'Proof' that AFCI devices really locate arcs.

[user 100]

He is saying even those that care can make mistakes.

And he is absolutely correct.

 

[iwire]

And he is absolutely correct.

For sure.

I care yet I have made my share of mistakes.

 

[peter d]

I care yet I have made my share of mistakes.

Who are you, and what did you do with iwire?

 

[mbrooke]

That is what is known as an opinion, not a fact.

Then I take it you have a better way of catching glowing connections? If so you could be a millionaire.

So you feel only electricians do wiring in homes?

At times I seriously believe only electricians should be allowed to touch home wiring. It would certainly eliminate a tremendous amount of code violations. This video is a perfect example:

https://www.youtube.com/watch?feature=player_embedded&v=DVo0_IBrza0

 

[mbrooke]

He is saying even those that care can make mistakes.

Wait, so now your telling me we need all these extra code mandates? :?

 

[user 100]

Wait, so now your telling me we need all these extra code mandates? :?

iwire was only interpreting (correctly) what templdl pointed out. And there is a lot of truth in what templdl posted-basically no matter how careful you are (or looked at another way no matter how many nec mandates are in place) mistakes are going to be made. We cannot eliminate risk in this trade now matter how many contingencies we put in place.

 

[mbrooke]

iwire was only interpreting (correctly) what templdl pointed out. And there is a lot of truth in what templdl posted-basically no matter how careful you are (or looked at another way no matter how many nec mandates are in place) mistakes are going to be made. We cannot eliminate risk in this trade now matter how many contingencies we put in place.

But should code try and mitigate that risk? And to what extent?

 

[user 100]

But should code try and mitigate that risk? And to what extent?

Yes, it should but only to a reasonable extent.

 

[mbrooke]

Yes, it should but only to a reasonable extent.

But the million dollar question is what extent.

My personnel belief is before the NEC mandates anything we need to have an unbiased source investigate the exact cause of dwelling fires in meticulous detail. At this point we having nothing but assumptions about fire statistics.

 

[growler]

My personnel belief is before the NEC mandates anything we need to have an unbiased source investigate the exact cause of dwelling fires in meticulous detail. At this point we having nothing but assumptions about fire statistics.

I fully agree. I will admit that I have no idea of how the majority of electrical fires start.

 

[romex jockey]

Yes we do Growler....

you along with the rest of us have witnessed incendiary events our entire careers

In fact we see them posted on pro forums by the hour

But you give me $10,000,000 , dominion of NRTL 's , and i'll have you posting the moon is made of green cheese ....


~RJ~

 

[iwire]

My personnel belief is before the NEC mandates anything we need to have an unbiased source investigate the exact cause of dwelling fires in meticulous detail. At this point we having nothing but assumptions about fire statistics.

My personal belief is that every person I meet should hand me a crisp $100.00 bill. I also believe we both have the same chances for that to happen.

We need to keep in mind that the NFPA is a private entity, it is not a government run or paid for organization. No one can tell the NFPA how to do things, the only way to force them to do something is for areas to stop adopting the NEC as the code. But we don't see many areas do that, most areas adopt it and make amendments to it if they have issues with certain sections.

I am not so sure the NFPA should be a non-profit but that is really beyond my level of concern.

It is my understanding that the NFPA was created by insurance companies and manufacturers from the start so to say more than 100 years later it is a conflict of interest seems a bit late.

I have no idea how to make the NEC better but I am 100% sure that if it was being written and produced by a government agency that it would be much, much, much worse.

 

[templdl]

To detect 'glowing connections" in my opinion from a remote location such as would be breakers or fuses would pose to be a most difficult task. With breakers or fuses they are monitoring the current that passes through then. They have no idea of the load that they are serving. Isn't a glowing connection basically a resistive load in series with the load? That if there was no load there would be no need to pass current through a compromised connection unless it was a unintended connection between the L-N or L-G.
What type of glowing current would even cause a breaker of fuse to respond to a glowing connection when both devices are respond to a given TC curve?
Besides the GF feature the intent of the AFCI is to recognize snd respond to the erratic current nature of an arc fault, either series are parallel, which most if not all of use have concluded is a fallicy.
Personally I do think the the common branch circuit breakers of load centers be given a second look and not accepted the way they presently are. Because the manufacturing costs is extremely sensitive, I used to know what the actual costs were years ago, it is dirt cheap. It is a given that those breakers must be manufactured with a bimetalic element that trips the bresker is calbraterd to match the tasting of the breaker. However, the mag/instantaneous element is not. If I can recall, the only difference between 15, 20, and 30a trip breakers are the thermal elements. Should more attention be given to the instantaneous response of these breakers in order for them to respond the faults? As I said before SqD seems to have addressed this issue by reducing the mag calibration while offering a high mag which I believe was a former std calibration as optional. While C-H still used the original mag calibration as standard which equates to the SqD high mag and offers a low mag as optional which soimilsar to the SqD std breaker.
So the manufactures have already made inroads in the consideration of the mag pickups, but I think more serious consideration should be given. The mag elements are really very crude and cheep. If more attention would be given to the engineering and manufactue of a more precise mag element that may take a giant step to responding to faults. I know it would add to the cost but I think it would be incremental if it makee sense to do.

