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Arc-Fault Interuptor Breakers

On Sun, 22 Apr 2007 00:35:03 -0400 snipped-for-privacy@aol.com wrote: | On 22 Apr 2007 00:48:47 GMT, snipped-for-privacy@ipal.net wrote: | |>It would also help to require sufficient extra outlets in bedrooms so that |>the ones that do get covered up by furniture won't matter because at least |>one other nearby will be available. How about a duplex every 2 feet? | | | This is a design issue. If the designer can identify the likely bed | locations they can place the outlets properly for the night stands. In | my bedroom remodel this ended up being 4 quads and two 4 way switch | loops with switches at 3 locations for the overhead and one switched | receptacle in each quad. Most builders hitting a price point will not | do this. | In the quads that ended up being away from the bed location I swapped | a duples for one of those green nightlights.

I also think it is a code issue. The code writers _are_ legitimately concerned with safety, including those aspects that result in fires due to damage in cords plugged into outlets. That's one justification for AFCI requirements. Closer outlet spacing, especially in bedrooms, would also further the cause of greater safety.

Of course it is my intent to design a house with much better electrical wiring along the lines of my own desires. This will include more outlets than the code requires, including the previously mentioned extras in the bedrooms and other rooms where furniture may concentrate (all outlets may still be covered, but at least some will end up being behind light weight furniture, instead of behind a bookcase full of books). I don't know that I need quads in the bedrooms, given the extra outlets. But a few other places definitely will have them.

My kitchen pattern will be a little more complex. Each point will have

2x duplex 5-15R, 1x single 5-20R, 1x single 6-20R. The singles will be each on their own dedicated circuit. The duplexes will be on 2 circuits but will share the circuit with the outlet point 2 or 3 points down for a total of 4 or 6 circuits. My father knows an electritician who went to the extreme of every duplex on its own dedicated shared neutral in the kitchen. But I figure if I need more than the 4 to 6 multi-outlet circuits plus all the single-outlet dedicated circuits, I have other issues to worry about (like how to dump all the heat).

I'd like to do this in the kitchen:

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it would more likely have to be:
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these might be done with a 3 pole breaker for the right duplex:
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And no 3-way/4-way switches for me. Momentary up/down switches controlling relays (machnically latching in some cases, electrically held on in others) is my current plan at least for multi-point controlled lights and maybe a few others.

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| I have never seen bedframes hitting plugs as a cause behind AFCIs. | Electrical cords lying on the floor that get walked on, under rugs, or | otherwise abused have been mentioned. There was an economic analysis

Including chewed on by animals.

| done by the CPSC. It was based on the number of electrical fires with | bedrooms a major point of origin. According to the analysis, AFCIs were | cost-effective in preventing fire damage, injury and death. The analysis | may be right or wrong, but there was a justification for AFCIs in bedrooms. | | But I don?t think there was any study that demonstrated the | effectiveness of AFCIs that have been installed in bedrooms that was | used as a basis for extending the use of AFCIs ?everywhere?.

Animals can get out of the bedroom.

|> That being said, most of the electrical devices used in bedrooms are |> going to be two wire devices, (lamps, electric space heaters, clocks, |> vacuum cleaners, radios, cell phone/cordless phone chargers, etc.) | | Two wire cord s produce parallel faults, which is what the existing | AFCIs are required to detect. One of the UL AFCI tests is for parallel | arcs in ?zip? cord, which is the common electrical cord in bedrooms. The | 75A parallel arc detection level is based on UL field tests of outlets | that found 75A was available for a fault at all tested outlets and at | the end of almost all plugged in lengths of 6 feet of #18. | |> |> Three wire arc-fault detection would be normally not add any greater |> protection for most applianced used in this location. | | One of the UL AFCI tests is for a series arc in Romex with ground. Since | existing AFCIs don?t detect series arcs I presume detection is by the | series arc becoming at least partially a ground fault which will be | detected. | | Also UL did some tests on ?glowing connections? - series arcs - at wire | connections to receptacles. In 9 of 16 tests leakage to ground developed | that tripped an AFCI. (In 6 of 16 tests the wire burned open.)

Loose plugs can also cause this.

Back in 1979 there was a fire that destroyed an entire apartment building in a large apartment complex I lived in. The fire was ultimately traced down to the receptacles being painted, and subsequent poor contact when a plug is pushed in. That's not exactly an AFCI issue, but in certain cases I could see where a series arc detection might catch this.

|> Thus, any fault to ground, even an arc-fault could conceivably be |> protected by conventional, less-expensive GFCI's (although not |> currenlty required in bedrooms). | | But that wouldn?t detect parallel arcs that don?t involve ground. Or, if | the new AFCIs ever appear, series arcs that don?t involve ground. And an | arc fault with a ground present does not necessarily develop ground leakage. | | -- | bud--

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| It will be interesting what changes jurisdictions make when they accept | the 2008 NEC. If, for example, SquareD does not have the new AFCIs | available does that mean you can't use SquareD panels.

I'm already planning to go with C-H panels.

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