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.”

  • ?
    Tuesday, June 19, 2018


    With the new code for 600.6(a)(1), the disconnect switch must be located at the point where the feeder or branch enters the sign. If I put a disconnect at the back of the sign following this code, I can still put a toggle switch at the front of the sign in any letter or part of the sign?

    Sergio Bertot

  • ?
    Monday, June 18, 2018


    We were having a discussion in our office regarding this particular installation. We have an exterior utility meter socket mounted back to back with an interior electrical service panelboard on a concrete block wall. We have a short EMT conduit nipple connecting the two enclosures through the back of each, compression connectors, completely encased in the concrete block. The means of disconnect and overcurrent protection is in the panelboard. We installed grounding bushings on the threads of each EMT connector within the enclosures. Is there anything in the code that prohibits using EMT in this application?

    Sincerely, Dennis DiPasquo



    Hey Dennis thanks for your question. The use of  EMT as you describe seems acceptable but make sure you comply with the wire bending space rules in 312.6 and 408.55. Sealing the raceway as stated in 300.7 is also necessary.

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.

NECA SAFETY PRODUCTS: NECA publishes valuable electrical safety books and CDs for the industry. Visit to view or purchase NECA safety products.

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