National Electrical Installation Standards

Standards as High as Your Own

Wednesday, November 15, 2023


Hello Code Friends. My company performed a job for a customer that required installation of a straight pull service with 8 (eight) parallel 4-inch Aluminum Rigid Conduits. Each Conduit had a fill of 32% (5-600MCM). We used a standard size Conduit Body for the pull. The customer stated we are in violation of NEC 314.28 (A)(1). We countered that 314.28(A)(3) allowed the use of a smaller Conduit Body. Who is using the correct interpretation of the Code?  Best, Richard Springer


Hi Richard, thanks for the question. This will depend on the conduit body. You are correct Section 314.28(A)(3) does permit the use of a listed conduit body smaller than the dimensions listed in (A)(1) & (A)(2). However, some conduit bodies have a maximum volume or maximum number of conductors stamped on them, and in many cases that volume is more restrictive than Table 1 or 2 of Chapter 9. This would be considered manufacturer installation instructions and part of the listing of that conduit body, and therefore it would supersede Section 314.28(A)(3).

ABOUT CQD: The Code Question of the Day (CQD) is NECA and ELECTRICAL CONTRACTOR Magazine’s flagship National Electrical Code (NEC®) public forum for the industry, sponsored by EATON. The daily distribution of Q&A generates a lively dialogue and shares relative Code-based practical responses.

SUBMIT YOUR CODE QUESTION: Click here to submit a question to for inclusion in an upcoming edition of the Code Question of the Day, or email

CHARLIE TROUT: 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. Even though Charlie passed away in October of 2015, his work continues in spirit. NECA continues to maintain this question forum for its many subscribers in memory and recognition of all his significant contributions to making the NEC what it is today.

NECA STANDARDS: NECA publishes the National Electrical Installation Standards™ (NEIS™), a series of ANSI-approved performance and quality standards for electrical construction. NEIS can be purchased in the NECA Store in three formats: a printed or  PDF download of a standard or, as an  annual subscription service.

NECA SAFETY PRODUCTS & PUBLICATIONS: NECA produces electrical safety publications and products for the industry including jobsite safety guides, handbooks and resource kits. View a full listing of available resources and products »

IMPORTANT NOTICE: Unless the question requests a response based on a specific edition, all answers are based on the latest edition of NFPA 70® National Electrical Code®.

This correspondence is not a formal interpretation of the NEC® and any responses expressed to the questions are opinions and do not necessarily represent the official position of NECA, NFPA, the NEC Correlating Committee any Code-making panel or other electrical technical committee. In addition, this correspondence is neither intended, nor should it be relied upon, to provide professional consultation or services. 

UPDATE YOUR SUBSCRIPTION PREFERENCES: Subscribe or Unsubscribe from this list.