Electrical code question

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wrote:

\When I was working in the computer biz, one of the things we did was lightning mitigation and analyzing grounding electrodes was a big part of it. One of the first things you find is there is no such thing as "ground". I have found up to 35 volts difference between building ground electrode systems that were less than 50 feet apart and that was using a low impedance meter. They had what seemed to be very robust electrodes so the difference was in what earth potential was. This is generally caused by current imposed on these electrodes. There are a number of things that can cause this, not the least of which is a compromised neutral. Another problem is the voltage drop in the PoCo neutral conductors themselves. I took my clamp on down the street looking at current in the ground wire on the poles and got some surprising results. There was over 2 amps on some of them. I had close to an amp on my grounding electrode conductor with my main breaker turned OFF. (I had a similar number on the PoCo neutral) I was providing the grounding for the grid. Granted I have a better ground electrode system than most since it integrates several thousand square feet of concrete slab, 5 ground rods, many feet of buried copper wire and an inground concrete pool.
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snipped-for-privacy@aol.com posted for all of us...

I touched one of the pole grounds when I was a kid. I felt it! Learned not to mess with stuff on poles.
--
Tekkie *Please post a follow-up*

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What risk? And to be legal in Ontario kitchen countertop outlets have had to be "splits" for decades - and the "only" way to do that legally is with a "split" circuit and tied breakers.
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You have several (dryers, ranges and any other 240v appliance with a 120v load), get over it. There may also be some on the 120v circuits you do not know about. It was common to wire bedrooms on a multiwire if they were on the other end of the house and split them out in a ceiling light box. It was just recently that the 2 pole breaker or any other identification was necessary.
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On 05/24/2015 07:57 AM, snipped-for-privacy@aol.com wrote:

There's nothing to "get over". The shared 120 volt control circuit contained within the metal cabinet of the 240 volt appliance is typically protected (current limited) by a 1 amp fuse or so.
The $10 chinese radio plugged into an Edison circuit wall outlet...not so much.
> There may also be some on the 120v circuits

Not in my home but you are welcome to as many Edison circuits as you like. I fully support your right to do so.
> It was common to wire bedrooms on a multiwire

It's also common and code compliant to use clamps on ground rods too but they always seem to corrode and become loose over time. I always use an exothermic CADWELD connection. Does the fact I don't use mechanical clamps bother you too?
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That is certainly not true in the dryer. The motor is generally 120v and runs right off the 30a phase leg. BTW your whole house is on a multiwire circuit from the utility and they share the neutral and ground on a single, down sized wire. Doesn't that bother you?

I have never seen a residential cadweld and I have inspected thousands. I am not bothered by it. You seem to be the one who is bothered.
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<stuff snipped>

But I suspect there wasn't any wannabe electrician 17 yr old rewiring the power company's pole-mounted transformers. I know that my house *had* been rewired by a 17 yr old, so I would (and did) worry way more that any Edison circuit I found wouldn't be wired correctly in my house, not on the poles outside. Turns out I was right to worry.
I would guess that any house over 50 years old has had some sort of very underqualified homeowner "electrician" do some sort of electrical work in the house. From what people have posted elsewhere, I don't think Edison circuits are well understood by weekend electricians. Anyone touching anything they don't understand can lead to trouble. I know that multiwire circuits are the way the whole power grid works. And I know that Edison circuits it have some advantages and specific uses. But I think it's clear that the original reason to use them, cost savings, is extinct, or nearly so.
That's because 12/3 is way more expensive than 12/2 almost everywhere I looked (and that's not even using sale prices). 12/3 is SO much more expensive (nearly twice as much at some sites) that there's no wire cost savings and very little labor savings. And even if you did manage to save $20 on wire, the dual pole (or multiple one pole) GFCIs you'll have to buy to get proper GFCI protection will eat up those meager savings in a NY second.
(-"
--
Bobby G.



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there wasn't any wannabe electrician 17 yr old rewiring the

I would not knock the 17 year old. If I was 17 again, I would trust my wiring more than a licensed electrician I know that is over 50 years old.
Seems like everyone makes a big deal out of wiring a house. As long as the breakers and wire size is correct and the connections are tight, there is not much to worry about. Just make sure it is done to code.
That done to code takes me back to the over 50 year old licensed electrician. I worked with him in a large plant. Most everyone laughed at himand the way he did things. Never did see why they did not let him go. Well, I do as the only requirement at the plant was to show up every day. That man would do outside work for people. Even when the electrical inspector told him to do something a certain way, he would do it some other way and complain about how the inspector was always turning his work down.
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Well, you didn't see this kid's work, notching joists at exactly the wrong place, bringing a neutral from a different circuit into his bedroom because all he had access to was a switch leg and no outlets. He had finished the basement himself with no insulation or vapor barrier using spike nails that caused massive damage to the very soft blue cinder block. He also apparently used scraps of whatever junkheap wire he could find to make his kluged connections. I had to rip much of it out and start over again. He also put 20A breakers on old, 15A cloth covered wire because the 15A breaker that was there "tripped too often."
Are you *still* sure I should trust this guy? (-:

That's not going to encourage your best quality workers to stick around.

other

The world is full of nitwits, some of them even hold licenses. (-: I am going to have to relocate a message I saw posted in one of the electrical forms by someone who makes even you nitwit look competent. He was wrong about the basics but quoted scientists and legit (though woefully misapplied) theories to back his claims.
Wiring a home has become a little more complicated with the advent of GFCIs and AFCIs.
For me it was a question of what I needed to upgrade protection to the latest NEC. I found that AFCI double pole breakers for MWC were non-existent at the time, although now there are a few manufacturers making them.
Eventually every breaker in a panel will protect against arc faults, ground faults, overloads and short-circuits because that's where it makes the most sense to protect branch circuits.
I use GFCI's on the first outlet in circuits that I installed and used the line connections to protect downstream but that turns out to make trouble shooting more troublesome. Did the breaker blow? Check the panel. Did the GFCI trip? Look behind the desk (actually I made damn sure all the GFCIs were accessible easily, if not visually).
Then I had a devil of a time trying to work AFCIs into the mix and ended up protecting only two outlets (space heater and A/C) with a discrete outlet-format AFCI for each because the panel mounted AFCI's were, like 2 pole GFCI, incredibly expensive compared to their outlet-format counterparts.
--
Bobby G.



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On Sat, 23 May 2015 06:39:36 -0400, snipped-for-privacy@aol.com wrote:

+1. To an electrician they are absolutely no problem when properly used. Any time there are 2 circuits in a single box, it is the "only" way to be legal.
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On Sat, 23 May 2015 10:00:38 -0400, snipped-for-privacy@snyder.on.ca wrote:

Huh? There is nothing "illegal" about 2 circuits in a box.
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On Sunday, May 24, 2015 at 8:11:24 AM UTC-4, snipped-for-privacy@aol.com wrote:

As usual, he likes to just make it up as he goes.
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wrote: > > +1. To an electrician they are absolutely no problem when properly

He could be right if we're talking split receptacles. They might be "disallowed" if the circuits were not fed with a tied breaker. The expectation is that if you kill power to an outlet that both upper and lower halves will be dead. In the split wire receptacle it requires a tied breaker.
But again, why would you want to feed an upper and lower duplex receptacle from two different circuits when you could just add a second circuit and outlet? Has anyone ever lived at a place that had *enough* outlets? (Hyperbole alert)
--
Bobby G.



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On Mon, 25 May 2015 00:44:55 -0400, "Robert Green"

You are arguing with the wrong guy. I am not the one who was promoting that ancient Canadian split receptacle rule on the countertop. . There is still no good reason why you couldn't bring a MW circuit into a 2 gang box, put 2 GFCIs in there and split put your counter top receptacles from there.
That is not what we were originally talking about tho. It was using a MW to feed the dishwasher and disposal.
To the point of the actual note you responded to, I was asking why Clare thinks you can't have 2 separate branch circuits in the same box.
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wrote:

lower

receptacle

Whoops. My apologies.

Wouldn't their breakers have to be either dual pole or tied-handle to address the NEC's obvious concern with leaving something live that someone might reasonably expect to be dead? I believe lots of people expect that when they cut power to a breaker (using the plugged-in radio playing loudly method, for example) that the outlet it controls will be completely dead.
Feeding two discrete circuits from different breakers into one duplex outlet clearly re-creates that danger in a slightly different format.
--
Bobby G.



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On Mon, 25 May 2015 07:53:16 -0400, "Robert Green"

You will need to use the 2 pole or handle tie breaker under the current code but that is fairly recent.
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On 05/21/2015 10:42 AM, Ivan Vegvary wrote:

My Whirlpool dishwasher and a KitchenAid disposer are on the same 20 amp circuit and never had a problem.
I don't know if it meets code but I can't imagine it is unsafe in any way.
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On 5/21/2015 12:43 PM, Mayhem wrote:

Did the same here, running two 20 amp lines seemed silly to me. I did run them both at the same time right after I installed them to see if it would trip the breaker while I still had the downstairs wall open. No problems showed up with both under load.
Here the disposal only runs while we are cleaning off the plates to put in the dishwasher. The dishwasher isn't turned on until that step is done so in reality they never run at the same time anyway.
John
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Ivan,

For that kind of "Edison" circuit, the two breakers must be on opposite sides of the incoming 240V supply. That way each 120V "hot" leg is out of phase with the other as the AC cycles back and forth. When one leg is positive, the other leg is negative. The neutral never has more than a single load on it.
It's a safe and common way to wire some circuits, but I still prefer to run separate cables for each circuit. That way breakers can be moved around in the panel if needed without fear of overloading the cable (if both breakers were placed on the same phase the neutral would carry twice the load). The cost difference of two cables vs a three-wire cable is usually minimal for most homes.
Anthony Watson www.mountainsoftware.com www.watsondiy.com
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On Saturday, May 23, 2015 at 11:22:49 AM UTC-4, HerHusband wrote:

AFAIK, there is no other kind of Edison circuit. The whole point of an Edison circuit *requires* that it be on opposite legs.
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