Electrical Code Final Part 1

where service-entrance condutors are installed in parallel in two or more race ways or cables, the size of the grounded conductor in each raceway or cable shall be based on the total circular mil area of the parallel ungrounded service-entrance conductors in the raceway or cable, sized in accordance with 250.24(C)(1), but not smaller then ______ AWG. A. 1/0 B. 2/0 C. 3/0 D. 4/0

1/0

Grounding electrodes of bare or electrically conductive coated iron or steel plates shall be least ______ in. thick.

1/4

One or more metal in-ground support structure(s) in direct contact with the earth vertically for _______ ft or more, with or without concrete encasement is permitted to be a grounding electrode in accordance with 250.52.

10

A bare 4 AWG copper conductor installed horizontally near the bottom or vertically, and within that portion of a concentrate foundation or footing that is in direct contact with the earth, can be used as a grounding electrode when the conductor is at least _______ ft in length.

20

The grounded conductor brought to service equipment shall be routed with the phase conductors and shall not be smaller then specified in Table _______ when the service-entrance conductors are 1,100 kcmil copper and smaller. A. 250.102(C)(1) B. 250.122 C. 310.16 D. 430.52

250.102(C)(1)

Each tap conductor to a common grounding electrode conductor for multiple separately derived systems shall be sized in accordance with______, based on the derived undergrounded conductors of the separately derived systems.

250.66

When a ground ring is used as a grounding electrode , it shall be installed at a depth below the earth's surface of not less than ______.

30 in.

Where rock bottom is encoutered when driving a ground rod at an angle up to 45 degrees, the electrode can be burred in a trench that is at least ______ deep

30 in.

Grounding electrode conductors ________ AWG and larger that are not exposed to physical damage can be run along the surface of the building construction without metal covering or protection.

6

Grounding rod electrodes shall be installed so that at least ________ of the length is in contact with the soil.

8 ft

For a separate building or structure supplied by a separately derived system when overcurrent protection is provided where the conductors originate, the supply conductors shall contain a(n)______

Equipment grounding conductor

The building or structure grounding electrode system shall be used as the______Electrode for the separately drive system

Grounding

The common grounding electrode conductor installed for multiple separately derived systems shall be permitted to be a______pipe that complies with 250.68(c)(1)

Metal Water

Tap connections to a common grounding electrode conductor for multiple derived systems may be made to a copper or aluminum busbar that is______and sufficient length to accommodate the number of terminations necessary for installation.

Not smaller than 1/4 in. thick x 2in. wide

For a single separately derived system, the grounding electrode conductor connects the grounded conductor of the derived system to the grounding electrode at the same point on the separately derived system where the______is connected.

System Bonding Jumper

Main bonding jumpers and system bonding jumpers shall not be smaller than specified in _________ . A. Table 250.102(C)(1) B. Table 250.122 C. Table 310.15(B)(16) D. Chapter 9, Table 8

Table 250.102(C)(1)

A grounding electrode shall be required if a building or structure is supplied by a feeder.

True

For grounded system, normally nonncurrent-carrying conductive material enclose electrical conductors or equipment shall be connected to earth so as to limit the voltage-to-ground n these material . A. True B. False

True

Grounding electrode conductors that are not subject to physical damage can be run exposed along the surface of the building construction if securely fastened to the surface on which it is carried.

True

Grounding electrode taps from a separately derived system to a common grounding electrode conductor are permitted when a building or structure has multiple separately derived systems, provided the taps terminate at the same point as the system bonding jumper.

True

Temporary currents resulting from abnormal conditions, such as grounding faults, are not considered to be objectionable currents A. True B. False

True

The grounding electrode conductor for a single separately derived system is used to connect the grounded conductor of the derived system to the grounding electrode.

True

The grounding of electrical systems, circuit conductors, surge arresters, surge-protection device and conductive normally noncurrent-carrying metal parts of equipment shall be installed and arranged in a manner that will prevent objectionable current. A. True B. false

True

Two or more grounding electrodes bonded together are considered a single grounding electrode system.

