AFCI Coverage

[480sparky]

I have bolded my statement above.

CharlieB said "...ancillary rooms", you included master baths. My comment says that because Bathrooms are a location handled elsewhere, that they would fall under the rules that are specific to that classification of a location.

I am confused at how it matters that there is no mention of Baths in 210.12

If a bath happens to be ancillary to a BR, then one could think that it should be included (based on CharlieB's first post), but since baths are handled specifically elsewhere (210.8, 210.11, etc) they shouldn't.

General rules apply, but something specific overrules it

Pretty much all AFCI dwelling rules are in 210.12. AFCIs are also in 440.65, 550.25 and 760.51(B). No mention of AFCI is made in 210.8 or 210.11.

 

[cycotcskir]

Pretty much all AFCI dwelling rules are in 210.12. AFCIs are also in 440.65, 550.25 and 760.51(B). No mention of AFCI is made in 210.8 or 210.11.

I agree. Maybe we are thinking the same thing, but from 2 different directions. In any case, I agree with what you have said, you just threw me for a loop there in that one post.

 

[MVanB]

When AFCIs first came out, I wondered why the bedrooms were targeted, and someone told my exactly what you stated here.

Only problem is, the reason most people spend the most time in the bedrooms of their homes is because they are asleep. How does sleeping cause more electrical fires?

It's not the sleeping that causes the fires, it's the sleeping that more than likey leads to the higher incidence of deaths related to house fires.

That is not correct. The only thing that really dove picking the bedrooms as the first place to require AFCI protection was the fact that they needed a place to start and bedrooms don't have a lot of loads that may cause issues with the AFCIs. It was really a large beta field test for devices. As far as a higher percentage of electrical fires being traced to the bedroom circuits, that is not correct. More fire deaths do occur in the bedroom, but the majority of fires do not have the point of origin in the bedroom.

I agree, however, I have seen lot's of loaded bedrooms w/out AFCI protection of the circuits, (Some folks do live in their bedrooms with all types of equipment, ie. medical, media, etc). Usually these are older homes with older branch circuit wiring and overfused circuits. I would submit that the target for the AFCI's should be with older homes where remodeling and service/subpanel updates are being performed. It seems to me that these devices would be a reasonable safety measure where older branch circuits and/or breakers are in place.

 

[charlie b]

My claim was that that isn't needed because ancillary or not, a bathroom is specifically defined elsewhere. It is just a redundancy, to me.

I guess I wasn't clear. What the WAC does is to (1) Limit the AFCI requirement to bedrooms only, and (2) Define "bedroom" in such a way that it includes the closet but not the bathroom. It is not defining bathroom, it is merely excluding it from being part of the definition of bedroom.

 

[480sparky]

I guess I wasn't clear. What the WAC does is to (1) Limit the AFCI requirement to bedrooms only, and (2) Define "bedroom" in such a way that it includes the closet but not the bathroom. It is not defining bathroom, it is merely excluding it from being part of the definition of bedroom.

So the closet requires AFCI?

 

[charlie b]

So the closet requires AFCI?

In Washington State, yes. But the family room, den, dining room, and the others added in the 2008 NEC do not. Interestingly, however, the city of Seattle appears to be headed towards adoption of the NEC version of this article, making it more restrictive than the state.

 

[480sparky]

In Washington State, yes. But the family room, den, dining room, and the others added in the 2008 NEC do not. Interestingly, however, the city of Seattle appears to be headed towards adoption of the NEC version of this article, making it more restrictive than the state.

I can understand the connection between the BR and closet, especially since many homes have the closet only accessible while in the BR.

But what about high-end homes where that isn't true? Such as this:

 

[charlie b]

How did you get a copy of my house plans? :roll:

As I read the WAC wording, the fact that you can't get into either of the two walk in closets in the bottom of your sketch, without first walking into the master bedroom, causes the two closets to fall within their definition of "bedroom." So they get AFCI protection.

 

[480sparky]

How did you get a copy of my house plans? :roll:

I'm buldiing my ice fishing shack for next winter.

As I read the WAC wording, the fact that you can't get into either of the two walk in closets in the bottom of your sketch, without first walking into the master bedroom, causes the two closets to fall within their definition of "bedroom." So they get AFCI protection.

So if the WICs were accessible some other way, they wouldn't need AFCI? I recall being in a house where, when walking from the living room to the master BR, you went through a short hallway, with his-n-hers closets on either side. If you kept going straight, you'd be in the MBR. No AFCI needed in those closets then?

Edit to add:

Would this closet need AFCI?:

 

[charlie b]

Would this closet need AFCI?:

My take would be "no." The AHJ might disagree, however. The question is whether that closet is ancillary to the function of the bedroom, as opposed to being associated with the laundry room.

