Number of outlets

[sparks1]

That is not how they work. They work by some fancy (proprietary) algorithm that looks at an arc signature. To minimize false trips they do no look for an arc signature of a parallel arcing fault unless the current exceeds 75 amps. They are designed to detect arcing faults which they claim are responsible for the majority of dwelling unit fires.

Many others claim that the majority of dwelling unit fires are caused by joule heating at a poor connection, something an AFCI without
a GFP circuit does no better at detecting and clearing than does a standard thermal magnetic breaker.

Ok then , since you are at least trying make a constructive claim. You say, "They work by some fancey proprietary algorithm " is boloney . They work similar to a GFCI breaker . The GFCI breaker sences line to neutral load and trips with any unbalance 5 to 6 ma . AFCI works in a similar fashion. It will trip at 30ma when the available fault current is too low (could be 75amp level?) to clear the fault preventing an arcing condition
that leads to a fire. A thermal magnetic breaker will not respond fast enough at 500% 5sec to long to extinguish an arc

 

[Ingenieur]

Ok then , since you are at least trying make a constructive claim. You say, "They work by some fancey proprietary algorithm " is boloney . They work similar to a GFCI breaker . The GFCI breaker sences line to neutral load and trips with any unbalance 5 to 6 ma . AFCI works in a similar fashion. It will trip at 30ma when the available fault current is too low (could be 75amp level?) to clear the fault preventing an arcing condition
that leads to a fire. A thermal magnetic breaker will not respond fast enough at 500% 5sec to long to extinguish an arc

Actually his description is accurate
the device looks at a waveform signature and compares it to 'good' and 'bad' profiles
some arcing is normal, ie, reactive loads discharging
The arcing distortion makes V look like a square wave and the current notched, spiked, etc

most also have a 30 mA GFI built in since arcing is often to ground

 

[jim dungar]

... when the available fault current is too low ...

How does any device know what the available fault current is?

Are you talking about the amount of 'through' fault current flowing because of an arcing event?

Technical discussions are bad enough, but they are worse when the vocabulary is misunderstood.

 

[iwire]

I am an expert and I have allready have explained it over over again. I'm done here beating a dead horse. You can take a horse to water but you can't make him drink it. If you don't get it too bad
I'm done with this post sparking singing off

No, you have not explained how a properly wired circuit starts fires due to too many outlets.

If you can't explain it to us you will not be able to explain it to the CMPs.

 

[sparks1]

No, you have not explained how a properly wired circuit starts fires due to too many outlets.

If you can't explain it to us you will not be able to explain it to the CMPs.

I have explained it .. Re read the post you just don't understand it unfortunately . Since
there is a overall lack of support and understanding here by most of the the replys posted here there wouldn't be much point In me trying to deal with all the red tape created by NEC & NFPA bureaucracy a proposal in 2017 ???Maybe someday someone else will get the hangof it,figure it out and make the change.

 

[GoldDigger]

No, you have not explained how a properly wired circuit starts fires due to too many outlets.

If you can't explain it to us you will not be able to explain it to the CMPs.

I suspect that his whole argument is based on the fact that all the receptacles will be wired daisy chained from one to the next (and maybe backstabbed) with the result that the loop resistance of the circuit will grow much faster than the resistance of the total length of wire involved.
And if the loop resistance got high enough that the VD at the last outlet in the run was maybe 50% at full load then a short circuit at the far end of the loop would not trip the breaker in time to prevent a fire.

I do not find that argument particularly persuasive, in particular since with that many outlets I would probably do some star type distribution to minimize the length of the longest loop.

I do not think that the CMPs would be persuaded either.

 

[iwire]

I suspect that his whole argument is based on the fact that all the receptacles will be wired daisy chained from one to the next (and maybe backstabbed) with the result that the loop resistance of the circuit will grow much faster than the resistance of the total length of wire involved.
And if the loop resistance got high enough that the VD at the last outlet in the run was maybe 50% at full load then a short circuit at the far end of the loop would not trip the breaker in time to prevent a fire.

I do not find that argument particularly persuasive, in particular since with that many outlets I would probably do some star type distribution to minimize the length of the longest loop.

I do not think that the CMPs would be persuaded either.

I want to hear it from the man who makes the claim.

 

[sparks1]

No, you have not explained how a properly wired circuit starts fires due to too many outlets.

If you can't explain it to us you will not be able to explain it to the CMPs.

It too high an impedance what more don't u uderstand

 

[iwire]

I have explained it .. Re read the post you just don't understand it unfortunately . Since
there is a overall lack of support and understanding here by most of the the replys posted here there wouldn't be much point In me trying to deal with all the red tape created by NEC & NFPA bureaucracy a proposal in 2017 ???Maybe someday someone else will get the hangof it,figure it out and make the change.

This is a cop out, you won't try because you cannot.

 

[iwire]

It too high an impedance what more don't u uderstand

Yes the impedance can increase.

How does that start a fire?

 

[sparks1]

No, you have not explained how a properly wired circuit starts fires due to too many outlets.

If you can't explain it to us you will not be able to explain it to the CMPs.

I tried to explain it and keep it simple but you prefer to listen to some big complicated agorithem explaination that maybe
Came from the manufacturing engineering team of how they want you to think it works.

You ideally want a high availabe fault current to clear a fault. For example
A Short circuit, ground fault etc with too many outlet points combined with too high a resistance and distance factored in to the mix add in a few loose connection now the available fault current go way down not enough to do much of anything . How many times have you tried to short a circuit breaker to trace a circuit and wonder why the the breaker didn't trip. Of course I'm not suggestion to short a breaker out as it is a dangerous practice but my point is many of the circuit breaker we install have not been test to trip in the field after installation. So we don't know if they are really going to work????Some electrician will think oh the breaker is bad when in fact the breaker is perfectly fine but won't trip because the available fault current imposed on the circuit is too low
I hope I try to explain it that about it in a nut shell

 

[Fulthrotl]

So this is clearly a big problem in my opinion
No way to stay within 3% VD here .
vd starts at from the time we leave the xtrm not the panel anther issue entirely

voltage drop, is 2% for feeders, and 3% for branch circuits.
premesis wiring only.

the POCO service entrance conductors are not part of that.
where on earth did you decide to include the service entrance conductors?

 

[George Stolz]

Yes the impedance can increase.

How does that start a fire?

That much should be obvious. I wish I had seen it before: 10 outlets. It seems so clear!

Pretty soon the rule will be requiring an AFCI at the power plant, and we'll be restricted to one outlet per city block; it'll make The Hunger Games look like Sesame Street.

Hitchhiker: You heard of this thing, the 8-Minute Abs?
Ted: Yeah, sure, 8-Minute Abs. Yeah, the excercise video.
Hitchhiker: Yeah, this is going to blow that right out of the water. Listen to this: 7... Minute... Abs.
Ted: Right. Yes. OK, all right. I see where you're going.
Hitchhiker: Think about it. You walk into a video store, you see 8-Minute Abs sittin' there, there's 7-Minute Abs right beside it. Which one are you gonna pick, man?
Ted: I would go for the 7.
Hitchhiker: Bingo, man, bingo. 7-Minute Abs. And we guarantee just as good a workout as the 8-minute folk.
Ted: You guarantee it? That's - how do you do that?
Hitchhiker: If you're not happy with the first 7 minutes, we're gonna send you the extra minute free. You see? That's it. That's our motto. That's where we're comin' from. That's from "A" to "B".
Ted: That's right. That's - that's good. That's good. Unless, of course, somebody comes up with 6-Minute Abs. Then you're in trouble, huh?
[Hitchhiker convulses]
Hitchhiker: No! No, no, not 6! I said 7. Nobody's comin' up with 6. Who works out in 6 minutes? You won't even get your heart goin, not even a mouse on a wheel.
Ted: That - good point.
Hitchhiker: 7's the key number here. Think about it. 7-Elevens. 7 dwarves. 7, man, that's the number. 7 chipmunks twirlin' on a branch, eatin' lots of sunflowers on my uncle's ranch. You know that old children's tale from the sea. It's like you're dreamin' about Gorgonzola cheese when it's clearly Brie time, baby. Step into my office.
Ted: Why?
Hitchhiker: 'Cause you're ******' fired!

 

[jim dungar]

A Short circuit, ground fault etc with too many outlet points combined with too high a resistance and distance factored in to the mix add in a few loose connection now the available fault current go way down not enough to do much of anything.

So would a reasonable summary of your position be:
"a circuit with too much impedance can lead to a breaker not tripping due to not enough through fault current"?

