# Hypothetical AFCI question...

**URL:** <https://forum.nachi.org/t/hypothetical-afci-question/18306>\
**Category:** Electrical Inspections\
**Created:** [July 12, 2007, 5:44pm UTC](https://forum.nachi.org/t/hypothetical-afci-question/18306 "2007-07-12T17:44:41Z")\
**Posts on this page:** 14\
**Page:** 1

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**Author:** ![mgault](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mgault/32/57038_2.png) [@mgault](https://forum.nachi.org/u/mgault)\
**Post date:** [July 12, 2007, 5:44pm UTC](https://forum.nachi.org/t/hypothetical-afci-question/18306/1 "2007-07-12T17:44:41Z")

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If the bathrooms in a home are GFCI protected (the Master and Hall bath’s tied to a local GFCI receptacle in the powder room) can a 20 Amp AFCI breaker be installed for them all in the panel board?

If not, why?

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**Author:** ![dvalley](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dvalley/32/206092_2.png) [@dvalley](https://forum.nachi.org/u/dvalley)\
**Post date:** [July 12, 2007, 5:48pm UTC](https://forum.nachi.org/t/hypothetical-afci-question/18306/2 "2007-07-12T17:48:58Z")

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Michael,

AFCI’s are for bedroom receptacles only and are completely different from GFCI’s.

No, an AFCI breaker can not protect bathroom outlets.

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**Author:** ![mgault](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mgault/32/57038_2.png) [@mgault](https://forum.nachi.org/u/mgault)\
**Post date:** [July 12, 2007, 5:57pm UTC](https://forum.nachi.org/t/hypothetical-afci-question/18306/3 "2007-07-12T17:57:56Z")

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AFCI are ‘required’ only on bedroom circuits now. My question (and I understand what they do) is why is it wrong?

Don’t they act as a regular 20amp ‘breaker’ in the panel board when the circuit itself is GFCI protected ‘downstream’ by the local GFCI receptacle in the powder room?

And while doing so (if they do) would they not provide the additional arcing protection for which they are designed?

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**Author:** ![dvalley](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dvalley/32/206092_2.png) [@dvalley](https://forum.nachi.org/u/dvalley)\
**Post date:** [July 12, 2007, 7:52pm UTC](https://forum.nachi.org/t/hypothetical-afci-question/18306/4 "2007-07-12T19:52:40Z")

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> [@mgault](#):
>
> AFCI are ‘required’ only on bedroom circuits now. My question (and I understand what they do) is why is it wrong?
> 
> Don’t they act as a regular 20amp ‘breaker’ in the panel board when the circuit itself is GFCI protected ‘downstream’ by the local GFCI receptacle in the powder room?
> 
> And while doing so (if they do) would they not provide the additional arcing protection for which they are designed?

Mike,

These will assist you in answering your questions…I was wrong about the AFCI protecting GFCI’s in the bathrooms. See **last** question.

**What makes the AFCI protection any different from that in a standard circuit breaker?**

AFCI’s have the electronics to open the circuit for low-level line-to-neutral faults when three to eight half-cycles exceed 50A peak (within .5 second), whereas a standard circuit breaker might not open for many hundreds of half-cycles.

**What is the difference between a GFCI and an AFCI?**

GFCI circuit breakers are designed to protect against ground faults of 4 to 6 mA or more, short-circuits, and overloads. AFCI/GFCI circuit breakers are designed to protect against ground faults of 5 mA or more, arcing line-to-neutral faults, short circuits, and overloads. AFCI/GFI circuit breakers are designed to protect against ground faults of 30 mA or more, arcing line-to-neutral faults, short circuits, and overloads.

**Does an AFCI/GFI provide the same level of protection as a GFCI device?**

No, AFCI/GFI circuit breakers will de-energize the circuit when the ground fault exceeds 30 mA, whereas an AFCI/GFCI opens at 5 mA. However, AFCI/GFCI circuit breakers should only be installed on circuits where nuisance tripping would not be a problem.

**Is it okay to replace a regular circuit breaker with an AFCI circuit breaker if there are GFCI receptacles on the circuit in question?**

Yes. The GFCI receptacle should not interfere with the AFCI protection circuitry.

