National Electrical Installation Standards

Standards as High as Your Own

?
Thursday, April 11, 2019

Question:

How many grounding rods are required in Robeson County? Also we have a lot of pig iron In our ground. What is the best method of putting the rod in the ground?

Donna Clark
A

Answer:

Hey Donna thanks for your question. All of the electrodes described in 250.52(A)(1) through (A)(7) must be bonded together to create a grounding electrode system as stated in 250.50. If none are present something needs to be installed and if you are using only ground rods then two need to be installed as stated in 250.53(A)(2). an exception to that section allows one rod if it has a resistance to earth of 25 ohms or less. You need to check with Robeson County officials to see if they have any local requirements.

There are various ground rod installation tools available including manual drivers, adapters for demolition and rotary hammers, or the old method of using a sledge hammer. What is best is determined by how many you need to install and how much you want to spend.

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 NECA-NEIS.org 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 necanet.org/store to view or purchase NECA safety products.

 CONTACT US: To submit a Code question, subscribe, or unsubscribe from this list, please e-mail: codequestion@necanet.org.