True

When installing auxiliary electrode, the earth shall not be used as an effective ground-fault current path.

True

When supplying a grounded system at a separate building or structure, an equipment grounding conductor shall be run with the supply conductors and connected to the building or structure disconnecting means and to the grounding electrode(s).

True

High-impedance grounded neutral systems shall be permitted for three phase ac systems of 480v to 1000v where______. A. the conditions of maintenance and supervision ensure that only qualified persons service the installation B. ground detectors are installed on the system C. line-to-neutral loads are not served D. all of these

all of the above

If the use of multiple grounding connections result in objectionable current and the requirements of 250.4(A)(5) or (B)(4) are met, it shall be permitted to ______ A. discontinue one or more but not all of such grounding connections B. change the locations of the grounding connections C. interrupt the continuity of the conductor or conductivity path causing objectionable current. D. any of these

any of these

The grounding electrode conductor shall be connected to the grounded service conductor at the ______ A. load end of the service drop B. load end of the service lateral C. service disconnecting means D. any of these

any of these

______ on equipment to be grounded shall be removed from contact surface to ensure good electrical continuity A. paint B. lacquer C. enamel D. any of these

any of these

The connection of the system bonding jumper for a separately derived system. shall be made ________ on the separately derived system from the source to the first system disconnecting means or overcurrent device.

at any single point

Electrically conductive materials that are likely to ______ in underground system shall be connected together and to the supply system grounded equipment in a manner that creates a low-impedance path for ground-fault current that is capable of carrying the maximum fault current likely to be imposed on it. A. become energized B. require service C. be removed D. be coated with paint or non-conductive material

become energized

Where practicable, rod, pipe, and plate electrode shall be installed ______.

below permanent moisture level

For underground systems, noncurrent-carrying conductive materials enclosing electrical conductors or equipment shall be connected to the ______ in a manner that will limit the voltage imposed by lighting or unintentional contact with the higher-voltage lines. A. ground B. earth C. electrical supply source D. none of these

earth

For grounding systems, electrical equipment and electrically conductive material likely to become energized, shall be installed in a manner that creates a low-impedance circuit capable of safety carry the maximum ground-fault current likely to be imposed on it from where a ground fault may occur to the _____ A. ground B. earth C. electrical supply source D. none of these

electrical supply source

For grounding systems, normally concurrent-carrying conductor materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected together and to the ______ to establish an effective ground-fault current path. A. ground B. earth C. electrical supply source D. none of these

electrical supply source

Where a main bonding jumper is screw only, the screw shall be identified with a(n) _______ that shall be visible wit a screw installed. A. silver or white finish B. etched ground symbol C. hexagonal head D. green finish

green finish

Where an alternating-current system operating at 1,000V or less is grounded at any point, the ______ conductor(s) shall be routed with the ungrounded conductors to each service disconnecting means and shall be connected to each disconnecting means grounded conductor(s) terminal or bus. A. ungrounded B. grounded C. grounding D. none of these

grounded

Where the main bonding jumper is installed from the grounded conductor terminal bar to the equipment grounding terminal bar in the service equipment, the ______ conductor is permitted to be connected to the equipment grounding terminal bar. A. grounding B. grounded C. grounding electrode D. none of these

grounding electrode

Buildings or structures supplied by multiple services or feeders shall use the same_______ to the ground enclosures and equipment in or on that building.

grounding electrode system

Bare aluminum or copper-clad aluminum grounding electrode conductors shall not be used where in direct contact with _______ or where subject to corrosive condition.

masonry or earth

Where the supply conductors are larger than 1,100 kcmil copper or 1,750 kcmil aluminum, the main bonding jumper shall have an area that is _______ the area of the largest phase conductor when of the same material. A. at least equal to B. at least 50 percent of C. not less than 12.5 percent of D. not more then 12.5 percent of

not less than 12.5 percent of

If a building or structure is supplied by a feeder from an outdoor separately derived system, a system bonding jumper at both the source and the first disconnecting means shall be permitted if doing so does not establish a _______ path for the grounded conductor.

