ECN Forum Forums General Topics of the Trade General Discussion Area AFCI Issues Thread

Isn't funny that the submitter is Eaton corporation.(C-H)

This proposal is simply for monetary gains for a manufacturer plain and simple.

Has anybody tallied a count of accepted proposals from manufacturers or big names in the industry verses the little guys.

I started too, but just can't stay with it long enough, My attention is more tunnel visioned to specific articles.

Roger

If my understanding of the code definition of "outlet" is correct, all circuits supply "outlets." I think the distinguishing feature of the first proposal you posted, earlydean, is that it requires AFCIs only for circuits supplying outlets in "living areas." The 2005 code doesn't have a definition for "living area," so I don't know exactly what that term means.

It does appear that there is an existing exception for life support equipment, so the first item in my list is covered.

I note in reading through some of the proposals and comments on them, that section 700-something prohibits putting fire alarms on AFCIed circuits. It would appear that they themselves don't have enough confidence in these contraptions to allow them to be used when the rubber really hits the road.

Consider the following set of facts:
1. The NFPA themselves don't have enough confidence in the reliability of AFCIs to even allow them to be used on fire alarm circuits;
2. There is a lot of evidence that AFCIs have a high level of unreliability in the form of false tripping;
3. People on this forum have done their own tests of available AFCI that showed that they are incredibly unsuccessful at detecting actual arc faults.

These facts cause me to reiterate the main point the list in my original point, that there are many uses of electricity where a falsely-tripping AFCI will cause very bad problems. These applications should be permitted to be on circuits without AFCIs.



[This message has been edited by SolarPowered (edited 08-04-2006).]

earlydean,
That might be true if there was an AFCI device on the marker that could do what the manufacture's said they could do in the original proposals for the AFCI...some 13 years ago. Unfortunately there is no such device on the market at this time. There isn't even a combination device on the market at this time and that type of AFCI is required to be used starting 1/1/08.
Don

My concern with AFCIs is I that I don't understand how they work. I can understand how GFCIs work but is there a unique electrical or electronic signature associated with arc faults?
And what is an arc fault anyway?
And are they that common?
Are there any statistics showing a lower incidence of fires in houses equiped with these devices or is it just that they are required only in new construction? [Compare this with the history of seat belts in cars.]
~Peter

Yes, there is a unique characteristic response of an arc fault. As I understand it, AFCI breakers generally monitor line voltage and current and contain a microprocessor to monitor the waveform. They also contain GFCI protection, but only for 30ma or greater to protect from ground faults that could cause fires, not to protect personnel. (So it doesn't count as GFCI unless it's listed at 6ma)

The arc fault current waveform is typically fairly sinusoidal while there is significant voltage, but drops to 0 during the null point of the cycle creating shoulders. Likewise, the voltage appears fairly sinusoudal through the lower voltage portions of the cycle, but the top of the sine wave is clipped as the arc forms, with short spikes as the arc is formed and extinguished. It has to detect this arc and trip within 8 cycles. And NOT trip for "normal" arcing, like arcing when a switch is switched, or during operation of dimmers, switched power supplies or other devices that create dirty power and harmonics. Basically, they're tuned to only trip with a short circuit current of at least 5A AND a characteristic arc-fault response.

[This message has been edited by SteveFehr (edited 08-04-2006).]

AFCIs are snake oil. It is a solution looking for a problem it might fix. We have a couple years of experience. Can anyone definitavely give us a number of fires that were prevented?
Statistics should show us something if this is the panacea that would justify this billion dollar fix. The AHJs that opted out of the AFCI rules should have had worse fire statistics on their new homes.

All of the alarms in the world don't help if you are not home when the AFCI trips. Do you really want to come home from a long weekend to find all your food spoiled, pipes frozen or your house flooded? Do you really want to be in the middle of your year end tax preparation and have your PC crash? How all about all your buddies missing the last 30 seconds of the big game while you run downstairs to reset the breaker? That could get you hurt.
Sure I could put this stuff on a UPS or battery backup but if the fault is downstream of the UPS or battery you have negated the protection you were supposed to have with the AFCI.
All of this for a device we can't even prove has saved a single life.
Comparing this with GFCIs is not any more valid than comparing safety glasses with wearing a tin foil hat.


[This message has been edited by gfretwell (edited 08-05-2006).]

And so far AFCI's seem to be creating more problems than they fix.


Wow. If manufacturers of these PITA devices can try to force through a Code Change to enhance thier own sales, then maybe I can submit some changes to Articles 540 (Motion Picture Projectors) and 640 (Audio Signal Processing, Amplification, and Reproduction Equipment)to make MY contract requirements for dedicated neutrals and properly phase-sequenced subpanels a Code Requirement!! {sarcasm in case you didn't get it. } My years of field experience has proven that my techniques will save equipment damage and potential fire hazards from burning amplifiers and runaway film projectors.


George hit it right on the head. Even Harry Homeowner will get the bright idea to try changing out those pesky AFCI's with the sure (to cause a) fire "advice" from the box store know-it-alls. Let's see how that will adversely affect house fire statistics. (Not to mention the number of DIY's injured or killed messing around in live panels.)


Seems to be the direction we've been heading, especially if this boneheaded proposal gets put in the Code.



Again, George nailed it:


and:


If they haven't gotten it right in thirteen years, that should be a HUGE WARNING FLAG right there!!! I don't recall GFCI's taking that long to reach a state of high reliability and low cost.

What a mess!!!!!

MX. there's the diference. GFCI's were nOT accepted, and faced tremendous opposition, for nearly 20 years. Even once the technical "bugs" were worked out, there were numerous 'human engineering' issues to be dealt with, before they could reliably wired correctly.
Indeed, the latest "fix" for mis-wiring only took effect last month!

Adoption of GFCI's was slow, and the application was quite limited, until the thing was prooven in the field.

How great was the resistance to GFCI's? I remember the inventor touring the country, placing his young daughter into a tub of water, and dropping a toaster in- to proov the things worked! (And this guy surrendered his patent, and nad no profit to make!)

The opposite has happened with the AFCI. A fancy new invention is assumed to be a great idea, then mandated for use everywhere.

I do not have the code book with me but I belive there is a exception to afci"s when it comes to medical equipment in the home. When I look up the article I"ll let you know. Although only in my third year as a apprentice Im old enough to remember when the contraversey regaurding GFCI"S was going on. Im not totally sold on the afci"s yet as i belive all the (Bugs) have not been worked out yet. Especially with the smoke and O2
detectors in the house. Touchy subject at best

This webpage is full of statistics from the Fireman's association:
Click Here

Seems to me too, that most fires in homes are caused by dumb actions by the home dwellers!

Edited to shrink link

[This message has been edited by Roger (edited 08-05-2006).]