Common Ground Bewteen 120V & 277V

[Wrd4spd]

I have some light poles @ 277V and they come with integral convenience outlet (120V). I am running separate hots an neutrals (colored differently), but can I tie the grounds together at an upstream shared j-box and use a common ground for both connections? I know it seems wrong, but what code section does it violate - if it does at all?

 

[GoldDigger]

EGCS are not associated with one or another system and will all share the same building GES. I do not see a problem, code or otherwise.
You should not be bonding EGC to either neutral at the pole and the NEC does require separate neutrals for all branches for anything but an MWBC.
Since you have two voltages you cannot combine them into an MWBC.

 

[Wrd4spd]

Thank you for the reply - That was my line of thought as well. Some thread I was reading last night seemed to imply that separate grounds were required and that they had to be colored differently, etc, etc. Had me doubting myself....

 

[GoldDigger]

Thank you for the reply - That was my line of thought as well. Some thread I was reading last night seemed to imply that separate grounds were required and that they had to be colored differently, etc, etc. Had me doubting myself....

Since grounds are allowed to be bare and thus no color, I suspect the author was confusing grounded with grounding, an easy enough thing to do.
You just raised a good point, namely that the two neutrals do need to be different colors. One gray perhaps?
Or maybe with a colored tracer stripe.

 

[iwire]

You can use one EGC out to the pole but at the building you must make sure it also splits and follows their related circuit conductors back to each of the panels the circuits originate from. See NEC 300.3(B)