AFCi/GFCI protection

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infinity

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Do AFCI circuit breakers also provide GFCI protection? I'm asking because the instruction manual for a Kidde CO detector states that they are not to be installed on a GFCI protected circuit. I would assume that this means that they can't be on an AFCI circuit if it provides GFCI protection. Do they?
 

Jim W in Tampa

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infinity said:
Do AFCI circuit breakers also provide GFCI protection? I'm asking because the instruction manual for a Kidde CO detector states that they are not to be installed on a GFCI protected circuit. I would assume that this means that they can't be on an AFCI circuit if it provides GFCI protection. Do they?

Yes but at a much to high value of about 50 ma.What they might be saying is dont install in a panel that is fed from a gfci.
 

bphgravity

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AFCI's are not Class A gfci devices that are referenced by the smoke alarm manufacturer. The GFPE sensing device in the afci's are more tuned to faults that create fire rather than prevent shock.
 

roger

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Trevor, GFP is not an issue with NFPA 72 whereas GFCI is.

If you have access to NFPA 72 check out Chapter 11, specifically Power Supply.

Roger
 

infinity

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The appropriate power source is 120 volt AC Single-Phase supplied from a non-switchable circuit, which is not protected by a ground fault interrupter.


This is what it says in the users guide. Makes no mention of a specific class or GFPE protection. Sounds to me like this cannot go on an AFCI device that also provides GFCI protection.
 

stickboy1375

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Maybe the instructions were written before arc faults came out, and they are saying they dont wont them on GFI's for the same reason they don't wont them on a switch?
 

roger

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Trevor, NFPA 72 11.6.3(5) says

Operation of a switch (other than a circuit breaker) or a ground-fault circuit-interrupter shall not cause loss of primary power. Smoke alarms powered by AFCI-protected circuits shall have a secondary power source.


It makes a point to specify GFCI leaving GFP out.

Roger
 

infinity

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So the NEC requires AFCI protection for a dwelling bedroom. I install a CO detector with the instructions stating that it cannot be supplied by a GFCI protected circuit. AFCI breaker provides GFCI protection. How do I make this code compliant?
 

mdshunk

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Right here.
infinity said:
So the NEC requires AFCI protection for a dwelling bedroom. I install a CO detector with the instructions stating that it cannot be supplied by a GFCI protected circuit. AFCI breaker provides GFCI protection. How do I make this code compliant?
Pick a different CO detector, or install the CO detector on its own non-AFCI/GFCI circuit, locate it outside of the bedroom, and inter-tie to the smokes AFCI circuit it with the UL relay module designed for that purpose.
 

roger

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Trevor AFCI breakers provide GFP not GFCI.

Ground-Fault Circuit Interrupter (GFCI). A device intended for the protection of personnel that functions to de-energize a circuit or portion thereof within an established period of time when a current to ground exceeds the values established for a Class A device.

FPN: Class A ground-fault circuit interrupters trip when the current to ground has a value in the range of 4 mA to 6 mA. For further information, see UL 943, Standard for Ground-Fault Circuit Interrupters.

Ground-Fault Protection of Equipment. A system intended to provide protection of equipment from damaging line-to-ground fault currents by operating to cause a disconnecting means to open all ungrounded conductors of the faulted circuit. This protection is provided at current levels less than those required to protect conductors from damage through the operation of a supply circuit overcurrent device.

With this being the case there is no issue.

Roger
 
AFCI breaker provides protection from arcing
GFCI provides protection from you being the ground.(Sort of)
GFP provides protection from and for equipment. both are in 100
two different things smokes and cos can and should be on afci 210.12a
 
AFCI breaker provides protection from arcing
GFCI provides protection from you being the ground.(Sort of)
GFP provides protection from and for equipment. both are in 100
two different things smokes and cos can and should be on afci 210.12a
 

infinity

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roger said:
Trevor AFCI breakers provide GFP not GFCI.

With this being the case there is no issue.

Roger


Thanks Roger. The problem I have is that the wording of the user manual is vague. It mentions Ground Fault Interrupter. Assuming that they meant a GFCI device with a 4-6ma trip rating then I agree with you. But isn't a GFPE device still a ground fault interrupter? Or is that term not really defined at all?
 

al hildenbrand

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Minnesota
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infinity said:
But isn't a GFPE device still a ground fault interrupter? Or is that term not really defined at all?
This simple turn of phrase would be exactly the kind of thing that legal action, following a mishap that included the CO detector's behavior contributing to a negative outcome, could hinge a decision on. That would be a decision probably only in one case, however.

The CO detector manufacturer's department of installation instruction editors needs to give their legal expert a very strong cup of coffee. :mad:
 

tallgirl

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I have an issue with smokies being on AFCI-protected circuits. It seems that this might cause the device to lose power at precisely the time it's needed the most -- when an arc-fault initiated fire has begun.

Am I all wet or is the "best practice" to interleave AFCI circuits and smoke detectors so that an arc fault in a space does not disconnect the smoke detector in the same space?
 

roger

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Julie, I would think that is the reason for this "Smoke alarms powered by AFCI-protected circuits shall have a secondary power source." requirement.

Roger

 

tallgirl

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roger said:
Julie, I would think that is the reason for this "Smoke alarms powered by AFCI-protected circuits shall have a secondary power source." requirement.

Roger


Right, but typically the "secondary power source" is a battery that people may forget to replace. I know people who just ignore (no, really) the annoying chirp-chirp-chirp they make. Separating the smoke detector from the AFCI that's likely to trip if there's a fire in the room seems like a good idea.
 

roger

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tallgirl said:
Right, but typically the "secondary power source" is a battery that people may forget to replace. I know people who just ignore (no, really) the annoying chirp-chirp-chirp they make.

Well, that's their problem. It may be natures way (with the assistance of some stupid NEC required device) of population control.
icon10.gif


We can't save those who don't try to save themselves.

For the record, I don't think much of AFCI's.

Roger
 
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