National Electrical Installation Standards

Standards as High as Your Own

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  • June 26, 2020

    Greetings, Thanks for the NEC question forum. Here is the question: If a 1600-ampere parallel feeder is installed in (4) 4-inch PVC conduits, what is the minimum size required for an equipment grounding conductor for the feeder. Does this equipment grounding conductor need to be installed in each of the four PVC conduits? Thanks for your time. Andy Preston
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  • June 25, 2020

    Hello Friends, If I install a circuit to a 3 HP motor and the motor is thermally protected, do I need to provide additional overload protection for the motor? Tim Anderson
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  • June 24, 2020

    Dear Code Question of the Day, I have an installation of 12-2 UF installed for a branch circuit for lights mounted to a pole in the backyard. Can the UF be stapled directly to the pole as it leaves the earth and is run up the pole? Are they rules in the Code that address this? Marty Dutton
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  • June 23, 2020

    Hello, Can a plug-in circuit breaker be installed in a panelboard and be backfed to serve as a main breaker for the Panelboard? Thomas Gentry
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  • June 22, 2020

    Greetings Code Question of the Day, Thought this would be useful information from Underwriters Laboratories (UL). UL Product iQ helps you quickly locate product Certification information. The Product iQ database marries the trusted UL safety certification information with a modern, user-friendly search engine that is relied on by hundreds of thousands of users. The powerful search features within Product iQ will help you maximize your time. Visit this URL for more information: A friendly CQD subscriber
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  • June 19, 2020

    Comment on Code Question of the Day for May 12, 2020: Good morning, This is a follow up on the follow up. I couldn't let his statement go as fact, "Was told to was due to no overcurrent protection outside of the 13,200-volt primary fuse on utility step down transformer, Tom Grabowsky". There is a misconception among many electricians/inspectors/engineers that the fuse in front of the utility transformer will provide protection for the service entrance conductors, IT WILL NOT! The primary fuse is to protect the primary that feeds the transformer but not the transformer. The intent is to keep the lights on for the neighborhood in case of a fault close to or in the transformer. Most electric utilities fuse their transformers such that it takes 300% or more current to open the time delay fuse. In other words, your service entrance conductors will likely burn open before the utility fuse opens. Take care and stay safe, Charlie Eldridge
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  • June 18, 2020

    Comments on CQD 06-08-2020 Comment: The disconnect in question may be just a work switch that is non-fused. Often those switches when dislocated from the base look like they have copper bars installed instead of fuses, and in fact they do. They are a work switch and are non-fused. In the on position the, switch slide, pushes completely into the base , thus making contact. When the slide is withdrawn and turn upside down and reinserted the switch is in the off position and does not fit completely into the base, thus the switch is in the off position. I suspect this is a non-fused work switch. Gregory Arvanitis Comment: Good Day! I read the Code Question of the Day each day and find it a great way to start the day thinking about the Code and how it applies. I believe your response to the CQD from Friday June 5th was not complete and could be misinterpreted. The question asked about copper pipe that had been installed in the fuse holders for the air conditioning unit disconnect at the back of the house. The response would indicate that fuses would always be required to be installed at this location. Article 440, Part II, requires a disconnect to be at the unit, but this disconnect is not required to have overcurrent protection within it. If proper overcurrent protection is being provided from the branch circuit panelboard, then no additional fuses would be required. The one problem I do see with the installation described is using copper pipe which is not in accordance with the listing for the fused disconnect. Manufacturers do provide solid element, non-fused, units, commonly called "slugs" to install where fuses are not required. These slugs are rated for the full ampere rating of the fused switch. Thank you and keep up this excellent forum for the industry. Chuck Mello Comment: A set of fuses might not be required if the circuit is protected by an approved breaker (the big five are all approved) if the condensing unit is approved to be protected by a breaker (they almost all are). Then the question is limited to the fuse holders being listed for the “replacement fuse”. Odds are the copper pipe used has spread the fuse holders beyond their design and won’t hold the correct fuse anyway. Chances are good that’s why the pipe was used in the first place. So, it might be that the only correct solution would be to either replace the fused disconnect with a new fused disconnect and correctly sized fuses or replace the disconnect with a non-fused disconnect and ensure that the breaker is sized correctly. Matthew Hermanson
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  • June 17, 2020

