do we really need AFCIs

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don_resqcapt19

don_resqcapt19

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retired electrician
UL did an investigation on hammer and staple damage to NM cable that indicates that the arc from that type of damage is too short and has too little energy to start a fire. The arc self extinguishes at about 1/2 cycle....The AFCI has to see at least 8 half cycles before it will trip.

Influence of Damage and Degradation on Breakdown Voltage of NM Cables

From the executive summary:
The test results indicate that the probability of sustained arcing and ignition is low for hammer-damaged NM cable. The results also show that though a carbonized path may eventually be formed, this path formation did not lead to subsequent ignition of the cable jacket or surrounding materials, and self-extinguished after a short period of arcing.
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It seams this is just one more thing that they told us the AFCI was designed to protect against, but we now find out that this type of damage does not result in fires.
 
don_resqcapt19 said:
UL did an investigation on hammer and staple damage to NM cable that indicates that the arc from that type of damage is too short and has too little energy to start a fire. The arc self extinguishes at about 1/2 cycle....The AFCI has to see at least 8 half cycles before it will trip.

Influence of Damage and Degradation on Breakdown Voltage of NM Cables

From the executive summary:


It seams this is just one more thing that they told us the AFCI was designed to protect against, but we now find out that this type of damage does not result in fires.
Click to expand...

No, but I do not do resi right now, so I be can frivilous on the subject.:)
 
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mike7330 said:
Did UL do any studies on lamp cord (zip cord) arcing?
I would think that would be a bigger problem than staples.
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Parallel arc faults that do not trip the OCDP, but can start fires, may be detected. Series arc faults in cords that get flexed a lot, which can also start fires, probably not.
 
GoldDigger said:
Parallel arc faults that do not trip the OCDP, but can start fires, may be detected. Series arc faults in cords that get flexed a lot, which can also start fires, probably not.
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It appears to me that this study involved parallel arc faults and they could not even trip an AFCI let alone start a fire.
 
mike7330 said:
Did UL do any studies on lamp cord (zip cord) arcing?
I would think that would be a bigger problem than staples.
Click to expand...
This study was not about AFCIs...it was about damaged NM cable. However, the study seems to show that one of the things that they have told us that the AFCI is designed to protect against can't really happen. The original proposals that resulted in the AFCI requirement said that ~40% of the dwelling unit fires that are said to be of electrical origin were from faults in the fixed wiring of the building.
 
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Bah humbug. Why spend money on testing. We all instinctively KNOW that sparks cause fires, and wires shorting out have to burn.

Independent, third party testing is so ridiculously unnecessary. You can never trust those guys.
 
Having worked for one of the leading developer and manufacturer I knew some of the design engineers personally. It is with all confidence that I believe in these products. However, the real proof is in the pudding, by pudding I do mean the insurance companies.
I have been extremely disappointed that the insurance companies haven't found that the AfCIs haven't been determined to reduce fire losses. If it is determined that AFCIs save lives and fire losses I wouldn't thine that insurance companies would provide premium credits or other incentives to promote the use of AFCIs in old construction.
As such I'm not seeing any results. Is the need for this product been overstated?
 
Well most here know my thoughts on AFCI's and why I helped get 210.12 removed from Indiana's electrical code, the only electronics in an AFCI that to me actually did something was the GFP, I have yet to see any other part of an AFCI that did anything that a faster acting breaker with a 30ma-50ma GFP could not accomplish the same amount of protection, we were sold a bill of goods that did not do what they claimed they would, as we were told they would stop a series arc which they will not do as they later twisted their responses to this claim by saying they only meant that it was only after a series arc evolved to a parallel short which any breaker can do the same thing, I have seen so many of the guillotine knife test on a two conductor lamp cord that ended in the breaker ahead of the test setup tripping before the AFCI did, in one case the lamp cord actually caught fire, of course this was back in the early days of AFCI development but from what I have read the only changes are that the AFCI breaker will trip faster now on a parallel arc or fault to which any breaker could be design this way, but motor loads would be a problem, but wait a minute, motor loads are a problem when on a AFCI go figure:rant:
 
ptonsparky said:
I will have to say one of mine tripped nicely when I poked my non contact tester in a box and managed to push a hot on to an EG. Nice little spark, no molten copper or at least not much. GF or AF, something worked.
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I have seen that happen with standard breakers...how do you know what part of the AFCI breaker caused the trip?
 
templdl said:
Having worked for one of the leading developer and manufacturer I knew some of the design engineers personally. It is with all confidence that I believe in these products.
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It just seems as more information comes out, there are more and more questions as to what they really do. Based on the report I cited, I wonder if sustained arcing, either series or parallel is even possible at dwelling unit voltages?
However, the real proof is in the pudding, by pudding I do mean the insurance companies.
I have been extremely disappointed that the insurance companies haven't found that the AfCIs haven't been determined to reduce fire losses. If it is determined that AFCIs save lives and fire losses I wouldn't thine that insurance companies would provide premium credits or other incentives to promote the use of AFCIs in old construction.
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If they really work, it will still be years before there would be any meaningful stats to show that. The dwelling unit cause and origin information that is available shows that only about 15% of the dwelling unit fires that are said to be of electrical origin occur in dwelling units less than 20 years old.
As such I'm not seeing any results. Is the need for this product been overstated?
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I think there are a number of things at work here.

First, the issue of the age of dwelling units that have fires that are said to be of electrical origin.

