I think everyone who's ever installed one has simply wished they had some verifiable proof, other than just the manufactures claims, to demonstrate to homeowners that that they would actually work as intended. Pressing the test button and having the status LED's light up is neat, but doesn't seem to really mean much. I like how they say they have "proven to be so effective"... They must mean in the laboratory, because that seems to go against everything that is now known about how they don't work in the field.
"AFCIs have proven to be so effective that the 2011 National Electrical Code (NEC) includes requirements for AFCI installation in residential construction. The NEC requires that AFCI technology be installed for bedroom circuits as well as other living areas of the home, including living, dining, and family rooms. Though these requirements are currently limited to newly constructed homes, older homes with aging wiring systems can also benefit from the added protection of AFCIs. Depending on the size of the home, the cost to install AFCIs ranges from $140 to $350."
I hear you. They are to protect against faulty wiring typically found in old houses but required in only new construction.
My biggest gripe is there is no effective way to locate the fault if its starts tripping. You look at an average living room. Are you going to be responsible for moving a customers stuff from the wall to gain access to the recepts? Once in there you will have to pull every device to look for anything that could be the culprit. Even after that, Crawing around the attic and crawl space, you are lucky to see 5% of the circuits wiring. Odds are the problem lies in the wall somewhere. You send the customer a bill for a days time when two days later, the breaker trips yet again. You think that customer will still cut you a check? How easy is it going to be to get paid? We are going to be stuck holding the bag.
I still think the most effective trouble shooting tool might be a GFCI breaker. At least it will let you decide if this is a ground fault (usually a grounded neutral) or some kind of arc signature fault from a piece of equipment. I doubt these things ever found a real arc.
There are some AFCIs now that include diagnostic LEDs and that will help. Unfortunately the majority of AFCIs installed in the housing boom were older technology. I wonder how many get thrown away after the home warranty expires and get replaced with a standard breaker.
I do wonder how they decide which fires would be prevented with AFCIs. I am not even sure how they decide if a fire was "electrical". I suspect that is whenever they don't have a better cause.
This video that's been circulating around the web looks a little unnerving. It seems to show that they may be next to worthless for a fairly substantial, sustained, heat generating series arc, which is strange because we were always told that the original branch-feeder AFCI's where supposed to work for that type of arcing fault. I think everyone is probably aware that the newer combination type AFCI's are having real issues detecting the parallel faults they were claimed to be able to handle. So, I'm wondering where that leaves us now as far as the integrity of the overall AFCI design goes. I'm thinking that sooner or later someone is going to call their bluff and demand some sort of verifiable independent real world field testing be done on these devices. I mean other than the homeowners and contractors that have been indirectly mandated to pay for it. AFCI Test
I looks like the guy is using a Cutler Hammer CH style breaker for the arcing demonstration in the video, which is kind of has me reminiscing, because I can remember back as an apprentice doing work in an attic on a live circuit fed with a standard 15A CH breaker two floors down in the basement and literally arc welding with it by touching the hot wire against the side of a grounded J-box. Never was able to get it to trip, but I had done that several other times over the first few years and that was just something those CH breakers were well known for, back then anyway.
I think you have the serial and parallel adoption backward. I also wonder if the typical bad splice actually arcs at all. The classic description is a high resistance joint is that it increases resistance the hotter it gets in a thermal runaway, until it either blows open or starts a fire. When they were pitching this (and one of the C/H developers was a neighbor) the example he was selling back in the last century was a pinched zip cord behind the bed, buried in dust bunnies, hence the original bedroom requirement.
I believe it was this parallel fault that the AFCI ver 1.0 detected. The series fault came in at ver 2.0 or 3.0
I could be wrong tho. All I know is they were still trying to get ver 1.0 working when it showed up in the 1999 code to be effective 1/1/02 when they promised they would actually have one on the market. We have been beta testing those designs now for 10 years and there were several obsolete versions installed at the point of a government gun. It does beg the question whether the CPSC should require the manufacturers to recall all of the old ones (parts and labor) since they are the ones who pressed NFPA to make them code before they were ready. Maybe if there was a down side for the manufacturer, they would not be so fast in making their latest bright idea the law of the land.
You're right Greg, I had my memory card in backwards. Thinking back over the years, I can't say I recall actually having a problem with AFCI's at the initial installation and load testing that I do at finish, but troubles sometimes start once the HO begins plugging in something of theirs like a power tool, a vacuum or some other type of portable appliance.
Complaints from the resi ECs has slowed down to a trickle about the AFCI issues they have. Complaints relayed to my office from homeowners regarding 'the new safety things' pop up less frequently. Is that a good thing??
Most of the issues that I'm aware of at the begining of AFCIs required (2008 NEC, here in NJ) were related to the workmanship, & trying to use MWBC (3-wire). The learning curve has reached it's crest!!
We (Twp) purchased two Ideal 61-165 indicators/testers which turned out to be a bad move. Not mentioned within the instructions was that they should not be used for repetative testing, which caused a overheating issue.
The next hurdle that is looming on the horizon....AFCI for solar PV!!
Or, maybe, folks are simply replacing the AFCI's with standard breakers .... or just not complaining anymore.
I've seen that many times in industrial operations - just because the complaining stops you cannot assume the problem was solved. More often, folks just quit wasting their energies making complaints that were ignored.
PV doesn't need an AFCI. PV needs an 'off' switch!
Reno: Guess I'll never know, based on your point. BTW, your point is well taken on my end.
Back in my EC days, which were 95%+/- comm & industrial (when we had industry) when the 'new' GFI things were first out, the complaints also were out. I guess, with the evolution of the device (AFCI) eventually the technology will work as intended.
So far, I heard on the street that there is one inverter that is supposed to have AFCI built in. Noone has seen it yet.