National Electrical Installation Standards

Standards as High as Your Own

Monday, April 30, 2018


Hello Charlie, long time reader here. My name is Steve, I'm a Vermont electrician with a question about meter enclosures I'm hoping you can help me with. It would appear there is a dispute in just what the 1/4" knockouts on the bottom of your meters are really for.

Some say it's for the GEC (Grounding Electrode conductor), usually a bare #6 or #4 copper wire to simply run through. Others claim a 'Kenny Clamp' or other sort of listed connector is to be used. What is to code?....are  the  NEC passage(s) below being applicable

Thank you for your time, Steve  Vermont Electrician



Hey Steve thanks for your question. Holes can be provided in enclosures by manufacturers for a variety of purposes including drainage and ventilation. Knockouts are also often provided to be used for ease in installing connectors to enclosures but are not provided in all enclosures. The enclosure manufacturer should be able to tell you what theirs are intended to be used for. There is no specific requirement in the NEC to secure grounding electrode conductors (GEC) to enclosures or to provide a specific bushing or fitting. See 250.64(E)

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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.

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