ARC fault/GROUND fault confusion

[TomC750]

Just finished framing up the basement and about to start on the wiring. In looking at the main panel upstairs I see there are AF/GF breakers for both kitchen receptacle circuits, and dishwasher. The office, master bedroom, kitchen lights, living room, gas range, microwave and garage lights are each on AF breakers. In the basement I have a sub panel that will be serving two bedrooms, bath and a general area. But based on what I see upstairs, it appears to me I would need ARC faults on each circuit except the bath, but I do not understand the rationale behind what circuits need what. I live in Tennessee and the 2017 code applies.
All input appreciated.

Tom

 

[exranger06]

AFCI is required in just about every room of a house. The only places they're NOT required are bathrooms, garages, unfinished basements, crawl spaces, attics, and outdoors. They're also only used on 120V circuits.

GFCI is generally required for receptacles only (not lighting or hardwired appliances, usually), whereas AFCI is required on any 120V circuit, regardless of what it powers. GFCI is required for all receptacles in a garage, basement, crawl space, outdoors, laundry areas, kitchen countertops, bathrooms, and anywhere a receptacle is within 6 ft of a water source.

In short, most circuits need AFCI, some need GFCI, and some need both.

GFCI doesn't have to be built into the breaker. You can use a regular breaker (or AFCI breaker, if required) and use a GFCI receptacle instead. And you can feed regular receptacles off of a GFCI receptacle and they'll be GFCI protected too.

 

[billconner]

AFCI around here, just 15 and 20 amp circuits.

 

[Zeke]

AFCI is required in just about every room of a house. The only places they're NOT required are bathrooms, garages, unfinished basements, crawl spaces, attics, and outdoors. They're also only used on 120V circuits.

GFCI is generally required for receptacles only (not lighting or hardwired appliances, usually), whereas AFCI is required on any 120V circuit, regardless of what it powers. GFCI is required for all receptacles in a garage, basement, crawl space, outdoors, laundry areas, kitchen countertops, bathrooms, and anywhere a receptacle is within 6 ft of a water source.

In short, most circuits need AFCI, some need GFCI, and some need both.

GFCI doesn't have to be built into the breaker. You can use a regular breaker (or AFCI breaker, if required) and use a GFCI receptacle instead. And you can feed regular receptacles off of a GFCI receptacle and they'll be GFCI protected too.

Good explanation.

 

[Zeus36]

For residential:

AFCI protection must be present in the following rooms:

• Kitchens
• Family Rooms
• Dining Rooms
• Living Rooms
• Parlors
• Libraries
• Dens
• Bedrooms
• Sunrooms
• Recreation Rooms
• Closets
• Hallways
• Laundry Areas

Under the 2017 NEC, bathrooms, and garages are not included. However, they will probably be added to the above list in the 2020 NEC. AFCI protection is also required in any of the rooms or areas mentioned above where branch-circuit wiring is modified, replaced, or extended.

GFCI is required in:

• Bathrooms
• Garages, and accessory buildings that have a floor located at or below grade level and used for storage and work areas
• Outdoors
• Crawl spaces at or below grade level
• Unfinished portions of basements not intended as habitable rooms
• Kitchens, where the receptacles are serving countertop spaces
• Sinks, where the receptacles are within 6-feet from the top inside edge of the sink bowl
• Boathouses
• Bathtubs and shower stalls, where the receptacles are within 6-feet of the outside edge of the tub or shower stall
• Laundry areas
• Boat hoists, for outlets not exceeding 240-volts
• Kitchen dishwashers, whether they are cord-and-plug connected or hard-wired
• Crawl space lighting outlets

 

[billconner]

You all got this. Can you clarify:

Circuits without receptacles?

Circuits other than 15 or 20 amps?

 

[Norcal]

Dishwashers require GFCI protection.

