National Electrical Installation Standards

Standards as High as Your Own

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  • September 20, 2019

    In table 9 of the NEC there are 2 values that are used for R for example; I go to #10 wire, then the column for .85pf, then to steel conduit and the R values are 1.1 and 3.6. I have always used the 1.1 for my calculations but what is the top value used for?Arthur Retana
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  • September 19, 2019

    I have an installation where the grounding electrode conductor enclosure consist of both rigid metal conduit and PVC. Should each end of the rigid metal conduit (rigid 90s) be bonded. They have the threaded end where the wire exits the enclosure bonded, but not where the rigid changes to PVC. If so, how? I think I know, I just have a contractor that disagrees and I wanted to get your knowledgeable input to share with the contractor? Thanks,Lee
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  • September 18, 2019

    NEC Article 350.30 (A) Exception No. 4, states following: “Lengths not exceeding 1.8 m (6 ft) from the last point where the raceway is securely fastened for connections within an accessible ceiling to luminaire(s) or other equipment. For the purposes of 350.30, listed LFMC fittings shall be permitted as a means of securement and support.” 1. I am looking for last sentence clarification “For the purposes of 350.30, listed LFMC fittings shall be permitted as a means of securement and support.” Is this only applicable to Exception 4 for the ceiling luminaries or is it applicable for entire 350.30 (A) and (B) article? 2. Exception 4 allows LFMC fittings as means of securement and support. Do the fittings have to be specifically listed for LFMC support or can they just be listed for use with LFMC? Thanks Chris
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  • September 17, 2019

    What is the difference between Article 376.23(A) and 376.23(B)? What is an example or application of 376.23(A)?Thank you for this forum, Paul
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  • September 16, 2019

    Can a 120/240v panel be fed from a 120/208v feeder?Domenic Ladevaia
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  • September 13, 2019

    Is it permitted to use a metal pipe hand rail as a conduit ? I saw this and just cant believe it was allowed to run 120 V 1phase I assume through and existing 1-1/2 inch metal pipe handrail by putting reducing bells on the ends and runing liquitite to each endJeffrey Davis
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  • September 12, 2019

    Do I need to install a 50 amp GFCI breaker for an oven if it's less than 6 feet from the sink?Paul Green
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  • September 11, 2019

    I work at a facility that has miles of chain link fencing, and that fencing has ground rods with a GEC every 50'. Whenever new fencing is built we do the same thing. When I ask why are we grounding fencing that is already 2' in the ground the answer is always, "this is how we've always done it'. Do you have any insight or history on why fence grounding is necessary. Thanks for all your help. Chloe R.
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  • September 10, 2019

    Is the dishwasher in a residential home required to be on its own circuit?Cory Beard
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  • September 9, 2019

    How to splice 500 MCM in the middle of a 200 yd placement. They did a direct burial, this is in Cambodia. The cable was damaged by an excavatorDaniel Henry
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  • September 6, 2019

    Contractor says these grounds do not need to be secured. Sure looks at and XXXX sure a tripping hazard. But . . is it a code violation? Thanks in advance for any light you can shed.Courtney Canfield
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  • September 5, 2019

    I’m wiring some exit signs above drop down ceiling, and I’m under serious pressure to get this project done, so I was wondering could I bent a 90 coming out of the 1/2in KO in the top of the exit sign and extent it about a foot above the ceiling grid then use S/O cable or service cable to wire the exit sign. Then run the S/O cable out of the stub up 90 6ft over to the box to tie into existing power. What does NEC say about this? Thank you,Royce B, Hart Jr
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  • September 4, 2019

    Good morning, I was doing some recent reading on running conduit (EMT) thru wood framing. My question relates to the practice of notching the studs and running the conduit horizontal to the framing and only protecting it at each framing member. Wouldn’t this be considered a violation since the raceway doesn’t maintain 1 1/4 back from the face of the framing. Wouldn’t the raceway/ conduit have to be protected the entire length of the run with a 1/16 inch steel plate if it wasn’t maintaining the setback? - Tim P
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  • September 3, 2019

    What would be the best way to bring power down to assembly benches when Steve Haak
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  • September 2, 2019

    I recently attended an Arc Flash training class and the instructor spent a lot of time giving his personal opinion rather than delivering information. The issue of fuse reducers came up and he said they were illegal since the 2006 code or some such nonsense... he never could tell me why and got really agitated when I asked for more information. I have looked them up on the manufacturers site and they are UL listed and I cant find anything in the code telling me they have been banned. Do you have any information?Travis Crockett
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