# Multiwire branch circuits



## Gamit (Dec 30, 2009)

I know now when you share a neutral you need to make sure the over current device must disconnect both phases does this apply in both commercial and residential?


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## wildleg (Apr 12, 2009)

Gamit said:


> I know now when you share a neutral you need to make sure the over current device must disconnect both phases does this apply in both commercial and residential?


 yes .


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## william1978 (Sep 21, 2008)

I agree with wildleg it applies to all multi wire branch cir's.


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## 480sparky (Sep 20, 2007)

The overcurrent device is not the requirement..... it is only a common disconnect.

210.4(b).

True, 99.999999% of the time, it will be the breaker.


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## Toronto Sparky (Apr 12, 2009)

I don't know about house wiring but I.C.I. only use common trips when they are feeding a single device.

3 circuits 1 neutral feeding three separate circuit receptacles (not in same box) = three single pole breakers. (neutrals must be pigtailed)


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## Gamit (Dec 30, 2009)

Toronto Sparky said:


> I don't know about house wiring but I.C.I. only use common trips when they are feeding a single device.
> 
> 3 circuits 1 neutral feeding three separate circuit receptacles (not in same box) = three single pole breakers. (neutrals must be pigtailed)


How can you use 3 sp breakers when your sharing the neutral


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## McClary’s Electrical (Feb 21, 2009)

Toronto Sparky said:


> I don't know about house wiring but I.C.I. only use common trips when they are feeding a single device.
> 
> 3 circuits 1 neutral feeding three separate circuit receptacles (not in same box) = three single pole breakers. (neutrals must be pigtailed)


 
agreed, only need a handle tie if on the same yoke


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## 480sparky (Sep 20, 2007)

Gamit said:


> How can you use 3 sp breakers when your sharing the neutral


He's in Canada...........:whistling2:


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## McClary’s Electrical (Feb 21, 2009)

Gamit said:


> How can you use 3 sp breakers when your sharing the neutral


 
easy,,,3 phase panel

210.4 (b) applies only if on the same yoke. He clearly worded otherwise


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## Bob Badger (Apr 19, 2009)

mcclary's electrical said:


> easy,,,3 phase panel
> 
> 210.4 (b) applies only if on the same yoke. He clearly worded otherwise


The NEC now requires all MWBC breakers to be handle tied regardless of what they supply or where.


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## McClary’s Electrical (Feb 21, 2009)

Bob Badger said:


> The NEC now requires all MWBC breakers to be handle tied regardless of what they supply or where.


 
Sorry Bob, I should have been more clear I'm on 05'


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## 480sparky (Sep 20, 2007)

mcclary's electrical said:


> easy,,,3 phase panel
> 
> 210.4 (b) applies only if on the same yoke. He clearly worded otherwise



Read it again..............


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## Toronto Sparky (Apr 12, 2009)

So you are telling me if I run sets of circuits (A,B,C,N) in conduit from the panel to provide circuits in a factory I have to put each set on a three pole breaker? 
Thats just crazy.. Who decided to change the rule to this? And what was their logic?
Guess the only way around this is to stuff the conduits with neutrals.

I think this will confuse the future Electricians who assume they can take apart neutrals if they turn off the breaker feeding the plug they are working even if the box has other wires feeding straight though.
Unless someone is going to go around and rewire all the old buildings wired before the rule change.


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## McClary’s Electrical (Feb 21, 2009)

480sparky said:


> Read it again..............


 
There's no need to I know what it says. I'm on 05' it only applies to the same yoke


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## Gamit (Dec 30, 2009)

Bob Badger said:


> The NEC now requires all MWBC breakers to be handle tied regardless of what they supply or where.


Thanks thats what I thought! By now everyone should be using the 2008 NEC...


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## mattsilkwood (Sep 21, 2008)

Toronto Sparky said:


> So you are telling me if I run sets of circuits (A,B,C,N) in conduit from the panel to provide circuits in a factory I have to put each set on a three pole breaker?
> Thats just crazy.. Who decided to change the rule to this? And what was their logic?
> Guess the only way around this is to stuff the conduits with neutrals.
> 
> ...


 I couldnt agree more. The '08 has some funny rules.


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## 480sparky (Sep 20, 2007)

mattsilkwood said:


> ......The '08 has some funny rules.


And none of them are "Ha, ha!" funny, either.


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## mattsilkwood (Sep 21, 2008)

480sparky said:


> And none of them are "Ha, ha!" funny, either.


 Yea I should have stressed that.


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## sparky105 (Sep 29, 2009)

it's not in our code yet I believe but it should be.


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## Bob Badger (Apr 19, 2009)

Gamit said:


> By now everyone should be using the 2008 NEC...


You would think so but many areas are still using the 2005 and some the 2002.


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## raider1 (Jan 22, 2007)

Bob Badger said:


> You would think so but many areas are still using the 2005 and some the 2002.


