National Electrical Installation Standards

Standards as High as Your Own

Friday, January 4, 2019


Re: CQD answer published Wed, December 26, 2018 - Hot Tub Conductor Sizes

Friday’ answer revised hot tubs. As an electrical inspector for 24 years I rarely came across a hot tube that did not require full size conductors in accordance’s with 110- 3b. Typically the enforcement required full size conductors be installed from the tub disconnect to the tub, however   BEWARE I started to see manufacturer recommendations that require all conductors to be full sized from the source. Always read the manual from the manufacturer and have it available for the AHJ.

John Kendall



Hey John thanks for your follow up comment. You make a good additional point. The NEC rules must be followed but any instructions included in the listing or labeling of equipment must also be followed as stated in 110.3(B).

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.

 CONTACT US: To submit a Code question, subscribe, or unsubscribe from this list, please e-mail: