Questions and Answers
Where Type NM cables pass through cut or drilled slots or holes in metal members, the cable shall be protected by __________.
For locations not specifically identified in Table 300.5, a lesser cover depth than required in Column 5 shall be permitted where specified in the installation instructions of a(n) __________.
Backfill used for underground wiring shall not damage __________ or prevent adequate compaction of fill or contribute to corrosion.
Conduits or raceways through which moisture may contact live parts shall be __________ at either or both ends.
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All conductors of the same circuit shall be __________ unless otherwise specifically permitted in the Code.
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Aluminum raceways, cable trays, cablebus, auxiliary gutters, cable armor, boxes, cable sheathing, cabinets, elbows, couplings, nipples, fittings, supports, and support hardware __________ shall be provided with supplementary corrosion protection.
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Short sections of raceways used for __________ shall not be required to be installed complete between outlet, junction, or splicing points.
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__________ is a nonferrous, nonmagnetic metal that has no heating due to hysteresis heating.
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Wiring methods and cabling systems, listed for use in other spaces used for environmental air (plenums), shall be permitted to be installed in ducts specifically fabricated for environmental air-handling purposes __________.
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Parallel conductors shall have the same __________.
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If cables meeting the requirements in 310.15(B)(3)(4)a through c with more than 20 current-carrying conductors are installed longer than 24 in, without maintaining spacing, are stacked, or are supported on bridle rings, a __________ percent adjustment factor shall be applied.
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For one-family dwellings and the individual dwelling units of two-family and multifamily dwellings, single-phase feeder conductors consisting of __________ ungrounded conductor(s) and the neutral conductor from a 208Y/120 volt system shall be permitted to be sized in accordance with 310.15(B)(7)(1) through (3).
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The service or feeder ratings addressed by 310.15(B)(7) are based on the standard ampacity ratings from 240.6(A).
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The minimum size copper conductor permitted for branch circuits under 600V is __________ AWG.
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Surface-type cabinets, cutout boxes, and meter socket enclosures in damp or wet locations shall be mounted so there is at least __________-in. airspace between the enclosure and the wall or supporting surface.
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In walls constructed of wood or other __________ material, electrical cabinets shall be flush with the finished surface or project therefrom.
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Each cable entering a cutout box __________.
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Nonmetallic boxes can be used with __________.
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Outlet boxes required in 314.27 shall be permitted to support __________ locking support and mounting receptacles used in combination with compatible attachment fittings.
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Handhole enclosure covers shall require the use of tools to open, or they shall weigh over __________ lb.
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At Type AC cable terminations, a(n) __________ shall be provided.
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Type AC cable installed in thermal insulation shall have conductors that are rated at 90°C. The ampacity of the cable in this application shall not exceed that of a __________ rated conductor.
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Type MC cable shall be listed and fittings used for connecting Type MC cable to boxes, cabinets, or other equipment shall __________.
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Type NM and Type NMC cables shall be permitted in __________, except as prohibited in 334.12.
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Type TC cable shall not be __________.
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Type UF cable can be used in commercial garages.
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IMC, elbows, couplings, and fittings shall be permitted to be installed in concrete, in direct contact with the earth, or in areas subject to severe corrosive influences where protected by corrosion protection __________ for the condition.
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IMC shall be secured __________.
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Galvanized steel, stainless steel, and red brass RMC elbows, couplings, and fittings shall be permitted to be installed in concrete, in direct contact with the earth, or in areas subject to severe corrosive influences when protected by __________ approved for the condition.
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A run of RMC shall not contain more than the equivalent of __________ quarter bend(s) between pull points such as conduit bodies and boxes.
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Horizontal runs of RMC supported by openings through __________ at intervals not exceeding 10 ft and securely fastened within 3 ft of termination points shall be permitted.
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Threadless couplings and connectors used with RMC in wet locations shall be __________.
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Running threads shall not be used on RMC for connection at __________.
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FMC shall be supported and secured __________.
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In an FMC installation, __________ connectors shall not be concealed.
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For the purposes of 350.30, __________ LFMC fittings shall be permitted as a means of securement and support.
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Where flexibility is __________ liquidtight flexible metal conduit shall be permitted to be used as an equipment grounding conductor when installed in accordance with 250.118(6).
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PVC conduit shall be permitted for exposed work where subject to physical damage if identified for such use.
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The cut ends of PVC conduit shall be trimmed to remove the burrs and rough edges.
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EMT couplings and connectors shall be made up __________.
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ENT is composed of a material resistant to moisture and chemical atmospheres, and is __________.
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ENT shall not be used where exposed to the direct rays of the sun, unless identified as __________.
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Bushings or adapters shall be provided at ENT terminations to protect the conductors from abrasion, unless the box, fitting, or enclosure design provides equivalent protection.
