This article was posted 04/18/2006 and is most likely outdated.

Taking 110.3(B) too far?
 

 
Topic - NEC
Subject - Taking 110.3(B) too far?

April 18, 2006  

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Taking 110.3(B) too far?

Considering our very litigious society, installation of listed products is becoming more and more common, even when the NEC may not require listing of a particular product, such as for a general use luminaire.  When installing listed products, section 110.3(B) is required to be complied with.  To paraphrase section 110.3(B), listed products must be installed within the parameters of the listing and labeling instructions.  While that sounds very easy to comply with, many times this can become a very difficult thing to address. 

For example, what about the wire nut type of connectors that come with some luminaires?  Since these come with the listed product, and are shown in the instructions, does this mean that we must use them?  What if they are too small?  What if they are too big?  What if you just hate the fact that they are cheaper and perhaps less reliable than the connectors you like to use? Does throwing them away and using your own (listed) wire nuts then void the listing of the luminaire? 

I should hope not, but as silly as this sounds, this is the literal interpretation of some installers and inspectors.  How far do we go with 110.3(B)?  Sometimes I think we take it too far.  Let me give you an example of a question that was brought up at the Mike Holt Code Forum:

Question: “I am presently working as a journeyman electrician on the remodeling of an exhibit/shop/promotion. On Thursday the job foreman displayed concern that some pendant light fixtures had been installed and the 1" X 8-32 machine screws provided by the manufacturer had not been used to attach the fixture plate to the 4" to round plaster ring mounted on the outlet box. Instead (in most instances), we had used 1/2" X 8-32 machine screws (industry standard, and produced by a major manufacturer) to secure the fixture plate to the plaster ring. In every instance there was direct metal to metal contact between the fixture plate and plaster ring, and at least 1/4" of the machine screw was visible inside of the box. However, the foreman claimed that since the 1" X 8-32 machine screws provided by the fixture manufacturer was not used, this was a potential violation of the UL listing of the light fixture and potentially exposes the electrical contractor (and individual electrician) to increased liability.

Now, of course, there was no question that unauthorized "field alterations" to fixtures, devices or other equipment will, in fact, violate the provisions of that items UL listing. For instance, failing to use the provided light fixture installation plate will render the UL listing invalid because such plates are necessary for heat dissipation, grounding and/or other purposes. But, the specific issue here was whether or not the act of not using the factory provided screws was a violation. Have you any specific knowledge or comments concerning this issue.”

Now I personally think that this is an example of getting much too excited about the minutia of the entire job, and as an inspector myself, I personally think there are much more important things to worry about.  However, this seems to be a legitimate question considering the literal language of 110.3(B). Here is Underwriters Laboratories (UL) response to this question:

“The length of the screws packaged with the luminaire takes into account that there are installations that involve different spacings between the luminaire and the junction box. Also, it permits the manufacturer to use one set of screws for many different luminaire models, thereby reducing their inventory. The clause in UL 1598 that addresses the length of luminaire mounting screws is 10.2.1. It specifies that the length of the screw has to be at least 1/2 in. longer than the distances between the mounting surface and the luminaire surface with the screw hole.

You have elected to replace those screws with shorter screws of the same diameter and thread pitch. The use of those shorter screws that protrude past the other side of the threaded hole by at least 1/4 inch are sufficient to secure the luminaire. This does not void the UL Listing.”

As you can see from UL’s response, a small alteration, such as using a different screw, is probably nothing to worry about.

Ryan Jackson
Electrical Code Consultant,
Mike Holt Enterprises, Inc.

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Comments
  • In the world of electrical construction we all look at things from a money point of view. If the screws provided were 1" and free of charge why would I want to use anthying else.

    PS. How can I ask UL a question and get a responce

    Joseph Gauthier
    Reply to this comment

  • You could have cut the included screws shorter and avoided any question. They are the same screws, albeit somewhat shorter.

    Dave Parks
    Reply to this comment

  • Any modifications you make are potentially eleiminate or at least rteduce the manufacturer's liability and increases the installers.

    Laszlo Weress
    Reply to this comment

  • UL may be reached on their website. They also have telephone numbers available listed by location and section supervisor. Contact any AHJ for these.