 

[Junkman]

My home was built in 1983, and we added an additional bathroom in 1992. The garage and bathrooms are all on GFIC, and I am assuming that it is grandfathered as to what is presently required. If we were to add onto the home today, would the entire house need to be upgraded to the new codes, or only the part that was added onto? At the time it was built, the dishwasher wasn't required to have a GFIC, and I don't think that the kitchen outlets are on a GFIC either. I will have to check on those, but it should be easy to upgrade the breaker if that is the case. I was told that the arc fault breakers can be problematic in older homes, is that true or not? Thanks, Junk

 

[Zeke]

My home was built in 1983, and we added an additional bathroom in 1992. The garage and bathrooms are all on GFIC, and I am assuming that it is grandfathered as to what is presently required. If we were to add onto the home today, would the entire house need to be upgraded to the new codes, or only the part that was added onto? At the time it was built, the dishwasher wasn't required to have a GFIC, and I don't think that the kitchen outlets are on a GFIC either. I will have to check on those, but it should be easy to upgrade the breaker if that is the case. I was told that the arc fault breakers can be problematic in older homes, is that true or not? Thanks, Junk

AFCI's don't like combined neutrals so it could be a problem. One circuit and one continuous neutral and they work fine. Except when they don't.

 

[duneslider]

I know there is a lot of talk about AFCI being "snake oil" but if you are trying to keep with code and have a "safe" install can AFCI be replaced with gfci? So, in this case it being a basement, I believe the newest code calls for gfci in basements. Is gfci technically a superior method and if you did everything gfci you would be meeting and/or exceeding the minimum standard? So, just skip the afci and make everything gfci instead?

Does the new gfci in basements apply only to outlets? Or do light circuits also need protection?

 

[dave*99]

I know there is a lot of talk about AFCI being "snake oil" but if you are trying to keep with code and have a "safe" install can AFCI be replaced with gfci? So, in this case it being a basement, I believe the newest code calls for gfci in basements. Is gfci technically a superior method and if you did everything gfci you would be meeting and/or exceeding the minimum standard? So, just skip the afci and make everything gfci instead?

Does the new gfci in basements apply only to outlets? Or do light circuits also need protection?

AFCI protects from sparking (arcing) wiring causing a fire.
GFCI protects people from being electrocuted.
So in a word, no. You can't.

 

[rooster59]

Some of my corded power tools in perfect working condition will trip afci, I assume due to having carbon brushes and a normal bit of low level sparking. Old German Metabo drill, Skill saw, stuff like that. They never trip a gfci. Garage has only gfci, else where would I run these?

 

[exranger06]

I know there is a lot of talk about AFCI being "snake oil" but if you are trying to keep with code and have a "safe" install can AFCI be replaced with gfci? So, in this case it being a basement, I believe the newest code calls for gfci in basements. Is gfci technically a superior method and if you did everything gfci you would be meeting and/or exceeding the minimum standard? So, just skip the afci and make everything gfci instead?

Does the new gfci in basements apply only to outlets? Or do light circuits also need protection?

AFCI and GFCI are not interchangeable. They're two entirely different things that serve different purposes. That's why some areas require AFCI, other areas require GFCI, and some areas require BOTH.

GFCI in basements applies only to receptacles. Lighting doesn't need GFCI, unless it's a crawl space.

 

[dave*99]

There are few one word answers to code requirement questions.

Before any solid answers to even basic questions can be had, consider which code cycle your jurisdiction is on, your location, the extent of the job (upgrade, new construction, simple repair)
NEC was updated in 2020, 2017, 2014, etc.

Here is an example: My house in NJ (new construction) was completed in 2021 and my permits were issued in 2019 a year before construction started and were based on the 2014 code which was grandfathered on new permit issues for 6 months after NJ adopted the 2017 code. I know, it's a lot to unpack that statement. The applicable code is based on the date permits are applied for. My builder made sure my application was submitted before the cutoff date on the next code cycle which was about to occur. So consider this - in June 2021 during final inspection, the electrical inspector relied on 2014 code.

GFCI was not required for my dishwasher. I believe if I waited a month longer to file for permits, my dishwasher would have a GFCI.

I have about 12 AFCI breakers in the house. if I waited to file for permits, I might have more.... It goes on and on.

New requirements (and additional associated costs) are added at each code revision.

