Hotline,
Your reference to 210.4 (b) is for residential.....not comm or industrial.
Of course it is, that was my point, there is no requirement for commercial or industrial as you know.
My customers would not like a short on one office cube circuit to take out 2 other circuits.
Now you will say do not run multiwire circuits, but I do not make the office cubes (modular office partitions) and if they are wired for common neutral that is just how it is, beyond that I prefer to use multiwire circuits.
I have never had an inspector stick his nose in job specs and will not listen to them if they do.
I have had many prints that show multiwire circuits and never have they asked for common trip.
Feel free to install common trip breakers if you like but I will not.
What accidents are you speaking of, only qualified people should be opening boxes in any environment but most certainly in commercial and industrial installations the servicing electrician should be aware of common neutral circuits.
