National Electrical Installation Standards

Standards as High as Your Own

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  • November 24, 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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  • November 25, 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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  • December 1, 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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  • December 2, 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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  • December 3, 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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  • December 4, 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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  • December 7, 1998

    You are placing service equipment in the mechanical room and it is located about 16 feet from the outside wall. Since you are using only 2 sticks of conduit and 1 coupling, the electrical inspector said it was O.K., even though you have no disconnects on the outside. Does this installation meets the requirements of the NEC.
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  • December 8, 1998

    You have installed a new 20 circuit, 100A, 120/240v, 1 phase, 3w service panel, for a new home, and have used all of the available spaces for the circuits. Is this an NEC violation?
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  • December 10, 1998

    How do you determine which is the grounded wire, when wiring a light fixture?
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  • December 11, 1998

    A class B ground-fault circuit-interrupter will trip when the current exceeds what value?
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  • December 14, 1998

    Are you permitted to install a circuit using surface metal raceway (like Wiremold) under a raised floor in a data processing area?
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  • December 15, 1998

    What is the horsepower rating of a standard 125 volt plug (like the one on a lamp cord)?
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  • December 16, 1998

    Your customer is building a house with a mud-room/bathroom (next to the back door) and says he does NOT want a receptacle installed; may you leave it out?
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  • December 17, 1998

    I'm installing a multioutlet assembly along the back of a workbench of an electronics lab, this strip is 12 feet long and has receptacles spaced 3 inches apart. How many VA would you calculate for this strip, if you expect a number of pieces of equipment to be used at the same time? I think it should be 8640 VA (180 VA per receptacle, right?) but my lead says it is only about 1/4 of that, who is right?
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  • December 18, 1998

    Is it permissible to install 2 wires under the same set-screw in a neutral?
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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.

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