Second the lack of real information on the cause and origin of dwelling unit fires. Few of these fires are deeply investigated. In many cases if there is anything electrical near the point of origin, the cause will be listed as electrical, so it is likely that the number of fires that are said to be of electrical origin is an inflated number..

Third, the AFCIs do not directly detect what I believe to be the most common cause of electrical fires...that of a high resistance connection.

As most of you know, I have never been a fan of the AFCI. I have spoken out, both in the forums and the code making process, with questions about these devices going back to the first proposals to require them. I have never been convinced of the need for or the functionality of the AFCI. As I read new information, like the report cited in this thread, I become even less convinced. Part of the issue for me is that I don't trust a lot of the information that is out there that comes from industry sources. This lack of trust of these sources goes back to the fact that the original AFCI proposals said that they had a device that would do what they now tell us that the combination AFCI will do...the only problem is the fact that those original proposals were some 13 years prior to the existence of the combination type AFCI.
 
don_resqcapt19 said:
As most of you know, I have never been a fan of the AFCI. I have spoken out, both in the forums and the code making process, with questions about these devices going back to the first proposals to require them. I have never been convinced of the need for or the functionality of the AFCI. As I read new information, like the report cited in this thread, I become even less convinced. Part of the issue for me is that I don't trust a lot of the information that is out there that comes from industry sources. This lack of trust of these sources goes back to the fact that the original AFCI proposals said that they had a device that would do what they now tell us that the combination AFCI will do...the only problem is the fact that those original proposals were some 13 years prior to the existence of the combination type AFCI.
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the chief electrical inspector of a city near here, and i, decided one day to
see if we could make an AFCI trip. we plugged in a lamp as a load on a
circuit, and tried opening up wire nuts, to draw an arc. we tried every
way possible to get that thing to trip, at some points drawing enough
of an are to span over 1/8".

the only thing we found could activate an AFCI, was my ideal suretest,
and the test button on the device.

the only thing i'm convinced that an AFCI can reliably do is increase the
profit margin of the manufacturer of the device. and i strongly suspect
that is why they exist today.
 
Who Writes the Code

Who Writes the Code

One thing I like to remember is that the code is written by manufacturers. It seems to me that the only companies with the money to send staff to code development panels and meetings and the like are manufacturers with money to make. People in the trenches (engineers, electricians, AHJ) have jobs that require them to work, not attend meetings. As a result, the code is written by manufacturer representatives. So, it is not surprising that we get code requirements that sell new equipment, even equipment that does not yet exist.

I would like to see Consumers Reports perform real world testing of AFCI products to see how many really do what they claim. I think the results would be abysmal.
 
ptonsparky said:
I don't "..GF or AF, something worked." IMO, it was the GF portion, but IDK. Mine do not have the ability to tell me why. Until they easily have that ability, they are mostly just an expensive PIA. IMO.
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I agree with you regarding the GF working. As such then the basic 5ma gfci would be just fine.
If the afci's other attributes are as good as stated they would be a good candidate for older structures using vintage wiring techniques. They would be a godsend for wire methods that had no EGCs making the GF feature of the afci useless.
With as great as the afci manufacturers say that their products are don't you think that they would be promoting their us in the old construction market?
 
I think the answer should be obvious:

No, we do not need AFCI's.

I think it's really too bad because AFCI technology is something good in principle. However, the absolutely shameful way in which they have been promoted and marketed has done irreparable harm to the manufacturers' reputations.
 
beanland said:
One thing I like to remember is that the code is written by manufacturers. It seems to me that the only companies with the money to send staff to code development panels and meetings and the like are manufacturers with money to make. People in the trenches (engineers, electricians, AHJ) have jobs that require them to work, not attend meetings. As a result, the code is written by manufacturer representatives. So, it is not surprising that we get code requirements that sell new equipment, even equipment that does not yet exist.

I would like to see Consumers Reports perform real world testing of AFCI products to see how many really do what they claim. I think the results would be abysmal.
Click to expand...

Code is written by anybody that submits a proposal - then the proposal makes it through the process.

You are on the right track with only people willing to spend the money to push an issue is the manufacturers though.

If a large enough group puts enough money into an effort to eliminate AFCI's from the NEC just like the manufacturers put a lot into trying to get them in the NEC, then they likely will eventually get their way.
 
Fulthrotl said:
the chief electrical inspector of a city near here, and i, decided one day to
see if we could make an AFCI trip. we plugged in a lamp as a load on a
circuit, and tried opening up wire nuts, to draw an arc. we tried every
way possible to get that thing to trip, at some points drawing enough
of an are to span over 1/8".

the only thing we found could activate an AFCI, was my ideal suretest,
and the test button on the device.

the only thing i'm convinced that an AFCI can reliably do is increase the
profit margin of the manufacturer of the device. and i strongly suspect
that is why they exist today.
Click to expand...

:thumbsup:
 
Well, I'm in the camp that thinks AFCI is a scam. I know many us of older guys make the comparison to GFCI in the early days, but I think this is a different situation. At least with GFCI the benefits and results are easily demonstrated and that technology just needed time to mature and become stable. The most recent issue of AIEI Magazine has an article on the UL process for the testing of AFCI devices. It did not make me warm and fuzzy about the benefits of AFCI. It's also worth noting that the author is employed by Eaton. I can't help but ask, if they are so great, where are all the trade articles with real world testing glowing about how great they are?
 
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