Thread: AFCIs

We have a new article on AFCIs on our site:
Articles by the Code Check

Thank you
Douglas Hansen

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Good article. Thanks.

Thank you. It looks like the technology is much improved.

Originally Posted by Douglas Hansen

We have a new article on AFCIs on our site:
Articles by the Code Check

Thank you
Douglas Hansen

Douglas Hansen,


Row 2 data of Table 1, and Footnote 1, 'appear' to be in conflict with the text of the article.

(Specifically, indicating in Table (0.050 amps) & Footnote ("The 50 milliamp ground-fault detection of AFCIs is voluntary and not part of the UL standard.") that ground-to-line protection is afforded at 50 mA; when in the body of the article -- under "Ground Fault Detection" subheading reads: "The ground fault detection of AFCIs is voluntary on the part of the manufacturers, and is generally set at 30 milliamps. This does not qualify as replacement for a Class A GFCI. There are some types of equipment which require GFPE -- Ground Fault Protection of Equipment -- at the 30 milliamp level." "...(There are some branch-feeder AFCIs marked with a 30 mA ground-fault detection level.)". None of those instances an accuracy threshold or range of sensitivity/responsiveness provided - such as in GFCI protection @ 5 mA +/- 1 mA = 4-6 mA).

Would you please explain the differences/distinctions between: the data values & footnote information provided in Table 1 (50 mA GFP) and the information discussed in the article text (30 mA GFP).

I look forward to your reply. I thank you for the opportunity to peruse your article on this important safety subject.

H.G.

There are two levels of ground fault protection, Class A and a Class B. Class A is the 5mA level for personnel protection. Class B is the 30 mA.

AFCI breakers incorporate Class B GF protection.

Originally Posted by Jim Port

There are two levels of ground fault protection, Class A and a Class B. Class A is the 5mA level for personnel protection. Class B is the 30 mA.

AFCI breakers incorporate Class B GF protection.

Obviously Mr. Port, am FULLY aware of the difference between Class A and Class B protection, which has NOTHING to do with my question to Mr. Hansen.

You missed the point of my post completely!!

Mr. Hansen's article includes a Table 1 (in the middle of pg. 2), entitled AFCI Arc Detection Capabilities (and currents necessary to activate the AFCI protection), wherein he indicates the devices being discussed provide a lesser degree of protection than 30 mA GFPE, as his table data & footnote (1) indicate Branch/Feeder, Combination, and Outlet Branch Circuit AFCI devices are responsive at 50 mA (0.050 amps), not 30 mA, line-to-ground!

Am NOT discussing the GREATER degree of protection afforded by GFCI equipment at 5 mA (0.005 amps). The SUBJECT of discussion is AFCI equipment, previously and presently in the marketplace, and what is forthcoming, and protection of EQUIPMENT, not personnel.

Jim,

Now look what you've done ... shame on you!

You've given Watson his big colorful crayons back. Tsk, tsk.

First off HG, thanks for catching this contradiction. Even though the article was peer reviewed, no one else caught this. While there is some justification for the way I wrote it, I will be making some changes. I will post the corrected version after hearing from anyone else that might have comments or suggestions.

The table is not about the sensitivity or safety level of the devices; it is about the minimum level of current the device has to see to be capable of tripping. I think I should change the title of the table to reflect that. I went back through my files to find the origins of this table, and it appeared first in a 2003 presentation from one of the major breaker manufacturers.

A background story is in order here. In 2002, at a major trade show, one of the breaker manufacturers set up a display with their AFCIs and a gadget they created to produce a sputtering arc. It was a spinning conductive disc with an abrasive surface and an arcing contact rod. The rep turned the handle, spun the disc, and we got to see sparks fly. It was all going through an AFCI breaker, which was supposed to trip. It didn't. The problem was that the trade show was in a very old hotel, and the exhibit area was powered through hundreds of feet of extension cords. There was so much voltage drop that by the time it got to their display, they didn't have the needed 75 amps of available fault current.

At that time, there was a breaker manufacturer that had set their ground-fault detection at 50mA. As I discussed in the article, some AFCIs today have no ground-fault detection, though when they do, it is going to be at 30mA.

The point of the table, from the standpoint of the manufacturer who first came up with it, was to show the much lower current levels needed to activate combination type or outlet branch-circuit type AFCIs. The manufacturer in question claimed that these would experience nuisance tripping, which has not been the case. The lines in the table regarding the line-to-ground arc and the series with ground arc are really irrelevant to that point, and are not helping communicate the major point. The major point of the table to me is that branch-feeder AFCIs do not detect series arcs, which are much more common than parallel arcs. That they can do this with lower available fault currents helps them to function when the arc is at the end of the line, in an appliance.

