Mid Term Flashcards
T/F Equipment designed to open circuits under fault conditions shall have an interrupting rating not less than the available voltage and circuit current at the line side of the equipment.
True
T/F Wet locations are subject to moderate degrees of moisture, but are generally out of the weather.
False
T/F A short circuit is the unintentional connection of two ungrounded conductors that have a potential difference between them.
True
T/F At least two entrances to electrical rooms shall be provided to give access to the working space about all electrical equipment rated less than 1200 A.
False
T/F The NEC® is revised and updated every six years
False
T/F The basic rule when selecting termination devices is to always use a termination device identified for the type of conductor material.
True
T/F Explanatory material appears in the NEC® in Informational Notes.
True
T/F The minimum headroom of working spaces above electrical equipment in commercial buildings is 61⁄2’.
False
T/F Electric equipment with ventilating openings shall be installed so that openings are not obstructed to prevent the free circulation of air.
True
T/F The NEC® may be used as a design specification by qualified persons.
False
The first ___ chapters of the NEC® apply generally unless they are modified by the latter chapters.
four
Chapter ___ of the NEC® is independent of the other chapters, and none of the provisions apply unless they are directly referenced.
eight
Equipment that is required to be readily accessible shall be capable of being reached quickly without the use of tools, with an exception for ___.
keys
A conductor’s ___ is the amount of amperes it can carry continuously without exceeding its temperature rating.
Ampacity
Boxes installed within walls that are required to be taken down to gain access are not considered ___.
accessible
The word ___ indicates that an NEC® rule is mandatory.
shall
The two-fold purpose of the NEC® is to protect ___ from the hazards associated with the use of electricity.
persons and property
Most voltages referenced in the NEC® are ___ voltages.
nominal
Interpretations and approval of equipment are granted by the ___.
AHJ
The AHJ can permit alternate ___ for installation, if they believe the installation is equally effective at meeting the intended objective.
methods
Although installed in conformance with the NEC®, all electrical installations may not be adequate for ___ expansion of electrical use.
future
The NEC® is not intended to be used as a(n) ___ specification.
design
If the AHJ finds the equipment or installation to be acceptable, it is ___.
approved
___ conductors are conductors not encased in a material recognized by the NEC® as electrical insulation.
Covered
Connectors, couplings, locknuts, and bushings are examples of electrical ___.
fittings
___ means recognized as suitable for the use, purpose, etc.
Identified
Equipment that is required to be located in sight from other equipment shall be visible and not more than ___ feet from the other equipment.
50
Equipment that has been ___ is published in a directory by the testing lab certifying that it has met established standards and is acceptable to the AHJ.
listed
One of the primary purposes of raceways is to support conductors and protect them from physical ___.
damage
The NEC® requires that all electric equipment and conductors be ___ to be deemed acceptable to the AHJ.
approved
When not specified, all conductors in the NEC® are considered to be ___.
copper
All unused openings other than those intended for the operation of equipment are required to be effectively ___ to afford equivalent protection.
closed
Terminals for more than one conductor shall be ___.
identified
If a splice is underground, the device shall be listed for ___ use.
direct burial
For motors or motor controllers, one of the ___ shall be readily accessible as required by the NEC®.
disconnecting means
T/F Branch circuits with not over 120 V between conductors are permitted to supply auxiliary equipment of electric-discharge lamps.
True
T/F A GFCI receptacle or circuit breaker is set to trip at 10 mA.
False
T/F All 125 V, 15 A, and 20 A receptacles installed in dwelling bathrooms shall be GFCI-protected.
True
T/F All receptacles which serve countertops in dwelling kitchens shall be GFCI-protected.
True
T/F All receptacles in dwelling unit crawl spaces at or below grade shall be GFCI-protected.
True
T/F No point along the wall line for a dwelling unit countertop shall be more than 48” from a receptacle outlet.
False
T/F At least one receptacle outlet shall be installed within 36” of the outside edge of each bathroom basin in all dwelling units.
True
T/F There may be installations where grounded conductors of different systems are installed within the same raceway, cable, or box.
True
T/F A milliampere (mA) is equal to 1000 amperes.
False
T/F A GFCI device will trip the switching contacts when an imbalance exceeds 3 mA.
False
For an area to qualify as a bathroom, a ___ shall be present.
sink (basin)
___ conductors are the conductors from the service point to the service disconnecting means.
service
___ conductors are all circuit conductors between the service equipment and the final branch-circuit overcurrent device.
feeder
The ___ is that portion of the electrical circuit between the last overcurrent device and the outlets or utilization equipment.
branch circuit
A(n) ___ load is a load where the waveform of the steady-state current does not follow the wave shape of the applied voltage.
nonlinear
In general, the grounded conductor of a branch circuit shall be identified by a continuous white or ___ outer finish.
gray
In dwelling units, a GFCI-protected receptacle is required when located within ___ feet from the inside edge of the bowl on the sink.