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**Author:** ![dvalley](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dvalley/32/206092_2.png) [@dvalley](https://forum.nachi.org/u/dvalley)\
**Post date:** [July 12, 2007, 7:53pm UTC](https://forum.nachi.org/t/hypothetical-afci-question/18306/5 "2007-07-12T19:53:22Z")

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> [@mgault](#):
>
> AFCI are ‘required’ only on bedroom circuits now. My question (and I understand what they do) is why is it wrong?
> 
> Don’t they act as a regular 20amp ‘breaker’ in the panel board when the circuit itself is GFCI protected ‘downstream’ by the local GFCI receptacle in the powder room?
> 
> And while doing so (if they do) would they not provide the additional arcing protection for which they are designed?

These will assist you in answering your questions…I was wrong about the AFCI protecting GFCI’s in the bathrooms. See **last** question.

\*\*What makes the AFCI protection any different from that in a standard circuit breaker?  
\*\*  
AFCI’s have the electronics to open the circuit for low-level line-to-neutral faults when three to eight half-cycles exceed 50A peak (within .5 second), whereas a standard circuit breaker might not open for many hundreds of half-cycles.

\*\*What is the difference between a GFCI and an AFCI?  
\*\*  
GFCI circuit breakers are designed to protect against ground faults of 4 to 6 mA or more, short-circuits, and overloads. AFCI/GFCI circuit breakers are designed to protect against ground faults of 5 mA or more, arcing line-to-neutral faults, short circuits, and overloads. AFCI/GFI circuit breakers are designed to protect against ground faults of 30 mA or more, arcing line-to-neutral faults, short circuits, and overloads.

\*\*Does an AFCI/GFI provide the same level of protection as a GFCI device?  
\*\*  
No, AFCI/GFI circuit breakers will de-energize the circuit when the ground fault exceeds 30 mA, whereas an AFCI/GFCI opens at 5 mA. However, AFCI/GFCI circuit breakers should only be installed on circuits where nuisance tripping would not be a problem.

**Is it okay to replace a regular circuit breaker with an AFCI circuit breaker if there are GFCI receptacles on the circuit in question?**

Yes. The GFCI receptacle should not interfere with the AFCI protection circuitry.

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**Author:** ![dvalley](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dvalley/32/206092_2.png) [@dvalley](https://forum.nachi.org/u/dvalley)\
**Post date:** [July 12, 2007, 7:53pm UTC](https://forum.nachi.org/t/hypothetical-afci-question/18306/6 "2007-07-12T19:53:25Z")

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> [@mgault](#):
>
> AFCI are ‘required’ only on bedroom circuits now. My question (and I understand what they do) is why is it wrong?
> 
> Don’t they act as a regular 20amp ‘breaker’ in the panel board when the circuit itself is GFCI protected ‘downstream’ by the local GFCI receptacle in the powder room?
> 
> And while doing so (if they do) would they not provide the additional arcing protection for which they are designed?

These will assist you in answering your questions…I was wrong about the AFCI protecting GFCI’s in the bathrooms. See **last** question.

\*\*What makes the AFCI protection any different from that in a standard circuit breaker?  
\*\*  
AFCI’s have the electronics to open the circuit for low-level line-to-neutral faults when three to eight half-cycles exceed 50A peak (within .5 second), whereas a standard circuit breaker might not open for many hundreds of half-cycles.

\*\*What is the difference between a GFCI and an AFCI?  
\*\*  
GFCI circuit breakers are designed to protect against ground faults of 4 to 6 mA or more, short-circuits, and overloads. AFCI/GFCI circuit breakers are designed to protect against ground faults of 5 mA or more, arcing line-to-neutral faults, short circuits, and overloads. AFCI/GFI circuit breakers are designed to protect against ground faults of 30 mA or more, arcing line-to-neutral faults, short circuits, and overloads.

\*\*Does an AFCI/GFI provide the same level of protection as a GFCI device?  
\*\*  
No, AFCI/GFI circuit breakers will de-energize the circuit when the ground fault exceeds 30 mA, whereas an AFCI/GFCI opens at 5 mA. However, AFCI/GFCI circuit breakers should only be installed on circuits where nuisance tripping would not be a problem.

**Is it okay to replace a regular circuit breaker with an AFCI circuit breaker if there are GFCI receptacles on the circuit in question?**

Yes. The GFCI receptacle should not interfere with the AFCI protection circuitry.

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**Author:** ![jpope](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jpope/32/59425_2.png) [@jpope](https://forum.nachi.org/u/jpope)\
**Post date:** [July 12, 2007, 8:13pm UTC](https://forum.nachi.org/t/hypothetical-afci-question/18306/7 "2007-07-12T20:13:43Z")

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Yes. You can have an AFCI breaker on circuits with GFCI receptacles. One does not interfere with the other. . .

