In the spirit of Alan's request that we comment on the code proposals that we have problems with, I'd like to start a couple threads here in the General Forum, where they will be more visible, for people to share ideas for comments to the CMPs.

I have the following major issue with the proposed residential AFCI requirement: If what I read is correct, there are no exceptions--ALL 15 & 20 amp circuits will have to be AFCIed. There are a number of places where there are very good reasons NOT to have AFCIs, because of the risks that devolve from spurious tripping:

1. Grandma's ventilator. (I'm talking about the medical variety, that keeps her breathing.)

2. The sump pump.

3. The freezer.

4. Furnace circuits in Fargo, North Dakota.

5. There are reports of various properly-operating equipment that trips AFCIs, such as treadmills.

6. As a business, I do engineering development in an office in my home. Some of my commercial equipment, and designs under test, may be incompatible with AFCIs.

7. I have business computing equipment that I don't want to have tripping out. (Although I recognize that "the rats nest of 'surge-strips' at the computer" may be exactly what the proposal is intend to protect against. There appears to be a fundamental conflict here.)


I will leave it to others to argue about the cost and "nanny-state" aspects. Cost I can tolerate; tripping out the sump pump when I'm away is something I can't tolerate.



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

I suspect Home Depot will be stocking up on regular single pole breakers and the handy man will have lots of work. It may end up being like the pool door alarms. I always said there was only a dozen or so of them and they just kept rotating through new houses. It is the first question most customers ask on their "new home walk".

How do I disconnect this thing?

Greg, what I'm hoping for in this thread is cogent arguments that can be presented to the folks who make the Code, so that we can get a code that we can live with without resorting to fixing things after the inspector leaves.

It's very possible that if, say, the code requires an AFCI on the sump pump circuit, and you make the very reasonable correction of replacing that AFCI with a normal breaker, that there could be very bad repercusions if a fire were later to occur. An EC who made the change might find himself legally liable for the fire; a homeowner who made such a change might find that his insurance is voided by the intentional circumvention of code. If a death were to result from said fire, one could even find oneself facing manslaughter charges. If the code had a an exception that covered the sump pump circuit, such issues would be avoided.


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

Well, it seems whenever any new technology is required, a lot of folks resist the change!

Grandma's ventilator has battery back-up and an alarm
The sump pump has a high limit alarm, and maybe legally required standby power. And, if it is really that important, then it will be hard-wired to a non-GFCI or AFCI circuit.
The freezer could have an alarm.
The furnace is already hard wired. (hard wired does not required AFCI.)
Appliances that trip the AFCI do so because the AFCI is doing its job. The industry will have to manufacture motors that do not arc. Brushes are out, induction motors are in.
Incompatibility with AFCI, I suspect will be much less than these screaming sticks in the mud.

AFCIs are required, not because of a nanny-government. They are required because we have a new technology that can save lives.

Induction motors for everything? I think not.

Alan

earlydean, your comments suggest that the secondhand report I've heard that AFCIs will be required on all 15- and 20-amp circuits is not completely accurate, as you appear to believe that direct-wired circuits are exempted. Can someone provide a link to the actual language that is currently proposed for the 2008 Code?

http://www.nfpa.org/assets/files/PDF/ROP/NEC2008ROP.pdf

This is on page 81 of 998:

"2-111 Log #2606 NEC-P02 Final Action: Accept in Principle in Part
(210.12)
____________________________________________________________
Submitter: Thomas Domitrovich, Eaton Electrical
Recommendation: Revise text to read:
210.12 Arc-Fault Circuit-Interrupter Protection.
(A) Definition. Arc-Fault Circuit Interrupter. (No change)
(B) Dwelling Unit Living Areas . All 120-volt, single phase, 15-
and 20-ampere branch circuits supplying outlets installed in dwelling unit
living areas shall be protected by a listed arc-fault circuit
interrupter installed to provide protection of the branch
circuit.
Exception: (No change)"

and this on page 89:

"2-142 Log #3488 NEC-P02 Final Action: Accept
(210.12(B))
____________________________________________________________
Submitter: Alan Manche, Square D Co.
Recommendation: Revise 210.12(B) as shown below:
(B) Dwelling Units. All 120-volt, single phase, 15- and 20-ampere branch
circuits installed in dwelling units shall be protected by a listed arc-fault circuit interrupter, combination type installed to
provide protection of the branch circuit."

There are two submissions, one for just circuits supplying outlets, and this one for all circuits.

Now we had better stop this branch of the discussion or the moderator will pull the plug and send us to the 2008 NEC page!

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).]

reno:

Thanks for the information on the GFCI's. I wasn't aware of the time line involved, but my limited reading on the subject seemed to make it less time that I had thought.

Bold emphasis below added by me:


Now if someone can convince the CMP to wait on the use of AFCI's on ALL circuits untill the things are proven to work safely and properly, we'll all be better off.

Steve,
They don't trip for switching because they don't look at that type of arc. They only look at parallel arcing faults...faults from hot to neutral. They will trip on a ground fault because of the GFP protection. They may trip on a poor connection (series fault) if the fault progresses to a parallel arcing fault or to a ground fault...but will they do this before or after the fire starts.
Don