6
Branch-circuit conductors shall be ___ AWG or larger.
14
Receptacle outlets installed in a dwelling for specific appliances shall be located within ___ feet of the appliance.
6
The required dwelling unit outdoor receptacles shall be not more than ___ above finished grade level.
6’ 6”
At least one receptacle outlet shall be installed in ___ feet or longer hallways of dwelling units.
10
The required 125 V, 1Φ, 15 A or 20 A receptacle on rooftops for heating, air-conditioning, and refrigeration servicing shall be within ___ feet of the equipment.
25
A listed wall-mounted control device shall be provided at each floor level for a lighting outlet installed in an interior dwelling stairway with ___ or more risers between floors.
6
_ is the ratio of the maximum demand of a system, or part of a system, to the total connected load of a system or the part of the system under consideration.
Demand factor
The main concern in ___ branch circuits is that the neutral shall never be opened while the circuit is energized.
multiwire
Branch-circuit EGCs smaller than 4 AWG shall have a continuous outer finish that is either green or green with one or more ___ stripes unless it is bare.
yellow
All conductors of a(n) ___ branch circuit shall originate from the same panelboard.
multiwire
A current flow of ___ mA will most likely cause the heart to stop pumping.
100
Multiwire branch circuits are restricted to supplying ____ loads.
line-to-neutral
__ protection is for the benefit of the equipment, while GFCI is intended to protect personnel.
GFPE, ground-fault protection equipment
Heavy-duty and medium-type lamp holders shall have a rating of not less than ___ W.
660
T/F The Optional Calculation can be used to find the total ampacity of a multifamily dwelling with natural gas cooking equipment.
False
General lighting loads for dwelling units are calculated at ___ VA per square foot.
3
or 1Φ systems, the formula ___ is used to determine minimum ampacity of ungrounded conductors.
I=VA / V
The Optional Calculation for dwelling units consists of heating and A/C loads and ___ loads.
general
Any outlet loads not covered by the other rules found in 220.14 must be calculated at ___ VA per outlet.
180
Feeders for several motors are calculated using the sum of the FLC tables of all motors plus ___% of the largest motor (Standard Calculation).
25
A(n) ___ is the amount of electricity required at a given time.
demand
Each single or multiple receptacle on a single strap is calculated at ___ VA.
180
Demand factors may be applied to ___ of the six loads of the Standard Calculation.
4
Four or more appliances that are fastened-in-place in a one-family dwelling are calculated at ___ percent of the total load for all four appliances (Standard Calculation).
75
The total load for household clothes dryers is calculated at ___ VA or the nameplate rating, whichever is higher (Standard Calculation).
5000
__ loads are loads that are not on at the same time.
Noncoincidental
The ___ load is the maximum unbalance between any of the ungrounded conductors and the grounded conductor.
feeder neutral
Each dwelling shall be supplied with a(n) ___ A branch circuit to supply laundry receptacle outlet(s).
20
Heating or A/C loads are calculated at ___ percent of the nameplate rating and the largest load is used (Standard Calculation).
100
After the minimum ampacity of the dwelling service has been calculated, Table ___ and 310.12(A) are used to determine the size of service-entrance conductors.
310.15(BX2)(16)
The demand load for household electric ranges rated in excess of ___ kW is calculated per Table 220.55 (Standard Calculation).
1 3/4
__ outlet loads are calculated per the rules found in 430.22, 430.24, and 440.6.
motor
___ branch circuits supply all receptacle outlets located in the kitchen, pantry, breakfast room, dining room, or similar areas of dwelling units (Standard Calculation).
small appliance
If a dwelling unit contains fewer than four separately controlled electric space-heating units, the loads are calculated at ___% of their nameplate ratings (Optional Calculation).
65
The load for household clothes dryers in dwelling units is required by 220.54 to be ___ VA or the nameplate rating, whichever is greater.
5000
T/F Occupancies which utilize a fire pump for life safety protection are permitted to have a separate service provided solely for the fire pump.
True
T/F Hubs for use with service masts shall be identified for the use.
True
T/F GFPE is designed to operate at settings not greater than 200 A.
False
T/F In general, only service conductors shall be installed in service raceways or service cables.
True
T/F For a panelboard to be suitable for use as service equipment, not more than six main disconnecting means may be provided.
True
T/F Conductors located on the line or supply side of the service point are covered by the NEC®.
