Wiring question

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On 9/22/2011 8:00 AM, Robert Green wrote:

There wasn't any need for a neutral in the past. It is the various electronic switch devices that created the need.
--
bud--


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wrote:

There have been areas where the inspectors DEMANDED 3 wire cable to be used to switches because the DEMANDED the power be black and the traveller red. It also made it easier to install ceiling fans.
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I can see inspectors "demanding" that when normal cable is used for a switch loop that the white wire be colored but "demanding" 3 conductor (plus ground) cable is an unnecessary cost increase.
When you have 2 or so switches per room, the cost of the extra wiring definitely adds up. If someone in retrospect "needs" three conductor cable, it's just not a big thing to "fish" the cable while only making a few small holes in the drywall.
N.B.: In high rise units and other places where conduit (including some form of flexible conduit) is standard, switch loops do use a red and black covered wires. Of course in new conduit work the rules require a bit of "spare" conduit space.
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On Sun, 25 Sep 2011 09:42:07 -0400, John Gilmer

The intent - and result, of REQUIRING 3 wire cable for "tail switched" lighting circuits was to encourage "head switched" lighting circuits, so when the SWITCH is off, the entire CIRCUIT is dead. Power to the switch, then from tere to the lights - not the other way around. And that often takes more wire too.
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On 9/25/2011 8:42 AM, John Gilmer wrote:

Note that clare lives in Ontario.
I agree that you should be able to re-color the white in a cable like romex.
But as I noted in a previous post, the 2011 NEC now generally requires a neutral at switch locations (404.2-C). The reason is to avoid the problem at the start of this thread. A neutral is not required if raceways have extra capacity to add a neutral, or when the wall is easily refished (including open at the top on that floor level - common in offices with drop ceilings).

If you need to add a neutral to romex it isn't usually all that easy.
(And I don't believe making holes in the drywall is what the NEC intends for the exception.)

There used to be "new-" and "old-work" tables for conduit fill; they disappeared long ago. There isn't any "spare" conduit space that can be used later.
--
bud--

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wrote:

As the NEC now requires a neutral in that situation, these inspectors were just ahead of their time. Very often you will find Canadian requirements are more stringent, safety wise, than american - but I'm not aware these requirements were provincially, or even nationally, instituted. An inspector in many cases had the authority to require, or not require, whatever HE wanted to require or not require, if not in a "uniform code" community.

If you are using 3 way switches you need 3 wire anyway.

To put it mildly

No, and I needed to ADD wiring to my daughter's multi-level townhouse to install ceiling lights in the bedrooms (thankfully all with "attic" exposure) and did not want the mess of punching and patching drywall - so I drilled down through the upper plates, and through the cross-bracing (fire-stop) down to the existing wall switches and fished NMD3 cable down through those 3/4" holes and into the provided holes/cable clamps in the top of the switch boxes. By re-wiring the switched receptacle I was able to use the "switch drop" cable as a power feed to the switch - allowing me to feed both a switched ceiling light and a non-switched ceiling fan. Took me 4 hours for one, two hours for the second and almost 6 for the third - but I got them done before having the attic re-insulated. It was hotter than Hades up there, even in May, and 4 foot extension bits were a NECESSITY. The fish tape with an LED lamp on the end was pretty slick too - too bad I didn't have my fancy little flex-tube inspection camera then yet- - - -.

Unless the electrician is thinking ahead and not pinching pennies and just, as matter of habit, installs over-size for the requirement (which makes his job today, and in the future, a lot easier)
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On 9/26/2011 7:50 PM, snipped-for-privacy@snyder.on.ca wrote:

What an absolutely marvelous idea. The AHJ can require whatever they want.

Under the new NEC rule you need 4 wires. Often (always?) this can be wired as a California 3-way (the electrical kind) and each switch location would have a hot wire and the switched wire to the light.

You can put a lot of wires in a 1/2" conduit.
--
bud--

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wrote:

OK, I can see how it would work with a GFCI BREAKER. I was thinking GFCI outlet - where it would NOT necessarily show up.

But a little hard in my house - since it is all FUSED.

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On Tue, 20 Sep 2011 22:55:42 -0400, snipped-for-privacy@snyder.on.ca wrote:

Electrically there is a difference. It shows up on systems that have metal raceways. When you run power conductors with the neutral, the magnetic fields cancel. If you run the neutral through a different metal raceway you get inductive heating.

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I'm sure you could see that difference with a TDR, also.
<...>
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wrote:

PARDON?????? How is it goiung to know the neutral is crossed if both neutrals are running in the same raceway with both powers? When you have 20 circuits running in one raceway or conduit is when the neutrals DO get crossed. I'd really like to see you determine which circuits have "crossed neutrals" bu sensing and measuring either the magnetic field or the inductive heating - even if the two circuits are NOT in the same raceway or conduit.

