National Electric Code (NEC) Article 250.

Listed FMC can be used as the equipment grounding conductor if the length in any ground return path does not exceed 6 ft and the circuit conductors contained in the conduit are protected by overcurrent devices rated at _____ or less.

20A.

The largest size grounding electrode conductor required is _____ copper.

3/0 AWG.

Interior metal water piping that is electrically continuous with a metal underground water pipe electrode and is located not more than _____ ft from the point of entrance to the building shall be permitted to extend the connection to an electrode(s).

5 ft.

A(An) _____ AWG or larger copper or aluminum grounding electrode conductor exposed to physical damage shall be protected in rigid metal conduit, IMC, Schedule 80 PVC conduit, reinforced thermosetting resin conduit Type XW (RTRC-XW), EMT, or cable armor.

6 AWG.

Each tap conductor to a common grounding electrode conductor for multiple separately derived systems shall be sized in accordance with _____, based on the derived ungrounded conductors of the separately derived system it serves.

Article 250.66.

A grounding electrode conductor shall be permitted to be run to any convenient grounding electrode available in the grounding electrode system where the other electrode(s), if any, is connected by bonding jumpers that are installed in accordance with 250.53(C).

True.

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

True.

When ungrounded circuit conductors are increased in size to account for voltage drop, the wire-type equipment grounding conductor shall be proportionately increased in size according to the increase in size of the ungrounded conductors using their _____.

circular mil area.

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

grounding electrode.

Grounded electrical systems shall be connected to earth in a manner that will _____.

limit voltages due to lightning, line surges, or unintentional contact with higher-voltage lines and stabilize the voltage-to-ground during normal operation.

Equipment grounding conductors, grounding electrode conductors, and bonding jumpers shall be connected by _____.

listed pressure connectors, terminal bars, exothermic welding.

Where an ac system operating at 1,000V or less is grounded at any point, a(an) _____ shall connect the grounded conductor(s) to each service disconnecting means enclosure.

main bonding jumper.

Exposed structural metal interconnected to form a metal building frame that is not intentionally grounded or bonded and is likely to become energized, shall be bonded to the _____.

service equipment enclosure or building disconnecting means, grounded conductor at the service, grounding electrode conductor where of sufficient size.

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.

the source or the first disconnecting means.

In grounded systems, 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.

together and to the electrical supply source.

When sizing grounded conductors for parallel raceways installed for a separately derived ac system and the system bonding jumper is not located at the source, they shall also be installed in parallel and not smaller than _____.

1/0 AWG.

Listed liquid tight flexible metal conduit (LFMC) is acceptable as an equipment grounding conductor when it terminates in listed fittings and is protected by an overcurrent device rated 60A or less for trade sizes 3/8 through 1/2.

False.

The bonding jumper used to bond the metal water piping system shall be installed in accordance with 250.64(A), 250.64(B), and 250.64(E) and the points of attachment of the bonding jumper(s) shall be _____.

accessible.

Where practicable, rod, pipe, and plate electrodes shall be installed _____.

below permanent moisture level.

For the continuity of equipment grounding conductors and attachment in boxes, a connection used for _____ shall be made between the metal box and the equipment grounding conductor(s) in accordance with 250.8.

no other purpose.

If a building or structure is supplied by a service or feeder with _____ or more disconnecting means in separate enclosures, the grounding electrode connections shall be made in accordance with 250.64(D)(1), 250.64(D)(2), or 250.64(D)(3).

two.

Where ungrounded supply conductors are paralleled in two or more raceways or cables, the bonding jumper for each raceway or cable shall be based on the size of the _____ in each raceway or cable.

ungrounded supply conductors.

A rod or pipe electrode shall be installed such that at least _____ of length is in contact with the soil.

8 ft.

If exposed structural metal that is interconnected to form the building frame exists in the area served by the separately derived system, it shall be bonded to the grounded conductor of each separately derived system and each bonding jumper shall be sized in accordance with Table 250.102(C)(1) based on the largest grounded conductor of the service.

False.

Where isolated metal water piping systems are installed in a multiple-occupancy building, the water pipes can be bonded with bonding jumpers sized in accordance with 250.104(D).

False.

A grounding 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).

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 used as a circuit conductor.

True.

Electrical equipment secured to and in _____ contact with a metal rack or structure provided for its support shall be permitted to be considered as being connected to an equipment grounding conductor if the metal rack or structure is connected to an equipment grounding conductor by one of the means indicated in 250.134.

True.

Grounding electrode conductor 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 that the taps terminate at the same point as the system bonding jumper.

True.

Mechanical elements used to terminate a grounding electrode conductor to a grounding electrode shall be accessible.

True.

Two or more common grounding electrodes that are bonded together shall be considered as a single grounding electrode system in this sense.

True.

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

True.

Where circuit conductors are installed in parallel in multiple raceways or cables and include an EGC of the wire type, the equipment grounding conductor shall be installed in parallel in each raceway or cable, sized in compliance with 250.122 based on the overcurrent protective device for the feeder or branch circuit.

True.

Where more than one concrete-encased electrode is present at a building or structure, it shall be permitted to bond only one into the grounding electrode system.

True.

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 _____.

an equipment grounding conductor.

The intersystem bonding termination shall _____.

be accessible for connection and inspection, consist of a set of terminals with the capacity for connection of not less than three intersystem bonding conductors, not interfere with opening the enclosure for a service, building/structure disconnecting means, or metering equipment

Electrical continuity at service equipment, service raceways, and service conductor enclosures shall be ensured by _____.

bonding equipment to the grounded service conductor, connections utilizing threaded couplings on enclosures, if made up wrench tight, other listed bonding devices, such as bonding-type locknuts, bushings, or bushings with bonding jumpers

A listed exposed work cover shall be permitted to be the grounding and bonding means for a surface-mounted metal box if the _____.

device is attached to the cover with at least two fasteners that are permanent (such as a rivet) or have a thread locking or screw or nut locking means, and the cover mounting holes are located on a flat non-raised portion of the cover.

Expansion, expansion-deflection, or deflection fittings and telescoping sections of metal raceways shall be made _____ continuous by equipment bonding jumpers or other means

electrically.

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

1/4 in.

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.

Short sections of metal enclosures or raceways used to provide support or protection of _____ from physical damage shall not be required to be connected to the equipment grounding conductor.

cable assemblies.

Bare or covered aluminum or copper-clad aluminum grounding electrode conductors without an extruded polymeric covering shall not be installed where subject to corrosive conditions or be installed in direct contact with _____.

concrete.

Conductors with insulation or individual covering that is _____, or otherwise identified by this section shall not be used for ungrounded or grounded circuit conductors.

green or green with one or more yellow stripes.

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

water meters or filtering devices.

It shall be permissible to ground meter enclosures immediately adjacent to the service disconnecting means to the _____ circuit conductor on the load side of the service disconnect, if service ground-fault protection is not provided.

grounded.

A rebar-type concrete-encased electrode installed in accordance with 250.52(A)(3) with an additional rebar section extended from its location within the concrete foundation or footing to an accessible location that is not subject to corrosion is permitted for connection of grounding electrode conductors and bonding jumpers providing the rebar _____.

is continuous or effectively connected to the grounding electrode rebar, extension is not in direct contact with the earth without corrosion protection, is not used as a conductor to interconnect the grounding electrode system.

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.

not less than 12 1/2 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(an) _____ path for the grounded conductor.

parallel.

For ungrounded systems, noncurrent-carrying 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 creates a low-impedance path for ground-fault current that is capable of carrying _____.

the maximum fault current likely to be imposed on it.