    Jim Yancey-NCDOI

    Jim Yancey
    Reply to this comment

  • As a chief inspector, I am constantly irritated that we even need to discuss/debate these issues. Although, nobody will admit it, daily, hundreds of life safety violations are being cerrtified by unqualified, uncertified, incompetent inspectors (improper sevice grounding, improper generator grounding,etc). A good competent inspector can always find some minor code violation on any given installation. However, the good inspector wants to leave an inspection assured that the inspection, to the best of his/her knowledge, there were no life safety violations. Sure, there are small detail issues that could effect life safety, but the knowledgeable inspectors know where the line is crossed. If we see an increase of litigation in the future ( I for one strongly believe we will), it will be directed at inspections by incompetent inspectors. This, the lawyers will soon learn, is an open "goldmine" for litigation. And, it may be just what the industry needs.

    Thank you, Rich

    Rich
    Reply to this comment

  • Hear, hear!!!!!!!!

    Laszlo Weress
    Reply to this comment

  • UL does not list or test fasteners. this is a pointless discussion

    Bob
    Reply to this comment

  • As you can see from UL’s response, a small alteration, such as using a different screw, is probably nothing to worry about.

    My boss recommends rock screws. What do you think about that? Small change or violation?

    greg L
    Reply to this comment

  • You go Ryan!

    Bob
    Reply to this comment

  • Unfortunately, we live in a land where suing is becoming a career. 110.3(B) is a warning as to what is on the horizon. If we are begining to pick this article apart word for word, there will be greater arguments than this to come. Are we going to have to have legal counsel on staff to make sure everyone understands that they need to go by the UL listing as well? Should we have a UL exam? Are we creating a society where common sense is not necessary because we have instructions so people do not have to think?

    Mike Sullivan
    Reply to this comment

  • Minutia! Wow, I'm glad my inspector is not that intense! However, I am impressed that he/she had the brains to see that little detail. 99% of the inspectors I work with think that if you staple the wire 10" from the box you are OK. I might be against the grain here but I think inspectors make our product better and safer. I think I will look more closely at every little thing just to be sure that they/them won't find even the tiniest glitch.

    Walter Sydoriak
    Reply to this comment

  • What gets me is that ordinary wirenuts are not listed for use in wet, damp, outdoor, or corrosive locations yet manufacturers use them in outdoor rated fixture. Ideal has written right on the box: "For use in dry locations only." This past October I was shocked by classic wirenuts that were in an outdoor box on a 480 volt circuit because the steel spring had rusted and split the insulation shell.

    As for fixture screws, I often buy longer screws, cut the heads off, and then install them as studs coming out of the box. This makes installing a typically outdoor fixture easier because I can put the fixture over the studs and put on the nuts just like with modern automobile tires. It also makes cross-threading the screws less likely. If you have ever tried to change the tire on a 1960s Volkswagen Beetle you know that lug bolts rather than lug studs and nuts area very inconvenient way to mount a tire.

    Mike Cole mc5w at earthlink dot net

    Michael R. Cole
    Reply to this comment

  • If you delve into the exciting world of screws from a mechanical engineering perspective, you learn that for most typical screw thread designs and applications, the first 3-4 threads closest to the surface hold 90-95% of the load, and the rest provide negligible added support (the other 5-10%). Those extra threads on longer bolts aren't doing much for you. As the screw is loaded, the topmost threads stretch and bind on the threads of the hole, taking the load away from those threads below, which can and do relax. If the screw breaks, it will likely shear at the stressed section, leaving the rest of the screw behind.

    In this day and age, yes you do need a lawyer at every turn. A friend decided to sign up to be a Boy Scout leader when his sons reached that age. A retired Naval Officer, he said the paperwork and background checking was more intense than his Top Secret clearance. When we were kids, it was just a handshake and thanks for volunteering Dad.

    What has the world come to?

    Matt
    Reply to this comment

  • I think we as Electricians have quit doing our job. The code was written to help us not make our lives miserable. We have the ability to use common sense and know what is a safe installation. Somthings are better left to a true tradsman and not the individual who has taken a tech writing course and trying to decide what should or should not be used. A true electrician will be responsible for his installation and will under stand what can be subsituted correctly per the NEC.