 

[exranger06]

You all got this. Can you clarify:

Circuits without receptacles?

Circuits other than 15 or 20 amps?

Circuits without receptacles: AFCI is still required in most rooms of the house. GFCI most likely not required, with a few exceptions.

Circuits other than 15 or 20 amps: AFCI is required ONLY on 120V, 15 and 20 amp circuits, not required on any other voltage or amperage. GFCI IS required on all receptacles in certain areas (garages, bathrooms, outdoors, etc), regardless of the voltage or amperage.

 

[n8n]

Just to toss this out there - I ended up doing some electrical work on a house that I owned ~15 years ago. At that time the AFCI requirement was only for bedrooms and hadn't been expanded to the rest of the house. What I found out was that at least at that time, any AFCI breaker also included some GFCI capability but it was not at a "personnel protection" level but at an "equipment protection" level. So the breaker would trip on overcurrent, arc fault detection, or ground fault but it was not listed as a GFCI. Today, you can purchase a combination breaker that is listed as both an AFCI and GFCI and will work in locations where both are required. This would have helped me a bit at that old house, as half the 2nd floor was original ungrounded rag wire so I had both an AFCI breaker and a GFCI receptacle in the first box from the panel which seemed super janky to me, but I never had any issues wityh the two GFCIs fighting each other. (homerun was old BX and half the upstairs I rewired myself - out of necessity as some old renovations had been done very poorly, this is why I had to do upgrades since I pulled a permit for the work - so it *was* grounded, but I chose to just GFCI the whole thing rather than turn it into a whole mess of Special Instructions.)

 

[exranger06]

For residential:

AFCI protection must be present in the following rooms:

• Kitchens
• Family Rooms
• Dining Rooms
• Living Rooms
• Parlors
• Libraries
• Dens
• Bedrooms
• Sunrooms
• Recreation Rooms
• Closets
• Hallways
• Laundry Areas

Under the 2017 NEC, bathrooms, and garages are not included. However, they will probably be added to the above list in the 2020 NEC. AFCI protection is also required in any of the rooms or areas mentioned above where branch-circuit wiring is modified, replaced, or extended.

GFCI is required in:

• Bathrooms
• Garages, and accessory buildings that have a floor located at or below grade level and used for storage and work areas
• Outdoors
• Crawl spaces at or below grade level
• Unfinished portions of basements not intended as habitable rooms
• Kitchens, where the receptacles are serving countertop spaces
• Sinks, where the receptacles are within 6-feet from the top inside edge of the sink bowl
• Boathouses
• Bathtubs and shower stalls, where the receptacles are within 6-feet of the outside edge of the tub or shower stall
• Laundry areas
• Boat hoists, for outlets not exceeding 240-volts
• Kitchen dishwashers, whether they are cord-and-plug connected or hard-wired
• Crawl space lighting outlets

As Dave*99 said, different areas are under different code cycles, but just wanted to say that there were no changes to AFCI requirements in the 2020 or the 2023 NEC. There were some changes to GFCI requirements:

2020 NEC: GFCI required in ALL basements, whether they're finished basements or unfinished.
GFCI required on ALL receptacles in the listed areas, including 240V receptacles (it was previously only 120V receptacles)

2023 NEC: GFCI now required on ALL kitchen receptacles, not just countertop receptacles. Receptacles located down low on the wall, over 6 ft away from the sink, still need GFCI. GFCI also required on hardwired countertop cooktops and wall ovens, and of course required for 240V oven range receptacles.

 

[TomC750]

Hole smokes, My question was answered and then some! Thanks to all who responded.

Tom

 

[jar944]

Some of my corded power tools in perfect working condition will trip afci, I assume due to having carbon brushes and a normal bit of low level sparking. Old German Metabo drill, Skill saw, stuff like that. They never trip a gfci. Garage has only gfci, else where would I run these?

I hate afci for that reason. Running a corded circular saw on a afci circut can be beyond irritating.

 

[duneslider]

AFCI and GFCI are not interchangeable. They're two entirely different things that serve different purposes. That's why some areas require AFCI, other areas require GFCI, and some areas require BOTH.

