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| Subject - AFCIs and old wiring. | |
| Energreen |
Hi All, I'm working on an old house (service upgrade) that has one branch circuit with 12/2 (cloth covered) and NO ground wire. This circuit feeds bedroom receptacle outlets. I think I need to provide an AFCI circuit breaker. However, I'm under the impression that AFCIs don't work unless there's a ground wire. I'm hoping someone will help me out by answering some questions and offering some advice. 1) Do AFCIs work when there's no circuit ground conductor? 2) What would you do in this situation? Thank You very much! EG |
| kbsparky | 1) AFI's should work without an equipment ground conductor. They are designed to sense certain waveforms that are generated by arcing within or across the circuit conductors, and trip out when a certain level of those are sensed. 2) Unless the local inspector-critter requires it, I would not install them on existing circuits. Not for a service upgrade, where you are not modifying any of the interior wiring. Some may disagree with me on this point, but my feeling is those AFI's have not been on the market long enough for me to feel good about installing them anywhere besides where I am required to use them. There have been too many failures and recalls for my blood  I have had to replace too many of them in recent months. 
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| Energreen | Thank you KB Sparky. You have confirmed what I've been thinking about the equipment ground conductor, or lack of one. From some reading I did on a different part of this forum I learned that among other types, AFCIs detect an arc to ground... but I realize now that there must be a ground present in order for that arcing to occur! I also find your insights on existing circuits very helpful. I'll keep those in mind. Thanks again, EG |
| blackrd | I believe if your AHJ has adopted 05 NEC, afci are required on panel change outs, as well as proper panel labeling, etc. |
| Geoff | quote: blackrd, do you happen to know the code reference# that requires afci's? |
| Wirenutz | quote: "Less Effective" was my official response from Mr. Dave Dini (check cmp-2 past memebers) when i wrote him @ Ul thinking i had found the answer to all the K&T around here quote: Not assume any personal liability as a contractor for majic widgets that have wishy washy specs the manufactures dang well know we haven't the collective grey matter to concieve of quote: My state contacted Mr. Jeff Sargent of the nfpa on this, he claims it is not the nec's intent to require upgrades of OCPD's to afci capable ones in an upgrade the reason? multiwire circuits.... ~W~ |
| blackrd | No, I saw it in an article by an inspector. I have contacted the publisher of EC magazine to contact Mr.Flach (the author of said article) and I am hoping to get the official word on this. I can see no afci' on multi-wire for obvious reasons but I am positive this authority called for afci' when possible. I'll be back. |
| blackrd | Update. I was able to phone Mr.Flach in New Orleans. I misqouted Mr.Flach. He said the article I am refering to was regarding running new circuits to bedrooms needing to be upgraded to afci breakers(new wiring or circuit upgrades). He said panel upgrades are not required to provide afci protection, just new circuits. I apologize for my misinformation, and am banishing myself from the forum for 5 minutes. |
| blackrd | Update #2. The author of the article I sited was not Mr.Flach, but David Shapiro. I found the old article, reread it, and Mr.Shapiro indeed did say that afci protection was required on panel upgrades in resi work. I have e-mailed Mr.Shapiro and asked him to clarify this further for us. I have given him this wweb address, so maybe he will appear here personally. Mr. Shapiro is the author of a book, "old electricwiring:maintenance and retrofit." He is also an inspector affiliated with IAEI. |
| Ryan_J | I don't beleive that AFCI's are required in a retrofit application. The only thing in the NEC that I am aware of that is retroactive is GFCI protection, which is spelled out in 406.3 |
| Wirenutz | David was an IAEI regular, and posted a great ditty from his George Washington Chapter IAEI re; afci's when the controversy was hot ~W~ |
| Ryan_J | quote: There are 2 pole AFCI's available that are designed to be used with multiwire branch circuits. |
| davey | Okay, Kevin, it took a while to log on, but I made it. I've got to be careful what I say, because the agreement says I give over ownership of what I write, and I write further about this in Electrical Contractor. Stay tuned. Briefly, for the need for AFCIs on old wiring, that's what they were developed FOR--the country's in-place aging wiring stock is why the CPSC urged manufacturers to develop them. For the "requirement," such as it is, to install when replacing equipment, consider a parallel with GFCIs. For the issue of multiwire circuits, at least some manufacturers do make multi-pole independent-trip AFCIs. 'Nuff said. |
| Scott Vickrey | You give over ownership so that We can show it to members on this forum without asking you. This was made necesary recently by someone who demanded I went through and remove all their posts. This was a nightmare. It is only a measure to keep the forum operating smoothly. I may need to change the wording so it doesn't scare people. |
| Wirenutz | quote: well it's high time isn't it? we've only been required in my state since the '99 cycle ~W~ |
| blackrd | I do believe this has been a good exchange, and I thank everybody,including Mr.Shapiro, for their participation.
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| Energreen | Wow! I've been away for two days and I'm totally impressed with all the dialog that's taken place about this topic. Thank you all for all the great and helpfull information! EG |
| Wirenutz | i'll take it 'stay tuned' refers to Davey's log off in his collum re; March issue EC mag. note the parallel implied to GFI's, no doubt a great way to market anything via the sucess of a similar widget the problem i've had from day one with AFCI's is thier inability to mitigate a series arc. oh, you can refer to the white book and the 'carbonized' 'non-carbonized' ditty that everyone takes as meaning series/parralell, but then you can go out and weld your name via a series setup. Or just place a load on your new bedroom circuit and break the hot in the panel , many have. Besides,Does anyone here think a 75A threshold ,being well beyond the incinderary limits of most residential combustibles, is going to prevent those old K&T circuits from starting a fire? I've stuffed over 20 afci's in a panel, try adding $1200 to those 100 amp service upgrades folks, they want justification Are you going to guarantee they will never have an electrical fire ? Still, the GFI anonolgy is a good one, just look at GFI's growth in the nec since 1971, cycle by cycle it has grown to encompass a greater % of wiring right? In fact, why not just protect a dwelling subpanel with say, a 60A GFI ? Economicaly speaking this would be peachy keen, not to mention just ONE sensitive device to maintain instead of all those devices with the new improved lockouts So, in the same vien of thought, why not a 60A AFCI ? Or even a combo unit? A PITA you say, well....someone should call up our European friends and have a chat, seems our NEC claims ( since 02') that we are International , that;s right folks, we're in charge (pun intended) we're callin' the shots! Who do they think they are supplying whole house protection with thier earth leakage main breakers and all? rather jumping the gun isn't it? ~W~ |