National Electrical Installation Standards

Standards as High as Your Own

?
Friday, May 25, 2018

Question:

Changing 200 amp panel located 7’ from the meter base, requires an exterior safety switch. The new panel is a main breaker, does the safety switch have to fused or can it be non fused?

Pete McCarthy

A

Answer:

Hey Pete thanks for your question. It is not clear from your example why the exterior safety switch is required. The service disconnecting means must be installed nearest the service conductors entrance point as stated in 230.70(A)(1). If the panelboard main meets those conditions the exterior switch is not required by the NEC. But having a switch on the line side of the panelboard has safety advantages such as being able to completely deenergize everything in the panelboard. If a switch is installed on the supply side of the panelboard, as you describe, it is the service disconnecting means and the service overcurrent device must be part of that switch or immediately adjacent to it as stated in 230.91.

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.