National Electrical Installation Standards

Standards as High as Your Own

The National Electrical Code is the bedrock of the electrical construction business.

Do you know all the ins and outs of the Code? NECA and Electrical Contractor magazine are pleased to present their daily online feature, “Code Question of the Day.”

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    Friday, February 22, 2019


    Hi Charlie:

    Thanks for all you do with the code question of the day.

    On a recent job class 2 wiring was installed in PVC conduit to protect the wire in a wet location. Does strapping requirements apply for a conduit system if used for class 2 wiring. It is a bit grey, but it would seem to me it would. 725 does not require adherence to chapter 3 wiring methods for class 2 unless specifically stated.

    Thanks! Mike

  • ?
    Thursday, February 21, 2019


    What is the difference of multi-conductor cable versus a flexible cable? I use multi-conductor cables as feeders via cable tray from distribution board to panelboard. Are multi-conductor cables shall be installed in accordance with flexible cables or cords where cannot be used as substitutes for the fixed wiring of a structure?

    Jessie Santos



    Hey Jessie thanks for your question. The difference between cables and flexible cords is a little blurry especially with the title of Article 400 - Flexible Cords and Flexible Cables. If we look as some of the different types in Table 400.4, some are called cables and some are called cords. But if the product being used is in Table 400.4 - in general it would not be allowed to replace the fixed wiring as stated in 400.12(1).

    The wiring methods allowed in cable trays are in Table 392.10(A). Notice that flexible cables or flexible cords are not included.

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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