National Electrical Installation Standards

Standards as High as Your Own

Tuesday, May 5, 2020


Comment on Friday April 10 Question on the 120/240 Delta high-leg system.

HI CQD folks, thanks for your work. I still enjoy it more than 5 years after retirement! Regarding Friday April 10th question. In San Francisco, high leg is colored purple and on the B leg. Utility requires high leg on C at the meter. As an inspector, I required transitioning from C to B at the service after the meter section. When the NEC started requiring high leg to be orange, we had a dilemma. What is the safest way to proceed? We decided to keep purple to be more consistent with existing systems.

David Green



Hello David,

The NEC has an exception for meters so the high-leg can remain on the C phase as you indicate. See Section 408.3(E) Exception. The NEC does not have a provision for using the color purple for high-leg conductor identification. It sounds like this may be a local electrical code rule or amendment to the national rules, which is the case in some jurisdictions. Not to mention what a utility company may require. Typically, the utility rules will not apply on the load side of the utility meter. Thanks for participating. 

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.