I think the dog and pony show I witnessed at the trade show in 2002 would have worked with a combination AFCI.

HG, can you do me another favor? Since I will be reposting a new file on our site, could you delete the link you added to your message to Jim? It would be best not to have multiple versions out there.

Thank you

Douglas Hansen

Originally Posted by H.G. Watson, Sr.

Obviously Mr. Port, am FULLY aware of the difference between Class A and Class B protection, which has NOTHING to do with my question to Mr. Hansen.

You missed the point of my post completely!!

.

Watson,

No one said I was addressing you. I simply added this to provide additional information to anyone that was unaware that an AFCI also had a GFI component. I try to post information to help people, not insult their intelligence like others. People that are secure in their knowledge to not need to belittle others in order to feel important.

My what a presumptionous @$$ you are. Please feel free to put me on your ignore list.

Originally Posted by Douglas Hansen

First off HG, thanks for catching this contradiction. Even though the article was peer reviewed, no one else caught this. While there is some justification for the way I wrote it, I will be making some changes. I will post the corrected version after hearing from anyone else that might have comments or suggestions.

The table is not about the sensitivity or safety level of the devices; it is about the minimum level of current the device has to see to be capable of tripping. I think I should change the title of the table to reflect that. I went back through my files to find the origins of this table, and it appeared first in a 2003 presentation from one of the major breaker manufacturers.

A background story is in order here. In 2002, at a major trade show, one of the breaker manufacturers set up a display with their AFCIs and a gadget they created to produce a sputtering arc. It was a spinning conductive disc with an abrasive surface and an arcing contact rod. The rep turned the handle, spun the disc, and we got to see sparks fly. It was all going through an AFCI breaker, which was supposed to trip. It didn't. The problem was that the trade show was in a very old hotel, and the exhibit area was powered through hundreds of feet of extension cords. There was so much voltage drop that by the time it got to their display, they didn't have the needed 75 amps of available fault current.

At that time, there was a breaker manufacturer that had set their ground-fault detection at 50mA. As I discussed in the article, some AFCIs today have no ground-fault detection, though when they do, it is going to be at 30mA.

The point of the table, from the standpoint of the manufacturer who first came up with it, was to show the much lower current levels needed to activate combination type or outlet branch-circuit type AFCIs. The manufacturer in question claimed that these would experience nuisance tripping, which has not been the case. The lines in the table regarding the line-to-ground arc and the series with ground arc are really irrelevant to that point, and are not helping communicate the major point. The major point of the table to me is that branch-feeder AFCIs do not detect series arcs, which are much more common than parallel arcs. That they can do this with lower available fault currents helps them to function when the arc is at the end of the line, in an appliance.

I think the dog and pony show I witnessed at the trade show in 2002 would have worked with a combination AFCI.

HG, can you do me another favor? Since I will be reposting a new file on our site, could you delete the link you added to your message to Jim? It would be best not to have multiple versions out there.

Thank you

Douglas Hansen

Mr. Hansen,

Thank you for your considered reply. I have removed as you requested.

I did notice two minor (style) items as follows:


1. At pg. 5, end of the third paragraph opened subsection reference with an open bracket left unclosed (i.e. missing close bracket):

"....at the first outlet of the circuit {210.12(B)}. "

And again in the first sentance of the fourth paragraph:

" Replacement receptacles {section 406.4(D)(4)} in areas that..."

Not sure if examples above were choice or a possible oversight (I'm notorious for unintentionally omitting a close-parenthesis or close-bracket myself), and haven't remained "up" on NFPA or NEC Style changes.


2. Page 6, third paragraph from the top of page and under "What Could Go Wrong?", an unnecessary comma between the month and year:

"In November, 2004, Square D announced a recall..."

Not sure if the above was a style choice, an oversight, or an indication that perhaps you had meant to look up the specific date of the declared voluntary recall and to insert it later, or if you had at one time included a more specific date and when editing missed the comma in the delete action.



I very much enjoyed the "voice" in the article, the organization and presentation of the subject matter. Your article further inspires (this retired old goat who hasn't kept up-to-date on the more recent history) to further review activites of the STPs & CMPs as I have a few specific technical questions regarding changes to the voluntary Standards (test & performance specifics) recent and forthcoming developments.

