AFCI & GFCI & Dual Function???

[duneslider]

Hello all, trying to understand some codes that I am not clear on for some basement work I will be doing. I understand that GFCI is required on all outlets in basement, this matches what is there now, all existing outlets in basement are fed from GFCI outlets.

My understanding is that bedrooms will need to be GFCI and AFCI protected. In two areas where I am planning bedrooms there is a GFCI outlet near them that I was planning to just tie into to run the outlets in the rooms. So, to do this code compliant, can I swap out the regular 15amp breaker feeding the gfci outlet with an AFCI breaker and leave the gfci, or pull the gfci and put in a Dual function breaker? Or is there a different way that would be cheaper? Or do I forget about AFCI and just leave it GFCI since I likely won't be having this inspected anyway...

My previous house did have issues with AFCI nuisance trips but I have not had any issues at all in this house and assume the breakers are better today than 18 years ago? Anyway, what say the real electricians?

 

[dcg9381]

can I swap out the regular 15amp breaker feeding the gfci outlet with an AFCI breaker and leave the gfci, or pull the gfci and put in a Dual function breaker?

Yes, these are the two ways I know to do it.

Personally, having a "new" home that has quite a few of the dual-function breakers, I've found them "problematic" for faulting on higher load devices like vacuums. The recommendation has been to use an Arc fault breaker with a GFI outlet in the first position.. For some reason that works better... Not a fan of the dual breaker in terms of function.

 

[duneslider]

Yes, these are the two ways I know to do it.

Personally, having a "new" home that has quite a few of the dual-function breakers, I've found them "problematic" for faulting on higher load devices like vacuums. The recommendation has been to use an Arc fault breaker with a GFI outlet in the first position.. For some reason that works better... Not a fan of the dual breaker in terms of function.

Good info. Going with the AFCI's may be the better route in my case.

 

[exranger06]

Bedrooms don't need GFCI, only AFCI. Unless the bedroom is in a finished basement area, in which case it's also a "basement outlet" that also needs GFCI.

There are some areas of a house that require both AFCI and GFCI (kitchen outlets, for example). In those cases, you can use either a dual function breaker, or use an AFCI breaker with GFCI receptacles. Either way will work and would be code compliant.

 

[PCustoms]

Bedrooms don't need GFCI, only AFCI. Unless the bedroom is in a finished basement area, in which case it's also a "basement outlet" that also needs GFCI.

Did you read the OP?

 

[sparky 1971]

Hello all, trying to understand some codes that I am not clear on for some basement work I will be doing. I understand that GFCI is required on all outlets in basement, this matches what is there now, all existing outlets in basement are fed from GFCI outlets.

My understanding is that bedrooms will need to be GFCI and AFCI protected. In two areas where I am planning bedrooms there is a GFCI outlet near them that I was planning to just tie into to run the outlets in the rooms. So, to do this code compliant, can I swap out the regular 15amp breaker feeding the gfci outlet with an AFCI breaker and leave the gfci,

Yes, but it's not just bedrooms. It will be any finished area. It's easier to list what doesn't need AFCI: unfinished rooms, bathrooms, garages, outside. The end. Of course, everything in the basement needs GFCI. Even the effing sump pump is supposed to have GFCI.

or pull the gfci and put in a Dual function breaker

If you want to, but it will cost a little more.

? Or is there a different way that would be cheaper? Or do I forget about AFCI and just leave it GFCI since I likely won't be having this inspected anyway...

My previous house did have issues with AFCI nuisance trips but I have not had any issues at all in this house and assume the breakers are better today than 18 years ago? Anyway, what say the real electricians?

I will get scolded by the safety Nazi's if I say how I feel about AFCI "protection". Apparently, there are a few people out there that actually believe that AFCI's save lives.

 

[Zeke]

Did you read the OP?

He didn't definitively say the bedrooms were to be in the basement. That's what it sounds like, but I don't see that exact wording. I assume that's what he's doing. He assumes we understand.

Sometimes it's not easy understanding each person's questions.

