Grouping of MWBC

[Dennis Alwon]

I came across this in a text book and before I contact the author I want to throw it out here and see if you agree. I totally disagree. It seems like he is trying to say that multiwire branch circuit grounded conductors must be grouped but if the isn't a multiwire branch circuit then it doesn't need it as shown in "G". I think he is overlooking 200.4

200.4 Neutral Conductors. Neutral conductors shall be installed
in accordance with 200.4(A) and (B).
(A) Installation. 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.
(B) Multiple Circuits. Where more than one neutral conductor
associated with different circuits is in an enclosure, grounded
circuit conductors of each circuit shall be identified or
grouped to correspond with the ungrounded circuit conductor(
s) by wire markers, cable ties, or similar means in at least
one location within the enclosure.

Here is the explanation for fig G

 

[infinity]

Must be an old book and I agree the statement is wrong. The neutral versus grounded conductor nonsense went away several code cycles ago in the 2008 NEC when the inserted the definition of the term Neutral Conductor. The letter G wording ignores that.

 

[augie47]

Maybe he's like me and living in the past You are, of course, correct but the requirement for multiple circuits was introduced in 2014. He hasn't caught up.

 

[don_resqcapt19]

The author needs to review the definition of "neutral conductor" and "neutral point".
However I do recall it being taught, in the past, that a grounded conductor that is only associated with one ungrounded conductor is not a neutral.

 

[hillbilly1]

I kinda agree with you, at the panel, it would make no difference, but at the next box down, the grounded conductor could be used on a different hot that it was paired with at the first box.

 

[Dennis Alwon]

The author needs to review the definition of "neutral conductor" and "neutral point".
However I do recall it being taught, in the past, that a grounded conductor that is only associated with one ungrounded conductor is not a neutral.

The author is well respected Charles Miller

 

[Dennis Alwon]

The author needs to review the definition of "neutral conductor" and "neutral point".
However I do recall it being taught, in the past, that a grounded conductor that is only associated with one ungrounded conductor is not a neutral.

Well technically that is true. A grounded conductor is only a neutral when there is ")" amps on the conductor.. At least that is my understanding but it is not in the code book AFAIK

 

[infinity]

I do recall it being taught, in the past, that a grounded conductor that is only associated with one ungrounded conductor is not a neutral.

That was the thinking years ago but with the definition of neutral conductor it is no longer true.

 

[Jon456]

The author is well respected Charles Miller

What was the publishing date on this textbook?

 

[Dennis Alwon]

What was the publishing date on this textbook?

2020 Edition

 

[roger]

2020 Edition

That being the case he is wrong. (I do agree with him technically though)

Roger

 

[Dennis Alwon]

I am sure as the years go by somethings get missed. I was pretty certain it was an error but I wanted to make sure

 

[infinity]

I am sure as the years go by somethings get missed. I was pretty certain it was an error but I wanted to make sure

Could have been a reprint of an old copy into the new book.

 

[Dennis Alwon]

Could have been a reprint of an old copy into the new book.

Exactly but I don't remember when it was that a multiwire branch circuit needed ties but single circuits did not. I remember when both didn't need ties or markings but not when one did and not the other

 

[don_resqcapt19]

The author is well respected Charles Miller

The only person that never makes a mistake is a person that never does anything

 

[don_resqcapt19]

Exactly but I don't remember when it was that a multiwire branch circuit needed ties but single circuits did not. I remember when both didn't need ties or markings but not when one did and not the other

200.4(B) was new to the 2014 code and the language in the 2020 is the same as in the 2014.