National Electrical Installation Standards

Standards as High as Your Own

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  • August 5, 1998

    You are wiring a commercial building which is at grade or pedestrian level, are you required to run a sign circuit?
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  • August 6, 1998

    You are going to install a medium-base screw-shell lampholder at a distance of 14' above a floor and supply it with a 277v (nominal, to ground) circuit, will this be a correct installation?
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  • August 7, 1998

    Your customer wants 4 separate services, one each for general service, electric heat rate, fire pump and emergency lights, will the NEC allow that many? A No. B Yes, if the engineer has it laid out that way. C Yes, if the inspector and the power company says it is OK. D None of the above.
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  • August 8, 1998

    An inspector observes the service drop crossing the roof overhang to a through the roof raceway. After measuring the drop (3 1/2 feet from the edge to the conduit, and 5 1/2 feet along the edge from the point of the drop crossing to even with the conduit), he writes you up for to much of the drop crossing the roof. Was he right? How much of the drop crosses the roof?
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  • August 9, 1998

    In dwelling units and guest rooms of hotels, motels, and similar occupancies; what are the limitations of cord and plug connected loads?
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  • August 10, 1998

    Your customer wants you to install festoon lighting and has set his supports 35 feet apart. What is the minimum size wire that he may use?
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  • August 11, 1998

    How many chapters does the NEC have? A 7 B 8 C 9 D 10
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  • August 12, 1998

    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 18 in B 36 in C 8 ft. D None of the above.
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  • August 13, 1998

    What is the maximum number of service disconnecting means permitted in a service panel (main lug only panel)? A 1 B 2 C 6 D 42
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  • August 14, 1998

    Is it permissible to install 2 wires under the same set-screw in a neutral?
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  • August 15, 1998

    Which of the following meet the requirements for service conductors to be considered to be outside of a building? A Install the conduit in the crawl space. B Install the feeder under the garage floor. C Install the service conduit under a hand lain, brick floor. D Install the feeder under not less than 2 inches of concrete beneath the building.
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  • August 16, 1998

    You are installing 2 service risers on a building that is to be served by 1 service drop. What is the maximum distance apart that the NEC will allow the weatherheads to be located?
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  • August 17, 1998

    In a home, why is it required to provide a means to disconnect all ungrounded conductors simultaneously at the originating panelboard, in the case of a multiwire branch circuit feeding a split-wired receptacle?
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  • August 18, 1998

    If a customer wants to add load to his service, may he do it based on the power company's history of his load?
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  • August 19, 1998

    The service entrance grounded conductor's minimum size has what relationship with the grounding electrode conductor?
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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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