wye system, ____ reduction is allowed for nonlinear loads.
no
To determine a reasonable minimum size for a neutral conductor, two types of loads must be considered— linear and _______.
nonlinear
Equipment grounding conductor(s) or equipment bonding jumpers entering a box count as ____ conductor(s) unless there are more than four equipment grounding conductors.
one
Local ______________may adopt the NEC® as written or amend the Code with more or less stringent regulations.
ordinances
A point in a wiring system from which current is taken to supply utilization equipment is known as a(n) ____.
outlet
Supporting screws for nonmetallic boxes must be mounted ____ of the box unless the box is constructed in a manner that prevents contact between the conductors in the box and the supporting screws.
outside
"Inverse time" refers to the speed of opening of ____ devices.
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
overcurrent
Feeders are the part of the electrical system that connects the branch-circuit ____ to the electrical service equipment.
panelboard, panelboards
NEC® 310.10(G) sets forth the requirements for installing ____ conductors. These requirements are intended to ensure the conductors will share the current equally to prevent overloading individual conductors.
parallel
A multiwire circuit must consist of conductors connected to different ____.
phases
A key provision found in most of the cable articles states that the cable must not be installed where subject to ____ damage.
physical
Volume in boxes can be increased by using ____ rings, domed covers, extension rings, or similar items.
plaster, mud
An attachment ________ establishes connection between conductors of the attached flexible cord and the conductors permanently connected to the receptacle.
plug
Temperature ____ means the difference between motor winding temperature and the ambient temperature.
rise
A motor may be loaded continuously up to the horsepower obtained by multiplying the rated horsepower by the ____ factor.
service
If the ampacity of a feeder does not match a standard OCPD rating, then the next higher ____ rating may be used.
standard
Wireways are ____ with hinged or removable covers for housing and protecting electric wires (and cables).
troughs
To get accurate current readings where harmonics are involved, ammeters referred to as "____ rms" must be used.
true
____ voltage is the most common cause of motor failure.
unbalanced
A cable assembly's ________ or gray 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
Generally, ungrounded (hot) conductors can be any color except white, gray, green, or, green with __________stripe(s).
yellow