 

[iwire]

I tried to explain it and keep it simple but you prefer to listen to some big complicated agorithem explaination that maybe
Came from the manufacturing engineering team of how they want you to think it works.

You ideally want a high availabe fault current to clear a fault. For example
A Short circuit, ground fault etc with too many outlet points combined with too high a resistance and distance factored in to the mix add in a few loose connection now the available fault current go way down not enough to do much of anything . How many times have you tried to short a circuit breaker to trace a circuit and wonder why the the breaker didn't trip. Of course I'm not suggestion to short a breaker out as it is a dangerous practice but my point is many of the circuit breaker we install have not been test to trip in the field after installation. So we don't know if they are really going to work????Some electrician will think oh the breaker is bad when in fact the breaker is perfectly fine but won't trip because the available fault current imposed on the circuit is too low
I hope I try to explain it that about it in a nut shell

OK so your basic assumption here is that more connections increases the total circuit impedance to the point the breaker will not open during a fault.

Well if you raise the impedance enough you may well put the instantaneous trip out of the picture but you have not put the thermal part of the breaker out of the picture.

If the high impedance circuit has so much impedance it cant trip the thermal part of the breaker it also is not drawing enough current to hurt the conductor.

As far as an over temperature at a specific connection, keep in mind your theory says this high impedance is caused by multiple connections in the circuit, that means the power being dissipated is not at one connection causing high temps, it is a little bit of loss at each connection. And truthfully it will take a ton of properly made connections to cause this to happen at all.

As has been pointed out the length of the circuit conductors has a lot more to do with it than the number of connections.

The people you are calling morons are some very dedicated electricians who hang at these forums because they are into their jobs. They do care about safety, but they want the code to be written with facts, not opinions and personal preferences.

I hope you hang around.

 

[sparks1]

No, you have not explained how a properly wired circuit starts fires due to too many outlets.

If you can't explain it to us you will not be able to explain it to the CMPs.

Some valid points are made here
The stab in connections as one example
I can't tell you how many times I had to troubleshoot loose connection problems
that heat up melting the back of outlet or have one fall apart in you hands. How many panel fire I've seen because of loses connection heating up. It'scalled the creeping effect. Do nothing and wait for it to happen.
Sure the code starts at the service point but the vd starts at the transformer and the additional impedance . That's all part of the calc I'm using,it doesn't go away on it own. Remember fellas it use to be kept simple. Remember when you could tear out the page in you code book and submit your proposal. Yes there are various level of skills across this industry and even an electrician with the most basic skills could submit one and could have his voice hear in the process .
now the process is riddled with the special interest would give you some algorithm reason to use it
They have been taking over the whole industry for years but to line there pocket with million of $
They have taken our industry away from us hard working stiffs and put it in the toilet.
We need to take it back! And have a voice it our bread and butter
I would more then welcome the idea to go in front of any electrical board and discuss this proposal then have to wait and go through a dragged out process for NEC to make up there minds through a rediculus process would much more interesting and net a better result

 

[Little Bill]

Some valid points are made here
The stab in connections as one example
I can't tell you how many times I had to troubleshoot loose connection problems
that heat up melting the back of outlet or have one fall apart in you hands. How many panel fire I've seen because of loses connection heating up. It'scalled the creeping effect. Do nothing and wait for it to happen.
Sure the code starts at the service point but the vd starts at the transformer and the additional impedance . That's all part of the calc I'm using,it doesn't go away on it own. Remember fellas it use to be kept simple. Remember when you could tear out the page in you code book and submit your proposal. Yes there are various level of skills across this industry and even an electrician with the most basic skills could submit one and could have his voice hear in the process .
now the process is riddled with the special interest would give you some algorithm reason to use it
They have been taking over the whole industry for years but to line there pocket with million of $
They have taken our industry away from us hard working stiffs and put it in the toilet.
We need to take it back! And have a voice it our bread and butter
I would more then welcome the idea to go in front of any electrical board and discuss this proposal then have to wait and go through a dragged out process for NEC to make up there minds through a rediculus process would much more interesting and net a better result

Why don't you turn your passion towards either getting rid of the AFCI requirement and/or having them prove they work instead of the non issue of "too many outlets"!

All the loose connections you mentioned wouldn't be helped by limiting the number of outlets. That's usually just poor workmanship.

