Re: 230-2(d)
it is fairly common to see older industrial buildings in our city that have 120/240/1ph or 24/3 delta; with additional 120/208/3 or 277/480/3 added for the requirements of the current business occupying the space.
Now that I work for the city Fire Dept. I really see a lot more of the reason for 230-2; especially 230-2 (e). In a fire emergency, the Fire dept. will kill the power prior to fire suppression. If there are multiple services with PERMANENT signage (not to be confused with felt pen labeling), they can ID all the services, at night, in smoke, and successfully kill all the power.
Better still:
One service point-multiple voltage/phase as required, all in one place, all clearly labeled with PERMANENT SIGNS.
Even better still:
Upgrade service; with feeders & XFormers's for lower voltages and single phase.
It's only money, but cheap safety.
It's liable to be more efficient power distribution, with consequent lower electric bills.
Additional comment about labeling:
CA Fire Code (2000 UFC) art. 85-requires Electrical Rooms and Mains to be labeled with legible and plainly visble signs (see "at night, in smoke" above.
Thanks for all the inputs, on all the NEC issues, all of you; I learn something every day.
