Electrical code question

Magic smoke will be forced out of the small radio perhaps even a loud magic noise, too. (-:

While a reputable electrician would probably not make this particular mistake, it's possible for a future modification or rearrangement of breakers in the panel to inadvertently move one or both individual breakers (especially in older work) so that they both end up on the same 120V leg of the panel - which is improper when a shared neutral is involved. If the split circuit is installed that way, the shared unbalanced load could exceed the rating of the wire.

Maybe some NEC expert can tell us when the use of a double-pole breaker became a code requirement for Edison circuits because I know it wasn't always that way (or that way in 1988). My kitchen had an Edison circuit

*without* a tied breaker until I rewired it with separate runs. Without the tied breakers or a double pole breaker that kills power to both phases, it is quite possible for someone to be shocked while working on the circuit, since the neutral wire of the supposedly "dead" circuit could be carrying current from the sister "live" circuit. DAMHIKT. (-:

There's so little benefit, IMHO, that the risk of using Edison circuits today doesn't seem worth it. If voltage drop is a problem, use a larger diameter wire. If you can't afford the extra wire, check the car's seat cushions for spare change or sell some blood. (-:

Besides, the last time we had this discussion I believe I pointed out that because "Romex" 12/2 w/G and 14/2 w/G is so widely used, it can often be had on sale for much less than 12/3 or 14/3 w/G, thus totally negating any real savings in wire costs.

Same problem with the 2 pole GFCIs needed to protect an Edison circuit. I can always find a good sale price on the single circuit GFCIs. I don't recall ever seeing a double pole unit on sale. I do recall when I looked at

2P GFCIs they cost way more than 2 separate 1P GFCIs. I recall paying a little more than $10 a pop for 20A Leviton GFCIs just a while back when I ran a new sump pump circuit.

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The 2P units Google shows are in the $80-$110 range. So it looks like the Edison circuit is going to end up costing way more than two comparable single branches, at least if you don't pay list price for your components.

I don't see the tradeoffs being worth it but obviously some people do. For me it violates the KISS rule.

Reply to
Robert Green
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How is that different than loosing the line neutral (which, statistically is much more likely) Then EVERY circuit in the panel will have extra high voltage on the lower load side, and low voltage on the heavily loaded side/

Reply to
clare

I believe it was a code requirement long before 1988, at least in Ontario. My 1974 house, with a fuse panel, has ganged fuse pullouts for all the split circuits, and they were a requirement back when I helped my electrician father wiring houses as far back as 1965 or

1966.

Canadian code is often much more strict than american code when it comes to safety - so what it was in the US of A is anyone's guess.

Reply to
clare

You end up needing to use oversized boxes to handle the wire fill in many cases, and again, CANADIAN code requires (or at least required in the past) 2 circuits in the same box to be on a tied breaker or a pullout fuse block whether they are split/siamesed or totally separate. If you kill a circuit in a box, you have (in canada) the assurance that if wired to code, the entire box is deader than a herring.

Reply to
clare

I guess the argument can be made that the less points of potential failure like that, the better. And if it's the service netural that goes open, it's probably less likely that you'd have a big imbalance because for a whole house, there would be many loads on each leg, tending to average things out. So, I think the possibility that you'd see close to 240V appear on one leg would be a lot less.

Reply to
trader_4

I don't live in Canada. Best I can find is that it became part of the code in 2008, but that's certainly not definitive - just came across a few discussions that seem to indicate that's when the NEC required the tie handle or dual pole breakers.

In Canada, perhaps, but I don't think that was the rule in the US based on the reading I've done. Perhaps an American NEC expert has the answer. I know we used to have some NEC-heads here once upon a time.

Well, I suspect it's not a guess, but a very clearly documented fact that we just don't have yet and since I cleared my browser history, I can't even provide the cites that implied it was a relatively new code requirement in the US. I believe it became mandatory in 2008, but that's a guess - it wasn't what I was paying attention to.

The bottom line for me is WHY would anyone use an Edison circuit and a

*very* costly two pole GFCI (compared to two single pole) when they could get by easily with two discrete circuits? It also seems counter-intuitive to plug two power-hungry devices into the same outlet which is what gets done with a split-wire receptacle.

Maybe you save some bucks by not having to rough in a second outlet but my personal rule of thumb is that you can't have enough outlets in today's modern kitchen. Using a split-wire receptacle seems to reduce rather than increase the total outlet count. Then, someone might use one of those one-to-six outlet adapters which, depending on how they are wired, will burn up when plugged in because it combines the hots of both sides of the split-wire receptacle. I'm sorry, but just because Canada does it that way doesn't mean it's superior in any way. From what I can determine, it's NOT safer and it's not cheaper. So why bother?

If you list out the pros and cons, the biggest con turns out to be the high cost of a two pole GFCI protector. That cost totally negates any potential saving in wiring $ except in huge houses. The fact that 12/3 and 14/3 is far more difficult to find on sale also tends to negate the cost saving.