    James V Campbell
    Reply to this comment

  • I usually use screws and wire nut that do not come with the fixture or device where it appears the supplied misc. hardware looks like junk which it usually does. If an inspector has a problem with it, I would think the inspector either can not find anything wrong with the overall installation or he (or she) is trying to show how booksmart they are. Do not think I am "attacking" inspectors for I m one myself. I'll take bulletproof over junk any day and it can be done without violating 110.3(b)

    FYI for thoes who are interested, www.osha.gov has actully good information and training about using "Listed or Approved" products and how to apply them to you work and to the Law. OSHA calls them Natationally Reconized Testing Labratories (NRTL's). UL.com is another excellent source of info and training as well.

    OSHA info: http://www.osha.gov/dts/otpca/nrtl/index.html

    UL info : www.ul.com

    -Sparky

    "Good judgment comes from experience. Experience comes from bad bad judgment

    Sparky
    Reply to this comment

  • it sounds like you work for a real pain in the butt

    rick
    Reply to this comment

  • As a code consultant here at NCDOI I see this a lot. I believe this began years ago in the 80s when most states including us started allowing inspectors to be certified who had little or no experience in the electrical field.

    Over the years I have seen this get even worst ,now many of them not only have no experience in the electrical field, they have no experience in construction at all.

    I personally would like to see us go back to and require that all inspectors have a minimum amount of experience in the electrical field before becoming an inspector.

    I do not understand how you can properly apply the NEC when you do not know the intent and do not understand the application. I believe the public deserves more.

    Some of the appeals we get here at the state level border on the ridiculous and waste everyone's time.

    Jim Yancey-NCDOI Code Consutant

    Jim Yancey
    Reply to this comment

  • Perhaps the NEC should contain an FPN that allows the use of common sense? That is what ran through my mind while reading it.

    Remember, the code is not an instruction manual on how to assemble and build but rather a set of minimum standards that will from time to time require interpretation and common sense.

    Rick Broderick
    Reply to this comment

  • Mike, I have enjoyed your newsletters and fourms for several years now and have always enjoyed your answers.... I still await your answer on this question. Not the one about the leinth of the screws or the one about upgrading the wire nuts.....

    I have NEVER just followed the NEC, My standards are MUCH higher than that..." To Code" simply means the bare minimum and I have always took liberal advantage of the fact that "Better is always better"

    No inspector has ever said," You know son, you could have gotten away with xxxx"

    So the questions still stands... is the UL requirement to be followed EXACTLY or as a basic minimum requirement like the nec.???

    On a side note, I have never had an inspector look at the packing slip/list of a light fixture and note that the screws were the wrong size or that the nuts were not the org. nuts that came in the box...Just my luck this will all change tomarrow... knock on wire...( Doh!!! that doesn't work, does it ???)

    RandyO
    Reply to this comment

  • I use one and half times fixture thickness for screw mounting on sufficient to secure the luminaire.

    Larry Trowbridge
    Reply to this comment

  • I would agree with the 1/4 inch protrusion as sufficient attachment.

    Kip Kennedy
    Reply to this comment

  • "Common sense" implies a quality that we all share. Nothing is further from reality. What is plainly evident to one person can be an illogical decision to others. That division widens more when education and profession gets involved. A non-technical lawyer may find no logic in the decision made by an experienced journeyman, yet an engineer would see the logic in the same decision, be it the correct one or not. Be that as it may, if there are clear instruction by the manufacturer on an installation process, they better be followed. I am always amazed by the length to which some installers go in not following the drawings, just out of their inability to understand why the installation needs to be just so. They may feel uncomfortable to install something differently that they "used to" and commonly resent asking questions. ("Men never ask for directions")

    Laszlo Weress
    Reply to this comment

  • In a search for the correct connecting device (plug) to be applied to a product, I was led on a circuitous (no pun intended) path in the NEC to an "exception" which allowed the use of a particular device provided the equipment utilizing this device was "listed". I found the term "listed" to be synonymous with "U.L." whereby a rating, in this case horsepower, by NEMA could be overwritten by U.L. This appears to me to be a case where the intent of a rule: to limit inrush current burden on a device, could be superseded without explanation by a "for profit" organization.

    Mark Prairie
    Reply to this comment

  • This is an interesting scenario. While it may be true that a shorter screw can secure this fixture in place of the mfg's supplied screw with sufficient threads , another issue to consider is are the factory screws of a different percentage thread designed to provide more metal-to-metal contact. Thanks.

    Mike McDonald
    Reply to this comment


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