Electrical Service Entrance

Here's how to do it: 1. Get in your car. 2. Drive to your city's municcipal building. 3. Go inside the building and ask to speak to the electrical contract inspector. 4. Ask him how to do it for your area. 5. Do what he says, and save your home owner's insurance just in case anything ever happens - whether related or not related to the wiring job.

Vermin's answer is the right one, because codes vary. Depends on where your building is located. No "one size fits all" answer given here could be depended on.

You can have more than 1 service in Commercial Applications. You best bet is to disscus this with your local Power Co. Thier there to help ad will take all the guess work out of it.

It sounds like you are not in violation of the code. 120/208 3 ph, is not the same as 120/240 single phase, even though 120 volts can be had from either. The suggestions above are good and should be considered. Your thoughts about using only 3 phase for household power as well as for commercial power might ought to be reconsidered. Things like ovens and hot water heaters take longer to heat at 208V versus 240V, and some 240V motors (compressors starting under load, for example) don't do as well at 208V.

You may want to look into a phase converter. It will convert single phase to three phase. Whether its 4W or 4KW, this may be a viable option for you if you are looking to power a couple of machines.