# Sharing Neutrals Question



## weetoolow (Nov 6, 2013)

Hi All,

I am commercial electrician. However, I have went back into the field after several of being out of construction all together. 

I need a little help, is it still permitted to share the neutrals on a 3 phase service or is the code now to pull a separate neutral for each circuit?


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## flyboy (Jun 13, 2011)

weetoolow said:


> Hi All,
> 
> I am commercial electrician. However, I have went back into the field after several of being out of construction all together.
> 
> I need a little help, is it still permitted to share the neutrals on a 3 phase service or is the code now to pull a separate neutral for each circuit?


200.4 Neutral Conductors. Neutral conductors shall not be used for more than one branch circuit, for more than one multiwire branch circuit, or for more than one set of ungrounded feeder conductors unless specifically permitted elsewhere in this Code. (2011 NEC)


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## BBQ (Nov 16, 2010)

Yes you can still do that with some additional rules.

The NEC calls it a MultiWire Branch Circuit. (On the forum we call it a MWBC)

1) You have to use a handle tie across the single pole breakers or you can use a multi-pole breaker.

2) If the MWBC circuit enters the panel by a raceway with other circuits you have to group the MWBC so you can tell which neutral is being used with which hots.



> *Branch Circuit, Multiwire.* A branch circuit that consists
> of two or more ungrounded conductors that have a voltage
> between them, and a grounded conductor that has equal
> voltage between it and each ungrounded conductor of the
> ...





> *210.4 Multiwire Branch Circuits.
> (A) General. *Branch circuits recognized by this article shall
> be permitted as multiwire circuits. A multiwire circuit shall be
> permitted to be considered as multiple circuits. All conductors
> ...





> *240.15 Ungrounded Conductors.
> 
> (B) Circuit Breaker as Overcurrent Device. *Circuit breakers
> shall open all ungrounded conductors of the circuit both
> ...


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## Electricpresky (Nov 6, 2013)

I'm not clear on the question... Are you asking about tapping off the service or are we talking about breakers? If we're talking about the service it depends are we talking about a main distribution panel... Cause it has extra lugs for that purpose but as far as three phase if you're sharing a neutral the wires need to be be on a two, three, ect.. Breaker


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## BBQ (Nov 16, 2010)

Electricpresky said:


> I'm not clear on the question... Are you asking about tapping off the service or are we talking about breakers? If we're talking about the service it depends are we talking about a main distribution panel... Cause it has extra lugs for that purpose but as far as three phase if you're sharing a neutral the wires need to be be on a two, three, ect.. Breaker


What the heck are you talking about?:blink:


And you don't have to use a two or three pole breaker, you can use single poles with handle ties. 

I posted the rules ...


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## Electricpresky (Nov 6, 2013)

Yes you can but the chances of the supply house having them in stock depending on what kind of breakers you're talking about is slim so you have to outweigh the thing and as far as I know you can't breaker tie 277/480... I could be wrong and if I am could someone direct me to that... Cause I've never seen and was told on a job by an inspector that it's not aloud... But then again he thought the 120 panel was 277.


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## Electricpresky (Nov 6, 2013)

nec article 210.4 b looked it up in the book today while waiting for an inspector.


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## BBQ (Nov 16, 2010)

Electricpresky said:


> nec article 210.4 b looked it up in the book today while waiting for an inspector.


Yes and did you also read 240.15(B)(1) posted above?


Which code cycle are you on?


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## guest (Feb 21, 2009)

Electricpresky said:


> I'm not clear on the question... Are you asking about tapping off the service or are we talking about breakers? If we're talking about the service it depends are we talking about a main distribution panel... Cause it has extra lugs for that purpose but as far as three phase if you're sharing a neutral the wires need to be be on a two, three, ect.. Breaker





Electricpresky said:


> Yes you can but the chances of the supply house having them in stock depending on what kind of breakers you're talking about is slim so you have to outweigh the thing and as far as I know you can't breaker tie 277/480... I could be wrong and if I am could someone direct me to that... Cause I've never seen and was told on a job by an inspector that it's not aloud... But then again he thought the 120 panel was 277.





Electricpresky said:


> nec article 210.4 b looked it up in the book today while waiting for an inspector.


As MTW would say:


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