GFCI in basements applies only to receptacles. Lighting doesn't need GFCI, unless it's a crawl space.

So, previous versions of the code said the outlets in basements needed to be AFCI for some "safety" purpose. Now the code says they need to be GFCI now for safety. If AFCI was important why would the new code not say the outlets needed to be AFCI AND GFCI?

I can't say I have run many tools on AFCI but I do have a vacuum that would consistently trip the AFCI in my bedroom but it would not cause issues on any other plug/circuit in the house.

I know they make the afci/gfci breakers but what areas require both protections?

And just because I want to understand better, is AFCI really protection for things plugged into the outlets and not the actual circuit wiring? Arcing in the actual circuit wiring would be handled by a standard breaker right? Or would loose connection arcing be more of a AFCI thing and the breaker is only going to trip on a short or over current issue?

 

[dave*99]

So, previous versions of the code said the outlets in basements needed to be AFCI for some "safety" purpose. Now the code says they need to be GFCI now for safety. If AFCI was important why would the new code not say the outlets needed to be AFCI AND GFCI?

I can't say I have run many tools on AFCI but I do have a vacuum that would consistently trip the AFCI in my bedroom but it would not cause issues on any other plug/circuit in the house.

I know they make the afci/gfci breakers but what areas require both protections?

And just because I want to understand better, is AFCI really protection for things plugged into the outlets and not the actual circuit wiring? Arcing in the actual circuit wiring would be handled by a standard breaker right? Or would loose connection arcing be more of a AFCI thing and the breaker is only going to trip on a short or over current issue?

No, they didn't.

 

[dave*99]

And just because I want to understand better, is AFCI really protection for things plugged into the outlets and not the actual circuit wiring? Arcing in the actual circuit wiring would be handled by a standard breaker right? Or would loose connection arcing be more of a AFCI thing and the breaker is only going to trip on a short or over current issue?

Imagine a receptacle with a loose wire stabbed into the back of it. Then another receptacle down the wall is fed from the "loose" one. You plug in something to the good receptacle (or even the bad receptacle). The bad one starts arcing and sparking inside the plastic junction box and catches fire. The arcing and sparking occur at current levels too low to trip a standard breaker.

That's what an ARC FAULT CIRCUIT INTERRUPTER protects against. It does its job by looking for the "signal" that the sparking action generates. Some motors that spark at their brushes make a similar signal. The AFCI sees that and trips. We call that a nuisance trip.

And all of us on GJ have a heart attack and condemn AFCI's and those who put them in the code.

PS - circuit breakers protect from overcurrent causing wire or wire insulation to melt, shorts, etc. Not arcing faults. AFCI's protect from both overcurrent and arcing faults.

 

[duneslider]

Imagine a receptacle with a loose wire stabbed into the back of it. Then another receptacle down the wall is fed from the "loose" one. You plug in something to the good receptacle (or even the bad receptacle). The bad one starts arcing and sparking inside the plastic junction box and catches fire. The arcing and sparking occur at current levels too low to trip a standard breaker.

That's what an ARC FAULT CIRCUIT INTERRUPTER protects against. It does its job by looking for the "signal" that the sparking action generates. Some motors that spark at their brushes make a similar signal. The AFCI sees that and trips. We call that a nuisance trip.

And all of us on GJ have a heart attack and condemn AFCI's and those who put them in the code.

PS - circuit breakers protect from overcurrent causing wire or wire insulation to melt, shorts, etc. Not arcing faults. AFCI's protect from both overcurrent and arcing faults.

THanks for clearing that up. I have had very few issues with AFCI so I never understood all the hate with them. I have just had issues with that one vacuum on that one circuit. What is interesting in my old house I did find an outlet where the wire that was supposed to be backstabbed didn't get backstabbed and was just sitting on the side of the outlet touching the screw. It eventually stopped working and looked like it had arced enough to not make good enough contact. Never tripped the AFCI though.

