2014 NEC Chapter 2 Wiring and Protection

Pataasin ang iyong marka sa homework at exams ngayon gamit ang Quizwiz!

100

A #6 fixture wire is considered protected by a 20 amp overcurrent device up to _______ feet.

one and two family dwellings

A 125 volt, 15 or 20 amp receptacle shall be for the servicing of heating, air conditioning and refrigeration equipment in _______.

20'

A bare #4 copper conductor installed near the bottom of a concrete footing that is in direct contact with earth may be used as a grounding electrode conductor when the conductor is at least ______ in length.

#6

A bonding bar near the grounding electrode conductor. The bonding bar shall be connected to the grounding electrode with a minimum _______ copper conductor.

15amp

A circuit containing #12 THHN conductors is a ______ rated circuit when protected by a 15amp rated circuit breaker.

grounded

A continuous white or natural gray covering on a conductor shall be used only for the ______ conductor.

receptacle outlet.

A cord connector that is supported by a permanently installed cord pendent shall be considered a ______

25

A feeder tap in a raceway terminating in a single circuit breaker with an ampacity 1/3 of the feeder conductors May extend not over ______ feet.

18

A metal elbow installed underground in a run of nonmetallic conduit is not required to be grounded, it it is isolated by a minimum over of a least _______ inched to any part of the elbow.

Still an acceptable grounding electrode, but it must be supplemented by at least one additional grounding electrode.

A metal underground water pipe, in direct contact with the earth for at least 10 ft, has traditionally been a preferred grounding electrode. For all new construction, a metal underground water pipe is _______.

a clothes closet or bathroom

A panelboard for a residence shall not be installed in ______.

rod, pipe or plate

A single electrode consisting of a _______ which does not have a resistance to ground of 25 ohms or less shall be augmented by one additional electrode.

25

A single grounding electrode is permitted when the resistance to ground does not exceed ______ ohms.

it is supplemented by one or more additional electrodes

A single made electrode with a resistance to ground of more than 25 ohms is a proved as a grounding electrode system if _______.

shall be

AC circuits of less than 50 volts ______ grounded if supplied by a transformer whose supply system exceeds 150 volts to ground.

True

AC circuits of less than 50 volts must be grounded if supplied by a transformer whose supply system exceeds 150 volts to ground.

arc-fault circuit-interrupter

An AFCI is an _______.

shall not

An exothermic or irreversible compression connection to fireproofed structural metal ______ be required to be accessible.

False

An exothermic or irreversible compression connection to fireproofed structural metal is required to be accessible.

permitted

An individual 20 amp circuit is ______ to supply power to a single bathroom in a dwelling for receptacle outlet(s) and other equipment with in the same room.

True

An individual 20 amp circuit is permitted to supply power to a single bathroom in a dwelling for receptacle outlet(s) and other equipment within the same room.

at the point where the conductor receives its supply

An overcurrent device shall be located in a circuit _______.

ungrounded conductor

An overcurrent trio of a circuit shall be connected in series with each ______.

6'

Appliance outlets installed for a specific appliance shall be installed within ______ of the intended location of the appliance.

ground fault protection for personal and at least one 20 amp branch circuit

Bathroom receptacle outlets shall be by _______.

communications, signal and central alarm

Branch circuit in dwelling units shall supply only loads within that dwelling unit or loads associated only with that dwelling unit. Branch circuit required for the purpose of lighting, _______ or other needs for public or common areas shall not be supplied from a dwelling unit panelboard.

not be supplied from a dwelling unit's panelboard

Branch circuit in multifamily dwellings for the purpose of alarm, signal, communications, central lighting, or other needs for public or commercial areas shall _______.

ampere

Circuit breakers must be marked with their _______ rating in a manner that will be durable and visible after installation.

will not be burned or otherwise injured by their operation

Circuit breakers shall be so located or shielded so that persons _______.

clothes closets

Circuit breakers shall not be located in the vicinity of easily ignitable material such as in _______.

to facilitate overcurrent device operation in case of ground faults

Conductive materials enclosing electrical conductors are grounded to _______.