 

[Zeke]

Yes, but it's not just bedrooms. It will be any finished area. It's easier to list what doesn't need AFCI: unfinished rooms, bathrooms, garages, outside. The end. Of course, everything in the basement needs GFCI. Even the effing sump pump is supposed to have GFCI.

If you want to, but it will cost a little more.




I will get scolded by the safety Nazi's if I say how I feel about AFCI "protection". Apparently, there are a few people out there that actually believe that AFCI's save lives.

No scolding but I have had a couple of incidents where the AFCI would have done its job. I had an exterior light that happened to be on a receptacle circuit because it was a new cut in door and the circuit needed to be cut, 2 receps installed for the boxes needed to go over the new door, and also a required light and switch at the door for the outside. Somehow it managed to fill with water and started arching. This was a bedroom, so no GFCI.

I mean you could see and hear the arching. Of course there was a problem in the fixture box that needed attention. But the water got the thing going otherwise the problem would have gone unnoticed.

I had an interior wall sconce do the same thing. Bad leak and the old plaster wall got pretty wet. It was sizzling. No AFCI on the interior lighting circuits so I suppose I can't count that as an 'incident'.

 

[micromind]

I'm not a fan of AFCIs. I various testing I've done over the years, I have yet to find one that can detect the characteristics of an actual electrical arc and trip.

I believe their sole purpose is to enhance corporate profits, similar to snake oil.........

 

[Norcal]

I'm not a fan of AFCIs. I various testing I've done over the years, I have yet to find one that can detect the characteristics of an actual electrical arc and trip.

I believe their sole purpose is to enhance corporate profits, similar to snake oil.........

I refer to them as snake oil.

 

[dscheidt]

Yes, but it's not just bedrooms. It will be any finished area. It's easier to list what doesn't need AFCI: unfinished rooms, bathrooms, garages, outside. The end. Of course, everything in the basement needs GFCI. Even the effing sump pump is supposed to have GFCI.

I know people worry about a false trip causing a flood, but sump pumps are electrical devices in water that non electricians are going to mess with. no one unplugs a sump pump that's not clogged or turning on before sicking their hands in, you want to know you fixed it. I know of sump pumps that failed in ways that caused the gfci to trip. Someone would have had a bad day if they reached into the sump to fix a stuck switch or something.

 

[duneslider]

Thanks for the input. These are all in the basement, sorry that wasn't clear.

I really don't fully understand the difference between what the AFCI protects and the GFCI. The only afci trips I ever had were from my vacuum and only on one particular circuit. Any water related issues I have had the gfci tripped. Similar to the ones noted above my dad has an exterior outlet that somehow occasionally gets water in it and trips the gfci and the only way to get it to reset is to pull the cover and let it dry out really good. It's a brick wall so its been difficult trying to find the leak and there is no other evidence of water intrusion anywhere else. I have also had extension cords and christmas lights that got wet and tripped gfci's. I guess none of those situations were really arc's though. The only arc's I have ever caused tripped breakers.

I assumed my question would get derailed into AFCI love but I did get the info I needed, so thanks to all who shared.

 

[duneslider]

I'm not a fan of AFCIs. I various testing I've done over the years, I have yet to find one that can detect the characteristics of an actual electrical arc and trip.

I believe their sole purpose is to enhance corporate profits, similar to snake oil.........

I will say they seem very proud of them based on the pricing.

 

[billconner]

I will get scolded by the safety Nazi's if I say how I feel about AFCI "protection". Apparently, there are a few people out there that actually believe that AFCI's save lives.

I understand. I'll only add that the local electrical inspector believes he has seen the results or evidence of them preventing damage. And he seems pretty level headed and very knowledgeable.

I'm not taking sides but I'd rather pass inspections and just installed a combo breaker. Expensive and BIG suckers.

 

[BrandonV]

I really don't fully understand the difference between what the AFCI protects and the GFCI.

GFCI is looking for leakage current. If 50mA is going thru the hot and 40mA is returning on the neutral it senses you have a leakage (10mA) somewhere and will trip. The GFCI is worried about current going thru another path (e.g. you).

The AFCI is looking at frequency harmonics on what is passing thru it for characteristics that are typical of an arc between conductors, etc.