    Code Gurus, I read these daily. Appreciate your work here. My question is about replacement receptacles. Can I replace a non-grounding type receptacle with another non-grounding receptacle. There is an equipment grounding conductor in the outlet box. Also, is a permit required for this type of work? Fred Prichard
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  • June 16, 2020

    Hello Code Warriors, What are the specific codes or standards related to having someone office in an electrical room? I am guessing there are access and clearance issues but I cannot find prohibited language in the 2014 code. This is being applied in a manufacturing plant. Thanks, Jason Wolf
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  • June 15, 2020

    I check the CQD every day. Thanks for the responses. Can I pull a 2 AWG solid copper conductor in a 1-inch EMT? It seems hard to pull through multiple 90-degree elbows in the run. Wondering if the Code has a restriction. Frank Estes
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  • June 12, 2020

    Greetings, I have a 400-amp service to a house with 2 200-amp breakers for disconnects. The 2 200-amp sub panels are in the interior of the house with a concrete slab floor. Does the sub panel feeder have to be in conduit or just buried 18 inches using direct burial service feeders? Ted Stripling
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  • June 11, 2020

    Hello CQD, I have a code question or advise on existing pools that are adding slides, railings, pumps, saltwater, heaters, etc. etc. I just came from a job that had an old existing inground pool that just added a new cement patio all around the pool and one ladder, and 2 low voltage lights, and a new pump. When we got there everything was done and there isn’t any bonding whips to finish bonding the motor and saltwater control box? This is the first time I’ve come across being the last one to the party. There was no bonding installed so, my question is can I add an 8’ ground rod for our work and make sure we are not responsible for the rest of the installation? I know this isn’t recommended but not sure what else to do? I am going to call the local inspector but I’m afraid he’s going to open up a can of worms with this one. Also, do I need to call the pool company? Before I do, what should my intentions be? I’m located in New England. Thank you, Mike O’Neill
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  • June 10, 2020

    Hello and thanks for what you do. When I put my 200-amp service panel in, I put it in on its side horizontal is this wrong? Gordon Determan
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  • June 9, 2020

    Comments to CQD 06/03/2020: Regarding the June 2nd answer, you are correct on the 6" of free conductor but it is measured from where it emerges from its raceway, the wire must be long enough to extend 3 inches outside the opening of the box or the last extension. Thanks for continuing code question of the day I definitely enjoy it. Al Maline Your answer indicated “There are also other NEC requirements for length of free conductor that must be provided, such as in Section 300.14, which is generally 6 inches of free conductor beyond the edge of the box opening.” Comment: Section 300.14 does not require 6 inches beyond the edge of the box opening – that distance is taken from the entry point of the raceway. The required length beyond the edge of the box opening is 3 inches, not 6 inches. Scott Kauzlaric Comment on Answer to CQD 06-03-2020: Not to be picky, just accurate, for your 06/02/20 answer regarding a 4" or 4-11/16" box or extension ring, the 6" of wire past the box opening is incorrect. The 6" measurement starts at the conduit our cable sheath and the minimum at the opening is 3". 300.14 Length of Free Conductors at Outlets, Junctions, and Switch Points. At least 150 mm (6 in.) of free conductor, measured from the point in the box where it emerges from its raceway or cable sheath, shall be left at each outlet, junction, and switch point for splices or the connection of luminaires or devices. Where the opening to an outlet, junction, or switch point is less than 200 mm (8 in.) in any dimension, each conductor shall be long enough to extend at least 75 mm (3 in.) outside the opening. Exception: Conductors that are not spliced or terminated at the outlet, junction, or switch point shall not be required to comply with 300.14. Richard Cressotti
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  • June 8, 2020

    Good Morning Code Friends, Best to you and all involved. Well this is a 2020 NEC question, Art 210.8(F), Outdoor Outlets, so the big discussion with inspectors here in the office, is a well, irrigation pump, or septic lift an outdoor outlet, if so, now for dwellings that have these will require GFCI protection, what do you say. Thanks and Best, Butch Gosselin
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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.

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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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