Where installed within a building in a raceway enclosed by 2" of brick and where installed under not less than 20" of concrete beneath a building.

Conductors shall be considered outside a building ______.

6

Each electrode of one grounding system shall not be less than ______ feet from any other electrode of another grounding system.

threadless couplings and connectors made up tight for rigid metal conduit, IMC and EMT and standard locknuts or bushings

Electrical continuity at service equipment shall be assured by ______.

0.06"

Electrodes of nonferrous metal shall be at least ______ in thickness.

2

Feeders containing a common neutral are permitted to supply _______ sets of 4-wire feeders,

#18

Fixture wire shall be considered as protected by 20 amp branch circuit up to 50' if it is a ______ AWG.

10 ft

For hallways of ______ or more in length at least one receptacle outlet shall be required.

attached garage, detached garage with power and basement

For one-family dwelling, at least one receptacle outlet is required in each _______.

115/230

For the purpose of calculating branch-circuit and feeder loads, _______ is NOT a nominal system voltage.

for boat hoist installed indwelling unit locations, for the kitchen dishwasher branch circuit and outdoor in public spaces

GFCI protection is required for personnel ______.

will not

Ground-fault protection that functions to open the service disconnect _______ protect(s) service conductors or the equipment on the line side.

uninsulated, a continuous green, if covered and continuous green with yellow stripe, if covered

Grounding conductors running with circuit conductors may be ______.

25

Grounding of a metal raceway used to protected Romex is required if the raceway is _____ feet or over, or within reach of ground or grounded metal.

isolated and guarded

Handles or levers of circuit breakers, and similar pets which may move suddenly in such a way that persons in the vicinity are likely to be injured by being struck by them, shall be ______.

660 .... 750

Heavy-duty lamp holders shall have a rating not less than _______ watts of the admedium type, and not less than _______ watts of any type.

12

In each kitchen and dinning area a receptacle outlet shall be installed at each counter space _______ inches or wider.

manual override

Lighting outlets can be controlled by occupancy sensors equipped with a _______ that will allow the sensor to function as a wall switch.

below all energized conductors and below all transformers

Locations of lamps for outdoor lighting shall be _______.

readily accessible

Overcurrent device must be _______.

shall not

Overhead service conductors ______ be supported to hardwood trees.

False

Overhead service conductors can be supported to hardwood trees.

only as a replacement item in existing installations

Plug fuses of the Edison-base type shall be used ______.

may be located conveniently for permanent furniture layout

Receptacle installed in a guest room of a motel _______.

white

Receptacles, polarized attachment plugs, and cord connectors for plugs and polarized plugs must have the terminal intended for connection to the grounded conductor identified. Indemnification must be by a metal or metal coating that is substantially ______ in color, or by the word white or the letter "W" located adjacent to the identified terminal.

shall not

Service conductors supplying a building ______ be permitted to pass through the interior of another building or structure.

service head

Services cables must be equipped with a _______ listed for use in a wet location.

True

Supplementary overcurrent devices used in luminaries or appliances are not required to be readily accessible.

according to Table 250.102(C)(1)

Supply bonding jumpers must be sized _______.

Kitchen, pantry, breakfast room and dining room

The National Electrical Code requires at least two small appliance branch circuits for dwellings. Either or both of these two circuits shall be permitted to supply circuits in which of the following four rooms?

orange

The code has assigned the color ______ to the high-leg of a 4-wire delta connected secondary.

limited to storage or storage work areas

The codes defined "unfinished basement" as portions or areas of the basement ______.

gray

The color ______ May have been used in the past as an unguarded conductor. Care should be taken when working on existing systems.

accessible

The connection of a grounding clamp to a electrode shall be _______.

not required to be accessible

The connection of a grounding electrode conductor to a driven ground rod shall be ______.

service-entrance conductors

The de grounding electrode conductor is sized by the rating of the ______.

55amps

The feeder conductor ampacity must not be less than of the service-entrance conductors where the feeder conductors carry the lid supplied by service-entrance conductors with an ampacity of ______ or less.

#10

The frame of an electric range may be grounded by being connected to the grounded conductor of the 120/240v branch circuit, if the grounded conductor is not less than a _______ copper.

