# Name that violation 24 Dec 2018



## jar546 (Dec 24, 2018)

So this is what you see.  A multi-wire branch circuit (MWBC) from a 3 phase 208v panel that provides one neutral for all 3 circuits.  The circuits are for receptacles in this commercial application. 

Just based off of the photo, what NEC section is in violation?


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## Gregg Harris (Dec 26, 2018)

What year code and how many wires?


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## jar546 (Dec 26, 2018)

2014 and the info is in the description above.  3 circuits one neutral


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## ICE (Dec 26, 2018)

jar546 said:


> 3 circuits one neutral



That sounds like a hint.


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## jar546 (Dec 26, 2018)

ICE said:


> That sounds like a hint.



Well, MWBC does stand for multi-wire branch circuit.

It's hard to believe no one is picking up on this.


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## Robert Rudy (Dec 26, 2018)

Multi circuit wiring is a problem for remodels had this situation in a kitchen tore out all old multiwire put in new circuitry with each hot wire with a neutral


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## jar546 (Dec 27, 2018)

Robert Rudy said:


> Multi circuit wiring is a problem for remodels had this situation in a kitchen tore out all old multiwire put in new circuitry with each hot wire with a neutral



Why did you rip it all out and put in new?  Was it a GFCI problem?


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## Robert Rudy (Dec 27, 2018)

Robert Rudy said:


> Multi circuit wiring is a problem for remodels had this situation in a kitchen tore out all old multiwire put in new circuitry with each hot wire with a neutral


Yes we installed all new circuitry for refrigerators dishwashers disposal island cabinets microwave and added extra circuit behind refrigerator for later on and one under sink for insta hot
Thanks


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## steveray (Dec 27, 2018)

I believe what Jeff was asking was...Was that your choice in a remodel or was it "required" for some reason?


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## Robert Rudy (Dec 27, 2018)

Yes we replace all new circuits for refrigerator, dishwasher, insta hot microwave, GFI circuits around the kitchen u-shaped and a new one for microwave, disposal and out of the circuit so we could grab it later so we didn't have to open up sheetrock again if we had to from crawl space  in a box with a blank cover


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## Robert Rudy (Dec 27, 2018)

Yes it was my choice to bring everything up to code it's better off to get this done while you have it all open then sit there and try to fool with it the other issue when we found the kitchen and tore off the sheetrock from a previous remodel we had seven junction boxes for the under counter lights and this was totally bad and we also had wire nut light fixtures that weren't in any type of box they just wire netted the wires together and tucked it up into the soffit oh yes that was an insurance job good inspections around here stink


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## jar546 (Dec 27, 2018)

OK, I can't take it anymore.  I really thought this was a no-brainer.  First of all:

There is nothing wrong whatsoever with using multiwire branch circuits.  I prefer to see them in commercial applications only but they are certainly allowed in residential.  If you don't know what a multiwire branch circuit is (MWBC), it is when 2 or more current carrying conductors share the same neutral, providing the conductors are from different phases. In residential that would be limited to a double pole circuit breaker but we can use a 3 pole breaker for a commercial application with 3 phase power available.  There are ways to use handle ties on single pole breakers for both 240 and 3 phase.

MWBCs are great because you don't have to pull as many neutral wires which saves space in conduit, allowing the use of smaller conduit, takes up less space and terminals in  boxes and panels and uses no more load on a neutral than if you only had one circuit, and even help with voltage drop.  They are great in a commercial environment where only qualified people install or maintain the electrical equipment but can be a nightmare if unqualified people don't know what they are doing.

Here are the downsides to a MWBC:

1) Unqualified, inexperienced people working on MWBC or those that don't know an MWBC exists.
2) Lifting the neutral (ungrounded conductor) from the neutral bar can cause some serious problems depending on how the circuits are wired.
3) If not properly installed, they can cause some serious problems and damage to equipment or life safety issues.  All receptacles must be in parallel and never have a neutral in series feeding through a receptacle.  This is why a kitchen counter for example would have to utilize a 2-pole GFCI or every single receptacle would have to be a GFCI receptacle because you cannot daisy chain like you would normally.

So, with all of that being said, NEC 210.4 (B) states that _"Each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates."
_
Therefore, in the case of the above installation stating that the junction box serves an MWBC that are circuits 2, 15 & 41 in panel "C" makes it impossible to comply with NEC 210.4(B) because panels are manufactured with the left side being odd numbers from top to bottom and the right side being even numbers from top to bottom.  Each of the 3 circuits in question are on different areas of the panel not next to each other, therefore unable to be on a 3 pole breaker or even 3 single pole breakers with handle ties installed.

Also verified was that the breakers are on 3 different phases, which they are.  Circuit 2 is on A phase, 15 is on B phase and 41 is on C phase.

Upon further inspection a spare neutral and ungrounded conductor were found in the same JB that comes from the same panel C so the best course of action will be to use the spare ungrounded black conductor to pull another white grounded conductor, therefore providing all 3 circuits with their own neutral, eliminated the MWBC.  Of course the neutrals will have to be separated and grouped with their ungrounded conductors in the panel and the JB as per NEC 210.4(D) and 200.4(B)


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## Pcinspector1 (Dec 30, 2018)

Is a MWBC junction (outlet) like in the photo required to be marked in anyway? 
I can't fine where it's required to be marked, but I like that it's marked.


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## jar546 (Dec 30, 2018)

Pcinspector1 said:


> Is a MWBC junction (outlet) like in the photo required to be marked in anyway?
> I can't fine where it's required to be marked, but I like that it's marked.



Junction boxes are not required to be marked with MWBC circuits.  After another visit, this is no longer a MWBC and the circuits with separate neutrals are all marked and grouped together.


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