National Electrical Installation Standards

Standards as High as Your Own

Thursday, March 1, 2018


Re: CQD answer published Friday, February 23, 2018 -System Combination AFCI Products

Hey Charlie, thanks for all you do for the industry. Regarding today’s question, article 210.12 allows for different installation methods for AFCI protected circuits to be utilized. The “system combination type” under 210.12(A)(4)d can be complied with utilizing “System Combination” type products that have been evaluated under UL Product Category “AWDT”.  The category and approved products can be viewed thru UL’s ProductSpec website for evaluated products.  You can view the following link for approved products:

Sincerely, Kevin S. Arnold, P.E.



Hey Kevin thank you very much for providing that information and for the kind words. It is great to know that listed system combination-type AFCI's for use with 210.12(A)(4)(d) are now available. The wording in productspec.ul states that the molded case circuit breaker and outlet branch circuit AFCI are packaged together and marked as a system-combination AFCI. A diagram and table show the protection provided.

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: