LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
That would probably be what started the whole thing: fires from cords and extension cords in bedrooms.
AFCI's have they proven themselves?
- Thread starter brother
- Start date
- Location
- Illinois
- Occupation
- retired electrician
But they will mitigate a very high percentage of dwelling unit fires from all causes, while the best AFCIs could do even if the could prevent 100% of dwelling unit electrical fires would be to prevent less than 15% of dwelling unit fires
- Location
- Illinois
- Occupation
- retired electrician
I think we are a few decades away from having any statistically valid data as to the effectiveness of AFCIs. There are just not enough dwellings that have AFCI protection as compared to the total number of dwellings in the US.
However I have been listening in on some of the Task Groups for the 2026 code, and some non-supporters have been citing the increase in the total number of dwelling unit fires since AFCIs were first required on a limited basis in 1999. I don't see that data as saying AFCIs don't work, but it is interesting data.
However I have been listening in on some of the Task Groups for the 2026 code, and some non-supporters have been citing the increase in the total number of dwelling unit fires since AFCIs were first required on a limited basis in 1999. I don't see that data as saying AFCIs don't work, but it is interesting data.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
My understanding on how this all got started was the CPSC though we needed to have something that protects from arcing and that may prevent a certain amount of fires of electrical origin. Manufacturers took the challenge to make something, nothing wrong with that. But so far have not come up with anything that is really all that good at doing so without also having trouble differentiating from some current patterns that are deemed acceptable in some situations and we get undesired tripping.
They were not going to sit on what they spend on R&D until they have perfected something though, and promoted what they did come up with to the code making panels to get them on board with accepting it for use in code.
They lied to us from the start and sometime later came up with the combination type that detects series and parallel arcs that they previously said the older versions would do.
I still believe it is too difficult to maintain an arc at 120 volts long enough for it to be much of a fire hazard without additional interaction to keep feeding material into the arc. This is no different than welding with a stick welder - you keep moving closer to the work as the stick gets consumed, if you don't the gap grows too large and the arc goes out. I think possibly the biggest cause of electrical fires in the fixed wiring is failing connections that develop resistance - an AFCI can't differentiate between that or a desired resistance load.
My other concern (assuming AFCI's are the way to go) is after 30 to 40 years which seems to be the time when you start to find some failures in the install that maybe an AFCI would be beneficial to protect you from - will the electronics in the AFCI still be functioning? We all know that homeowners are well known to go press the test button on a monthly basis on these as well as all their GFCI's.
marcin_ose
New User
- Location
- Maysville, MO
- Occupation
- product designer
It seems clear from this extensive thread that a vast majority of electricians are not in favor of AFCI breakers. Is this fair to say, or are only the AFCI-haters speaking for all electricians - and somehow this thread is highly biased? This bias seems unlikely, because of the overwhelming response against AFCIs. If this thread is representative of the entire electrician population, then AFCI breakers clearly do not provide the value that they are intended to provide - which is fascinating because it blows one's mind how ridiculous and costly this mistake is. The global market size for the AFCI is about $5B - are we concluding honestly that this is a five billion dollar larceny - or is the situation more complicated than this?
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
It sure does, it sure does.
ptonsparky
Tom
- Occupation
- EC - retired
Close enough.
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
Not a scientific sample just own experience. Seen many burnt receptacles and fixtures that were not on AFCI and didn't trip a standard breaker and some that had started to burn the framing members when the event self extinguished without tripping a standard breaker. Now whether an AFCI would have tripped can't right say in every one of those, but the designed intended operation it should have. And, have seen conditions that start similar to that, that lead to the catastrophic failures seen on standard breakers, having tripped the AFCI. Seen it on a pinched wire under a light fixture, AFCI was tripping, change it to another AFCI still tripping, Add a standard breaker it didn't trip. Went to the last thing installed and found the pinched wire, repaired and put back the AFCI and it held. Couldn't see an actual break on the wire insulation but there was an obvious crush point on the insulation. Was the AFCI working as intended?
Another one recent found a circuit that never tripped on standard breaker but half the outlets not working. Eventually found a receptacle that had an arcing neutral that finally burnt the wire and receptacle to point of disconnecting enough that the circuit was no longer working downstream of device. Found simple loose, not visibly loose, connector with multiple little arc points under the wire and screw. This is similar to call I've received from GC complaining about AFCI tripping when running their table saw. Found similarly loose connection and tightened the terminal and AFCI no longer tripped. Was the AFCI working as intended?
AFA cost difference between standard breaker and AFCI-GFCI breakers it does seem to be disproportionate. But anytime something becomes "Mandatory" the price will become outrageous. Seen that with simple car insurance, when the state made it mandatory prices climbed 4 fold.
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
STOP SAYING THIS! AFCIs were never designed to detect overheating of equipment in the circuit. There have been several recent threads explaining this. They are designed only to detect AC waveform distortions that are purportedly associated with arcing that suddenly opens or closes a circuit. They cannot detect high resistance failures that don't open the circuit.
I suppose one could say that one way AFCIs are a giant failure is that it seems like nobody knows what they actually do. And I'll grant that if one thinks that AFCIs are a giant waste of money then it's rather a fine point whether they are waste money because they fail to do what they say they do (mostly false, IMO) or because they cost so much while claiming to do almost nothing (true, IMO).
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
I think there's a structural bias, and then there's the reality. By a structrual bias I mean one that arises from the situation, rather than due to electrician's personalities or indoctrination or something. Electricians see the high cost AFCIs. They would not see an immediate benefit, even assuming there is a long term benefit. They would (and did) see any teething problems that the technology has (lots of false positive trips). They also would be on the hook for fixing any real installation problems the AFCIs detect, but it would still be very difficult practically to determine if such a problem is real or a nuisance trip due to poor AFCI design. However AFCIs really work is super mathematical and a trade secret so even a smart, scrupulous electrician has no real way of knowing whether they can trust them. So AFCIs were going to be a hard sell to electricians in the field no matter what.
Then there's the reality, which in my estimation is that AFCIs apparently don't do much (except nuisance trip), and there's no long term evidence yet that they reduce house fires, injuries, or deaths. So yes, it's been a lot of cost for a benefit that can't really be proved.
Eddie702
Licensed Electrician
- Location
- Western Massachusetts
- Occupation
- Electrician
I agree that the newer romex does not seem as rugged as the old stuff. Less filler inside.
I've heard the same from people on local code council and all over. This isn't an aberration of a thread, nobody likes these things, they're a swindle.
There's flimsy statistical evidence they were needed in the first place, and flimsy testing to show that they would be effective against the issue they're supposedly solving.
Long-term statistical evidence for their benefit is going to be hard when we didn't even have clearly isolated evidence they were needed in the first place.
What we know:
- There are house fires sometimes
- Some % of them is caused by electrical fires, we're actually not sure at all how much given how many fires are listed as "unknown cause" and how weak and half assed many fire investigations are.
- Some % of the subset of electrical fires are caused presumably by arc faults, with even less certainty as to which is which, given fire inspectors just sort of wave their hands half the time it seems.
brycenesbitt
Senior Member
- Location
- United States
Don't forget the nuclear power plants.
Yes, the ones that are running for no purpose other than operating the tiny computer and relay in each of millions of AFCI devices 24/7/365.
Vampire power.
When AFCIs were first introduced, this is how things played out:
1) They increased the cost of wiring a house, so there was grumbling. But if they work as advertised, we’ll say OK, and move on.
2) Then came the nuisance trips resulting in callbacks. This started the “hatred.”
3) The manufacturers started adjusting the software algorithms to eliminate nuisance tripping. That began the “Wait a minute. How do we know they’ll still work?” No answer from the manufacturers because we now know they don’t work.
4) Then we started looking into how these things got into the code and discovered they were rammed down our throats by the manufacturers. At least one senior engineer resigned from the panel that was supposed to evaluate them in protest.
And here we are…..
macmikeman
Senior Member
- Location
- Planet macmikeman
There is one good thing or part to the AFCI debacle , they don't give you myocarditis or blood clots.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
I'm not so sure, can't stress anxiety and frustration contribute to those?
Unfortunately the standard for gathering fire incident data NFPA 921 seems lacking and in my opinion needs to be updated, I dont think any fire incident software now collects what type of breaker was involved in a fire incident.
And nobody is aggregating data on near misses (other than insurance companies).
For example small fires or electrical incidents that may cause smoke damage and get extinguished before 911 is called but result in a insurance claim.
It would be interesting to look at data from a major city say NYC that has held the code back several cycles and compare to a similar major city that is always on the latest NEC. If NYC is on the 2008 NEC then they are just doing AFCI's in what bedrooms?
I dont think you'll find any electricians wearing I ♥ AFCI's T shirts.
I'd also say this forum is has a very very high percentage of retired electricians (as in no longer practicing) and non-residential electricians whom tend to encounter more problems with AFCI's.
I have found AFCI's dont really cause callbacks for skilled residential installers at least the ones that I know and see around.
There is a different skill set that house ropers have than mc slingers' and big industrial guys, and the day in day out house ropers are not having the majority of AFCI issues.
I am not defending AFCI's but just saying what I see.
Case in point I fixed an AFCI issue for a local retired electrician whom was doing his own kitchen remodel and got stuck.
It was fun to meet him, he told me all about working big crazy union jobs and traveling all over, he actually wanted to set up some contactors so he would not even need to fix the issue with his 4-way switch.
In the end he just had a neutral crossed in a switch box with a old knob and tube neutral was a 1 hour fix, 10 min to fix 50min to chit chat he gave me a great old conduit bender.