Combo AFCI vs. AFCI

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Combo AFCIs check for arc faults line-to-ground, line-to-neutral and neutral-to-ground (all parallel arcs). They also detect series arcing (within the same conductor).

Hence, they're considered safer.
 
Ok

Ok

480sparky said:
Combo AFCIs check for arc faults line-to-ground, line-to-neutral and neutral-to-ground (all parallel arcs). They also detect series arcing (within the same conductor).

Hence, they're considered safer.
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Ok, I'm all for it, but why are they now required over the older AFCI variety code wise?
 
mltech said:
Ok, I'm all for it, but why are they now required over the older AFCI variety code wise?
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The old ones, AFAIK, did not detect line-to-neutral and neutral-to-ground arcs, nor series arcs. Only line-to-ground. But keep in mind, I'm not 100% sure on this.

As for why they're required, I'm sure it's in part due to the fact that it was the manufacturers that submitted the Proposal.
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480sparky said:
The old ones, AFAIK, did not detect line-to-neutral and neutral-to-ground arcs, nor series arcs. Only line-to-ground. But keep in mind, I'm not 100% sure on this.

As for why they're required, I'm sure it's in part due to the fact that it was the manufacturers that submitted the Proposal.
flute.gif
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Boy, they just keep finding ways to make the job pricier.
So only combo afci's in new residential construction? Can't wait to try it with lighting control...
 
mltech said:
Ok, I'm all for it, but why are they now required over the older AFCI variety code wise?
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They are required because that is what the original proposals for AFCIs said the AFCI could do. The non-combo ones could never do what was promised in the original proposals for the 1996 code (proposals that were submitted on or before the first Friday in November of 1993). It took the manufacturers some 13 years to produce the product that they said they had available in 1993.
 
480sparky said:
The old ones, AFAIK, did not detect line-to-neutral and neutral-to-ground arcs, nor series arcs. Only line-to-ground. But keep in mind, I'm not 100% sure on this. ...
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As far as I know the AFCIs have always had a 30 to 50mA ground fault detection circuit. That would open the circuit on a line to neutral or neutral to ground fault.

The original AFCIs did not even look at the signature of a parallel arc unless the current exceed 75 amps. The combos look for series arcs when the current exceeds 5 amps. I am not sure at what current level they look for parallel arcs.
 
mcclary's electrical said:
I'm curious to know why that would matter? Combo's in 05 too right?
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Well, Me too?
That's why I was asking around.
"Why do I have to use the new Combo AFCI breakers"
Nobody has yet to give a clear answer. I understand they offer better protection...
And I know the code says,

2005 NEC 210-12(B)
Combination Type AFCI in bedroom circuits
Branch/Feeder AFCI permitted until January 1, 2008

2008 NEC 210-12(B)
Combination Type AFCI
Expand to 1 pole, 15 - 20A circuits
installed in family rooms, dining rooms,
living rooms, parlors, libraries, dens,
bedrooms, sunrooms, recreation rooms,
closets, hallways, or similar rooms or areas

Yet, the supply houses are still selling the standard AFCI?
I however am installing the combos to ward off the inevitable.
I would however like clarification.
Thanks
 
mltech said:
"Why do I have to use the new Combo AFCI breakers"
Nobody has yet to give a clear answer. I understand they offer better protection...
And I know the code says...
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Well, if those two reasons don't do it for you, then I'm not sure what kind of reason would convince you :D
 
eprice said:
Well, if those two reasons don't do it for you, then I'm not sure what kind of reason would convince you :D
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I guess I should have said, why are they still selling the old ones?
Also, I think the lack of communication and acceptance of the code by AHJ's could cause some grief.
As I witnessed what happened to a fellow electrician in Miami.
The AHJ would not accept the older AFCI's and made them change 5 panels worth of breakers. I have a clear understanding of how these combo's work just not a clear understanding of how this is being enforced. We do work all over the state of Florida and this could make a large $ difference from county to county. And could price me out of work on new bids...
And thanks to all who chimed in on this...
 
mltech said:
I guess I should have said, why are they still selling the old ones?
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I think an argument could be made that in the case of an existing installation, replacement of a defective Branch/Feeder AFCI with a new Branch/Feeder AFCI would be allowed. Other than that, if AHJ's aren't enforcing the code, Branch/Feeder AFCI's will be installed and supply houses will continue to sell them.
Also, I think the lack of communication and acceptance of the code by AHJ's could cause some grief.
As I witnessed what happened to a fellow electrician in Miami.
The AHJ would not accept the older AFCI's and made them change 5 panels worth of breakers. I have a clear understanding of how these combo's work just not a clear understanding of how this is being enforced. We do work all over the state of Florida and this could make a large $ difference from county to county. And could price me out of work on new bids...
And thanks to all who chimed in on this...
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You raise a very good point here and I agree completely. It is important that AHJ's strive to enforce the code correctly and consistently in order to keep the playing field level for the electrician that wants to do it right.
 
The combos are not an 08 NEC requirement. They were required in the 05 code, with an effective date of Jan 1 08. If you are on the 05 code you have been using for 2 years.
Combos detect series arcs down to 5 amps. BC and Feeder type are only good to 75 amps.
Don is exactly correct. The mfgs lied to the industry.
 
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