National Electrical Installation Standards

Standards as High as Your Own

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  • October 29, 1998

    What is a HACR circuit breaker?
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  • October 30, 1998

    Your customer wants you to install 16 feet of continuous baseboard electric heaters along one wall of his home. What do you do with the receptacles that are located above the heaters?
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  • November 2, 1998

    The maximum fill in wireways or gutters used for sound recording installations is:
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  • November 3, 1998

    You are running a small feeder to serve three, 15 ampere, 120 volt, 2 wire branch circuits. What is the minimum size that the feeder may be?
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  • November 4, 1998

    What is the purpose of the NEC? A To act as a set of design specifications. B To protect property and people from electricity. C To safeguard people and provide good and efficient electric service. D To provide a means for training apprentices.
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  • November 5, 1998

    When taking the endbells off of a single phase induction motor, you will see the centrifugal switch connected in series with A the running winding. B the starting winding. C the rotor. D the starting capacitor.
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  • November 6, 1998

    I was ganging five steel device boxes together and notice the capital letters which are stamped on the built in clamps. The letters were a T on one side and an N on the other. What do they mean?
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  • November 9, 1998

    All receptacle outlets in a house shall be considered at not less than 180 volt-amperes. Is this a true statement?
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  • November 10, 1998

    What are Upper and Lower Explosive Limits?
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  • November 13, 1998

    You have a 50A circuit to feed 2 wall mounted ovens and a counter top unit. What is the smallest ampacity wire which may be ran from the junction box to serve the smallest oven?
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  • November 16, 1998

    What is pressure piling?
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  • November 17, 1998

    I have landed a #4 THHN Cu. circuit that feeds a calculated, noncontinuous load of 83 amperes. After the job was complete, the inspector turned it down because the circuit breaker didn't have a temperature marking on it. I complained that the wire was rated for 95 amperes at 90 degrees C, I was only using it at it's 75 degrees C rating, and besides, all circuit breakers are rated for 90 degrees C. Who was right?
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  • November 18, 1998

    What is the minimum trade size, schedule 80 PVC, conduit that may be used for a run of three 4/0, three 1/0, one 2/0, one #2 all THWN and one 1/0 bare?
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  • November 19, 1998

    You are installing 2 - 200A services for a new home. The services are located in the basement. A You are not required to have a light installed for the services unless the customer wants one. B You are required to have a light installed for the services. C You are not required to have a light installed for the services unless there is some kind of equipment that needs servicing. D The code does not cover this subject, you must use your own discretion.
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  • November 20, 1998

    A feeder supplies 1/3 continuous load and 2/3 noncontinuous load, how do you determine the load on the feeder?
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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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