Replies

1. 
   BillHartmann | Nov 25, 2002 11:04pm | #1

   The new FHB has an article on them.

   The NEC code requires them for new bedroom circuits after Jan 2002.

   What they do is look for the signature of electrical arcing. Arcing of the electrical connections or equipment plugged in can generate heat which can cause fires. The only ones avaialbe are part of circuit breakers that are installed in the pannel.

   GFCI's detect the difference is currents in the hot and neutral leads.

2. 
   booch | Nov 26, 2002 01:41am | #2

   Depends on where you live.

   The arc fault interrupters are well described in the FHB article this month. My company sells these as well as other electrical parts, mostly for industry but some for construction.

   I called the local rep (Square D) and asked about the requirements for Wisconsin. Even though the FHB article says the NEC 2002 requires them in all new construction it appears the Wisconsin Code does not require them this cycle. (2002 to 2005) So it depends on your state whether or not you need to have them in your application. I'd call the local inspector and see if your state or locality requires their use.

1. 
   4Lorn1 | Nov 26, 2002 08:10am | #3

   A lot depends on when the AHJ in your area adopts the newer editions of the NEC. Editions are not automatically adopted as they are released by the NFPA. Many jurisdictions run several editions behind the most current. Many inspectors will strongly suggest that you comply with the more important points of the newest editions. In most cases they are right in doing so but it is seldom enforceable.

1. 
   Mongo | Nov 26, 2002 08:25am | #4

   4Lorn,

   Cauldwell's article gave the arc fault protectors he wrote about a tepid welcome to the world of residential construction. Are you familiar enough with them to offer an opinion? Good? Bad? Could be better but not worth it? Could be better but still worth it?

   Thanks

1. 
   bake | Nov 26, 2002 06:33pm | #6

   I have heard if you pull the plug on any device (such as a lamp) which is still energized you get a trip, because you drew an arc. Deservedly so, I am wondering how many other conditions will trigger a false trip as well.

2. 
   4Lorn1 | Nov 27, 2002 07:56am | #7

   I'm not ignoring your question. The latest FHB just showed up this afternoon.

   I felt I wanted to at least see what RC had to say. On first blush I am a little disappointed in the article as it seems to state some conclusions without providing any great amount of design or technical background to support them. At this point I can't say I agree or not with his "tepid" evaluation or his view of cost versus benefit.

   These products are relatively new. I have installed a few but have little idea of how AFIs will hold up in widespread use and in the long run. The point being that I don't have any strong or well founded opinions on them. I intend to try to read up and ask around on this issue and post back in a few days.

1. 
   Mongo | Nov 27, 2002 09:40am | #8

   I value your input and appreciate any feedback on the subject.

   Thanks,

   Mongo

2. 
   BillHartmann | Nov 27, 2002 04:57pm | #9

   A friend of mine posted this on Compuserve.

   "Since you are trimming out new houses, what has been your experience with those new-fangled Arc-Fault breakers required on all bedroom outlets? We have been getting complaints from new homeowners who do stupid things like unplugging their vacuum cleaner while it's still running .... of course doing so creates an arc that those AFI's like to trip on.

   The other unintended side effect we have found so far is a "cheap" fluorescent light with a starter in it also trips out the AFI's. Of course, the inspector has said that the closet is "outside" of the bedroom, and as such is not required to have AFCI protection. NOW they tell us ... :-/"

   Edited 11/27/2002 9:05:30 AM ET by Bill Hartmann

3. 
   junkhound | Nov 27, 2002 05:44pm | #10

   The main impetus for AFCI began years ago due to polyimide aircraft wiring concerns, reference:

   http://www.spectrum.ieee.org/WEBONLY/pressrelease/0201/wire0201.pdf

   http://www.eaton.com web site has some good info on their aircraft afcis.

   That said, IMHO, I don't have any CFIs or AFCIs in my own house and won't ever unless by court order -- big nuisance if you are confident or your grounds and connections. Caveat is that this requires outlets near grounds to be blocked to protect from 2YO grandsons proclivity to stick stuff in outlets.

   Prediction for year 2020 - manufacturers will demonstrate and require per code 'new' technology (acutally 100 years old) showing that the power system should NOT be grounded anywhere in a house. This may actually be the only good thing in the last 50 years of the code. The only reason one side is grounded now is it was too hard (expensive, lots of tubes and relays and mag amps) 100 years ago to build the circuits needed to open a line if only one side of an isolated pair did touch a water pipe and introduce a hazared, etc. (nuclear plants have had ungrounded circuit since day one to improve reliability)

4. 
   booch | Nov 28, 2002 12:44am | #11

   Great link. Junkhound,

   Here is one from Square D. There are lots of Puff Pieces on their website that show the homeowner what not to do but here is the FAQ list from them on many issues of the AFCI's. It is called "The Truth about AFCI's"

   http://www.squared.com/us/products/circuitb.nsf/07a0210021262d45862564b5006e4f84/51617decf280b7f785256bf7004704ec/$FILE/0760DB0201r0602.pdf

   It is in adobe so it is easy to view.

   Here is the customer (puff) piece:

   http://www.squared.com/us/products/circuitb.nsf/07a0210021262d45862564b5006e4f84/bea8c320ac2c9e35852566330062fe35/$FILE/ATTQCVJ1/0760HO9801R902.pdf

   It is good reading but doesn't really hit the Why? as well as the first link.

5. 
   CAGIV | Nov 28, 2002 10:20am | #12

   Knowing little about electrical, the article was interesting to me, but the side story about AFCI confused me, I got the impression that the AFCI really isn't much of an improvement over a standard breaker.  So my question is to any elections or anyone else who knows is, what exactly besides passing code, does 8-10 times the cost get you for using the AFCI over a standard breaker

6. 
   junkhound | Nov 28, 2002 02:13pm | #13

   Nothing -- unless you have stock in a mfg, or have a house with crap wiring.

2. 
   booch | Nov 26, 2002 03:56pm | #5

   The tale on the Arc fault is that it isn't the function that is in question by the Wisconsin authorities, it is the value based on the expense. These are words paraphrased from the guy selling to me.

   In essence it is a good viable product but will be seen in only the high end homes for a while until it is demanded by code.