False
T/F Service conductors are provided overcurrent protection by overcurrent protective devices that have a rating or setting not higher than the allowable ampacity of the conductor.
True
T/F Overhead service conductors are required to be insulated or covered.
True
T/F A 100 A, 3-wire service is the minimum service disconnecting rating required for any one-family dwelling.
True
T/F Service disconnecting means are permitted to be installed in bathrooms.
False
T/F A minimum service disconnect rating of 30 A is required for service loads that consist of not more than two 2-wire branch circuits.
True
T/F The maximum setting permitted for a GFPE is 1000 A.
False
Where it is impractical to mount service heads above the point of attachment, the service head or gooseneck shall be permitted to be located not more than ___” from the point of attachment, of the overhead service conductors.
24
Individual meter socket enclosures ___ service equipment.
are not considered
The service disconnecting means shall consist of not more than ___ switches or circuit breakers.
six
As a general rule, a service disconnecting means is required to have a rating that is ___ the load to be carried.
equal to or greater than
The minimum size for most overhead service conductors is ___.
both 8 AWG Cu and 6 AWG Al
SE cable shall be supported at intervals not exceeding ___” and within ___” of every service head, gooseneck, or point of connection to a raceway or enclosure.
30; 12
___ listed wiring methods are permitted for the installation of service-entrance conductors in 230.43.
Twenty
A ___ is a group of overhead conductors between the service point and the utility’s electrical supply system.
service drop
The general rule of 230.2 limits each building or structure to ___ service(s).
1
The most common application on the line side of a service disconnecting means is for the connection of ____.
metering equipment
The ___ is the electrical supply, in the form of conductors and equipment, that provides electrical power to the building or structure.
service
The ___ is the overhead conductors between the service point and the utility electric supply system.
service drop
The ___ is the underground service conductors that connect the utility’s electrical distribution system and the service point.
service lateral
The ___ is the point of connection between the local electrical utility company and the premises wiring of the building or structure.
service entrance
___ conductors are the conductors that extend from the service disconnecting means to the service point where the service point is located at the connections made at the service drip loop.
Overhead Service
___ is the written consent of the AHJ.
Special permission
As a general rule, there shall be a(n) ___’ minimum clearance from final grade for all overhead service conductors.
10
The 8’ minimum vertical clearance for overhead service conductors shall be maintained in all directions for a minimum distance of ___’ from the edge of the roof.
3
A(n) ___ is an assembly consisting of a service raceway, guy wires or braces, service head, and any fittings necessary for the support of overhead service conductors.
service mast
Direct-buried conductors emerging from the ground shall be protected from physical damage up to a point which is at least ___’ above finished grade.
8
Type ___ cable is a factory-assembled cable assembly, consisting of one or more conductors with a flame-retardant, moisture-resistant covering, used primarily for services.
SE
___ is all of the necessary equipment to control the supply of electrical power to a building or a structure.
service equipment
Service conductors are permitted to be routed within a building if they are installed under not less than ___” of concrete beneath the building or structure.
2
Type ___ cable is commonly used for 120/240 V single-phase 3-wire services in one-family and multifamily dwellings.
SE
Overhead service conductors shall have a minimum vertical clearance of not less than ___ ft above rooftops.
8
T/F Flexible cords and cables shall be protected against overcurrent in accordance with their ampacities.
True
T/F All conductors installed in electrical distribution systems shall be insulated.
False
T/F THW conductors are permitted to be installed in wet locations.
True
T/F Conductors used for direct burial shall be identified for such use.
True
T/F When used for equipment grounding purposes, only covered or insulated conductors are permitted.
False
T/F Circuit breakers shall clearly indicate whether they are in the open or closed position.
True
T/F Overcurrent protective devices are permitted to be installed in clothes closets if they are located at least 12” from combustible materials.
False
T/F Circuit breakers used as switches for a 120 V fluorescent lighting circuit shall be listed and marked “SWD” or “HID”.
True
T/F Overcurrent devices are permitted in bathrooms.
False
T/F Copper and aluminum conductors shall not be terminated in a manner that causes the dissimilar metals to come in direct contact with each other.
True
T/F Paralleled conductors shall all be the same length.
True
T/F The least potentially damaging overcurrent occurs when there is an overload.
True
T/F The maximum standard rating for a fuse is 5000 A.
False
T/F Type S fuses are designed for circuits not exceeding 100 V.
False
T/F Insulated conductors are the most common conductors installed in electrical systems.
True
Plug fuses have a voltage rating of ___ V between conductors in most applications.
125
Insulated conductors installed in wet locations shall be of a type ___ for the use.
listed
A(n) ___ fuse is a plug fuse that incorporates a screw configuration that is interchangeable with fuses of other ampere ratings.