parallel

Swimming pool structures and structural _______ [680.26(B)(1) and (B)(2)] shall not be used as a grounding electrode.

reinforcing steel

Grounding and bonding connection devices that depend solely on ______ shall not be used. A. pressure connections B. solder C. lugs D. approved clamps

solder

An unspliced _______ that is sized based on the derived phase conductors shall be used to connect the grounded conductor and the supply-side bonding jumper, or the equipment grounding conductor, or both, at a separately derived system.

system bonding jumper

Where the resistance-to-ground of 25 ohms or less is not achieved for a single rod electrode, _________.

the single rod electrode shall be supplemented by one additional electrode

Where a supply-side bonding jumper of the wire type is run with the derived phase conductors from the source of a separately derived system to the first disconnecting means, its shall be sized in accordance with 250.102(C), based on _____.

the size of the derived ungrounded conductor

Where a metal undergrounded water pipe is used as a grounding electrode, the continuity of the grounding path or the bonding connection to he interior piping shall not rely on ________ and similar equipment.

water meters or filtering devises

The sized of the grounding electrode conductor for a building or structure supplied by a feeder shall not be smaller than that identified in______, based on the largest ungrounding supply conductor.

250.66

The common grounding electrode conductor installed for multiple separately derived systems shall not be smaller than______AWG copper when used in a wire-type conductor

3/0

Where the supplemental electrode is a rod, that portions of the bonding jumper that is the sole connection to the supplemental grounding electrode shall not be required to be larger than _______ AWG copper.

6

Concrete encased electrodes of______shall not be required to be part of grounding electrode system where the steel reinforcing bars or rods aren't accessible for use without disturbing the concrete.

Existing Building or Structures

A grounding electrode at a separate building or structure shall be required where one multiwire branch circuit serves the building or structure

False

When a permanently installed generator______, the requirements of 250.30 shall apply.

Is a separately derived System

A grounded electrode conductor, sized in accordance with 250.66, shall be used to connect the equipment grounding conductors, the service-equipment enclosures,and, where the system is grounded, the grounded service conductor to the grounding electrode(s). A. True B. False

True

Alternating-current circuits of less than 50V shall be grounded if supplied by a transformer whose supply system exceeds 150 volts-to-ground. A. True B. False

True

Ungrounded alternating-current systems from 50V to less than 1,000V shall be legibly marked "Caution: Ungrounded System-Operating ______ Volts Between Conductors " at ______ of the system, with sufficient durability to withstand the environment involved. A. the source B. the first disconnect means C. every junction box D. A or B

a and b

_______ shall not be used as grounding electrodes. A. Metal underground gas piping systems B. Aluminum C. Metal well casings D. a and b

a and b

For a separate building or structure supplied by a separately derived system when overcurrent protection is not provided for the supply conductors to the building/structure as permitted by 240.21(c)(4), the installation shall be______in accordance with 250.30(a).

a grounded and a bonded

Where used outside , aluminum or copper-clad aluminum grounding electrode conductors shall not be terminated within ________ in. of the earth. A. 6 B. 12 C. 15 D. 18

all of these

A main bonding jumper shall be a _______ or similar suitable conductor. A. wire B. bus C. screw D. any of these

any of these

Equipment grounding conductors, grounding electrode conductors, and bonding jumpers shall be connected by ______ A. listed pressure connectors B. terminal bars C. exothermic welding D. any of these

any of these

Grounding electrode conductors of wire type shall be _______ . A. solid B. stranded C. insulated or bare D. any of these

any of these

Tap connections to a common grounding electrode conductor to multiple derived systems shall be made at an accessible location by______. A. a connector listed as a grounding bonding equipment B. listed connections to aluminum or copper busbars C. the exothermic welding process D. any of these

any of these

Auxiliary grounding electrodes can be connected to the ________.

