National Electrical Installation Standards

Standards as High as Your Own

Friday, January 14, 2022


Thank you for this NEC question forum. Always picking up NEC knowledge. My question is about the minimum size equipment grounding conductor for a swimming pool pump motor. The branch circuit is a 15-ampere circuit with a 14 AWG copper conductor. The EGC is a 14 AWG and an inspector said that it needs to be a 12 AWG copper minimum. I don't really agree since the EGC generally does not have to be larger than the circuit conductors as stated in 250.122. I'm I correct, or is the inspector correct?

Thanks for your opinion.

Andy Thorson



Hi Andy,

Thanks for the comments and the question. The inspector has made the correct call on this one. Remember the NEC arrangement and application as governed by Section 90.3. The rules in Chapter 6 can modify the general rules in chapters 1 through 7, sometimes to be more restrictive, as is the case here. Section 680.21(A)(1) which indicates that wiring methods installed in the corrosive environment described in 680.14 shall comply with 680.14(B) or shall be type MC cable listed for that location. Wiring methods installed in these locations shall contain an insulated copper equipment grounding conductor sized in accordance with Table 250.122 but not smaller than 12 AWG. The restrictions are that the EGC must be insulated copper and it must be sized at 12 AWG minimum. The reasons are relatively clear in the first sentence in this provisions which eludes to corrosive environments. The restrictive sizing rule is related to corrosion concerns rather than capacity in this case.

Hope this is useful.  

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.