On Wed, 27 Sep 2006 02:07:58 -0500 Bud-- wrote: | snipped-for-privacy@ipal.net wrote: | |> On Tue, 26 Sep 2006 01:32:31 -0500 Bud-- wrote: |> | snipped-for-privacy@ipal.net wrote: |> |> It seems there is more than one defintion of "combination AFCI" based on |> |> some searches via Google. I decided to do this search because the NEC |> |> failed to define this, referring only to UL 1699. UL documents are very |> |> expensive (several times the cost of the whole NEC for just one testing |> |> document). |> |> |> |> I've seen definitions that describe a combination AFCI as one that has |> |> GFCI protection integrated. I've also seen definitions that describe a |> |> combination AFCI as one that combines the protection of a "branch/feeder |> |> AFCI" and an "outlet circuit AFCI". And I've seen definitions made in |> |> terms of a number of test parameters where a few different types of AFCI |> |> were compared in terms of what tests were being performed by the device |> |> (and the combination AFCI was not the most comprehensive). |> |> |> | |> | As you said, "Combination AFCI" is a UL definition, not NEC. |> | |> | Information on what Combinations AFCIs are is at: |> |
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|> | |> | They still have 30mA GFCI - 6mA has not been included (in anything I |> | have read). |> |> Cutler-Hammer has them, AFCI + 6ma GFCI. |> | | What I was trying to say is that AFCIs are not required to have a 6mA | ground fault trip. The CH devices are a combined AFCI and normal GFCI.
However, certain circuits _are_ required to have 6ma level protection. If you're going to have AFCI to virtually all 120 volt circuits in the house, that would probably include bathroom and kitchen, too. So one option is to combine the AFCI and the required 6ma GFCI in the same unit.
I guess that is a reflection of my own bias because I happen to think that GFCI receptacles are ugly. My intention all along has been to go with either a "hidden" (accessible, but located more like where one would place a panel) GFCI receptacles that control the ones that will be in the kitchen, or just use a GFCI breaker. The latter choice is more expensive. But I could also add AFCI protection at the same time with the Cutler-Hammer breakers. And I could also do so for 240 volt circuits.
Personally, I don't care about the bathrooms. Having AFCI+30maGFCI in the breaker, and 6maGFCI in the receptacle, is fine there. It's the kitchen where I am trying to have a very specific kind of look, and GFCI receptacles are not a part of that plan. So it most likely will be AFCI+6maGFCI in double pole breakers.
|> | A good paper from the Consumer Product Safety Commission on AFCIs is at |> |
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|> | It includes the rationalle for using AFCIs, information on how they work |> | and what shouldn't cause them to trip. |> |> Seen it. It's part of the contradictions I've mentioned. |> | | I wasn't impressed by the clarity but I don't remember it was that bad.
I'm not even sure it's all that accurate with respect to the fine details of things like what's in the UL 1699 document (which I don't have because such things are very expensive).
|> |> I also saw commentary in the NEC 2008 ROP that combination AFCIs are not |> |> even on the market, yet. So are they going into this blind and not able |> |> to know all the issues involved. |> |> |> | |> | My intent in the other thread was to ask if "Copmbination AFCIs" are now |> | available. When you said "Square-D, Cutler-Hammer, and GE have them" was |> | that specifically Combination? |> |> They were panel type. I don't know what they were marketed for. |> |> I know Cutler-Hammer has combination types of the definition of AFCI+GFCI |> and has them in both 6ma and 30ma, and in 1-pole and 2-pole. |> | | Looks like CH is combined AFCI and normal GFCI. That is not what UL or | the NEC had in mind for "Combination AFCI". Among other things, | "Combination" adds series arc detection.
And this _is_ my point about the contradictions. Some documents say or hint at one thing, and some say or hint at another. NEC is doing a poor job of explaining by merely making reference to the UL 1699 standard that hardly anyone will ever see. I believe they should literally spell out exactly what protections they expect to be present.
| No rumors on what is going on with "Combination" development?
I have no idea. I've just seen the products that both Square-D and Cutler-Hammer have. I just note that Cutler-Hammer have a sufficient product line for me to put in reasonable levels of protection for some rooms in my future house.
I'm planning to have "double duplex" receptacles in my kitchen. These will be a total of 4 outlets in a 2x2 arrangement, with the left on one 20 amp pole and the right on another 20 amp pole. This will be fed with one cable with the origination of the circuit being a two pole breaker. Whether this will be shared neutral or not I don't know at this time. If it were allowed to mark the BLUE wire as GRAY to make it be a 2nd groundED conductor (200.6 requires this) in a cable assembly, then I could avoid a shared neutral by using the cables intended for three phase WYE. I've heard that cables specific to this are available, but I've never seen then sold anywhere, either in stores or online. In any event, this finally leads me to planning to use an AFCI+6maGFCI two pole breaker, one for each of the 2x2 (since I do not want to have any daisy chaining of shared neutral). Other options include conduit with singles of all the right colors, or larger than 6 AWG (that would be absurd for a 20 amp circuit, of course).