8'

The grounding electrode shall be installed such that ______ of length is in contact with the soil.

grounded conductor at the service, grounding electrode conductor and service equipment conductor enclosure

The interior metal water piping system shall be bonded to the _______.

12"

The maximum distance that a SE cable strap can be from the meter base or service head is _______.

15

The maximum overcurrent protection for a #14 copper THHN wire installed in a raceway is ______ amperes.

120 volts

The maximum voltage allowed to supply listed electric-discharge lighting in residences, hotels, motels and similar occupancies is ______.

15 amps

The minimum allowed rating for the service disconnect of a single circuit installation is _______.

18

The minimum clearance for service drops, not exceeding 600 volts, over commercial areas subject to truck traffic is ______ feet.

125

The minimum feeder-circuit conductor size, before the application of any adjustment or correction factor, shall have an allowance ampacity equal to or greater than the noncontinuous load plus _______ percent of the continuous load.

#10

The minimum size of a copper equipment grounding conductor required for equipment connected to a 40 amp circuits _______.

whether it is in the open or closed position

The service disconnecting means shall plainly indicate______.

#6

The smallest aluminum or copper-clad conductor permitted for service-entrance is _______.

service equipment

The terminal bar in a panelboard is connected to the neutral bar only when the panelboard is used as ______.

a master handle and handle ties

Two or three single-pole switch or breakers, capable of individual operations, shall be permitted on multiwire circuits, one pole for each ungrounded conductor, as one multipole disconnect provided they are equipped with ______ to disconnect all conductors of the service with no more than six operations of the hand.

work areas, storages areas and tool storage area

Unfinished basements are defined as portions or areas of basements not intended as habitable rooms and limited to _______.

5 kw

Using the general method of calculation what is the minimum demand for a household clothes dryer?

65

Using the optional method of calculation for a single-dwelling unit, the central space heating would be calculated at ______ percent.

kitchen and bath

Wall-switch controlled receptacles in dwelling units in lieu of lighting outlets are allowed in all habitable rooms except _______.

#4 AWG

What is the MINIMUM size copper grounding conductor required to serve a multisection motor control center equipped with a 300-amp overcurrent device?

#3/0

What size copper grounding electrode conductor is required for a #1500 kcmil copper service conductor?

outside

When determining the load on the "volt-amps per square foot" basis, the floor area shall be computed from the _______ dimensions of the building.

#10

When outside overhead wiring is used, with no messenger cable, the minimum size cooper wire allowed for spans up to 50 feet is _______.

within the first five feet entering the building

When using the interior metal water piping system for the grounding electrode, the connection of the grounding electrode to the water piping system must be made ______.

3

When wiring a dwellings bathroom you shall install at least one receptacle no less than ______ feet of the outside edge of the basin.

branch-circuit

Where a ______ supplies continuous loads or any combination of continuous and noncontinuous, the rating of the overcurrent device shall not be less than the continuous load plus 125% of the continuous load.

grounded

Where a change occurs in the size of the ungrounded conductor, a similar change may be made in the size of the ______ conductor.

largest

Where a single equipment grounding conductor is run with multiple circuits conductors in the same raceway or cable, it shall be sized for the ______ overcurrent device protecting conductors in the raceway or cable.

white with colored stripes (other than green) or distinguished by other suitable means

Where conductors of different systems are installed in the same raceway, one system shall have a neutral having an outer covering of white or natural gray and each other system having a neutral shall have an outer covering of ______.

the extension cord's listing

Where flexible cord is used in listed extension cord sets, the conductor are considered protected against overcurrent when used within______.

underground metallic gas pipe

Which of the following may not be used as a grounding electrode?

at least one switch-controlled lighting outlet

Which of the following shall be installed at or near equipment requiring servicing such as HVAC equipment in attic or crawl spaces?

bonding

Which of the following shall be provided where necessary to assure electrical continuity?

18"

Which using 2 1/2" rigid steel conduit for a through-the-root 120/240 volt service mast, the minimum distance the conduit can protrude above the roof is ______.


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