 

[rooster59]

The licensed electrician who wired my house cut every corner, used the cheapest **** available, backstabbed outlets, big rooms with no 3-way switches, etc. I assume all up to code and “inspected”. Much of his stuff redone. My wiring, all commercial grade outlets, switches. Top shelf wire nuts, proper pigtails, etc. So why do I need AFCI?

 

[dcg9381]

So why do I need AFCI?

Code, IE 2014+ NEC... In many places.

That's not to say that I may or may have removed the combo AFI/GFI breakers in at least one personal residence as I find them flaky as hell.

 

[n8n]

AFCI's don't like combined neutrals so it could be a problem. One circuit and one continuous neutral and they work fine. Except when they don't.

I think now you can get a double AFCI breaker for some panels. I know 15 years ago that was a problem fortunately I didn't have any Edison circuits serving bedrooms.

 

[Zeke]

I think now you can get a double AFCI breaker for some panels. I know 15 years ago that was a problem fortunately I didn't have any Edison circuits serving bedrooms.

What I meant wasn't necessarily limited to multi branch circuits. Isolated neutrals along the individual circuits seemed to help me.

 

[Norcal]

The licensed electrician who wired my house cut every corner, used the cheapest **** available, backstabbed outlets, big rooms with no 3-way switches, etc. I assume all up to code and “inspected”. Much of his stuff redone. My wiring, all commercial grade outlets, switches. Top shelf wire nuts, proper pigtails, etc. So why do I need AFCI?

If you live in a tract home that is why, everything is bottom of the line & every corner that can be cut, will. As to AFCI's the idea behind them is good, but they lied as what they could do to get them required by code, and the customers have been the beta test since.

 

[Zeus36]

My home office is in what used to be a second Master Bedroom of a separate, but attached residence. When the electrician rewired it in 2009, all the bedrooms got AFCI breakers. I told him it was no longer a bedroom, but because there is a walk in closet, he said it didn't matter, if we moved, it would go back to being a bedroom. I have a tech/lab bench in the corner of my office, but can't run a sensitive drill press due to nuisance tripping. The electric space heater also trips the breaker. I was going to swap out the AFCI for a standard breaker, but my better half says "what happens if there is a fire and the insurance company finds there is no AFCI?" We will be S.O.L!

 

[dave*99]

My home office is in what used to be a second Master Bedroom of a separate, but attached residence. When the electrician rewired it in 2009, all the bedrooms got AFCI breakers. I told him it was no longer a bedroom, but because there is a walk in closet, he said it didn't matter, if we moved, it would go back to being a bedroom. I have a tech/lab bench in the corner of my office, but can't run a sensitive drill press due to nuisance tripping. The electric space heater also trips the breaker. I was going to swap out the AFCI for a standard breaker, but my better half says "what happens if there is a fire and the insurance company finds there is no AFCI?" We will be S.O.L!

If your AFCI breaker was made in 2009 it’s possible a new model may solve your issue. They have improved in the past 14 years.

 

[TomC750]

I guess what is not clear to me is if AFCI is required on a lighting only circuit. (2017 code). I am trying to not have any issues with my inspection when I have it done. All in all, great information here, just trying to digest it all!

 

[sparky 1971]

Just finished framing up the basement and about to start on the wiring. In looking at the main panel upstairs I see there are AF/GF breakers for both kitchen receptacle circuits, and dishwasher. The office, master bedroom, kitchen lights, living room, gas range, microwave and garage lights are each on AF breakers. In the basement I have a sub panel that will be serving two bedrooms, bath and a general area. But based on what I see upstairs, it appears to me I would need ARC faults on each circuit except the bath, but I do not understand the rationale behind what circuits need what. I live in Tennessee and the 2017 code applies.
All input appreciated.

Tom

Don't worry, nobody understands the rationale, because there is none.

I guess what is not clear to me is if AFCI is required on a lighting only circuit. (2017 code). I am trying to not have any issues with my inspection when I have it done. All in all, great information here, just trying to digest it all!

Everything that you are finishing with the exception of the bathroom will need AFCI. It doesn't matter if it's lighting only, receptacles only, or a mix of both.

