ECN Forum Forums Code Related Discussion NEC & other Code issues Arc Fault Breakers

Brendan,

Welcome!
Thank you for choosing to address us here. I see many problems in houses due to the simple replacement of a switch, receptacle or light fixture. It is something that the average Homeowner (or Remodeling Contractor) feels is certainly within their abilities. They just don't realize what problems can be caused by their sometimes poor connections, improper lamping etc. The present DIY boom is not helping either. I think it's a good thing for them (as long as they don't take it too much for granted)


With the present state of the technology, is it possible to manufacture a Circuit Breaker that would protect both the fixed wiring and the portable loads? Does that become much more complicated an issue?

Bill

An AFCI circuit breaker will protect both fixed wiring and connected equipment, however there needs to be a distinction made between parallel and series arcs.

A series arc is an arc fault at a break or gap in a single conductor in series with a connected load or arcing line to ground. Series arcs are difficult to sustain in real life situations, as they tend to “self-extinguish” as the break or gap expands. Also, they tend to be low current since they are in series with a load and also may alert the homeowner of their presence because lights and appliance will operate intermittently.

A parallel arc is an arc from line to line or line to neutral in parallel with a connected load. This type of arcing fault may not “announce” itself, and the load does not limit the available fault current. Parallel arcs are capable of sputtering for long periods of time, and can go unnoticed until a fire starts.

We have not been able to maintain a series arc in the laboratory. Additionally, all of the testing we've done indicates that there will be significant nuisance tripping issues with series detecting AFCI.

The more insidious parallel arcs are those that cause electrical fires. Our circuit breaker AFCI protects the entire circuit from these dangerous arcs, So yes, we have a device that will protect the entire circuit! Additionally, an AFCI circuit breaker will detect and interrupt receptacles that are experiencing glowing contacts, providing another level of protection.

Our industry tends to move very slowly. Luckily for me, my children were born in the day when GFCI is an accepted practice. My four-year-old daughter's life was saved by one of our Type CH GFCI breakers. I had installed a sub-panel to feed an outdoor receptacle, and was in my garage when I heard the breaker trip. Before resetting the breaker, I checked the front of the house and found her with the hose on, pouring water onto an extension cord that I had left plugged into the receptacle. She was standing in the puddle along with the female end of the cord. If this had happened before it was mandated by code, she could very likely have died.

There is an opportunity here for the electrical industry to educate consumers. I’m sure as electrical professionals you feel as bad as I do when you hear of a fire that was started by electrical wiring. And I’m sure you’ve thought that something should be done to stop this from happening. We’ve invested 9 years and millions of dollars to develop a technology to make electrical distribution safer. You now have the ability to do something in your own neck of the woods to make your community a safer place.

Well the largest AFCI i've found is a 60A 2-pole, I am still searching for a dual unit.
If you fella's see any prob with my sub-panel scheme let er' rip...

So you are telling us that you have developed an electronic device that has a 50 to 100 year operational life!! I don't believe that is even possible. What is the failure mode of an AFCI?
Don(resqcapt19)

Don,
how would you know it's a problem without a field tester?

Face it, manufacturer's rule our trade

Sorry Guys,

I really don't get the objections. Even if only some lives are being saved isn't it worth it?
If it was known that the technology existed to prevent some tragedies but it was not required by code I'll bet that there would be a big discussion about 'waiting for body count'

Bill

Brendan,

Thank you for being here. What is the tech of the AFCI? Is the device triggering on rise time, frequency, energy under the curve, waveform, or what? What differentiates the line to line or line to neutral arc fault from other situations that have arcs in normal operation?

Al

The resistance here is basically questioning the rationale, technical specific's & collected statistics behind arc-faults.

This has been the norm for any new product / method handed to the NEC, and essential in it's understanding, hopefully this forum maintains an unbiased approach.

The premis of 'save a few lives' could also be argued in the wearing of steel suits while driving automobiles. If tear jerker stories are needed, brother I got em'.
We loose 50K a year there, but the factors and specifics would be argued hard vs. blind acceptance.

If the NEC chooses an add-a-cycle approach per AFCI's , as it did with GFCI's, then i propose a residential panel and complying main breaker to address the issue.
This would be a european twist, more effective and economical. We hit the upgrades which are the aim (or should be).

Sparky,

Their value has already been proven to the NEC. I see no point in disputing it here. I'm sure that their effectiveness will continue to be under close scrutiny until the next code cycle, at which time there will be opportunity to change things. Until that time I personally am more interested in how they work than in entertaining conspiracy theories.

Bill

Bill,
My questions are really based on wanting to know how they work and if they really will be able to do what the manufacturers have said they will.
Brendan has told us they are really to protect the future of the installed electrical system. Will they have an effective life long enough to provide that protection? Do the have a fail safe function? GFCIs do not fail safe. Brendan has told us that we must educate our customers to check these types of devices. Joe Homeowner is not going to do that on a regular basis. How many of us check and log the results for our GFCIs?
Once the manufacturers can provide a fail safe unit that self checks at a preset interval and has all of the electronics that would normally fail on a low cost plug-in homeowner replaceable card and they have proved that they will be fully effective on both fixed and portable wiring systems, I will support them.
When we push a life safety item that doesn't fail safe and has failure rates up to 58% in lightening areas we are not doing the public any favors. Will the AFCIs do any better?
Don(resqcapt19)