Edison-Base
No conductor shall be installed in such a manner that the operating temperature of its ___ is exceeded.
insulation
When conductors are run in parallel in separate raceways, the raceways shall have the same ___ characteristics.
electrical
Plug fuses of 15 A and lower are identified by a(n) ___ configuration of the fuse window.
hexagonal
Cartridge fuses with no markings are rated for ___ A.
10000
Circuit breakers that are not marked have an interrupting rating of ___ A.
5000
___ conditions include installations where the conductors are exposed to oils, greases, vapors, etc. that break down the integrity of the conductors’ insulation.
corrosive
Ampacity of feeder taps not over 25’ shall not be less than 1⁄3 of the rating of the overcurrent protective device protecting the ___ conductors.
feeder
In general, fuses and circuit breakers shall not be connected in ___.
parallel
Equipment grounding conductors, in general when they are insulated, shall be provided with an outer finish that is ___ in color.
green
A(n) ___ is a circuit breaker with an intentional delay between the time when the fault or overload is sensed and the time when the CB operates.
inverse-time circuit breaker (ITCB)
In general, insulated grounded conductors (neutral) sizes 6 AWG or smaller shall be identified with an outer finish that is white or ___.
grey
The three basic classifications of insulation ratings are 60°C (140°F), 75°C (167°F), and ___°C (194°F).
90
The next ___ standard size OCPD of 800 A or less is permitted to be used where the OCPD does not correspond to a standard size.
higher
___ is generated when current flows through a conductor.
heat
___ AWG and larger ungrounded conductors installed in a raceway that enters a box shall be protected by an identified insulating fitting.
4
A(n) ___ is any current in excess of that for which the conductor or equipment is rated.
overcurrent
Locations can be classified as either dry, ___, or wet.
damp
T/F Electrical systems are grounded to limit and stabilize voltages to ground.
True
T/F The amount of current that flows in any circuit is determined by the voltage and resistance of the circuit.
True
T/F The grounded conductor shall never be smaller than 101⁄2% of the largest service-entrance conductor.
False
T/F The only choice for the grounding electrode of a separately derived system is the grounded building steel.
False
T/F In general, the EGC may be a bare, covered, or insulated conductor.
True
T/F Aluminum electrodes may be used as grounding electrodes.
False
T/F The grounded conductor is commonly a neutral conductor.
True
T/F In the 2020 NEC, the term “electromagnetic interference” has been changed to the term “noise.”
False
T/F Per 250.102(E), equipment bonding jumpers (EBJs) are required to only be installed inside of a raceway.
False
A wet location is a(n) ___.
installation in concrete slabs contacting earth
underground installation
location saturated with water or other liquids
A damp location is a(n) ___.
partially protected area
area subject to some moisture
Electrical service equipment which shall be bonded together includes ___.
service raceways with GEC
service conductor enclosures
metallic raceways protecting the metallic sheath
The connection of a communications system bonding bar to a GEC must be by a minimum ___ AWG copper conductor.
6
Rod and pipe electrodes can be buried in a trench with a minimum depth of ___’.
2 1/2
A(n) ___ is an electrical conductor that provides a ground-fault current path.
Equipment Grounding Conductor
AC systems of less than ___ V to ground shall be grounded when installed as overhead conductors.
50
___ wiring is basically all interior and exterior wiring installed on the load side of the service point or the source of a separately derived system.
Premises
The ___ conductors extend from the service point to the service disconnecting means.
service
The ___ is the connection between the grounded circuit conductor and the EGC at the service.
main bonding jumper (MBJ)
The ___ connects the EGC and the grounded conductor at the service or separately derived system to the grounding electrode.
grounding electrode conductor (GEC)
The minimum length of a rod or pipe electrode is ___’.
8
The minimum diameter is ___” for stainless steel rods and copper- or zinc-coated steel rods.
5/8
The minimum burial depth required for plate electrodes is ___’ below the surface of the earth.
2 1/2
Metal underground water piping with at least ___’ of piping in direct contact with the earth shall be part of the GES.
10
The minimum size of the EGC is based upon the rating of the ___ ahead of the supplied equipment.
overcurrent protection device(OCPD)
___ is the total opposition of any combination of resistance, inductive reactance, and capacitive reactance offered to the flow of an AC circuit.
Impedance
A(n) ___ is the connection between the ground circuit conductor and the equipment grounding conductor (EGC) at the service.
main bonding jumper (MBJ)
Interior metal wiring piping shall not be used as a part of the GES unless it is the first ___ feet of piping that enters the building.
5
Plate electrodes must have an area of at least ___ sq ft.
2