 

[user 100]

To detect 'glowing connections" in my opinion from a remote location such as would be breakers or fuses would pose to be a most difficult task. With breakers or fuses they are monitoring the current that passes through then. They have no idea of the load that they are serving. Isn't a glowing connection basically a resistive load in series with the load? That if there was no load there would be no need to pass current through a compromised connection unless it was a unintended connection between the L-N or L-G.
What type of glowing current would even cause a breaker of fuse to respond to a glowing connection when both devices are respond to a given TC curve?
Besides the GF feature the intent of the AFCI is to recognize snd respond to the erratic current nature of an arc fault, either series are parallel, which most if not all of use have concluded is a fallicy.
Personally I do think the the common branch circuit breakers of load centers be given a second look and not accepted the way they presently are. Because the manufacturing costs is extremely sensitive, I used to know what the actual costs were years ago, it is dirt cheap. It is a given that those breakers must be manufactured with a bimetalic element that trips the bresker is calbraterd to match the tasting of the breaker. However, the mag/instantaneous element is not. If I can recall, the only difference between 15, 20, and 30a trip breakers are the thermal elements. Should more attention be given to the instantaneous response of these breakers in order for them to respond the faults? As I said before SqD seems to have addressed this issue by reducing the mag calibration while offering a high mag which I believe was a former std calibration as optional. While C-H still used the original mag calibration as standard which equates to the SqD high mag and offers a low mag as optional which soimilsar to the SqD std breaker.
So the manufactures have already made inroads in the consideration of the mag pickups, but I think more serious consideration should be given. The mag elements are really very crude and cheep. If more attention would be given to the engineering and manufactue of a more precise mag element that may take a giant step to responding to faults. I know it would add to the cost but I think it would be incremental if it makee sense to do.

Lowered mag certainly makes better sense than afci. It would offer increased protection against faults, and another bonus is that it wouldn't contain any electronics that would be vulnerable to damage like the afci. Sometimes "new" isn't always good-Every year close proximity lightning strikes wipe out all those cordless phones attached to their bases, yet the veteran WE 500 (I think I still have one of those somewhere in my junk) still hums along.......

 

[growler]

My personnel belief is before the NEC mandates anything we need to have an unbiased source investigate the exact cause of dwelling fires in meticulous detail. At this point we having nothing but assumptions about fire statistics.

My personal belief is that every person I meet should hand me a crisp $100.00 bill. I also believe we both have the same chances for that to happen.

Bob have you considered the fact that many TV evangelist have done just that. They get perfect strangers to send them money and many times more than a $100 bill.

One person really can't change things but there is power in public opinion.

The reason that the NFPA is so powerfull is that the public has faith in the organization. Now people are losing faith in everything from the government to the dollar bill.

If the public is ever made aware of the fact that a very expensive solution to a problem that may not even exist was forced upon them by a certain organization what do you think would happen?

 

[Sierrasparky]

But should code try and mitigate that risk? And to what extent?

Ok to a reasonable level of risk. I have problem is when someone develops a product that may solve a problem ( I say MAY ) and the code makes it mandatory without fully vetting the product.

 

[mbrooke]

Ok to a reasonable level of risk. I have problem is when someone develops a product that may solve a problem ( I say MAY ) and the code makes it mandatory without fully vetting the product.

You mean like AFCIs I fully agree, and the code should be written in such a way that no one product is the answer to a problem. A perfect example is arc flash mitigation, a list of options are given that do not endorse a single product or method.

 

[iwire]

If the public is ever made aware of the fact that a very expensive solution to a problem that may not even exist was forced upon them by a certain organization what do you think would happen?

