AFCI ..Actual benefits??

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electricmanscott

electricmanscott

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Massachusetts Master Electrician, one man show.
What are the actual and real benefits of having Arc Fault Protection. Specifically in older homes what protection could one expect from replacing existing breakers with AFCI's?
 
Re: AFCI ..Actual benefits??

Originally posted by electricmanscott:
What are the actual and real benefits of having Arc Fault Protection. Specifically in older homes what protection could one expect from replacing existing breakers with AFCI's?
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The manufacturers get to sell an expensive product. :p

[ August 04, 2005, 04:03 PM: Message edited by: iwire ]
 
Re: AFCI ..Actual benefits??

In my (admittedly cynical) opinion the benefit is to the people selling them in droves because the code mandates them.

The benefit to the HO even if they did work as people think they do (which seems to be an open question), seems dubious at best.

The cost is something like 1/2 a billion dollars a year, and the savings from eliminated fires (assuming for the moment they worked) is a small fraction of that number.

It may be that a few lives could be saved, but it is hard to justify the magnitude of the expenditure involved on a guess like that.

I would think mandating more/better fire/smoke detectors would be a more cost effective and more effective answer to the non-problem being addressed with these things. Couple that with an education program to explain to people why they should not have extension cords in use that are in disrepair and you have a major winner.
 
Re: AFCI ..Actual benefits??

Specifically in older homes . . .
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I think they will be great when the combination type is available. Those haven't proven themselves yet and they are not required in older homes. If they perform as advertised, it would be the best thing since the GFCI in older homes. :D
 
Re: AFCI ..Actual benefits??

Benefits: Quick buck for manufacturer and supply house period. Somebody give me a count of people saved if any?
Personally I like the gfci but the afci is garbadge I will not put them in my house. We get way too many blackouts and brownouts in South Florida without me sabitogeing my own home.......
 
Re: AFCI ..Actual benefits??

I have yet to see the benefit of an afci breaker other than call backs for nusiance trips ;)
We installed 100`s upon 100`s of speced homeline panels with blue button trip to test buttons (Recall item)As far as I know they are still in place.There was a letter from schneider butnothing done yet :eek:
 
Re: AFCI ..Actual benefits??

Originally posted by electricmanscott:
What are the actual and real benefits of having Arc Fault Protection. Specifically in older homes what protection could one expect from replacing existing breakers with AFCI's?
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First question; it will comply with the code

Second question; I don?t know
:D :D
 
Re: AFCI ..Actual benefits??

The problem with any protective device is that you can never get statistics on its successes. Just suppose that a lamp with a slightly frayed cord does start arcing. Suppose further that the brand new AFCI that you just installed for this homeowner sees that arcing, and trips. What happens? All the HO knows is that the light went out. For all he knows, it might have been a burned out bulb. After some investigation, he sees the breaker has tripped, and he resets it. In the mean time, he had moved the lamp just enough to straighten out the section that had been arcing. The lamp might work just fine for another six months. The AFCI just prevented a fire, and no one, not even the HO, knows about it.

But even if the HO did a bit more investigating, found the frayed cord, and replaced the lamp, the event will not be recorded in any statistical database. Do you suppose the HO will make a 911 call, to report the fire that didn't happen?

So the real answer to your second question goes beyond jwelectric's "I don't know." The answer is "Nobody knows."
 
Re: AFCI ..Actual benefits??

I see this an another example of redundant psychology. We place sensors on our equipment to detect imperfect product output. This is fine but we also get requests to add more sensors to back up the existing sensors in case they fail to function properly - redundancy. When I get these requests I can't help myself but to ask, how many backup sensors should we use? What if sensor #1 and #2 both fail? Should we add sensor #3, #4, #5...or would all of this be eliminated if we just repair sensor #1 in the first place?
 
Re: AFCI ..Actual benefits??

