National Electrical Installation Standards

Standards as High as Your Own

 
?
Monday, August 5, 2019

Question:

Can you use 12ga thhn stranded wire in EMT conduit coming from a 20 amp breaker that feeds a few outlets and flood lights (led)?

What are the spacing dimensions required to secure conduit?

I was getting bids to run another 220v circuit into the laundry room and was wondering why you couldn't run two 220v outlets from one breaker?

I'm not an electrician but I've come across a few questionable things licensed electricians have done so to make me feel better I like to understand the logic behind the installation.

Thanks, Justin
A

Answer:

Hey Justin thanks for your questions.

1) Yes 12 AWG copper stranded conductors can be protected by using a 20 ampere circuit breaker - if the conductor does not have "reduced" ampacity due to adjustment factors or correction factors as stated in 240.4 and 310.15. The conductor would also need to have sufficient ampacity for the load as stated in 210.19.

2) Support spacing distances vary based on the type of conduit, raceway or cable. See the XXX.30 section in the Article in NEC Chapter 3 for maximum spacing distances and the distances for securing at terminations.

3) Branch circuits can supply more than one receptacle outlet if the conductors are suitable for the load, properly protected from overcurrent, and meet any specific requirements depending on what they are installed for as stated in Article 210, 240.4, and 310.15.

Using a Qualified Person, as that term is defined in Article 100, who is also locally licensed is much better and safer than trying to do the work yourself.

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 codequestion@necanet.org

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.