National Electrical Installation Standards

Standards as High as Your Own

NOTE: If searching by date you must select a full date.
  • April 3, 2017

    Re: CQD answer published Tuesday, March 28, 2017 -Triplex Cables “With this additional definition triplex and quadraplex cables are now specifically allowed but only for overhead service conductors, not feeders.” So, in your statement above, the code does not allowed triplex to be used as a messenger cable for outside branch circuits & feeders? Thanks, Alan Chech
    View Question & Answer

  • March 31, 2017

    Re: CQD answer published Friday, March 24, 2017 - Receptacle GFCI Protection 2 As you indicate a receptacle located in a cabinet below the sink does not require GFCI protection. Unless it’s for a Garbage disposal or dishwasher and IT does require a GFCI Many thanks! William Schell
    View Question & Answer

  • March 30, 2017

    Sir, I have worked in the field for many years and mostly on doing rewires and new home construction or additions to existing homes. In normal practice here in Minnesota we are normally using romex for the wiring system and all of it now is NMB so it has better ratings than the old NM. My usual practice is to wire completely using plastic boxes for inside outlets and for flush mounted outlets for the outside. If that is not possible (in doing old work or adding an outlet for outside) then a metal box is cut into the outside wall or a surface mount wp box is used. Along with the "in use cover" required on almost all outside outlets now days, we are also required to use a GFI or receptacle rated for damp locations. I sometimes try to install the GFI receptacle inside to prevent exposure of an expensive item to the weather at all. But in all cases we are to use a receptacle suited for damp locations. The whole issue should be made plain by code experts or at least a paragraph in the code book which states once and for all if romex is ever allowed to be enclosed in pipe of any kind. There seems to be as many answers to that question as there are inspectors and code experts. Ken Lynes
    View Question & Answer

  • March 29, 2017

    Re: CQD answer published Wednesday, March 22, 2017 - Equipotential Bonding This is pertaining to the question on attaching the equipotential bond to the service panel. In a situation where you lose the service neutral and your pool equipment and everything associated with it is attached, how will it be determined that the neutral doesn't exist? Eric Samek
    View Question & Answer

  • March 28, 2017

    Article 517.31(A) Requirements for The Essential Electrical System in a Healthcare Facility as being comprised of 3 Separate Branches, Life Safety, Critical & Equipment. Then in 517.31(C)(3) Mechanical Protection of the Essential Electrical System. Next line only states the wiring of Life Safety & Critical systems but makes no mention of the Equipment branch following those guidelines. In the past we always ran receptacles, fixtures etc.. on Normal Branch power in MC-HCF cable and all the E.E.S. branch in non-flexible conduit (with exceptions as stated in the article) My Question is 517.31(C)(3) telling me that the Equipment branch circuits do not have to follow the 5 rules/exceptions in 517.31(C)(3) that Life Safety and Critical branch circuit do? Thanks, Kelly Wofford
    View Question & Answer

  • March 27, 2017

    Charlie, Could you give me some examples of permissible and non-permissible applications for Triplex or Quadruplex XLPE cables and any other information with respects to if it is or is not listed and compliance with 310.10? For example, would it be acceptable for use in a temporary wiring application used outside, underground, for direct burial for 480 V three phase feeders? Thanks for providing the service, Derrick Atkins
    View Question & Answer

  • March 24, 2017

    Does a 50a, 208v receptacle in a commercial garage require gfci protection? Jim Dorsey
    View Question & Answer

  • March 23, 2017

    Re: CQD answer published Friday, March 17, 2017 -Receptacle GFCI Protection Would the cabinet meet the criteria of a “floor, wall, ceiling, fixed barrier, or opening” and not require the GFCI protection? Thanks, Zach
    View Question & Answer

  • March 22, 2017

    I’m curious about disconnecting means. Is there a rule that states if a piece of equipment is required to have a disconnect switch rather than accepting the disconnecting means of a cord and plug connection (besides in the cases of accessibility and section 430.109 E & F of 2014 NEC)? I’m not questioning if a piece of equipment should have a disconnecting means, rather if a specific type of disconnecting means is required – and in what situations. Thank you, Cale A. McKoon,
    View Question & Answer

  • March 21, 2017

    Is it "OK" to connect the equipotential bond grid to the main ground buss in the service panel? I say NO, electrician on job site says it must, and inspector passed it!..... Kirk Knapp
    View Question & Answer

  • March 20, 2017

    Charlie, I have a few questions about a fountain pump. According to 680-51(E) the pump cord must be in an enclosure beyond the perimeter of the pond. There are requirements in 680-52(B) for sealing an in-water junction box, so I assume that is the preferred method for making electrical connection to the pump conductors. This makes the connections permanent and difficult to remove the pump in the winter and for service. Is it possible to sleeve the pump conductors through a PVC raceway and make the connections in a junction box above the ground similar to how a swimming pool wet niche fixture is connected. The problem with this method is the 10 foot maximum pump cord length in 680-51(E). The pump proposed has a 20 or 40 foot cord with an attachment plug. This violates 680-56(D) which requires the connections to be permanent if the pump is located in water. Dave R.
    View Question & Answer

  • March 17, 2017

    Re: CQD answer published Friday, March 10, 2017 -Barn Feeder Charlie, in the question about the barn supplied by a feeder you said that two ground rods are needed unless the 25 ohm rule is met. Is that enough or are other electrodes required. Thank you, Taylor
    View Question & Answer

  • March 16, 2017

    Good morning My question relates to receptacles installed for plug in transformers for automatic sinks. Is 210.8(B)(5) measured globally or linearly. Thanks Edward Sim
    View Question & Answer

  • March 15, 2017

    I have a question about outside branch feeders and circuits (art. 225). I work at a large industrial plant and we have several different structures including buildings and equipment skids. My question is concerning the number of supplies to these structures. Section 225.30 states that there can only be one feeder or branch circuit to each structure. Some of the skids have 4160 volt compressors and 480 volt cooling tower fans with 208 volt lights and 120 volt receptacles. If I have 20 of these skids it is not practical to bring 4160 volts to each one and then step it down to these other voltages for each skid. Am I violating the code if I have a one 4160 volt MCC that feeds all of the skids, one 480 volt MCC to feed all of the skids, etc.? Thanks for your help. Larry
    View Question & Answer

  • March 14, 2017

    I have a customer with 3 phase service equipment feeding. A 3 phase sub panel at 240v omitting the third c phase. Is this a violation of NEC Mike Dearing
    View Question & Answer

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.