Grounded conductor

[memyselfandI]

I was in a hurry when I posted the question. We in Virginia are still in the 2008 code cycle. I work in an industrial facility and the reason why I was asking is that the inspector asked why we didn't have a neutral pulled with the feeder and he mentioned that if another inspector were to come out and inspect it he would have made us pull a neutral in, even though the load being served does not require one. I see no requirement whatsoever that would back this interpretation unless it was a service, which by definition it is not.

 

[augie47]

You might keep in mind, IF you elect to install a grounded conductor with the feeder, NEC 215.2(A) specifies a minimum size.

 

[jim dungar]

.... it seems inconsistant to not require a grounded conductor in a panel regardless of the initial load intentions when somewhere down the road, the need for a grounded conductor "might" be required.

How about cost? It is not really that expensive to add an 'unused neutral' to a 30A circuit, but it is relatively costly to add one to a 1200A panelboard.

404.3(C) deals with 'general purpose branch circuits' not feeders. There is an exception to the NEC requirement for a neutral at a switch location, if there is the ability to easily add one in the future (e.g. the box is fed from a raceway or the box can be accessed through an opening).

 

[memyselfandI]

You might keep in mind, IF you elect to install a grounded conductor with the feeder, NEC 215.2(A) specifies a minimum size.

I know I saw that but it is a little confusing when we are talking about a GROUNDED conductor and not an EQUIPMENT GROUNDING CONDUCTOR(250.122). I know that there is a difference between the two.

 

[augie47]

215.2 is referencing the groundED conductor and stating it must be size as if it were a groundING conductor.
Been some discussion here as to why and the only answer I recall was "because" There was some assumption that, in the event of some weird fault it might need to act as an EGC but only the CMP folks know.

 

[memyselfandI]

215.2 is referencing the groundED conductor and stating it must be size as if it were a groundING conductor.
Been some discussion here as to why and the only answer I recall was "because" There was some assumption that, in the event of some weird fault it might need to act as an EGC but only the CMP folks know.

So how would 200.2 apply in my scenario? I have a 250A 480V 3 PH (no neutral) feed from a MSB to a MLO panel with OCPD that feeds equipment that do not require a neutral. If I read 200.2 correctly, if idoesn't fall under the list of exceptions then it IS required...everywhere not explicitly referenced.

 

[Dennis Alwon]

Dennis, as far as residential goes: How many sub panels have you installed without a neutral? Tis' a rare beast in resi IMHO.

Me: zero in resi, a few in commercial.

Only one or two that I have done but I have seen a few others. No question a rare beast but it is done. I have also seen 120V taken from these panels with no neutrals-- obviously unskilled workers involved.

 

[Dennis Alwon]

So how would 200.2 apply in my scenario? I have a 250A 480V 3 PH (no neutral) feed from a MSB to a MLO panel with OCPD that feeds equipment that do not require a neutral. If I read 200.2 correctly, if idoesn't fall under the list of exceptions then it IS required...everywhere not explicitly referenced.

Do you mean 215.2? That only refers to if a neutral is installed not whether it is required.

 

[Dennis Alwon]

BTW, 250.24 (C) talks about the grounded conductor brought to the service.