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Metal wireways are sheet metal troughs with __________ for housing and protecting electric conductors and cable.
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Power distribution blocks installed in metal wireways on the line side of the service equipment shall be marked 'suitable for use on the line side of service equipment' or equivalent.
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A multioutlet assembly can be installed in __________.
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The maximum number of conductors permitted in any surface metal raceway shall be __________.
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A cable tray is a unit or assembly of units or sections and associated fittings forming a __________ system used to securely fasten or support cables and raceways.
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Cable trays shall be __________ except as permitted by 392.18(D).
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In industrial facilities where conditions of maintenance and supervision ensure that only qualified persons will service the installation, cable tray systems can be used to support __________.
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Study Notes
Wiring Methods and Materials
- NM cables passing through metal members must be protected by listed bushings or grommets prior to cable installation to cover metal edges.
- A lesser cover depth than specified is permitted for listed low-voltage lighting systems.
- Backfill for underground wiring must not damage raceways, cables, or conductors and should allow for adequate compaction.
- Conduits facing moisture must be sealed or plugged at either end to avoid moisture contact with live parts.
- All conductors of the same circuit should be in the same raceway or cable unless otherwise permitted.
- Aluminum raceways and fittings in contact with the earth require supplementary corrosion protection.
- Short raceway sections can be used to protect cables from physical damage without a complete installation between attachment points.
- Aluminum is a nonferrous, nonmagnetic metal with no hysteresis heating effects.
- Wiring methods for environmental air spaces can be installed in specific ducts if they connect to related equipment or do not exceed four feet in total length.
- Parallel conductors must share the same length, material, and size in circular mil area.
- For installations of more than 20 current-carrying conductors, if spaced improperly or stacked, a 60% adjustment factor must be applied.
- Two ungrounded conductors and a neutral conductor are permissible for single-phase feeders in dwellings, sized as per certain ampacity ratings.
- Minimum size for branch circuit copper conductors under 600V is 14 AWG.
- Cabinets in damp/wet locations must maintain 1/4-inch airspace from walls or surfaces.
- Electrical cabinets must be flush or project from combustible material surfaces.
- Each cable entering a cutout box must be secured to the box.
- Nonmetallic boxes can be used with nonmetallic sheaths, raceways, and flexible cords.
- Listed outlet boxes can support locking support and mounting receptacles with compatible fittings.
- Handhole covers must weigh over 100 lbs or require tools for opening.
- Type AC cable terminations require fittings that protect conductors from abrasion and insulating bushings.
- Type AC cable in thermal insulation is limited to ampacity of a 60°C rated conductor.
- Type MC cable fittings must be listed for specific use with boxes and equipment.
- Type NM and NMC cables are permitted in specific dwelling types unless otherwise prohibited.
- Type TC cable cannot be installed in high-risk areas exposed to damage, outside of conduit, or under direct sunlight unless sunlight-resistant.
- Type UF cable usage is not permissible in commercial garages.
- IMC components need corrosion protection when installed in conditions prone to severe corrosion.
- IMC should be secured within 3 ft of conduit terminations or junctions.
- Approved corrosion protection permits installation of galvanized steel and brass RMC in harsh conditions.
- RMC cannot contain more than four quarter bends between pull points.
- RMC must be supported by framing members at intervals not exceeding 10 ft.
- Wet location connectors for RMC must be listed for such use.
- Running threads are not allowed at couplings for RMC.
- FMC installation must secure at intervals not exceeding 4.5 ft.
- Angle connectors in FMC installations must remain visible and not concealed.
- Listed LFMC fittings are permitted for securement in specific applications requiring flexibility.
- PVC conduit is approved for exposed work but must be identified for physical damage resistance.
- Cut ends of PVC should be smoothed to remove burrs and rough edges.
- EMT couplings and connectors must be made tight to ensure safety and integrity.
- ENT is moisture and chemical resistant, ensuring flame retardancy.
- ENT requires bushings or adapters at terminations for conductor protection.
- Metal wireways utilize removable or hinged covers for conductor protection.
- Power distribution blocks in metal wireways must be marked for line-side suitability.
- Multioutlet assemblies are limited to installation in dry locations.
- Surface metal raceways can only contain a number of conductors equal to their design capacity.
- Cable trays are structural systems meant to support and secure cables and raceways.
- Cable trays can be either exposed or accessible, under certain conditions.
- In industrial settings with proper supervision, cable tray systems may support various installations like raceways and conduit bodies.
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Description
Test your knowledge on wiring methods and materials as outlined in NEC Chapter 3. This quiz features key concepts and applications essential for electrical safety and installation practices. Perfect for students and professionals looking to enhance their understanding of the National Electrical Code.
