National Electrical Installation Standards

Standards as High as Your Own

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  • December 21, 1998

    If four apartments each have a 100A service, is it required to have 400 ampere service entrance conductors to the meter bank?
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  • May 4, 1999

    A garage is built with a 4/12 pitch on the roof and is under the service drop to the house. How much clearance must the drop have, over the roof? A 18in. B 36in. C 8 ft. D None of the above.
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  • December 23, 1998

    How many chapters does the NEC have? A 7 B 8 C 9 D 10
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  • December 24, 1998

    Isn't it true that service drop conductors must be readily accessible?
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  • December 28, 1998

    How much headroom is required in front of a 100A service located in the basement of a dwelling?
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  • December 29, 1998

    At a service, is a grounding electrode conductor permitted to terminate on an equipment grounding terminal bar, if a main bonding jumper is connected between the neutral busbar and the equipment grounding terminal bar?
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  • December 30, 1998

    Are conductors operating at 277 volts (with 600 volt insulation) permitted to occupy the same raceway or enclosure as conductors operating at 48 volts (with 300 volt insulation)?
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  • January 4, 1999

    When conduit nipples 24 inches in length or less are installed between boxes or enclosures, what is the maximum percentage of permitted conductor fill?
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  • January 5, 1999

    When installing metallic raceway and box systems, contact between dissimilar metals should be avoided where practicable in order to prevent __________ .
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  • January 11, 1999

    Service heads are required to be located _______ the point of attachment. a. above b. no lower than c. adjacent d. none of these
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  • January 12, 1999

    Direct-buried UF cable used with a 24-volt landscape lighting system is required to have how much cover?
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  • January 13, 1999

    Nonmetallic cable trays are required to be made of material which is: a. Fire-resitant b. Corrosion-resistant c. Flame-retardant d. Both b and c
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  • January 14, 1999

    The entity responsible for enforcing the National Electrical Code is: a. Underwriters Laboratories (UL) b. The authority having jurisdiction (AHJ) c. The National Electrical Contractors Association (NECA) d. The National Electrical Manufacturers Assocaition (NEMA)
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  • January 15, 1999

    A pullbox located above a suspended ceiling that has removable panels is considered: a. Concealed b. Accessible c. Recessed d. Readily accessible
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  • May 5, 1999

    I want to install an 8 inch square duct under my surface mounted panelboard that is 4 inches deep. Do I have to fur out the panelboard to meet 110-16? This does not seem reasonable since there is a square duct for circuits coming out of the panelboard.
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ABOUT CQD: NECA’s Code Question of the Day (CQD) is a leading National Electrical Code® forum for NECA and the industry. The CQD generates a lively dialogue and relative practical and Code-based responses to an ever-increasing and interactive audience.

IMPORTANT NOTICE: All answers are based on the latest edition of the National Electrical Code®, unless the question requests a response based on a specific edition. This correspondence is not a formal interpretation of the NEC®. Any responses expressed to the questions are opinions and do not necessarily represent the official position of NECA, NFPA, or any technical committee. In addition, this correspondence is neither intended, nor should it be relied upon, to provide professional consultation or services.

ABOUT CHARLIE: Charles M. Trout, better known as Charlie, was a nationally known NEC® expert and author. He served on several NEC® technical committees and is past chairman of CMP-12. In 2006 Charlie was awarded the prestigious Coggeshall Award for outstanding contributions to the electrical contracting industry, codes and standards development, and technical training. Charlie was also a member of NECA’s Academy of Electrical Contracting. Charlie’s experienced team of industry experts keep the CQD dialogue and discussions active and informative in the spirit of the man himself, as he wanted.

NECA STANDARDS: NECA publishes the National Electrical Installation Standards™ (NEIS™), a series of ANSI-approved performance and quality standards for electrical construction. Visit for more information. NEISÔ can be purchased in three formats: as paper books, on CD, or as electronic downloads.

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