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I have a main panel with circuit-breakers in the US, circa 1994. I've recently heard about "arc fault protected" breakers, and was wondering if they come in "standard sizes" so the typical homeowner can upgrade (perhaps via an electrician), simply plugging-in the new ones.

I've found some outlets in my house that were partially melted due to the builder using the "quick connect" feature on cheap outlets/switches, coupled with heavy draw (space-heater, vacuum cleaner, etc.). I'm slowly replacing the outlets (without the "quick connect"), but in theory, arcing could still occur.

Curious...
 

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Arc-fault breakers are a RED-HOT topic of contention among electricians, inspectors, building departments, code-making persons, etc.

Here's my personal opinion. They're one step worse than worthless. Here's why.

When they first became required, I was a bit skeptical of their ability to 'detect the characteristics of an electrical arc'. The only thing I knew of that can actually detect an electrical arc is a line protection relay that the power company uses on their transmission and distribution lines. Not only can it detect an arc, it can tell you how far away the arc occurred. It costs about $3500.

I decided to conduct an experiment. I hooked up an arc-fault breaker in a panel, and brought the two wires out to a test bench. I wired a cord cap on the end of the wires. Next, I cut the end off of a cheap two wire household extension cord. I then stripped about 4" of insulation off the end of the cord, so that all the fine strands of wire splayed out. Next, I plugged the cord into the cord cap that was connected to the arc-fault breaker.

Lots or arcs, lots of sparks, but the breaker didn't trip. I shook the end of the cord around. Even more arcs and sparks, but still no trip. Next, I shoved the bare ends of the cord onto a steel table top. That tripped the breaker. (Don't try this at home kids, I had insulating gloves on as well as other protective gear, plus 19 years of electrical experience.)

My conclusion is that the arc-fault breaker failed to detect the characteristics of an actual electrical arc that certainly would have caused a fire, had it been near anything combustible. The fact that it tripped when directly shorted seemed to indicate that it wasn't defective.

The reason my opinion is that they're less than worthless is based on the false sense of security one might have if these are installed. Frayed cord...no problem...I've got arc-fault breakers. Impossible to start anything on fire.

They might be improved by now, but when they first came out they were nothing more than a breaker with a magnetic trip unit set at about 75 amps (as opposed to about 150 for a normal breaker), and a 30 milliamp ground fault trip unit. One of the biggest complaints I hear about them is a basic vacuum cleaner will trip them. The starting surge of a 12 amp vacuum is about 100 amps.

All code-making committees have at least one manufacturers representative on them. The original purpose was to be sure that something they were thinking of requiring could in fact, be made. In the case of arc-fault breakers, it was the manufacturers that pushed the requirement the hardest. Hmmm......

Rob
 

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Yup, some vacuums & other devices will cause them to kick off
I'm not sure on the added value/protection either
But they are required now here, and almost everywhere else
 

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"Abstract:

Provided is an arc wave generator for testing an arc fault circuit interrupter (AFCI) for use in a test system for testing whether or not an arc fault circuit interrupter (AFCI) is operating normally, in which a false arc is generated for use in testing the arc fault circuit interrupter (AFCI)."

But, is their "calibrated arc" traceable to NIST?
 

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Yup, some vacuums & other devices will cause them to kick off
I'm not sure on the added value/protection either
But they are required now here, and almost everywhere else
It will be interesting to see some reports from the field on nuisance tripping on AFCI breakers now that the are required on virtually every 120V circuit in residential construction.
 

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I thought AFCIs were only required for bedroom outlets, and then only since NEC 2008. Lots of locations, mine included, still use NEC 2005.
 

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I thought AFCIs were only required for bedroom outlets, and then only since NEC 2008. Lots of locations, mine included, still use NEC 2005.

Well, if your area uses the 2005 then it is required in bedrooms. 2008 required it in more places.
 

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Changes occur as technology develops to prevent problems
IE GFCI & AFCI breakers
As better ways are "discovered" to wire or avoid problems new code is introduced or old code changed
And as Mfg see an opportunity to make more $$ selling something new :wink:

Who knows what the future holds?
 

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Over the years, is the NEC converging onto some final copy or does it continue to add substantial changes? Is it getting thicker?
Just curious.
2005= 772 pages

2008= 822 pages
 

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As far as the OP... that is a pointless waste of money. Not only are AFCIs junk, but you will have to virtually disassemble your panel to put them in. Your receptacles probably weren't melted due to an arc. Likely they were melted by high contact resistance. Your best bet is to just swap the outlets out. Far cheaper.
 

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Discussion Starter #19
As far as the OP... that is a pointless waste of money. Not only are AFCIs junk, but you will have to virtually disassemble your panel to put them in. Your receptacles probably weren't melted due to an arc. Likely they were melted by high contact resistance. Your best bet is to just swap the outlets out. Far cheaper.
That's what I'm slowly doing. Out of about 15 replaced so far, about 4 looked partially "melted". The ones I'm replacing are all cheap builder-grade, which don't hold anything plugged-in very tightly. All were installed with the "stab in the back" quick-connects.

Doesn't sound like AFCIs are quite ready for "prime-time"...
 

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"Once we have AFCI on all of the circuits and there are still fires of electrical origin, there should be a very large class action product liability suit that will remove the product from the market and punish the shareholders."
 
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