ECN Forum Forums General Topics of the Trade General Discussion Area Arc Fault

Electric-Ed this makes me wanna ask, how are they being produced now. ??
No doubt if the 2005 code changes to the suggested proposal that all services old and new install AFCI protection for all 120 volt circuits, as proposed by the CPSC then the cost of installation will really go up. I havent looked at the numbers yet but a GFCI breaker is about 27.50 and the AFCIs are almost 40.00. It sounds pricey to me.
WC

Replies:
Wocolt:
The political powers that be at our stste capital did not adopt the NEC section re: AFCI.
Our state has a "Uniform Construction Code" that consists of various national codes that are utilized within NJ. For each "Code" that is adpoted, there are various amendments, the AFCI requirement being one of them.
BTW, we are still under the '99 NEC, as the State did not adopt the '02 NEC as of today. They have been saying "any day now" for quite some time. Hopefully, they will act soon.

GWZ:
Interesting, your area "adopted" the NEC, but you have no inspections? What is the assurance that everyone "follows" the Code???

John

Virgil,

I thought that WV started requiring inspections. I know that Morgantown has thier own city inspector and that outside of the city you have to get an inspection agency.

I am allowed to inspect in WV, especially anywhere in Allegheny Power's service area.

I know that your in southern WV but I thought this was state-wide. Whats the rule?

M'66,

That would be great news!?!?

City of Lewisburg has a building inspector, but other than Allegheny Power, Nada as far as I know!

Right now, Greenbrier County has actually regressed from requiring a building permit, to some grey area between no requirement and just "over-looked" law. The controversy started when someone realized that Greenbrier County provided no service for their fees, and either had to provide inspections (as a service) or drop the permit requirement. It is still in limbo, as doesn't look real good for any inspection requirements in the near future.

My worth as a local EC would practically double if it happened.

Has anyone else run into vacuums or power tools causing nuisance trips?

I would be very interested in hearing from anyone who has been using AFCI breakers. In RI the code requiring the use of AFCI was just pass last fall. After many discussions with the local inspectors about installing these breakers on existing circuits, AFCI breakers are not going to be required on revamps. As I understand how these breakers work, they need a dedicated neutral as does a GFI. The problem being, a revamp with existing wiring would be impossable to estimate without testing all the neutrals first. I was also told by a factory rep. at a local trade show, in Sept, that a split wired AFCI breaker would soon be available, which would be another problem with a revamp of a service containing a split wired circuit. I also asked if a AFCI receptacle was in the R&D works and the answer was not to his knowledge. One final note on AFCI, at the same trade show this factory rep. had a demonstration setup trying to show how effective these breaker were. First he would cut through a live piece of zip cord with a razor blade, protected by a standard 15 AMP breaker. There was a flash, breaker tripped and a small burn hole in the razor blade. Now the same test with a AFCI breaker, huge flash and the better part of the razor blade was missing. Needless to say I do not have a lot of confidence in these new breakers.

This is very interesting.
Did the factory rep mention anything about failure rates for these afcis, and why it would take so much longer to trip than a standard breaker.
I read somewhere that SQ-D QO breakers open in one cycle or 16.667 mili-seconds. and also that the AFCIs open in approx 8 cycles or 133 miliseconds. All things being equal this is still very fast. In real terms about 3 blinks of an eye.
When I first read about the afci technology the idea was that on 15 and 20 amp breakers there could be sustainable faults of less than 20 amps say 5, 10 15 amps, this was in the EC & M magizine, and these devices were to pick up these arching fault and open the breaker. Now that doesnt seem to be the case.
From what I have been reading is that there must be a sustainable 75 amp Arc for the app.8 cycles before the breaker will open up.
again all things being equal, it would take 6-10 times 20 to trip a standard breaker in less than a cycle.
So what are we looking at here a very selective devive ?

From what you describe the standard breaker opens faster than the afci under that kind of fault.
It doesnt sound like the factory rep had much faith in afci s.
What was his opinion ?

WOC