In theory I could have 5A arcing between the hot and neutral heating up the wire to an fire hazard and a GFCI will be content with it. Now if those shorts went between N-G or H-G the GFCI would trip (they'd be ground faults).

In reality? I'm just an engineer but I've been told in the field AFCIs have a tendency to nucience trip a lot.

 

[billconner]

I think half my panel has been swapped to AFCIs (notice I did not say upgraded out of respect to the sparkys here. ) over last 5 years and not one nuisance trip. SQ-D if that matters. I think that deserves a YMMV.

 

[wyliesdiesels]

I will get scolded by the safety Nazi's if I say how I feel about AFCI "protection". Apparently, there are a few people out there that actually believe that AFCI's save lives.

you wont get scolding from me...

 

[sparky 1971]

you wont get scolding from me...

You're not one of the people that have fallen for the propaganda.... I haven't seen one for awhile, but I used to get a chuckle out of the posts where someone is wanting approval for installing AFCI's in an old house because of some article he read online. I am in the process of trimming out a big house and last week I bought 29 Homeline AFCI breakers for a grand total of $1736.75 after tax. The only dual function was the dishwasher/disposal receptacle. I try to use straight AFCI breakers, that way, if nuisance tripping starts and someone tosses the breaker and installs an old school, the GFCI is still there.

 

[dcg9381]

I am in the process of trimming out a big house and last week I bought 29 Homeline AFCI breakers for a grand total of $1736.75 after tax. The only dual function was the dishwasher/disposal receptacle. I try to use straight AFCI breakers, that way, if nuisance tripping starts and someone tosses the breaker and installs an old school, the GFCI is still there.

You're the electrician that I should have hired.

 

[LopezBart]

Our new place has all combined AFCI breakers; the outlets are GFCI if needed except for the kitchen, which has combined breakers. The only nuisance trips have been from a old deep fryer, which is going to be replaced. Well, we did have one power glitch in the middle of the night that tripped several breakers; the GFCI outlet in the pump house running the heat tape was the only one that caused problems.

 

[American Locomotive]

I really don't fully understand the difference between what the AFCI protects and the GFCI.

GFCIs work by measuring the difference in current flowing between the hot and neutral of a circuit. The current should be exactly the same between hot and neutral. If it sees a difference (well, a very, very small difference), it will trip the GFCI. The assumption is that if the hot/neutral current doesn't match, that means electricity is going somewhere it shouldn't - e.g., through a human body. GFCIs have definitely saved a lot of lives and prevented a lot of electrocutions. They most commonly come into play when things get wet, and the electricity starts flowing through the water into places it shouldn't.

AFCIs try to detect arcs/sparks, like say from a frayed wire using microprocessors and sophisticated circuitry. The problem with AFCIs, is that there are a lot of electrical devices that do inherently have arcs/sparks as part of their normal operation. Things like vacuums, powerdrills, blenders, etc... that have motors with sparking commutators. Welders are another big one that comes to mind. There are also old old-school devices that have a pair of breaker points inside that constantly make/break, creating sparks - like buzzers, bells, etc... Relays, contactors, etc...

The early AFCIs probably actually did something useful in the event of an arc, but they also nuisance tripped very often. The latest generation of AFCIs don't seem to nuisance trip, but I've seen people on YouTube test both series and parallel arcs, and the breakers don't even react. They fixed the nuisance tripping by making them essentially useless.

 

[dscheidt]

The early AFCIs probably actually did something useful in the event of an arc, but they also nuisance tripped very often. The latest generation of AFCIs don't seem to nuisance trip, but I've seen people on YouTube test both series and parallel arcs, and the breakers don't even react. They fixed the nuisance tripping by making them essentially useless.

The AFCI has to detect a substantial amount of current flowing through the arc to trip. Just a spark isn't enough. typical value is 75A for a 20A branch circuit breaker. (you might think "75A should trip a 20A breaker." True, but only if the draw lasts long enough. 75A for a the top 1/4 of a voltage cycle isn't going to trip a breaker, but it can create a spark with enough energy to start a fire. ) So unless those tests are properly instrumented, they're not very useful.