 

[don_resqcapt19]

I agree, however, I have seen lot's of loaded bedrooms w/out AFCI protection of the circuits, (Some folks do live in their bedrooms with all types of equipment, ie. medical, media, etc). Usually these are older homes with older branch circuit wiring and overfused circuits. I would submit that the target for the AFCI's should be with older homes where remodeling and service/subpanel updates are being performed. It seems to me that these devices would be a reasonable safety measure where older branch circuits and/or breakers are in place.

Yes, I would agree that the target should be older dwelling units as the fire cause and orgin documents used to get the AFCI rule in the code say that 85% of the dwelling unit fires that are said to be of an electrical orgin were in units at least 21 years old. One issue with the use of AFCIs in older units is that they lose some of there effectiveness. Many of the trips are caused by the ground fault protection and not the fancy arc signature recognition circuit. This protection is mostly lost when an AFCI is installed on a circuit that does not include an EGC.

 

[MVanB]

. . . One issue with the use of AFCIs in older units is that they lose some of there effectiveness. Many of the trips are caused by the ground fault protection and not the fancy arc signature recognition circuit. This protection is mostly lost when an AFCI is installed on a circuit that does not include an EGC.

Yes, I have heard of this. (If you have any good documentation supporting this please post).
So in essence what you are referring to is that because there are only the Hot and Grounded conductors in an older NM circuit wiring cable, or knob & tube for that matter; The abscence of the third Grounding conductor from the cable and/or circuit results in that circuit not having an EGC back to the service panel. Now rewiring costs have gone from a $30.00 AFCI breaker to hundreds of dollars running new cable for AFCI effectiveness. No longer as cost effective as the AFCI breaker itself. Hence, the introduction of AFCI into new construction and modern day circuits.

 

[Twoskinsoneman]

Yes, I would agree that the target should be older dwelling units as the fire cause and orgin documents used to get the AFCI rule in the code say that 85% of the dwelling unit fires that are said to be of an electrical orgin were in units at least 21 years old. One issue with the use of AFCIs in older units is that they lose some of there effectiveness. Many of the trips are caused by the ground fault protection and not the fancy arc signature recognition circuit. This protection is mostly lost when an AFCI is installed on a circuit that does not include an EGC.

Something that may be interesting and related. One of Mike H panel members on the NEC DVDs I've been watching said that when AFCIs were first introduced he recieved some 30+ calls for help trouble shooting AFCIs that kept tripping. He said out of the 30+ 100% turned out to be an accidental grounded conductor contacting the EGC usually when receptacles were shoved into their box.

I know this only partially relates to this thread but I've been waiting for a chance to share it.

 

[don_resqcapt19]

I don't have any real documentation, but the posts on this and other forums as well as conversations with manufacturer's reps indicate that maybe 80% or more of the AFCI trips are ground fault trips. One rep told me that he believes that the number could be 95%. He also told me that at least 98% of the "nuisance" trips are ground fault trips that are really installation defects .
Even today the AFCI does not directly detect a "glowing connection". It only trips when the heat from the glowing connection damages enough insulation to cause a parallel arcing fault or a ground fault. The GFP is a very important part of the protection...in my opinion by far the most important part when you look at how these things work. The branch circuit and feeder type doesn't even look at the arc signature unless the current is 75 amps or more. The new combination type looks when the current is 5 amps or more. However in both cases the GFP is set at 30 to 50 mA. It is not that easy to have a parallel fault that is not also a ground fault in a wiring system or equipment that has an EGC.

 

[quogueelectric]

The most usefull aplication of this technology would be to protect aluminum wiring in a house that is preexisting and being used. This is where the majority of catastrophic faults that I have come across come into play yet I never hear of anyone using this technology for what I am suggesting. I will try to have my alluminum wired customers at least slowly switch over to all afci protection for thier house provided it doesnt bring more liability to me. Like every year adding 2 afci breakers to slowly switch to full protection yet keeping costs within reason.

 

[slick 50]

Section 210.12 (B) states: All 120 volt, single phase, 15 and 20 ampere branch circuits supplying outlets installed in dwelling unit bedrooms shall be protected by a listed arc-fault circuit interrupter, combination type installed to provide protection of the branch circuit.

Looking for clarification (interpretation) of the above reference.
Does a 'dwelling unit bedroom' as stated above include the closet space off the bedroom?

Sometimes you must simply use common sense. I would think that the closest receptacle or switch to get power from would be from the bedroom therefore; make the closet AFCI protected anyway. I also beleive that particular closet does belong to that particular bedroom which would make it part of. Seems like every AHJ has a different outlook and beleifs so you might as well get it done even if it might be slightly overboard.

 

[Joe Rocker]

AFCI coverage

AFCI coverage

AFCI stuff is confusing. So new construction, outlets and lights are going to be AFCI protected. With that, also a walk in closet AFCI protected?
Thanks
Joe