Arc-Fault Code

Which is a good reason to put the requirements in regionally or conditionally until the kinks are worked out. Say, first 3 years new regulations apply only to homes built by and for contractors and for inspectors.

How is that different than a GFCI breaker (located outside the house) that controls three bathrooms and an outside outlet? Why are 3 rooms on one GFCI? Why a GFCI for regular rooms? Idiot electricians can make a mess of anything.

OTOH, GFCI outlets are so cheap there is no reason to muck things up this way. Put them wherever they're needed.

One way to resolve that in a new house is to have the electric designed and given to the electrician rather than house plans given to the electrician to wire to code.

Sincerely,

Donald L. Phillips, Jr., P.E. Worthington Engineering, Inc.

145 Greenglade Avenue Worthington, OH 43085-2264

snipped-for-privacy@worthingtonNSengineering.com (remove NS to use the address)

614.937.0463 voice 208.975.1011 fax

...or until the inspectors have paid for the decisions?

Can we extend this concept to congress?

Hogwash! Throw on another blanket! ...get cozy!

On 2 Feb 2004 09:11:08 -0800 bob peterson wrote: | I wonder how many lives, if any, will be saved by this particular code | change. That's supposed to be the reason for the code, but economic | interests seem to be what really drive things.

If arc fault detectors were real arc fault detectors, I'd want to have them in many places (and bedrooms first). But based on the designs I have seen, they are detecting arcs that specifically draw higher levels of currents, though not as high as a short would produce that a regular breaker would pop on. That's an arc between hot and either neutral or ground, but not a physical contact between conductors. It's a genuine fire hazard that normal breakers don't catch fast enough, so they are a good thing in that respect. But they are being marketed as doing what their designs won't do, and that's catch other forms of arcing that can also be dangerous, but have relatively low current (well under the whole circuit rating). Loose plugs, for example, will arc and/or produce hot spots, and can cause a fire. These AFCI devices can't detect that. If they could, it might be worth it.

I don't have an actual AFCI right now to test with, but it looks like they won't be as susceptable to RFI as GFCIs are. Well, I hope not. RFI will put a common mode current on the wires, which won't cancel out on the sensor. They will need a common mode RF filter to prevent the problem. AFCIs have a higher trip level, so maybe they won't be affected as much. Also, AFCIs will go in the breaker panel, mostly, and there is better opportunity to put some RF filtering on the wires.

On Wed, 04 Feb 2004 07:24:45 GMT Beachcomber wrote: | |>> > $40 per bedroom does not sound like a lot, but I seem to recall there |>> > are something like 300 million bedrooms in the US. The eventual |>> > replacement of all those CBs would indicate a cost well over $1 |>> > billion. All that for the dubious premise of saving 1 or 2 lives a |>> > year. |>> > |>> > If people want to spend $40 to replace an existing CB with an arc |>> > fault unit, I have no problem with it, but I think smoke detectors |>> > have far broader utility for protecting people from fire then do arc |>> > fault breakers. | | Does this mean I am no longer going to be able to run my arc-producing | appliances such as my Tesla coil with a rotary spark gap and my | Jacob's ladder on my bedroom outlets?

Actually, they won't detect that. They might will trip on a motor starting. Calling them "arc detect" is really wrong; they don't detect arcs per se. What they detect is a fault that has an arc as it conducting path, with a resultant lower current level that a full short. It's somewhat like a more sensitive quick trip breaker, but with specific features to measure current differences in the line; they have a common mode current sensor (which should have a net zero current when all is OK). The theory is, a regular breaker would wait too long to trip on an arc mode fault because the current is not so high (say, maybe 50 amps). A second or two delay could start a fire. I don't know how well that theory works in practice. But back to your question, these are not very sophisticated devices. They are not monitoring waveforms and RF energy to see if it looks like an arc. They won't detect many problems that still can cause a fire. And they won't trip on your Tesla coil unless it draws too much current on the excitation inrush (or has a real fault).

Are you doing this stuff:

Neither the Canadian Electrical Code or the Ontario Electrical Code requires that smokes for bedroom areas (normally located in the hallway), be on with the bedroom outlet AF circuit. The code does require that some lighting be on with the smokes. This is inetended to discourage people from turning off the breaker powering the smokes. Your local code may vary. Russell

You're right, it's a nuisance. So why do the Electrical companies do it? Let's assume 2 outside plugs on one GFCI and 3 washroom plugs on another GFCI. You've saved 3 GFCI's or about $30. Extra wire cost would be in the range of $5. Net savings $25. If you're wiring 500 new homes per year this adds up to $12,500. Why not save the money? Almost all new homes have customer requested extras. I've never seen a customer request GFCI's at all protected outlets. Appears customers don't care. Builders often have specific requirements for all of their homes (ie copper service wire, plastic boxes, etc.). If the builders considered it a selling feature they would require GFCI's at all protected outlets. None do. If your home has a GFCI outlet protecting a number of regular plugs and you don't like this, change it! You're local code may require that you change the box to a deep box. Join the line and load wires at each box with a tail for the GFCI and add the device. If you're good at it you can change the box and add the GFCI in ten minutes or so. Russell

on a

The NEC limits this somewhat by the number of circuits that can have no other outlets. Kitcahens and bathrooms have such limits. I usually see the outside receptacles on the garage GFCI if they are trying to cheap out.