I am interested to learn if the ground-fault detection, reliability, and responsiveness to line-to-ground fault conditions are equal to that of listed GFPE devices.

Thank you again for sharing.

H.G.

Thanks for the post Doug, some of us appreciate it. I went to the Safety glass article too and learned something.

As always, thank you for the information.

Question to anyone able to answer that goes back to the difference between Class A and Class B GFCI protection levels (5mA protection level versus 30 mA level protection).

Mr Hansen's article refers to upcoming changes in future NEC code,

2014: We anticipate that AFCI protection will be required for all 120‐volt circuits having outlets in kitchens and laundries, and that AFCI devices will be required to be readily accessible.

Are the AFCI combination breakers going to be able to provide sufficient GFCI protection in kitchens? Will there also have to be additional GFCI protected receptacles on the AFCI breaker protected circuits?

What about bathrooms, exterior outlets, garages, etc?

Originally Posted by Terry Beck

Are the AFCI combination breakers going to be able to provide sufficient GFCI protection in kitchens?

No.

Originally Posted by Terry Beck

Will there also have to be additional GFCI protected receptacles on the AFCI breaker protected circuits?

GFCI combination receptacles or deadfront GFCIs accessible, and ahead of the receptacles, or similar combination devices; yes for 125V 15-30A.

Originally Posted by Terry Beck

What about bathrooms, exterior outlets, garages, etc?

Similar to above, anticipated, eventually.

Mr. Hansen,

Thank you for the supportive PM, gratified you found the input constructive. I look forward to reviewing the revision of your article upon your return.

H.G.

Revised article is on our site
Articles by the Code Check


Thank you

Douglas Hansen

Mr. Hansen,Table 1, Row 2 indicates a footnote (marked 3) which is not present, there is presently only one footnote to the table. If you intended a footnote to "Series to Ground" it is missing, if you did not, you may wish to remove the superscript 3.I stopped reading the revision at that point (wherein the text first refered to Table 1 and I observed the above).

Originally Posted by H.G. Watson, Sr.

Mr. Hansen,Table 1, Row 2 indicates a footnote (marked 3) which is not present, there is presently only one footnote to the table. If you intended a footnote to "Series to Ground" it is missing, if you did not, you may wish to remove the superscript 3.I stopped reading the revision at that point (wherein the text first refered to Table 1 and I observed the above).

Thank you! It has been fixed (along with another typo).

I am hoping that you find the concept of that table more relevant now, as compared to the first version of the file.

Douglas Hansen
Code Check- Help With Building Codes

Douglas,

Here are a few of things I've noticed in the article, some minor and possibly not worth addressing, others may be worth addressing or further explanation.

"An arc results from an electrical current propagated through air." An arc can be caused by an electrical current through damaged insulation, such as when there is a nail or screw penetration into or through an NM cable such that the nail or screw has nicked into or through the insulation of one or more conductors (such as hot-neutral or hot-ground). May be just semantics, but I decided it was worth bringing to your attention so you could knowingly address that statement.

"(see table 1)" should be "(see Table 1)" as the table is titled Table 1.

Then when I went to Table 1, the parallel arc row of arc condition "Line-to-Neutral" has, under "Branch/Feeder", "Yes (75 amps)1" with the "1" on the end being a superscript to note 1. The note 1. states "These currents are not the same RMS currents that a breaker is reading. During an arc, a 75-amp peak current might have RMS current of less than 5 amps. Series arcs can actually product lower RMS currents than non-arcing circuits."

A couple of comments on that note 1.:
"These currents are not the same RMS currents that a breaker is reading. During an arc, a 75-amp peak current might have an RMS current of less than 5 amps. Series arcs can actually product lower RMS currents than non-arcing circuits."

The series arc comment is in note 1., which is referred to in the parallel arcs "Line-to-Neutral" row.

Originally Posted by Douglas Hansen

Thank you! It has been fixed (along with another typo).

I am hoping that you find the concept of that table more relevant now, as compared to the first version of the file.

Douglas Hansen
Code Check- Help With Building Codes

Your welcome. Guessing a "t" has beome an "e"?

Can't go back and look at the latest now, as when you resaved and uploaded, you used a format not compatible with my older reader version (bad encryption dictionary read error on this end, usually indicates same).

Wouldn't recommend inserting unnecessary (and incorrect ) article suggested by another.

I would re-write the footnote completely.

Originally Posted by H.G. Watson, Sr.

Wouldn't recommend inserting unnecessary (and incorrect ) article suggested by another.