Sadly little to nothing.

Now off to build my pulpit.

 

[mbrooke]

My personal belief is that every person I meet should hand me a crisp $100.00 bill. I also believe we both have the same chances for that to happen.

We need to keep in mind that the NFPA is a private entity, it is not a government run or paid for organization. No one can tell the NFPA how to do things, the only way to force them to do something is for areas to stop adopting the NEC as the code. But we don't see many areas do that, most areas adopt it and make amendments to it if they have issues with certain sections.

I am not so sure the NFPA should be a non-profit but that is really beyond my level of concern.

It is my understanding that the NFPA was created by insurance companies and manufacturers from the start so to say more than 100 years later it is a conflict of interest seems a bit late.

I have no idea how to make the NEC better but I am 100% sure that if it was being written and produced by a government agency that it would be much, much, much worse.

I agree, unfortunately few areas are willing to make changes. Being blunt most people who have that power have no clue about electrical. They automatically assume that the NFPA is a god send knowing all there is to know. And I have no doubt the CMPs know that.

No one can tell the NFPA how to do things,

Manufactures can.

To detect 'glowing connections" in my opinion from a remote location such as would be breakers or fuses would pose to be a most difficult task. With breakers or fuses they are monitoring the current that passes through then. They have no idea of the load that they are serving. Isn't a glowing connection basically a resistive load in series with the load?

In theory it would be impossible. The only 2 ways to do it is to monitor the connections directly or having electronic sensors through out the circuit that compare or measure voltage drop and then tell the breaker to trip on a high fall of potential.

That if there was no load there would be no need to pass current through a compromised connection unless it was a unintended connection between the L-N or L-G.
What type of glowing current would even cause a breaker of fuse to respond to a glowing connection when both devices are respond to a given TC curve?

In truth none. A glowing connection is just another resistance in series with a load, same as the natural impedance of a circuit.

Besides the GF feature the intent of the AFCI is to recognize snd respond to the erratic current nature of an arc fault, either series are parallel, which most if not all of use have concluded is a fallicy.

The UL reports done for the CPSC actually confirm arcing is not likely in a dwelling. So even the very supporting literature the CMP was presented says otherwise.

Personally I do think the the common branch circuit breakers of load centers be given a second look and not accepted the way they presently are.

I agree, and I think some may have to some degree in the 90s.

Because the manufacturing costs is extremely sensitive, I used to know what the actual costs were years ago, it is dirt cheap. It is a given that those breakers must be manufactured with a bimetalic element that trips the bresker is calbraterd to match the tasting of the breaker. However, the mag/instantaneous element is not. If I can recall, the only difference between 15, 20, and 30a trip breakers are the thermal elements.

I can not speak for other manufactures (if you know Im really curious ), but in Square D breakers 15, 20 and 30 amp all have the same magnetic trip:

http://static.schneider-electric.us...it Breakers/QO-QOB Circuit Breakers/730-4.pdf

Ditto for higher ratings:

http://static.schneider-electric.us...it Breakers/QO-QOB Circuit Breakers/730-5.pdf

http://static.schneider-electric.us...it Breakers/QO-QOB Circuit Breakers/730-6.pdf

http://static.schneider-electric.us...it Breakers/QO-QOB Circuit Breakers/730-7.pdf

However, what interesting is that single pole 15 and 20 amp breakers have a greatly reduced magnetic trip:

http://static.schneider-electric.us...it Breakers/QO-QOB Circuit Breakers/730-2.pdf

http://static.schneider-electric.us...it Breakers/QO-QOB Circuit Breakers/730-3.pdf

Should more attention be given to the instantaneous response of these breakers in order for them to respond the faults? As I said before SqD seems to have addressed this issue by reducing the mag calibration while offering a high mag which I believe was a former std calibration as optional. While C-H still used the original mag calibration as standard which equates to the SqD high mag and offers a low mag as optional which soimilsar to the SqD std breaker.

I think manufactures know something. In the 80s and earlier most single pole breakers had a magnetic trip value starting at 15x, 20x being typical with some going over 32x. That was exceptionally high, most double pole breakers today are less then that However in the 90s for reasons undisclosed the magnetic trip levels in 15 and 20amp breakers began to silently go down to an average of 10x. If I am correct QO has always been below 10x for some time prior to the 90s.

