Here is the paper from one of the originals on resi AFCIs. Note the processor:
https://www.cpsc.gov/PageFiles/98397/afci1.pdf
http://www.zlan.com/collin_county.htm
And there is this statement which I believe is key:
"Its pseudo GFI function will save thousands of lives."
http://www.mikeholt.com/mojonewsarchive/AFCI-HTML/HTML/AFCI_Inventor_Responds~20020814.htm
I only mention this because its RCD type protection that detects most hazardous conditions.
I am very familiar with those documents and equally familiar with Mr. Holts opinion to which I generally take with a grain of salt. However, I do hold Mr. Spencer and the folks that originally aided in the design of the DE Circuit Breaker in great regard. Now, it is assumed that when someone questions NEMA that it is a blanket discredit to all manufacturers that are collectively apart of NEMA but clearly the intent of the message was to the manufacturers who produce AFCI devices. I also believe that Mr. Holt sent out a letter to all of his members regarding AFCI's only to end up retracting the statements when he finally was able to visit the facility at Eaton with Dr. Engle and witness the testing process.
Look I am not blind to some potential issues and I am not discrediting anyones experiences at all, I can only say that I have not experienced them. However, I was privileged to travel around the country and meet with hundreds of electricians and inspectors and did not get any sense of the feeling that AFCI's had a wide spread problem. Sure, isolated issues that could be resolved by replacement or trouble-shooting but that is to be expected with any technical product that incorporates microprocessor technology. Again, is it perfect...obviously not; is it the best we have and to does it prevent potential arcs within the scope of the testing as shown in the supporting documents you have posted..Yes.
In terms of the GFI (GFP), it is assumed that because it has a protective theory of it's intended use, to protect the volitive circuitry in the devices themselves that it does add to the overall fire protective safety of the device. Well i will buy into the fact and even remove the assumed portion; yet UL is a paid association now who is charged with evaluating products for their intended use and currently under UL 1699 the GFI component is not required because it plays no role in the intended function of the product. While some manufacturers did (and some still do possibly) rely on this feature to pass the complete testing procedure for UL 1699 compliance others have obviously developed a method that passes without the GFI (GFP) function. What you are presenting is that experts believe that the GFI (GFP) function is a critical component that must be included and that when manufacturers leave that out they are some how immoral or pandering to the cost of production so I need to address that.
Firstly I represent a manufacturer (not of AFCI's) and our products are produced in accordance with UL standards. We do not shoot to exceed the standards, we shoot to meet the standards. This would be no different that an Electrician wiring a building in accordance with the NEC, the minimalist safe building that is legally permitted to be built. The choice to exceed the NEC is a design choice made by the installer and the client in accordance with economic factors, desire and needs. The manufacturer who chooses to simply produce to the standard is not to be vilified, they are to be accepted no differently.
AFCI technology speaking...on the most basic level of ARC detection their are specific characteristics that are replicable, modeled and perfectly acceptable to be used as foundation points in arc detection. The research that takes place are indeed now days done on finished product. However, continued research is constantly being done by the manufacturers to enhance the AFCI Technology because the manufacturing business is also a game of who gets it to market first and who enhances it to over shadow the competition, trust me (or not, thats your choice) every day manufacturers are trying to enhance and one-up the competition if only to say our product beats your product and NEMA, the collective body, can't restrict that competition.
When looking at the merits of a "premature" product as you stated and apply it to other technology that quite possibly have less interest on this forum. Nearly every year (seems like every day) a new iphone or android phone is produced as the latest and greatest. Sure I hear " But thats not required like AFCI's are and buying a new phone is a choice not a mandate " yet we are constantly being solicited with the latest and greatest things and consumers just have to buy. So how does that equate to AFCI's? Basically it will be impossible to simulate every known and unknown situation where as AFCI's would be that perfect holy grail product but clearly they have advanced from single circuit, combination type to multiwire branch circuit and now dual function type devices, they are advancing at a controlled pace and they have been proven to raise the level of safety against arcs detected that fall within the test characteristics at the least. However, to hold off on the technology that was available at the time because we fell it could be better is no different that going to a fortune teller and asking to know the lotto numbers for next weeks drawing; to delay would have been counter-productive to the effort to promote safety in my opinion.
I believe the problem originally was that AFCI's were touted as the Holy Grail and when random issues came to light (even if installer error) it tainted that statement made by various manufacturers or invested advocates but it does not diminish the technology and advancements in terms of arc detection at least in my less than intelligent mind.
I personally believe that the largest hurdle for manufacturers to overcome is the broadband noise generated within series arcs by specific products that is impossible to regulate (FCC). Looking for the peaks and spikes along and sudden drops in the waveform below zero point is easier to detect as in parallel arcs but the series arc has to be in my mind more of the challenge these devices face.
Rather than regurgitate the information in an effort to sound way smarter than I am as I am no AFCI applications engineer (obviously) I will simply post a document that will explain the various methods of Arc Detection. Every manufacturer provides this methodology in a similar way but the reason I posted this one is because it is from Siemens who I feel are pioneering the way on AFCI technology these days....which again is only my opinion. It is also important to note that I have very little contact within Siemens to sway my opinion while I know many leading experts at Eaton and Schneider and I still choose Siemens when I say they are cutting edge on AFCI development in my for what it's worth) opinion.
http://w3.usa.siemens.com/powerdist...i/1-pole-tabs/Documents/sie-cs-cafci-2007.pdf
In closing, are they perfect..No, Do they have issues with glowing connections (which i my mind are not arcs in the scope of UL 1699 but need to be evaluated) Possibly but the question is do they work as they were intended and as outlined in the scope of UL 1699 I believe yes. I happen to believe that characteristics are replicable in a vast many situations but not all situations. I have AFCI Combination Devices in my home, call me crazy (I know some will, they can't resist) but if they come out with a "Super-Duper Combination" AFCI device that the industry experts say will again raise the bar....I will buy it and as an electrical contractor (used to be) I will promote it for replacement to my customers right beside my Whole House Surge Protector marketing....:roll:
Blast away.....just my thoughts on the subject.