equipment grounding conductor

In underground systems, electrical equipment, wiring, and other electrical conductive material likely to become energized shall be installed in a manner that creates a low-impedance circuit from any point on the wiring system to the electrical supply source to facilitate the operation of overcurrent device should a(n)______ fault from a different phase occur on the wring system. A. isolated ground B. second ground C. arc D. high impedance

second ground

A conductor installed on the supply side of a service or within a service equipment enclosure, or for a separately derived system, to ensure the required electrical conductivity between metal parts required to be electrically connected is known as the "_____" A. supply-side bonding jumper B. underground conductor C. electrical supply source D. grounding electrode conductor

supply-side bonding jumper

For underground system, noncurrent-carring conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected together and to the supply system grounded equipment in a manner that create a low-impedance path for ground-fault current that is capable of carrying _____ A. the maximum branch-circuit current B. at least twice the maximum ground-fault current C. the maximum fault current likely to be imposed on it D. the equivalent of the main service rating

the maximum fault current likely to be imposed on it

NFPA 780, Standard for the Installation of Lighting Protection Systems provides information on the installation of ______ for lighting protection system [250.4(A)(1)]. A. grounding B. bonding C. a and b D. none of these

a and b

A ground ring encircling the building or structure can be used as a grounding electrode when the ______. A. ring is in direct contact with the earth B. ring consists of at least 20 ft of bare copper conductor C. bare copper conductor is not smaller than 2 AWG D. all of these

all of these

In order for a metal underground water pipe to be used as a grounding electrode, it shall be in direct contact with the earth for______.

10 ft. or more

Grounding electrodes of the rod type less than _________ in diameter shall be listed.

5/8 in.

Where more than one concrete-encased electrode is present at a building or structure, it shall be permitted to connect to only one of them.

True

______ alternating-current systems operating at 480V shall have ground detectors installed on the system. A. Grounded B. Solidly grounded C. Effective grounding D. Ungrounded

Ungrounded

Grounding electrical systems shall be connected to earth in a manner that will "______" A. limited voltages due to lighting, line surges, or unintentional contact with higher-voltage lines. B. stabilized the voltage-to-grounded during normal operation. C. facilitate overcurrent device operation in case of grounded faults. D. A and B

a and b

In an area served by a separately derived system, the______shall be connected to the grounded conductor of the separately derived system. A. structural steel B. metal piping C. metal building skin D. a or b

a and b

In grounded system, normally noncurrent-carrying electrically conductive materials that are likely to become energized shall be connected ______ in a manner that establishes an effective ground-fault current path. A. together B. to the electrical supply source C. to the closest grounded conductor D. A and B

a and b

A buried iron or steel plate used as a grounding electrode shall expose not less then ________ sq ft of surface area to exterior soil.

2

Current that introduce noise or data errors in electronic equipment are considered objectionable currents in the context of 250.6(d) of the NEC. A. True B. False

False

For ground system, the earth is considered an effective ground-fault current path. A. True B. False

False

The grounding electrode used for grounding strike terminations devises of a lighting protection system can be used as a grounding electrode system for the buildings or structures.

False

The frame of a portable generator shall not be required to be connected to a(n)_______if the generator only supplies equipment mounted on the generator cord and plug connected equipment using receptacles mounted on the generator, or both.

Grounding Electrode

The frame of a vehicle- mounted generator shall not be required to be connected to a(n)______if the generator only supplies equipment mounted on the vehicle or cord and plug connected equipment, using receptacles mounted on the vehicle.