So the manufactures have already made inroads in the consideration of the mag pickups, but I think more serious consideration should be given. The mag elements are really very crude and cheep. If more attention would be given to the engineering and manufactue of a more precise mag element that may take a giant step to responding to faults. I know it would add to the cost but I think it would be incremental if it makee sense to do.

Manufactuers have already studied this to some degree no doubt and I do beleive this subject should be revisted today, especally with newer homes no longer useing window AC units. Lowering the magnetic trip on a breaker is cheap, certianly cheaper then adding electronics.

Lowered mag certainly makes better sense than afci. It would offer increased protection against faults, and another bonus is that it wouldn't contain any electronics that would be vulnerable to damage like the afci. Sometimes "new" isn't always good-Every year close proximity lightning strikes wipe out all those cordless phones attached to their bases, yet the veteran WE 500 (I think I still have one of those somewhere in my junk) still hums along.......

I agree. Everyone but the US and Canada took that route. Its ironic though because that was the orignal soltuion to branch/feeder AFCIs but the idea was scrapped over electronics. Magnetic trip is not only surge resitnant as you say but does not busince trip on current ripples. And the cost is a no brainer.

 

[user 100]

Its not even cheaper, an AFCI wont do squat. IF a person can make a splice correctly you dont need GCI.

Personally, and I might get flack, but in truth the real issue isn't even the NEC; its DIYs, handymen and lazy electricians behind nearly all electrocutions and most fires. DIYs are probably the worse.

For years I have given advice on DIY electrical forums and the stuff I see is beyond mortifying. Ive lost all faith. People do not join these forums to ask how to do something correctly, they join to reassure themselves in their ignorance. The other DIY posters are equally clueless giving away advice that is usually incorrect and often down right dangerous. More often then not they will argue with any electrician for who tries to give correct advice pages on end since they did it on their own home and it hasnt burned down yet. The DIY web articles arent helping either, they are full of disinformation.

Perfect example: DIYs will ask how to ground 3 prong outlets. Other DIYs will frequently tell them to drive a ground and connect to that. Im often left explaining they can not since a ground rod will not clear a fault. I get corrected by others who post a dozen links to internet articles that support the exact same thing. I tell them if anything install a GFCI try to convince them that will be easier since its to code. Nope, GFCI doesn't offer surge protection like a ground rod :roll: In the end those without any experience look right, I look like an idiot for pages on end while the OP drives a ground rod, HI's 3 prong tester lights up and the home gets sold as having an updated properly grounded electrical system :rant:

And a lot of guys who have done service work have seen things that are beyond awful and yet we have not lost the faith. After a while you realize mbrooke that those horror shows simply go with the territory-nothing spectacular about them. We get a call, we go out and diagnose and we fix it or we don't and we leave. While many homeowners are ignorant remember that they are also people-not electricians-that simply don't know any better. Its true that some things they do are obviously stupid but we can't fret over their stupidity-we can only fix the problem if they call us.

Many if not the majority of those people who visit diy sites aren't looking for reassurance-they are usually just looking for info about how to fix something/ perform a particular task and save some money (who isn't interested in that?). Yes, some of those folks could easily afford an ec, but then there are those who really can't. Many times we would love to give someone fresh yellow southwire but it isn't gonna happen($$$). So what are those folks to do? A lot of the information given/received per diy forums is indeed misleading/dangerous, but lets be honest- alot of the time it isn't going to hurt anybody. A "grounded" carlon isn't exactly a killer, and neither is romex run through cpvc and a 5-15 terminated to pre-'62 cirtex will likely sit there silently until the house falls down around it, never biting anybody. Personally I don't care if somebody argues w/ an electrician on diy chatroom-if they are on there asking how to do something, then theoretically they weren't going to hire you anyway so they aren't a concern and we can't stop everyone from hurting themselves.

It must be noted too that there is a lot of good information on those same sites and that a lot of homeowners do apply it. I've seen some "amateur" installs that would rival the work of a guy that's been in the trade for 20 years. Remember too that despite their bluff many h.o.s will ultimately take the advice to "please call an electrician." One other key thing to know is that while there is a lot of bad work out there being done, todays homeowners are arguably more educated about home wiring than they have ever been due to resources available online. Look at it this way, at least they are talking about gfci protection and most of them know its needed in a bathroom or when they hookup the #14 to that 20amp breaker, at least they are using romex instead of an ext cord.

We may snicker about their lack of knowledge about bonding, but look at it through the eyes of a layman-That "ground wire" is attached to a buss that is connected to a rod in the physical ground, is it not?