NEC 250 pt ||

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

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 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.

20 amps

The largest size grounding electrode conductor required is _____ copper.

3/0 awg (250.66 table)

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 ( 250.68C{1})

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

8

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 ( 250.104)

The intersystem bonding termination shall _____.

All of these: ( 250.94A)

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 _____.

All of these: 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(250.68C{3})

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 _____.

Any of these

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

Any of these: (250.92)

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 (250.86 Exc no. 2)

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.

Electrical

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

Electricity ( 250.98)

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

Listed liquidtight 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

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

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

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

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

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

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

True( 250.68A)

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

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

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 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


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