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**Author:** ![pabernathy](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/pabernathy/32/178230_2.png) [@pabernathy](https://forum.nachi.org/u/pabernathy)\
**Post date:** [July 12, 2007, 8:18pm UTC](https://forum.nachi.org/t/hypothetical-afci-question/18306/8 "2007-07-12T20:18:35Z")

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Hmmm…Why would you think he can’t have a AFCI on the bathroom if he so wishes? They make 20A AFCI’s as well as 15A AFCI’s…

The NEC as of 2005 says it has to be in bedrooms only…but does not mean it can’t venture outside of the bedroom. If the wiring was done at a time when they obviously allowed the bathroom circuits to be on other circuits in the dwelling ( which is not allowed today mind you ) then putting a AFCI in the panel to protect the system is fine…will not bother the function of the GFCI at all since they work two different ways…

GFCI- Senses the difference between the Ungrounded and the Grounded Conductors…looking for a 4-6MA difference…while…  
AFCI- monitor the system detecting arcs and patterns of arcs so explain it simply…it samples the system so to speak.

So nothing says you can’t have an AFCI protecting a circuit that has a GFCI receptacle within it…in fact for those of us who support the AFCI it is indeed a move on the safer side.

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**Author:** ![pabernathy](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/pabernathy/32/178230_2.png) [@pabernathy](https://forum.nachi.org/u/pabernathy)\
**Post date:** [July 12, 2007, 8:19pm UTC](https://forum.nachi.org/t/hypothetical-afci-question/18306/9 "2007-07-12T20:19:37Z")

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Ahhh…sorry David I see you got back on track fella…🙂

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**Author:** ![dvalley](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dvalley/32/206092_2.png) [@dvalley](https://forum.nachi.org/u/dvalley)\
**Post date:** [July 12, 2007, 8:37pm UTC](https://forum.nachi.org/t/hypothetical-afci-question/18306/10 "2007-07-12T20:37:29Z")

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> [@pabernathy](#):
>
> Ahhh…sorry David I see you got back on track fella…🙂

Yup, we all learn something every day of our life.

Especially hanging out here and researching these questions.

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**Author:** ![pabernathy](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/pabernathy/32/178230_2.png) [@pabernathy](https://forum.nachi.org/u/pabernathy)\
**Post date:** [July 12, 2007, 8:41pm UTC](https://forum.nachi.org/t/hypothetical-afci-question/18306/11 "2007-07-12T20:41:02Z")

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it all good my brother…we learn everyday and it is what keeps us movin onward and upward.

You get a GREENIE for learning…Most Excellent

And Jeff gets a Greenie just because I like him…and I am in a GREENIE mood.

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**Author:** ![mgault](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mgault/32/57038_2.png) [@mgault](https://forum.nachi.org/u/mgault)\
**Post date:** [July 12, 2007, 9:48pm UTC](https://forum.nachi.org/t/hypothetical-afci-question/18306/12 "2007-07-12T21:48:29Z")

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Had to go out an do my 1300 appt. Back now.

Thanks Dave, Paul and (and always Jeff P) Yours were the responses I’d expected. …

I was telling a builder last week (about a 2 family Townhouse I had inspected) I believed it to be an added measure of safety _ **if** _ all the circuits receptacles were already protected by a GFCI receptacle to have the AFCI in the panel board, but that an AFCI breaker \ ***in lieu of** \*proper GFCI protection was wrong…

Glad I’m not a complete 'tard. 😃

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**Author:** ![pabernathy](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/pabernathy/32/178230_2.png) [@pabernathy](https://forum.nachi.org/u/pabernathy)\
**Post date:** [July 12, 2007, 10:05pm UTC](https://forum.nachi.org/t/hypothetical-afci-question/18306/13 "2007-07-12T22:05:00Z")

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You did EXCELLENT…you get a GREENIE for not being a complete 'tard…thehehehheeh:)

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**Author:** ![mgault](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mgault/32/57038_2.png) [@mgault](https://forum.nachi.org/u/mgault)\
**Post date:** [July 12, 2007, 10:08pm UTC](https://forum.nachi.org/t/hypothetical-afci-question/18306/14 "2007-07-12T22:08:29Z")

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Thank You Paul… :mrgreen:
