National Electrical Installation Standards

Standards as High as Your Own

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  • July 18, 2017

    Re: CQD answer published Monday, July 3, 2017 -Torqueing Terminations As a follow up to the torque question from last Friday. Please remind your readers for any listed termination that does not have a torque value marked on the item or package, it will require the torque values included in the Informative Annex I of the Code. I have been conducting an informal and non-scientific survey during my travels and have spoken with over 100 different utility installers across the US. It would be good to point out that the use of the nice new battery powered impact wrenches on the market do not meet the requirements of “a calibrated torque tool”. “If it will fit, I use it” is the most common answer. I can confirm Eric’s concerns of the service side installation practices of the meter terminations and I hope the practice ends and does not spread. Sincerely, Lee Herron, Director Specification Engineering, BURNDY
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  • July 17, 2017

    Hey Charlie what is the minimum distance for duplex receptacle from a natural gas valve for residential fireplace? Thanks, Paul L. Ferguson
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  • July 14, 2017

    There is an argument between two engineers in the company on the use of FMC. Question arose when the contractor is trying to serve two vaccuum pumps that are more than 6 feet away. One engineer argues that NEC 348-20(A)(2) limits the use of flexible metal conduit for utilization equipment to less than 6 feet. The other engineer references paragraph 348.10 "Uses Permitted", it states that Flexible Metal Conduit, 1/2" and larger, may be installed in unlimited lengths, provided that an EGC is installed with the circuit conductors. And he also points out that the 6 ft length limitation for FMC is in reference to the U.L. rating which states that FMC in lengths over 6 ft are not approved as acceptable ground fault pathways and therefore when over 6 ft the FMC CANNOT be considered as the circuits equipment ground conductor (EGC). So, when using FMC in "unlimited lengths" as allowed by 348.10, an actual wire conductor EGC must be pulled with the circuit conductors. There have been lots of back and forth on this, and this might be a interpretation issue of the code. My question is: Who do you think is right. and what are your opinions on FMC when installed more than 6ft? Is it allowed under the condition that the engineer referenced? Sincerely, Joe
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  • July 13, 2017

    Re: CQD answer published Friday, July 7, 2017 - In regards to the Code Question of the Day for July 6, 2017, I think the question concerns whether the use of LFMC is permitted where it is coming out of the floor and not conduit fill. It appears the original requirement was to install rigid conduit but since the floor stub out is on an angle, it will not work. If this is installed in an area where subject to physical damage then the use of LFMC is not permitted. (NEC 350.12 ) I would consider anything coming out of the floor subject to physical damage unless behind some other permanent barrier or pipe bollards. Rather than chiseling out around the rigid conduit stub out to correct it, an option may be to concrete encase the LFMC up to the underside of the panel or provide a steel enclosure (panel skirt) or other type of guard. You thoughts? Also thanks for continuing to provide important interpretations of the Code. Regards, Mike Cahill, PE
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  • July 12, 2017

    Is it against code to have multiple outlets at opposite ends of a house on the same circuit? Paul Chiaverini
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  • July 11, 2017

    My question is in regards to applying 220.5, when doing a calculation such as for article 440.22(a) if you have a R.L.A. of 17 amps and multiply by 175% you get 29.75 A. does 220.5 allow me to round up to 30 amps and use a 30 amp over current device. and would I be able to round up in the same manner in 430.52 exception 2 as well. Thank you. Dean Lewis
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  • July 10, 2017

    Good morning & thanks for your work. I have seen a lot of non metallic flex (Carflex) glued into PVC FS boxes and coupled into rigid pvc sch. 40. Is this code compliant? I've been unable to find any reference to it. Have a great day, Jeff
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  • July 7, 2017

    Do electric car chargers require GFCI protection? Wayne Tavares
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  • July 6, 2017

    Can I use 2 1/2 inch sealtite to connect a new panel to the floor stub out? Conduit was installed at an angle in the concrete and rigid will not work. I will be pulling 4--2/0 and 1 #6 from the SES. Rene Carriveau
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  • July 5, 2017

    I work in an older building (1954) and still have some of the original electrical panels located in common hallways. Some of the locks on the panels have broken and replacements aren't available. My question is: Can we put a small padlock on the panels to make them secure from students? Thanks in advance for your help Michael Fegeley
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  • July 4, 2017

    Re: CQD answer published Tuesday, June 27, 2017 -Grounding Electrodes If the metal waterline is used as the primary grounding electrode and the supplemental is a rod type electrode then that supplemental rod type must be supplemented by one other (assuming the first is not 25 ohms or less) water pipe + rod + rod = adequate grounding. (assuming the first is not 25 ohms or less) but, a rod type electrode only, has to be supplemented by just one rod type electrode rod + rod = adequate grounding (assuming the first is not 25 ohms or less) This to me, does not make much sense. I am sure that a water pipe 10 feet long has as much conductivity to ground as any rod type. I do not think this was the intent of the code. Can you give some reason that this was the intent? Thank you, Darren S. Benevento
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  • July 3, 2017

    Re: CQD answer published Friday, June 23, 2017 -Flexible Cords Above Ceilings 1. Ken Lynes brings up a common question in the 06/29/17 QCD. His first reference is to a ceiling mounted projector. However the ceiling projector is mounted below the ceiling tile. A receptacle mounted in the face of the ceiling tile solves this. This solution has been completed many times by many of us. Caddy, B-Line, and others have had the necessary hardware for decades to complete such an installation. The other solution is a retractable projector mount. However these mounts have a receptacle mounted inside the housing. Once again, there is a simple solution that has been available for some time now. His second reference is to a condensate pump located above the ceiling tile. Several condensate pump manufacturers have pumps listed for flexible wiring method connection. Here is an example, not an endorsement, of a product that is listed for flexible wiring methods: http://littlegiant.com/products/hvac/condensate-removal-pumps/vcc-20-p-series-low-profile-for-plenum-applications/ I do remember a mechanical contractor (back on a 2004 project), who only had about six or so inches of drop to reach the side wall about 30 feet away with the condensate line. It was a hard lid ceiling that had a five pounds per square foot rating. Typical hat channel sheet rock ceiling in a mall tenant space to obtain a clean ceiling look. With their poor quality installation of the condensate drain line, the condensate drain line itself had a “smile” to it in no time. (Current mechanical codes now require a minimum of 1% rate of fall for the entire length of the condensate line.) They replaced it with a common corded condensate pump. They saw many of these silver flexible thingys above the ceiling (AKA: MC cables). So they cut one and added a receptacle in a four inch square box. They plugged in the new condensate pump. Now all of these silver thingys powered the various lighting circuits. So around 10:00 pm each night they lost their power. They ignored the float switch conductors on the condensate pump. So from around 10:00 pm until around 8:00 am each night the condensate over-flowed the pump reservoir and onto the hard lid ceiling. Within a few weeks the ceiling developed a “smile” of its own. The store, which opened in August 2004, was closed by October 2004 for repairs and remodeling. Never mind the sprinkler head that was broken during the remodeling process. It took General Growth almost two hours to turn the sprinkler water off at around 250 gpm. When I showed up, I had my swimming trunks in my hand It is simply amazing how much water the particle board constructed cash wrap and back wrap can absorb. This entire comedy of errors started with a lackadaisical attitude about condensate disposal. Condensate pumps with flexible wiring methods are readily available at professional mechanical supply houses across the land. Yes, they do cost a bit more. But the solution has existed for decades. The store really should have had a floor cut and installed a stand pipe in the back wrap wall for a condensate drain above the ceiling. A relatively easy solution in a white box tenant space. Especially considering the mess the store turned into. Remember that building codes really are nice things that help keep us out of court. Matthew Hermanson 2. http://hartell.com/vgn-ext-templating/v/index.jsp?vgnextoid=0da0dca5e40d1410VgnVCM1000001836a50aRCRD&vgnextchannel=945ac379610f8410VgnVCM1000001e14b20aRCRD&vgnextfmt=default FYI Thanks, Alan Chech 3. Hi Charlie, this is something I have come across several times with having a condensation pump above a drop ceiling, the NEC answer is no which is correct, the problem is whoever orders the condensation pump orders the wrong one for that location. They make that pump with no cord on it that must be wired, hence can be wired for the location. Hope this helps. Butch Gosselin
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  • June 30, 2017

    Years ago I watched a Tom Henry study video. He went over torquing and stated it's the first thing he checked when inspecting house fires. I was sold immediately. What bothers me the most is the utility companies landing the line side of my meter with a taped up socket wrench and hammering it till the lugs almost break off the plastic. I've tried torquing breakers, neutral and ground lugs but it takes too much time in the residential world. With all of the different specs for wire sizes I spent more time adjusting the screwdriver than landing the panel. But if you've never torqued a breaker before you would be amazed at how much force it takes to get to the required inch pounds. Keep up the good work! Eric Gooding
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  • June 29, 2017

    Re: CQD answer published Friday, June 23, 2017 -Flexible Cords Above Ceilings Hi, I have followed this topic for a long time. No one seems to have a solution to the problem whether it be about how to power an overhead projector being powered with an attached power cord or the subject of the question on 6/23/2017. Given that there is a need for a condensate pump in a drop ceiling where I assume there is a condensing unit for air conditioning. Now I could remove the existing cord from the pump and direct wire it with an ac cable or greenfield approved for use in that space, but I would be causing another problem by changing the way the pump was constructed with an attachment cord. I would contend that the change would probably void the pump's UL certification; this sort of change is not allowed in many other cases so I feel it is not allowed here in this case either. So the electrician has a dilemma and there still seems to be no clear answer or clear way to accomplish the installation. I question the reason to NOT allow a cord connected device made to be installed in a ceiling to have an outlet installed and be plugged in to it for the device. Why do we create this problem in the first place? Is there no correct way to make this installation known to the contractor installing the air handling system? Yes I know there is the problem, but no one seems to come up with a solution. Ken Lynes
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  • June 28, 2017

    A future conduit is run from the main electrical panel/loadcenter, located in the garage, to the mechanical room in the basement. Is it required to terminate this conduit to a junction box or cap it? Can it remain open ended in the basement until conductors are installed? Thanks in advance. Justin Lett
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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.

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