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On 9/21/2011 5:49 PM, snipped-for-privacy@snyder.on.ca wrote:

If the loads on both circuits are identical, it won't. But consider two circuits, A and B. One conduit contains A's hot and B's neutral; a second conduit contains B's hot and A's neutral. Now load A at 30A and B at 10A. There's a net 20A current in each conduit.

If they're all in one conduit, you can't. If they're in different conduits, it's simple: don't load them the same.
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<stuff snipped>

neutrals
little LED

Well, that's something most homeowners or real estate agents aren't going to allow. I got bad enough looks from homeowners running around their houses unplugging things from outlets so I could plug in an outlet tester. One homeowner only agreed to that when I said I would have my wife film all the testing and give him a DVD to show others and perhaps save him a plug in/plug out session. I actually feel better knowing that short of massive work at the panel, I wouldn't have been able to catch the few "crosspulled" neutrals that I had.

That won't be happening any time soon in any house I'm buying. (-:
-- Bobby G.
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On Tue, 20 Sep 2011 21:25:39 -0400, "Robert Green"

No idea, but the live and neutral wires didn't all get into the right conduits when the wires were originally pulled in.

The electrician we called in to do some modifications was also asked to "map" the circuits on the 4 panels in the building - and in so doing determined there were crossed up neutrals. He said it was up to us - we could spend the money to get it ALL figured out and make it right, or he'd just pretend he didn't see it, because he wasn't about to tangle with the inspectors and convince them they made a mistake in the inspection....
He said it's no big thing, as long as the neutrals stay connected - just about every outlet or switched string of lights is on it's own breaker - split between 4 LARGE panels throughout the building.

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On Sep 17, 6:45 pm, snipped-for-privacy@snyder.on.ca wrote:

Andy comments
Well stated....
Andy in Eureka, Texas
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On Sep 16, 8:42pm, snipped-for-privacy@snyder.on.ca wrote:

That switch itself is in fact a load. A very small one, but it's still a load. If it did not pass current on the neutral, then it would not need the neutral. Could it deliver a serious shock as is? I would agree that it would not, provided everything else is wired correctly, meaning there is no disconnected neutral on the other circuit, etc. But it could cause future problems where someone later comes along and sees that neutral, assumes it is on the same ciruit as the hot and decides they want to use it for something else, like adding more outlets, causing an overload. That is the serious risk you run when you decide to ignore a code rule that is universally followed by almost everyone.
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On Sat, 17 Sep 2011 06:32:50 -0700 (PDT), " snipped-for-privacy@optonline.net"

If, as I suspect, the switching mechanism in the X10 is a voltage controlled switch (think FET or MOSFET device) there is NO current flow to the neutral.
Howver, you HAVE identified the danger - the POSSIBLE FUTURE danger which makes it illegal and unadviseable to use the "split neutral" configuration. The FACT that the orphan neutral is in the box makes it POSSIBLE for some future person (or even the OP, in the future) to use that neutral to complete the circuit for a REAL load, such as an aditional outlet or lamp. Since it is APPARENTLY possible to bring a neutral up from below, the much better way to approach this is to bring a FRESH CIRCUIT up from below to power this.
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On Sep 16, 7:42 pm, snipped-for-privacy@snyder.on.ca wrote:

Andy comments: Exactly. Now that Ivan has seen the problem from several angles, l think he can make an informed decision about what he wants to do...
Still, I HEARTILY reccommend him putting the X10 module in the fixture where it is used, rather than the wall switch..... if he has room... All the other arguments should be considered, but the convenience of a low current #14 white wire for one simple circuit may be the overriding factor......I am sure that a future electrician will see immediately that a non-standard method has been used and will re-think his options...
Andy in Eureka, Texas
PS Ivan, maybe you can do a search for a battery operated control module.... one that can replace the wall switch but has a couple of AA cells in it for the controller activation.... I haven't seen one, but I haven't looked, either...
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It's not up to Ivan to decide what's safe or unsafe. What makes you think Ivan has the technial expertise to even understand the issues involved? The NEC serves the purpose of deciding what is safe and what you claim is OK is a clear violation of NEC. Do you disagree with that?

A future electrician? Is Ivan an electrician? No, yet he's doing the wiring. A future Ivan comes along and expands the circuit using that neutral for other outlets. Or maybe Ivan himself because either he doesn't understand the real issues or 5 years from now he forgets. Or Ivan goes to put in a GFCI on that other circuit and can't figure out why it constantly trips.
Convenience is never an excuse for violating the NEC.

Maybe you should look at the NEC first.
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Would a multi wire branch circuit meet code and be safe?
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