The Grounding Electrode

Alternating-current systems of 50V to 1,000V that supply premises wiring systems shall be grounded where supplied by a three phase, 4-wire, delta-connected system in which the midpoint of one phase winding is used as a circuit conductor. A. True B. False

True

Alternating-current systems of 50V to 1,000V that supply premises wiring systems shall be grounded where the system is three-phase, 4 wire, wye-connected, with the neutral conductor uses as a circuit conductor. A. True B. False

True

An important consideration for limiting imposed voltage on electrical systems is to remember that the bonding and grounding electrode conductors should not be any longer than necessary and unnecessary bends and loops should be avoided. A. True B. False

True

reinforced bars for use as a concrete-encased electrode can be bonded together by the usual steel tie wires or other effective means.

True

Ground clamps and fittings that are exposed to psychical damage shall be enclosed in ______ or equivalent protective covering. A. metal B. wood C. concentrate D. A or B

a or b

A grounded conductor shall not be connected to normally non current-carrying metal parts of the equipment on the _______ side of the bonding jumper of a separately derived system except as otherwise permitted in Article 250.

load

Ungrounded alternating-current systems from 50V to 1,000V or less that are not required to be grounded in accordance with 250.20(b) shall have ______ A. ground detectors installed B. the ground detection sensing equipment connected as close as practicable to where the system receives its supply C. A and B D. ground fault protection for equipment

a and b

An electrode encased by at least 2 in. of concrete, located horizontally near the bottom or vertically and within that portion of the earth, shall be permitted as a grounded electrode when it consists of _______. A. at least 20 ft of 1/2 in. or larger steel reinforcing bars or rods B. at least 20 ft of bare copper conductors of 4 AWG or larger C. a or b D. none of these

a or b

For a grounded system, an unspliced ______ shall be used to connect the equipment grounding conductor(s) and the service disconnect enclosure to the grounded conductor of the system within the enclosure for each service disconnect. A. grounding electrode B. main bonding jumper C. busbar D. insulated copper conductor

main bonding jumper

NFPA 780, Standard for the Instillation of Lighting Protection Systems Provide information on the installation of ______ for lighting protection systems [250.4(B)(1)]. A. grounding B. earth C. A and B D. none of these

a and b

Local metal underground systems or structures such as _______ are permitted to serve as grounding electrode. A. piping systems B. underground tanks C. undergrounded metal well casings that are not bonded to a metal water pipe D. all of these

all of these

The upper end of a ground rod electrode shall be ______ ground level unless the above ground end and the grounding electrode conductor attachment are protected against physical damage. A. above B. flush with C. below D. b or c

b or c

The common grounding electrode conductor installed for multiple separately derived systems shall be permitted to be the metal structure frame of the building or structure that complies with 250.68(c)(2) or is connected to the grounding electrode system by a conductor not smaller than______ A. 3/0 AWG copper B. 250 kcmil aluminum C. a or b D. none of these

a or b

For a separate building or structure supplied by a feeder or branch circuit, the grounded conductor can serve as the ground-fault return path for the building/structure disconnecting means for existing installations made in compliance with previous editions of the Code as long as the installation continues to meet the conditions(s) that______. A. there are no continuous metallic paths between buildings and structures B. grounding-fault protection of equipment is not installed on the supply side of the feeder C. the neutral conductor is sized no smaller than the larger required by 220.61 or 250.122 D. all of these

all of these

For grounding systems, electrical equipment and other electrically conductive material likely to become energized shall be installed in a manner that creates a ______ from any point on the wiring system where a ground fault may occur to the electrical supply source. A. circuit facilitating the operation of the overcurrent device B. low- impedance circuit C. Circuit capable of safety carrying the grounding-fault current likely to be imposed on it D. all of these

all of these

The grounded conductor of an alternating -current system operating at 1,000V or less shall be routed with ungrounded conductors and connected to each disconnecting means grounded conductor terminal or bus, which is then connected to the service disconnecting means via a(n) _______ that is installed between the service neutral conductor and the service disconnecting means enclosed. A. equipment bonding conductor B. main bonding jumper C. grounding electrode D. intersystem bonding terminal

main bonding jumper