This might sound stupid but I`ve done that before :eek: Lets say a house is roughed in and there is an afci circuit and a non afci circuit in same 2,3 or4 gang,If neutrals are tied together when a load is put on the afci circit it trips.Have seen that time after time :roll:
What about the grounding conductors code says all grounds in a box will be tied together
correct me if I am wrong.I read it but am to fuzzy to search the article.Now if the non afci`s ground is tied into a afci ground wouldn`t that trip the afci ground to neutral fault :confused:
If I am correct then how are we code compliant and seperate the ungrounded conections without violating the NEC :confused:
If I am speaking out my rear (done that been there)Correct me please !!!!
 
Re: AFCI ..Actual benefits??

I see this an another example of redundant psychology. We place sensors on our equipment to detect imperfect product output. This is fine but we also get requests to add more sensors to back up the existing sensors in case they fail to function properly - redundancy. When I get these requests I can't help myself but to ask, how many backup sensors should we use? What if sensor #1 and #2 both fail? Should we add sensor #3, #4, #5...or would all of this be eliminated if we just repair sensor #1 in the first place?
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Very well put. What ever happened to the old lets get it right the first time additude, AFCIs, IMO cause more trouble than its worth, older homes, if required to have them in your neck of the woods, are where the problem lies. I rewired an older home but upon the wishes of the HO in his opinion and to save a buck or two insisted some of the old bedroom circuitry be left, after we came to an agreement it was left as is, well when AFCIs were installed, problem after problem, I had to rewire the bed rooms also, problem solved and extra cost to the HO.
 
Re: AFCI ..Actual benefits??

Originally posted by bthielen:. . . how many backup sensors should we use? What if sensor #1 and #2 both fail? Should we add sensor #3, #4, #5 . . . ?
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Suppose the sensors have a 95% reliability, and a 5% change of failure. The probability that two independent sensors would both fail is 0.25%. The probability that three independent sensors would both fail is 0.0125%. The probability that four independent sensors would both fail is 0.000625%. I'd stop at two.
. . . or would all of this be eliminated if we just repair sensor #1 in the first place?
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Absolutely! If (for example) you can get the failure rate down from 5% to 1%, you would be far better off, and at a much lower cost.
 
Re: AFCI ..Actual benefits??

Originally posted by allenwayne:
This might sound stupid but I`ve done that before. Lets say a house is roughed in and there is an afci circuit and a non afci circuit in same 2,3 or4 gang,If neutrals are tied together when a load is put on the afci circit it trips.
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Why would anyone tie neutrals together?
What about the grounding conductors code says all grounds in a box will be tied together correct me if I am wrong. I read it but am to fuzzy to search the article. Now if the non afci`s ground is tied into a afci ground wouldn`t that trip the afci ground to neutral fault?
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No, EGC's can be tied together; just not neutrals.
If I am speaking out my rear (done that been there) Correct me please !!!!
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It's difficult to tell from here, but . . .
 
Re: AFCI ..Actual benefits??

Thanks for the responses guys. All answers I pretty much expected. I have a friend who has a customer that wants all their breakers replaced with afci's. They had an electrical fire at one time and have done some research and feel that this is a good way to go. When it was suggested that the house be outfitted with hardwired smoke detectors they took a pass, Go figure. :roll:
 
Re: AFCI ..Actual benefits??

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The problem with any protective device is that you can never get statistics on its successes. Just suppose that a lamp with a slightly frayed cord does start arcing. Suppose further that the brand new AFCI that you just installed for this homeowner sees that arcing, and trips. What happens?
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Correct me if I'm wrong, but I thought the current AFCIs were not designed to detect any faults on external devices, only the interior wiring?
 
Re: AFCI ..Actual benefits??

Correct me if I'm wrong, but I thought the current AFCIs were not designed to detect any faults on external devices, only the interior wiring?
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I keep forgetting the difference between what they're said to do, what part of what they might do causes them to be required, and what they actually do.

But it does make sense that if they can only protect against branch circuit arcing within the building wiring that they only be used for bedroom circuits since those are the only circuits that could ever arc. :(
 
Re: AFCI ..Actual benefits??

Sam, the current technology is supposed to protect the building wiring and not necessarily the cords that are plugged into the circuits. The combination types are supposed to protect the cords as well. I think they will be great if they work as advertised. However, I still do not believe the Code should be used to sell a new and untested product. :mad:
 
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