In addition, running two high amperage devices like skillets and toasters out of one outlet box would, IMHO, tend to increase the chances of overheating something in that box. It could be anything from a bad backstab to an improperly inserted plug. And if that neutral back stab fails for any reason, you've got the potential magic smoke problem again.

There's also the question of whether bringing 240 volts into a wet kitchen area into one single box is a good idea to begin with. Anything that goes wrong becomes a potentially much more lethal 240 volt event.

So what makes an Edison circuit so great that they are mandated in Canada, eh? (-: I still don't see it. A second outlet run to the kitchen would probably cost less, in materials at least, than wiring up an Edison circuit. That second, standard 20A circuit would also be much more likely to survive a repair attempt by a homeowner than an Edison-type circuit.

I seem to recall someone here in the past had trouble distinguishing a switched outlet from an Edison circuit, yet another reason to avoid them.

I believe the only reason I had an Edison circuit here is that the house was built in the year of the steel penny when copper was in such short supply the US Mint stopped using it to make pennies that year.

When WWIII comes and copper becomes incredibly precious *again* I'll consider wiring with Edison circuits, but until then I'm happy with my on-sale $10USD GFCIs, my 250 ft coils of 12/2 w/g (blue, by the way, in case anyone from the color coding of NM wire thread is reading) and my extra

*metal* junction and outlet boxes. KISS unless you live in the Great White North, I guess. (-:
Reply to
Robert Green

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.
Reply to
gfretwell

Huh? There is nothing "illegal" about 2 circuits in a box.

Reply to
gfretwell

As usual, he likes to just make it up as he goes.

Reply to
trader_4

On Sunday, May 24, 2015 at 7:15:51 AM UTC-4, Robert Green wrote: wasn't what I was paying attention to.

Another factor is if you go the peculiar split receptacle approach that Clare says they use up north, you can forget about having the GFCI at the receptacle, where it's easy to reset/test. I've never seen a receptacle with built-in GFCI that's double pole. So, you'd need a double pole one at the panel. I'd rather have it near where the receptacle is.

I don't get the whole idea behind splitting a receptacle and putting each half on different legs. Here I see it done sometimes to put one half on a switch, the other on all the time, on the *same* circuit. That makes sense. Say what you want about Edison circuits, but this Canadian thing, I don't understand what the purpose is all about. And also, if you want to start in about potentially having two different circuits in a box live, it's funny that Edison gets dragged in as the solution. It would seem to me the finger should be pointed at whoever up in Canada required their screwy split outlets.

For the most part, it's not going to create a more lethal environment. If it gets wet, energizes some metal, etc, you still only wind up with

120V to ground. To get 240V, you'd have to somehow wind up across both legs, and that kind of fault would be extremely rare.
Reply to
trader_4

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.

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'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?

Reply to
Mayhem

Losing the neutral in *my* entrance panel is extremely unlikely. I actually check my panel and meter pan connection every 5 years. Of course the poco neutral is tagged to ground at my panel as well.

Reply to
Mayhem

I have lost the power company's neutral TWICE in the past year and a half. Once it just broke in the middle of the span from the pole to the house, and once it broke right at the pole mounted transformer. the first time I had no damage, the second time (when I was not even at home with anything on but maybe a couple security lights) I had a couple of blown GFCI outlets - and I mean BLOWN. Fire! Luckily the wallboard was not flammable, but there were scorch marks, even on the kitchen cabinets. Utility paid off quickly, but it didn't amount to much (maybe I should have put in for a new TV?)

Reply to
taxed and spent

Since you lose poco neutral so frequently, consider having a proper ground rod system installed.

Reply to
Mayhem

I do, but that will not end the problems created with a lost neutral.

Reply to
taxed and spent

I was never really sure why they wanted them on the same duplex anyway. If you really need both 20 a circuits in one box, why not use a 1900 box and put in 2 duplex outlets? You usually run out of sockets long before you run out of amps. I ended up with three 2 gang boxes serving the countertop along with a few singles.

Reply to
gfretwell

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.

Reply to
gfretwell

How will that help? Do you really think the ground ROD does anything? The only time the ground electrode will actually help with an open utility neutral is if it is a metal water pipe, connected to metal utility water pipe systems. Even a Ufer, the best of all ground electrodes, is not going to sink much neutral current in most places.

Reply to
gfretwell

It makes it virtually impossible to overload a circuit when each half of a duplex receptacle is on a separate circuit. You can plug a toaster and a coffemaker into one "outlet" with no danger of overloading it - and only have one wire required to be pulled for each "outlet" - giving you, in effect, a 30 amp circuit.

What I have seen done for dual GFCI (And even single gfci) protection is to run from the panel to a box with a gfci outlet, and feed-through from there to the house circuit. The GFCI protector is on the panel board with the electrical service panel, but is not IN the panel (for cases where a gfci or dual gfci is either not available or rediculously over-priced)

Reply to
clare

This was code in Canada before 20 amp circuits became code.

+1
Reply to
clare

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