 

[George Stolz]

Some valid points are made here
The stab in connections as one example
I can't tell you how many times I had to troubleshoot loose connection problems
that heat up melting the back of outlet or have one fall apart in you hands. How many panel fire I've seen because of loses connection heating up.

I am a staunch opponent of back stabs and Wagos, and scold my guys from using them. Nevertheless, I cannot deny the fact that the last time I went on a service call for this issue I found a receptacle landed both ways, and it was the screw that failed, not the stab. Does that make stabs superior to screws? No - it speaks to the fact that devices cannot overcome the human factor, and you can't quantify the human factor. A miserable connection is a miserable connection, and usually it lies at the feet of the installer.

You can write 800 more pages of code, and it will not overcome the human factor. You can limit outlets to one per circuit, and it will not eliminate the problem.

There is not a problem with the number of outlets allowed per residential circuit, and I resent that you think you know more than generations of electricians, engineers, inspectors, and have it all figured out. You have come to a foolish conclusion.

Sure the code starts at the service point but the vd starts at the transformer and the additional impedance . That's all part of the calc I'm using,it doesn't go away on it own.

Once again, it's very easy to fool yourself into thinking that you have all the variables in a math problem. We don't live in a math problem, we live in a three-dimensional world with infinite variables.

Remember fellas it use to be kept simple. Remember when you could tear out the page in you code book and submit your proposal. Yes there are various level of skills across this industry and even an electrician with the most basic skills could submit one and could have his voice hear in the process .
now the process is riddled with the special interest would give you some algorithm reason to use it
They have been taking over the whole industry for years but to line there pocket with million of $
They have taken our industry away from us hard working stiffs and put it in the toilet.
We need to take it back! And have a voice it our bread and butter

Agreed! I think the ship has sailed on that, however.

I would more then welcome the idea to go in front of any electrical board and discuss this proposal then have to wait and go through a dragged out process for NEC to make up there minds through a rediculus process would much more interesting and net a better result

I resent the idea that we have to edit the NFPA out of our NEC. Electrical boards should not have to edit the NEC. They have the least information at their disposal. Unfortunately, the NFPA has taken leave of their senses on more than one issue, and the inevitable result is more local amendments messing things up for the working man.

 

[don_resqcapt19]

Ok then , since you are at least trying make a constructive claim. You say, "They work by some fancey proprietary algorithm " is boloney . They work similar to a GFCI breaker . The GFCI breaker sences line to neutral load and trips with any unbalance 5 to 6 ma . AFCI works in a similar fashion. It will trip at 30ma when the available fault current is too low (could be 75amp level?) to clear the fault preventing an arcing condition
that leads to a fire. A thermal magnetic breaker will not respond fast enough at 500% 5sec to long to extinguish an arc

Again not completely correct...while all of the original branch circuit and feeder type AFCIs had GFP protection as part of the device, that is not the case for the currently required combination types. The GE combination type AFCIs do not have a ground fault circuit and one of the Eaton lines does not have it. (in my opinion the most important and most functional part of the AFCI is the GFP and AFCIS without it are next to worthless)

The tripping of an AFCI, except when operating as a standard thermal magnetic breaker has nothing to do with the amount of fault current other than it does not even look for a parallel arcing fault unless the current on the circuit exceeds 75 amps.

There is no question that they work using an arc signature recognition algorithm. The intent is that this algorithm can recognize the arc signature and clear a fault that a standard breaker would not detect. It is also the intent that they do not operate when they "see" a "normal" arc...that is one that occurs in the normal operation of the electrical equipment.

 

[don_resqcapt19]

...
I can't tell you how many times I had to troubleshoot loose connection problems
that heat up melting the back of outlet or have one fall apart in you hands. How many panel fire I've seen because of loses connection heating up....

But an AFCI cannot detect and clear a high resistance, high heat producing connection...in fact there is nothing currently on the market that can. The best chance of clearing this is GFP, and that only works if there is enough insulation damage to cause a ground fault before there was enough heat to cause a fire and that is not always the case, and even if it was, as I said in a previous post, the industry is moving to eliminate the GFP from the AFCIs.

The UL standard for AFCIs never required a GFP function, but without the manufactures could not get their AFCIs to pass all of the tests required by the standard. Now at least two manufactures have found a way to pass the required tests as they have eliminated the GFP function.