Bathroom afci protection ?

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Pharon

Senior Member
Location
MA

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
The NFPA seems to think that about 50%-75% of all electrical related home fires are caused by arc faults. The annual averages are around 48,000 fires and 450 deaths per year:

http://w3.usa.siemens.com/us/intern...n/SIE_WP_CAFCI_causes_of_electrical_fires.pdf

While part of me thinks they are wrong, part of me wishes they were right.

I was totally convinced that AFCI's were useless because of their inability to detect series arcs, but the Eaton video, as hard as it is to admit, was pretty convincing.

I will be doing my own testing come a nice spring day.

Research is expensive.

Please send money.

:D
 

bphgravity

Senior Member
Location
Florida
--
Requiring a disposal to have AFCI & GFCI protection is nonsense IMO

AFCI (fire prevention) and GFCI (shock prevention) protection serve different purposes. With AFCI protection, you are not just protecting the appliance, but the entire branch circuit that supplies the disposal. The typical wiring method used to supply the 120-volt, 15-and 20- ampere branch circuits in a dwelling is NM cable. NM cable, regardless of what it supplies, is subject to damage that may result in an arcing fault. This could be a nail, screw, sharp edge, overdriven staple, etc.

comparing grounding to AFCI devices as importance

I am not comparing the importance of AFCI protection to equipment grounding. Each were an evolution in the development of the code to make the final installation safer. While they are not comparable, each does it part to reduce the hazard associated with electricity. The mitigation of hazards usually takes efforts on several fronts. This is true for all industries where human safety is of concern.
 

romex jockey

Senior Member
Location
Vermont
Occupation
electrician
The NFPA seems to think that about 50%-75% of all electrical related home fires are caused by arc faults. The annual averages are around 48,000 fires and 450 deaths per year:

http://w3.usa.siemens.com/us/intern...n/SIE_WP_CAFCI_causes_of_electrical_fires.pdf

While an OCPD manufacturer may be convincing , wouldn't a UL study have a tad more weight Pharon?

UL 1977 Glowing Connection paper

Further, we can have a 'real world' take on this, because we as electricians do see joule effect electrical issues.

So what, in your (et all) opinion would come first, the high R connection? or the arcing one?

Which would be the chief incendiary electrical event ?

~RJ~
 

Pharon

Senior Member
Location
MA
While an OCPD manufacturer may be convincing , wouldn't a UL study have a tad more weight Pharon?

It's a Siemens url but the stats and citations are from NFPA if you bothered to read it.

Further, we can have a 'real world' take on this, because we as electricians do see joule effect electrical issues.

So what, in your (et all) opinion would come first, the high R connection? or the arcing one?

Which would be the chief incendiary electrical event ?

~RJ~

Yes, I'm well aware of the joule effect and the fact that there is currently NO technology that can trip a circuit to prevent it from causing a house fire. I also question the validity of the NFPA study - those stats came from fire fighters. But are fire fighters even qualified enough to determine whether a fire started because of the joule effect or a series arc? I don't think so.

Arc faults are caused by frayed wires, nails through Romex, etc. Joule effect is caused by a loose splice. If I had to take an educated guess, the latter would be the far more likely culprit of a house fire. But what do I know.

What I want to see on YouTube is a "real life" simulation of a nail through Romex tripping an AFCI, or a frayed lamp cord arcing to do the same. That would be far more convincing to me than biased marketing propaganda.

Until then I respectfully remain on the fence. I just don't see enough evidence yet either way to determine if AFCIs are BS.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
Which would be the chief incendiary electrical event ?

~RJ~

What I plan on doing is creating an arc in series with a space heater limiting the current to below the OCPD threshold. I plan on using old wiring from my scrap pile and covering the fault with combustible material and then moving the conductors to create a current limited series arc in direct contact with combustible material.

In the real world, this would be equivalent to a rodent nesting around and chewing on conductors, which I have seen on more than one occasion.
 

romex jockey

Senior Member
Location
Vermont
Occupation
electrician
Pharon,

i've read the stats for years , as well as the collection process for them.

Manufacturers love to wave them about, but the devil is , as always, in the details.

The basic discrimination of arc vs. joule effect isn't something we in the field should need to seek Utube video out to witness.

Quite the contrary in fact. It is a common exposure for many of us.

And so my post does not ask if you believe arc fault technology is valid , I merely ask which is the major incendiary culprit

Ul seems to have made it's opinion clear 40 years ago

And please , let's not hang it on the FF'ers who have little knowledge of electrical physics

~RJ~
 

romex jockey

Senior Member
Location
Vermont
Occupation
electrician
What I plan on doing is creating an arc in series with a space heater limiting the current to below the OCPD threshold. I plan on using old wiring from my scrap pile and covering the fault with combustible material and then moving the conductors to create a current limited series arc in direct contact with combustible material.

In the real world, this would be equivalent to a rodent nesting around and chewing on conductors, which I have seen on more than one occasion.

That would be grand Mark

You might even consider an old loose receptacle outlet for your space heater to plug into.....

~RJ~
 

Pharon

Senior Member
Location
MA
Bathroom afci protection ?

Pharon,

i've read the stats for years , as well as the collection process for them.

Manufacturers love to wave them about, but the devil is , as always, in the details.

The basic discrimination of arc vs. joule effect isn't something we in the field should need to seek Utube video out to witness.

Quite the contrary in fact. It is a common exposure for many of us.

And so my post does not ask if you believe arc fault technology is valid , I merely ask which is the major incendiary culprit

Ul seems to have made it's opinion clear 40 years ago

And please , let's not hang it on the FF'ers who have little knowledge of electrical physics

~RJ~

I'm not sure what point you're trying to make here if you're arguing against my previous post. If not, then disregard. I thought I answered your question.

