Let's say I have a 3 ph panel and a store with general lighting and plugs.Then add lighting throughout the space on circuits 1,3,2,4,and 12. Is there anything wrong with pulling homeruns of 1,3,12,n and 2,4,12,n?I can't see any reason it would violate any code but would it present any kind of safety issues?I had a situation like this were the common circuit was everywhere in the store and rather than pull a dedicated neutral to every location I thought I could add it to existing groups.My boss couldn't find fault with the reasoning but said no one ever does this . What am I overlooking?
I read this forum several times a week and even though much of the time I'm confused by the issues I am learning a little at a time. Thanks to everyone. Barry

It appears you are pulling two homeruns to ckt 12. Is this correct?
Three phases with one neutral is common practice. The neutral only carries the unbalanced current. However, I would not pull ckt 12 in both homeruns on the same neutral.
If the lighting is electronic ballast fluorescents, then we specify a neutral for each circuit due to harmonic currents generated by the switching characteristics of the electronics in the ballast. Our Moderator may have explained harmonics in the technical section. If not, I'm sure he will give us a good explanation.

Barry,
I see no problem with installing the circuits in that way.
Don(resqcapt19)