I have even heard there are jurisdicitions still using the 99 code.

Chris


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## Toronto Sparky (Apr 12, 2009)

But here we use the Canadian code as well as the Ontario amendments.
It's been a while since I looked at the book.. Seems it only comes up when your work gets rejected. (and mine never does :whistling2


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## 480sparky (Sep 20, 2007)

raider1 said:


> I have even heard there are jurisdicitions still using the 99 code.
> 
> Chris



Up until a few years ago, when we started state-wide licensing, there were a few AHJs that were still on 1990 and 1993.


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## McClary’s Electrical (Feb 21, 2009)

Gamit said:


> Thanks thats what I thought! By now everyone should be using the 2008 NEC...


 

Speak for yourself,,,I'm not wiring to 08' code until they make me. We just got in 05' and I'm not welcoming the 08',there are several changes I do not like.


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## Roger (Jul 7, 2007)

mcclary's electrical said:


> Speak for yourself,,,I'm not wiring to 08' code until they make me. We just got in 05' and I'm not welcoming the 08',there are several changes I do not like.


You are not alone, there are many 08 changes that I don't like and are simply for manufacturers benefit.

Some seem to be just for aggravation such as this MWBC rule.

Roger


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## Fission (May 14, 2010)

Roger said:


> You are not alone, there are many 08 changes that I don't like and are simply for manufacturers benefit.
> 
> Roger


In addition to that, with the adoption of the 2008 code my state (NJ) also finally went with AFCI's, so it's a big shock to us. Reasons like that are why with most of my sidework I tell the customer that it's better (a considerable cost savings) if they don't even get a permit at all.


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## McClary’s Electrical (Feb 21, 2009)

Roger said:


> You are not alone, there are many 08 changes that I don't like and are simply for manufacturers benefit.
> 
> Some seem to be just for aggravation such as this MWBC rule.
> 
> Roger


 
I agree,,,and the dumbest one ever,,laying on your back in a crawl space drilling a floor joist,,,weakening the structure,,,,for what???there is no reason a NM cable needs to be drilled into joist in a crawl,,,staples work just fine.

Many times I put a man in the crawl and drill stright down at each box,,,,,no drilling the walls all to pieces and it's really fast. 08's gonna stop that for no godd reason what so ever.


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## Fission (May 14, 2010)

mcclary's electrical said:


> I agree,,,and the dumbest one ever,,laying on your back in a crawl space drilling a floor joist,,,weakening the structure,,,,for what???there is no reason a NM cable needs to be drilled into joist in a crawl,,,staples work just fine.
> 
> Many times I put a man in the crawl and drill stright down at each box,,,,,no drilling the walls all to pieces and it's really fast. 08's gonna stop that for no godd reason what so ever.


That would only work well in houses with TJI floor joists which usually have holes in them already, just pop them out with a hammer.


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## RIVETER (Sep 26, 2009)

Fission said:


> In addition to that, with the adoption of the 2008 code my state (NJ) also finally went with AFCI's, so it's a big shock to us. Reasons like that are why with most of my sidework I tell the customer that it's better (a considerable cost savings) if they don't even get a permit at all.


Don't come down on me to harshly, but you are doing the customer a disservice by not including GFCIs in your work. You may think that you are helping them by saving them money but I guarantee if something weird happens they will tell their insurance company that you told them it was not necessary to install them. By going by the code you are protecting them as well as yourself.:thumbsup:


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## Fission (May 14, 2010)

RIVETER said:


> Don't come down on me to harshly, but you are doing the customer a disservice by not including GFCIs in your work. You may think that you are helping them by saving them money but I guarantee if something weird happens they will tell their insurance company that you told them it was not necessary to install them. By going by the code you are protecting them as well as yourself.:thumbsup:


I said AFCI's. And I was never there, never did any work at their house, no proof whatsoever, their word against mine :whistling2:

They know the risk, they know that their homeowners insurance has to cover any issues, they signed up for it so they have to live with it.


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## JohnR (Apr 12, 2010)

raider1 said:


> I have even heard there are jurisdicitions still using the 99 code.
> 
> Chris



Wow and I thought Connecticut was bad.

Our Wonderful state and AHJ. is using the 05 code for building, and the 08 for testing, I am hearing that we will not be using the 08 at all in the field but will be going directly to the 11 code for field.

Will probably keep testing on the 08 then too. Go figure. We are have mandated Continuing Ed classes (which really is good) but if you don't take one and say you did. 
Get caught, the state instead of making you take the CEU class , pulls your license and makes you get it back by taking the full test again. :icon_evil: On the 08 code which most guys have never even looked at.


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## Fusion (May 13, 2010)

I'd like to work in one of these areas that's still on the 1990 NEC. Life would be so much simpler. :thumbup:


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