I need no proof of joule effect. I think we all could use some non-biased proof that AFCIs work.

I'd also be curious to see if there's any downward trend in electrical fires over the next decade. That's the real proof in the pudding.

But I won't be holding my breath.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
I honestly don't know how one can determine that losing bathroom light is any more or less dangerous then losing any other light, if it is, why don't we require emergency lighting sources in there?
In the specific case of a windowless interior bathroom it could at least be annoying. Especially if you do not have clothes on at the time.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
...
I'd also be curious to see if there's any downward trend in electrical fires over the next decade. That's the real proof in the pudding.
...
It will be a long time before it would even be possible to see numbers that show they work. Assuming that the AFCI would be 100% effective in preventing fires of electrical origin, you would expect to have prevented a total of ~3000 dwelling unit fires after 10 years of 100% compliance with the 2014 NEC. Over those same 10 years you would expect to see well over 300,000 dwelling unit electrical fires. The difference is, that in general the AFCI requirement only applies to new construction. The 1% change is well with in the statistical error for the fire data, so no proof of effectiveness from that method.
 

peter d

Senior Member
Location
New England
It will be a long time before it would even be possible to see numbers that show they work. Assuming that the AFCI would be 100% effective in preventing fires of electrical origin, you would expect to have prevented a total of ~3000 dwelling unit fires after 10 years of 100% compliance with the 2014 NEC. Over those same 10 years you would expect to see well over 300,000 dwelling unit electrical fires. The difference is, that in general the AFCI requirement only applies to new construction. The 1% change is well with in the statistical error for the fire data, so no proof of effectiveness from that method.

On that same note, how many dwelling unit fires occur in new dwelling units because of the premises wiring? I suspect that number is extremely low, probably virtually nil.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
On that same note, how many dwelling unit fires occur in new dwelling units because of the premises wiring? I suspect that number is extremely low, probably virtually nil.
The available fire cause and origin data says about 40% originate in the fixed wiring of the dwelling unit. That is the reported data that is used to support the AFCI requirement.
 

kwired

Electron manager
Location
NE Nebraska
I don't believe that statistic for one second.

I might, but as mentioned would guess most are homes at least 10 -15 years old or older, with no AFCI's. When homes with AFCI's installed become that age, and assuming they do prevent fires, what assurance do we have the AFCI's will still be functional at this time when their features are needed the most?
 

peter d

Senior Member
Location
New England
I might, but as mentioned would guess most are homes at least 10 -15 years old or older, with no AFCI's. When homes with AFCI's installed become that age, and assuming they do prevent fires, what assurance do we have the AFCI's will still be functional at this time when their features are needed the most?

At this point in time, the only rough comparison we can make is to failure rates for GFCI devices.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
It's a Siemens url but the stats and citations are from NFPA if you bothered to read it.



Yes, I'm well aware of the joule effect and the fact that there is currently NO technology that can trip a circuit to prevent it from causing a house fire. I also question the validity of the NFPA study - those stats came from fire fighters. But are fire fighters even qualified enough to determine whether a fire started because of the joule effect or a series arc? I don't think so.

Arc faults are caused by frayed wires, nails through Romex, etc. Joule effect is caused by a loose splice. If I had to take an educated guess, the latter would be the far more likely culprit of a house fire. But what do I know.

What I want to see on YouTube is a "real life" simulation of a nail through Romex tripping an AFCI, or a frayed lamp cord arcing to do the same. That would be far more convincing to me than biased marketing propaganda.

Until then I respectfully remain on the fence. I just don't see enough evidence yet either way to determine if AFCIs are BS.


Incorrect, there are several concepts and some of them are currently hitting the market:


http://thermarestor.co.uk/
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
Yes, I've seen (and posted) that video in the past. But it would be nice to see a YouTube video where an average person (with no bias) could actually duplicate this scenario. Here's another one from NFPA demonstrating a more real-life scenario, but again - they are a biased source, IMO (ff to 2:40 mark):


That is not real life, far from it. The arcing lamp cord is a hoax.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
As mentioned, bathrooms as of the 2014 code cycle do not require AFCI.

I'm no programmer, but it seems to me to be an easy thing to program AFCI to trip reliably under arc conditions. Take a faulty circuit with bad insulation, over driven NM staple, etc., between ungrounded and grounded or grounding conductors. Any arcs will be random in nature, not cyclic or constant. Program breaker to ignore any arcs the first second, or, say, 20 cycles, it's energized, or when amperage changes (such as starting a vacuum cleaner); only have over-amperage protection. This should eliminate nuisance trips from vacuum cleaners and the like. After that, random spikes/dips in amperage in vs amperage out, such as a loose conductor would cause, would trip the breaker (again, same one second/one third second delay in trip so turning the vacuum off wont trip it either). All it would need is an internal clock, a voltmeter, and a way to record such spikes/dips, recognize the imbalance, and trip on an actual arc fault... or am I oversimplifying this to an illogical degree?

Its not that easy, because vacuum cleaners and switches opening produce a signature identical to that of dangerous arcing. You can get nitty gritty fine tooth, but it requires far more computing power then you can stick in a 2 inch add on.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
The cost benefit is not reasonable for the AFCI, especially when it is very likely that the combination of a lower instantaneous trip and GFCI protection would prevent over 99% of the fires that the AFCI is said to prevent at a much lower cost.



Branch feeder AFCIs are a direct rip off of GFP and mag trip. Both those ideas originated out of the IEC which has a legit concern in arcing since most countries using it have 230 volt L-G supplies. The concept was twisted into something its not in order to create a brand new product line.
 
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