I don't see where "another" has suggested inserting an unnecessary and incorrect article into that article. Guess maybe you need more than just updating of your older reader.

I believe I know what he is trying to say. Its not being communicated well.

Your suggestion doesn't "fix" the footnote and certainly doesn't improve it.

Peak Intensity vs. RMS intensity. The "current" is not "different".


An article is a part of speach ("a", "an", "the", etc.). And yes you are "another" (poster, responder, participant). Subject was (tactfully) implied and not specifically named.

Originally Posted by H.G. Watson, Sr.

Your suggestion doesn't "fix" the footnote and certainly doesn't improve it.

Watson, Dear Old Chap,

I made one suggestion to fix one part of the footnote - and it does fix that part.

I then pointed out that the rest of the footnote was referring to something which did not refer to it - that is not a suggestion as to how to fix the footnote, that is pointing out something that Douglas needs to review.

It is then up to Douglas to fix the footnote by re-writing it or by making it a 2nd footnote which is referenced by the appropriate row of reference.

An article is a part of speach ("a", "an", "the", etc.). And yes you are "another" (poster, responder, participant).

You got me on that one as I thought you were referring to me suggesting he put some other article, as in "article" like Douglas wrote, into his "article".

Subject was (tactfully) implied and not specifically named.

Nothing you do is "tactfully" done or implied. You go out of your way to try to degrade others to try to show off what you know or, more correctly, think you know.

On the other hand, I did not point out THE FACT that you missed those things, I was simply pointing those things out to Douglas. You expose your arrogance without any help from the rest of us. You always have, and apparently, always will.

I have a feeling that Douglas will soon regret having posted here with you and your posts always in attack mode.

Peck,

When are you ever going to realize you have no ability to read my mind, nor devine my intent, are incapable of discerning same, and that you do not speak for me (nor for just about anyone other than your own little self)?

Everything isn't all about you, in fact, most topic discussions are anything about you, at all. Then you have yet another attention demanding tantrum, in some rather sick attempt to twist every topic discussion to something about you. You've wasted a hefty percentage of your nearly 20,000 posts on this forum making jabs, stupendous remarks, digs, and petulant remarks.

Enough already. You're wrong yet again.

Originally Posted by H.G. Watson, Sr.

Enough already. You're wrong yet again.

Ah, Watson,

As you stated "You're wrong yet again.".

You are wrong so often that the correct information you include is lost and set aside as also being wrong. Your ego is so large that most of us here wonder why you even bother with the 'little folk' you think the rest of the world is.

I do, on occasion, defend you as you do, on occasion, provide good points of insight ... the problem is that one must hack their way through your anger at the world, your use of big red crayons, your attacks on anyone and everyone, and your ... the list is endless and to the point that many do not even bother to try and pick the jewels out of your tirades. And that, Watson, is a shame, but that is what you have reduced yourself and your posts to.

So many of us here tell you the same thing time and time again, but all you do is blast people, try to degrade people, and then try to post such outlandish posts that many not only no longer read your posts, may have you on their ignore list.

I delayed responding to Douglas because I thought you would reduce yet one more thread to your tirades, then I figured I would post and see what Douglas thought of those items before addressing others. If those items are as Douglas intends them to be, then the other may also be intended.

Alas, though, and as I expected, you cannot hold your tongue and allow a thread to continue with proper and thoughtful posts.

Peck,

Your inner green-eyed monster is showing (yet again).

Please stop presuming to speak for me and for anyone other than yourself.

When are you ever going to realize you have no ability to read my mind, nor devine my intent, are incapable of discerning same, and that you do not speak for me (nor for just about anyone other than your own little self)?

.

This is from a person that sees countertops in front of panels before the OP mentions them, guesses at voltages and talks about unsafe conditions that could exist behind a closed panel door? I guess it is hard to read that mind.

Originally Posted by H.G. Watson, Sr.

Peck,

Your inner green-eyed monster is showing (yet again).

Please stop presuming to speak for me and for anyone other than yourself.

And yet again, nothing more than trying to degrade others and not add anything positive to this forum.

Your inner self cannot be hidden from view, Watson.

"Reality check" on what is and is not:

http://www.combinationafci.com/resou...ation_afci.pdf

Mike Holt - An insider’s look at the NEC Code making process as it related to AFCIs

Originally Posted by H.G. Watson, Sr.

"Reality check" on what is and is not:

http://www.combinationafci.com/resou...ation_afci.pdf

Mike Holt - An insider’s look at the NEC Code making process as it related to AFCIs

Nice links.