National Electrical Installation Standards

Standards as High as Your Own

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  • May 12, 2020

    Hello, I have a temporary power pole and the inspector just red tagged my installation and stated that I cannot terminate two grounding electrode conductors to a ground rod using the same, single grounding clamp. Is this a violation of the Code, if so, what section applies. Thanks, Issac Small
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  • May 11, 2020

    Follow up to code question for 4/15/20 : Hello, I have done hundreds of 100- & 200-amp services and in the area served by PECO ( greater Philadelphia area ) they are the ones that insisted that the service disconnect be installed within 10 feet of where service cable enters building. Was told to was due to no overcurrent protection outside of the 13,200-volt primary fuse on utility step down transformer. Tom Grabowsky
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  • May 8, 2020

    Hello NEC Friends, Like all state, thanks for the code of the day. This question is a caveat to today’s question, does the code allow you to say strip out 6/2 NM and use it in a piping system but now use the 75 C column for 65 amps instead of the 60C at 55 amps. Thanks, and best to all during these trying times. Be a good neighbor and citizen.Butch Gosselin
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  • May 7, 2020

    Hello Code Nuts, I have a simple question. What is the minimum size equipment grounding conductor needed for a 15,000-volt, 3-phase, 100-ampere feeder? The system is a single-point grounded system. Each of the cables in the feeder have a copper tape shield that appears to be okay to use for this purpose. Is that acceptable? Any guidance would be very helpful, before we pull the feeder conductors into the duct bank raceways. Jim Tracey
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  • May 6, 2020

    Greetings Code Question Staff, Friday April 10th Question on the 120/240 Delta high-leg system. ANSI standard requires meter bases to use B phase for their operating voltage, which is 120 volts they will not work properly with a 208 to ground B phase. The B phase being the high voltage to ground and being marked orange did not appear in the NEC until 1975 most installations in our area before 1975 have the C phase as the high leg throughout the entire system and is marked red. Jimmy Cagle
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  • 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
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  • May 4, 2020

    Hello Code Question of the Day, I'm installing a outdoor hot tub. How close or far away must the GFI be placed? Richard Mikolajczyk
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  • May 1, 2020

    Hello, What size grounding electrode conductor would be required for a 4 Plex service with 4 100 amp mains? Thanks for any help you might be able to provide. James Sacry
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  • April 30, 2020

    Greetings Code Question of the Day, Here is my question. If a room has a floor drain does it require gfi protection? Alfred Harris
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  • April 29, 2020

    Comment on Code Question of the Day for 04-08-2020. In our fair City of White Plains, NY, we require all "Low Voltage" work to file permits. We do not require licensing. The permit allows us to inspect the install to the various articles and sections of the NEC. We are currently on the 2014 edition with an upgrade to the 2017 on May 12th. Getting back to the requirement, our view is if it is in the NEC, then we have the right to inspect. (Article 110, 800 etc.) Richard Mecca
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  • April 27, 2020

    Comment on Code Question of the Day for 04-08-2020. As always, I appreciate the insight you bring to code clarification. Keep up the good work. Response to this answer provided on 4/9/2020: The answer is no. The NEC does have multiple rules that require qualified persons which is defined in Article 100. Regulating the qualifications and certificates of contractors and electrical workers is beyond the scope of the NEC and is typically handled at the state or local jurisdictional level. The second part of this question is also a jurisdictional issue. Some jurisdictions exempt systems and installations of less than 50 volts from any permit or electrical inspections. The NEC does have rules that pertain to such systems. It's is always a good practice to verify the specific requirements regarding licensing with the local jurisdiction. I would like to add that certain systems that may fall below 50 volts such as: fire alarm systems, fire suppression systems, or fuel monitoring systems, that may fall under the jurisdiction of other codes, such as NFPA 72, and may be under jurisdiction of an authority other than the electrical inspector, such as the Fire Marshall. Depending on the state and local requirements, these types of installations may in fact require state licensure or certification and local permitting and approval for those engaged in that type of work. And as you clearly stated, it's always best to check with your local building department official to verify prior to commencing with the work. Vaughn Langless
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  • April 28, 2020

    Hello, My question is do conductors passing straight through a junction box need to be identified in that box ? Jeff Wright
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  • April 24, 2020

    I read the CQD every day. We've been having a debate about the number of receptacles in a duplex receptacle. I say two because there are two receptacles on a single mounting strap. Others I work with say it's one receptacle because it is on a single mounting strap. Can you clear up this for us? Thanks, Tim Simpson
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  • April 23, 2020

    Dear Code Question, If I have a 3-phase, 3-wire, corner grounded delta system, is there a rule in the Code for identification of the grounded phase? Thanks for any help you can provide. Ed Brink
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  • April 22, 2020

    Comment on the response to the Code Question of the Day on 03-24-2020. Thanks for the code question of the day. Great service. It is my understanding that the ground on any male plug cap is always the largest and longest prong. It goes in first and comes out last, so from eye level and below it should be ground up on the device and above eye level the ground should be down just for ease of use. If the devices are horizontal take your pick to orient the ground left or right. Once again thanks for the code question of the day. Frank Burdo
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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.

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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. 

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