 

[wyliesdiesels]

So, previous versions of the code said the outlets in basements needed to be AFCI for some "safety" purpose. Now the code says they need to be GFCI now for safety. If AFCI was important why would the new code not say the outlets needed to be AFCI AND GFCI?

I can't say I have run many tools on AFCI but I do have a vacuum that would consistently trip the AFCI in my bedroom but it would not cause issues on any other plug/circuit in the house.

I know they make the afci/gfci breakers but what areas require both protections?

And just because I want to understand better, is AFCI really protection for things plugged into the outlets and not the actual circuit wiring? Arcing in the actual circuit wiring would be handled by a standard breaker right? Or would loose connection arcing be more of a AFCI thing and the breaker is only going to trip on a short or over current issue?

Nope. If that were the case, then there would be no need for AFCIs in the first place, though i still dont believe they work how they claim they do.

The AFCI breaker protects anything downstream of it

 

[Junkman]

I was watching This Old House last night, and they were in Detroit at an abandoned home that was going to be renovated. The electrician was going around the home pointing out the various electrical outlets that were installed. When he came to one room, he commented that the outlet with just 2 spade openings was still acceptable since the only thing that will be plugged into them will be a lamp. I just can't imagine pulling a permit to renovate an abandoned home where the inspectors will not require that all the electrical be upgraded. Sure gives the watching audience poor advice to follow in their homes.

 

[Meursault74]

I was watching This Old House last night, and they were in Detroit at an abandoned home that was going to be renovated. The electrician was going around the home pointing out the various electrical outlets that were installed. When he came to one room, he commented that the outlet with just 2 spade openings was still acceptable since the only thing that will be plugged into them will be a lamp. I just can't imagine pulling a permit to renovate an abandoned home where the inspectors will not require that all the electrical be upgraded. Sure gives the watching audience poor advice to follow in their homes.

I just replaced a couple of receptacles in my home that were 2 pronged even though the metal box that contained them was grounded. I don't know why they were still that way as the rest of the house has the 3 prong all around. Most items we plug in are two pronged anyway so ground or not wouldn't make a difference at those outlets

The only reason I replaced them is I was doing some other electrical work (installing GFCI outlets) and had the tools and parts handy. Those 2 prong ones look strange in this day and age anyway.

I have no experience with arc fault breakers, but I don't ever plan on installing them.

 

[wyliesdiesels]

I was watching This Old House last night, and they were in Detroit at an abandoned home that was going to be renovated. The electrician was going around the home pointing out the various electrical outlets that were installed. When he came to one room, he commented that the outlet with just 2 spade openings was still acceptable since the only thing that will be plugged into them will be a lamp. I just can't imagine pulling a permit to renovate an abandoned home where the inspectors will not require that all the electrical be upgraded. Sure gives the watching audience poor advice to follow in their homes.

Ever heard of the term “grandfathered”?

 

[dave*99]

Most of would be upset if the inspector wandered away from the construction identified on the prints and permit application.
Let's say you pull a permit for a kitchen remodel, would you want the inspector to demand you rewire a bedroom circuit on the other side of the house?

 

[billconner]

Most of would be upset if the inspector wandered away from the construction identified on the prints and permit application.
Let's say you pull a permit for a kitchen remodel, would you want the inspector to demand you rewire a bedroom circuit on the other side of the house?

I think it could depend on why. Like a friction wad/splice clearly visible during normal course of kitchen inspection. So rarely would you want that or would it be appropriate.

 

[dave*99]

I think it could depend on why. Like a friction wad/splice clearly visible during normal course of kitchen inspection. So rarely would you want that or would it be appropriate.

I don’t disagree but:
The discussion is about grandfathered items like the 2 prong outlet in the context of the TOH story..
My post postulates an inspector expanding his look into an unrelated part of the entire permit/job just as a matter of course. See posts 34,36,37.

 

[billconner]

Fair enough. I just took the question at face value. I spend a lot of time with code development and thus a lot of inspector stories. A lot of them sincerely try to do a good job.